Evaluation of a heating protocol and stocking density impact on heatstressed fattening pigs

As climate change intensifies, heat stress mitigation for pigs becomes more important. Trials involving induced heat waves are useful to test several measures (e.g. reduced stocking density) at a faster rate, but only when accurately evaluated and validated. In the present study, we investigated the suitability of an artificial heating protocol at different pig weights (experiment 1). The impact of different stocking densities on fattening pigs during an artificial heat wave (experiment 2) was also investigated. Experiment 1: Forty 20-week-old pigs weighing 96.5 ± 7.3 kg (W100) and forty 17-week-old pigs weighing 72.7 ± 9.9 kg (W70) were housed in two compartments. An artificial heat wave (heat load) was induced for 3 days. During 3-day periods before, during and after the heat load, physiological parameters (respiration rate (RR), rectal temperature (Trectal), skin temperature (Tskin) and behavior) were measured and average daily feed intake was observed. Ambient temperature, relative humidity and temperature-humidity index (THI) were monitored. Experiment 2: A total of 150 fattening pigs were randomly divided into three treatment groups: SD1.3 (1.3 m2/pig), SD1.0 (1.0 m2/pig) and SD0.8 (0.8 m2/pig). All pens had a total pen surface of 4.88 m2, corresponding with 4, 5 and 6 fattening pigs in the SD1.3, SD1.0 and SD0.8 groups, respectively. The heat load was induced for 7 days on week 21. Respiration rate and Trectal were observed as in experiment 1. Average daily gain and average daily feed intake were also noted. During the heat load, THI reached ≥ 75 (78.4 (experiment 1) and 78.6 (experiment 2)), even when relative humidity decreased to ± 45%. Every physiological parameter showed significant increases during the heat load. The prolonged heating protocol in experiment 2 also provoked significant decreases in average daily feed intake (15%) and average daily gain (19%) for all groups. Weight within the studied range of 70-100 kg did not have a significant impact on any of the parameters. However, Tskin was affected by both weight and heat load (P < 0.05), where Tskin from W100 was always lower in comparison to W70. In addition, we found that 0.8 m2/pig doubled the increase of Trectal during the heat load, namely SD0.8 (0.22 °C) compared to SD1.0 (0.12 °C) (P = 0.033) and SD1.3 (0.13 °C) (P = 0.053). This suggests that pigs housed at higher densities are less able to regulate their internal heat production. However, RR and performances were not significantly affected by heat load in this experimental set-up. A stocking density of 1.0 m2/animal may be sufficient to mitigate some negative effects of heat stress.

Growth, filtration and respiration characteristics of small single-osculum demosponge Halichondria panicea explants

Filter-feeding demosponges are modular organisms that consist of modules each with one water-exit osculum. Once a mature module has been formed, the weight-specific filtration and respiration rates do not change. Sponge modules only grow to a certain size and for a sponge to increase in size, new modules must be formed. However, the growth characteristics of a small single-osculum module sponge are fundamentally different from those of multi-modular sponges, and a theoretically derived volume-specific filtration rate scales as F/V=V-1/3, indicating a decrease with increasing total module volume (V, cm3). Here, we studied filtration rate (F, l h-1), respiration rate (R, ml O2 h-1), volume-specific (F/V) and weight-specific (F/W) filtration rates, and the ratios F/R and F/W along with growth rates of small single-osculum demosponge Halichondria panicea explants of various sizes exposed to various concentrations of algal cells. The following relationships were found: F/V=7.08V-0.24, F=a1W1.05, and R=a2W0.68 where W is the dry weight (mg). The F/R and F/W ratios were constant and essentially independent of W, and other data indicate exponential growth. It is concluded that the experimental data support the theoretical F/V∝V-1/3.

Behavioural responses related to increasing core body temperature of grazing dairy cows experiencing moderate heat stress

Exposure to direct solar radiation, high ambient temperature, lack of wind movement, coupled with own metabolic heat production, makes grazing dairy cows vulnerable to heat stress. In pastures, it would be beneficial to monitor heat stress by observable changes in behaviour. We hypothesised that grazing dairy cows exhibit behavioural changes due to increasing heat load in temperate climate. Over two consecutive summers, 38 full-time grazing Holstein dairy cows were investigated in 12 experimental periods of up to 3 consecutive days where the cows were repeatedly exposed to various levels of moderate heat load determined by the comprehensive climate index (CCI). The CCI defines the ambient climate conditions, combining air temperature, relative humidity, solar radiation and wind speed. Vaginal temperature (VT) was automatically measured as an indicator of heat stress. In addition, as a less invasive method, we investigated if reticular temperature (RET) can be indicative of heat stress on pastures. Walking activity, lying-, feeding, and ruminating durations were recorded continuously with sensors. Respiration rate (RR), proximity to and competition at the water trough, social licking, self-licking, inter-individual distance, and fly intensity were directly observed. Data were analysed in the morning (0900-1100 h) and during the hottest time of day when cows were on pasture (1230-1430 h). The VT and RET showed similar patterns in relation to the CCI, suggesting that RET can be suitable for continuous monitoring of heat stress on pastures. In the morning, the cow's VT and RET did not relevantly react to the CCI. During the period 1230-1430 h, the cow's mean VT (mean vaginal temperature (VTMEAN); range: 37.7-40.3 °C) and mean RET (mean reticular temperature; range: 37.0-41.1 °C) were positively related to the mean CCI (mean comprehensive climate index) in this period (mean ± SD: 25.9 ± 5.71 °C). For cows with greater VTMEAN, an increased mean RR and decreased durations of walking, lying, feeding, and ruminating were found. These cows were also more likely to be in proximity to the water trough and to have small inter-individual distances. Changes in these traits seem to reflect behavioural adaptations to heat stress in a temperate climate and could be used to detect the heat stress in individual dairy cows on pastures.

Respiratory patterns and physical fitness in healthy adults: a cross-sectional study

BACKGROUND

The altered respiratory patterns have a significant impact on our health. However, the links between respiration patterns during spontaneous breathing and physical fitness remain unknown. Therefore, we sought to examine how the respiratory pattern during spontaneous breathing interacts with physical fitness.

METHODS

A total of 610 participants (aged 20-59 years) were enrolled; 163 men (age = 41 ± 11) and 401 women (age = 42 ± 9) were included for analysis. The parameters of the respiration pattern were respiration rate (RR) and inhalation/exhalation (I/E) ratio. The physical fitness components were body size, visuomotor reaction time, balance, flexibility, hand grip strength, back extension strength, vertical jump height, number of push-ups, number of sit-ups, and the maximum rate of oxygen consumption. The data were analyzed separately for two gender groups. Participants within each gender group were further divided into two age categories (young: 20-39 years, middle-aged: 40-59 years) for the analysis, and both correlational and comparative tests were used to solidify the results.

RESULTS

Neither RRs nor the I/E ratios were substantially correlated with physical fitness in women. In addition, the I/E ratios showed no significant correlation with physical fitness in young men, while the results from correlational and comparative tests were inconsistent in middle-aged men. Consistently, men with lower RRs exhibited significantly shorter visuomotor reaction times in two age groups, and demonstrated significantly higher vertical jump heights in the middle-aged group.

CONCLUSIONS

In women, respiratory patterns were not correlated with physical fitness. The relationship between middle-aged men's I/E ratios and their physical fitness warrants further investigation. Men with lower RRs may have better visual-motor coordination and/or sustained attention, while middle-aged men with lower RRs may also have greater leg explosive power and neuromuscular coordination, which should be considered for physical assessment and health improvement.

Measuring effect of mutations & conditions on microbial respiratory rates

Cellular respiration is central to a wide range of cellular processes. In microorganisms, the effect of a mutation or an environmental condition on the rate of respiration is usually determined by measuring oxygen consumption in the media. We describe this method and discuss caveats and controls for the method.

Novel statistical time series data augmentation and machine learning based classification of unobtrusive respiration data for respiration Digital Twin model

Digital Twin (DT), a concept of Healthcare (4.0), represents the subject's biological properties and characteristics in a digital model. DT can help in monitoring respiratory failures, enabling timely interventions, personalized treatment plans to improve healthcare, and decision-support for healthcare professionals. Large-scale implementation of DT technology requires extensive patient data for accurate monitoring and decision-making with Machine Learning (ML) and Deep Learning (DL). Initial respiration data was collected unobtrusively with the ESP32 Wi-Fi Channel State Information (CSI) sensor. Due to limited respiration data availability, the paper proposes a novel statistical time series data augmentation method for generating larger synthetic respiration data. To ensure accuracy and validity in the augmentation method, correlation methods (Pearson, Spearman, and Kendall) are implemented to provide a comparative analysis of experimental and synthetic datasets. Data processing methodologies of denoising (smoothing and filtering) and dimensionality reduction with Principal Component Analysis (PCA) are implemented to estimate a patient's Breaths Per Minute (BPM) from raw respiration sensor data and the synthetic version. The methodology provided the BPM estimation accuracy of 92.3% from raw respiration data. It was observed that out of 27 supervised classifications with k-fold cross-validation, the Bagged Tree ensemble algorithm provided the best ML-supervised classification. In the case of binary-class and multi-class, the Bagged Tree ensemble showed accuracies of 89.2% and 83.7% respectively with combined real and synthetic respiration dataset with the larger synthetic dataset. Overall, this provides a blueprint of methodologies for the development of the respiration DT model.

Advancements in coating technologies: Unveiling the potential of chitosan for the preservation of fruits and vegetables

Post-harvest losses of fruits and vegetables pose a significant challenge to the agriculture industry worldwide. To address this issue, researchers have turned to natural and eco-friendly solutions such as chitosan coatings. Chitosan, a biopolymer derived from chitin, has gained considerable attention due to its unique properties such as non-toxicity, biodegradability, biocompatibility and potential applications in post-harvest preservation. This review article provides an in-depth analysis of the current state of research on chitosan coatings for the preservation of fruits and vegetables. Moreover, it highlights the advantages of using chitosan coatings, including its antimicrobial, antifungal, and antioxidant properties, as well as its ability to enhance shelf-life and maintain the quality attributes of fresh product. Furthermore, the review discusses the mechanisms by which chitosan interacts with fruits and vegetables, elucidating its antimicrobial activity, modified gas permeability, enhanced physical barrier and induction of host defense responses. It also examines the factors influencing the effectiveness of chitosan coatings, such as concentration, molecular weight, deacetylation degree, pH, temperature, and application methods.

Physcion and chitosan-Oligosaccharide (COS) synergistically improve the yield by enhancing photosynthetic efficiency and resilience in wheat (Triticum aestivum L.)

As progressively increasing food safety concerns, diversified plant diseases and abiotic stresses, environmental-friendly bio-pesticides and bio-stimulants combinations may are likely to serve as a vital means of safeguarding green and sustainable food production. Accordingly, in this study, pot and field trials were performed to examine the application potential of the combination of physcion and chitosan-Oligosaccharide (COS) in wheat production. Wheat seeds were coated with physcion and COS and the effects exerted by them on morphology, physiology and yield of the wheat were investigated. As indicated by the results, the combination of physcion and COS not only did not inhibit the growth of wheat seedlings, but also synergistically increased root vigor and photosynthetic pigment content. Simultaneously, the lignin content in the roots and leaves was increased significantly. Moreover, the result confirmed that the combination of both substances reduced the MDA content, which was correlated with the up-regulation of the transcript expression level of antioxidant enzyme genes and the resulting increased enzyme activity. Furthermore, this combination synergistically increased the net photosynthetic rate (Pn) of the flag leaves and ultimately contributed to the increase in yield. Notably, the above-mentioned desirable cooperative effect was not limited by cultivars and cultivation methods. The conclusion of this study suggested that the combination of physcion and COS synergistically improved the photosynthetic rate and resilience in wheat, such that high wheat yields can be more significantly maintained, and future food security can be more effectively ensured.

A systematic review of physiological signals based driver drowsiness detection systems

Driving a vehicle is a complex, multidimensional, and potentially risky activity demanding full mobilization and utilization of physiological and cognitive abilities. Drowsiness, often caused by stress, fatigue, and illness declines cognitive capabilities that affect drivers' capability and cause many accidents. Drowsiness-related road accidents are associated with trauma, physical injuries, and fatalities, and often accompany economic loss. Drowsy-related crashes are most common in young people and night shift workers. Real-time and accurate driver drowsiness detection is necessary to bring down the drowsy driving accident rate. Many researchers endeavored for systems to detect drowsiness using different features related to vehicles, and drivers' behavior, as well as, physiological measures. Keeping in view the rising trend in the use of physiological measures, this study presents a comprehensive and systematic review of the recent techniques to detect driver drowsiness using physiological signals. Different sensors augmented with machine learning are utilized which subsequently yield better results. These techniques are analyzed with respect to several aspects such as data collection sensor, environment consideration like controlled or dynamic, experimental set up like real traffic or driving simulators, etc. Similarly, by investigating the type of sensors involved in experiments, this study discusses the advantages and disadvantages of existing studies and points out the research gaps. Perceptions and conceptions are made to provide future research directions for drowsiness detection techniques based on physiological signals.

Impact of vacuum ultraviolet (VUV) photolysis on ethylene degradation kinetics and removal in mixed-fruit storage, and direct exposure to 'Fuji' apples during storage

Accumulated ethylene in fruit storage/transportation causes rapid senescence resulting in reduced shelf-life and postharvest losses. The aim of this study was to investigate the application of vacuum ultraviolet (VUV) photolysis modular reactor for fruit storage. The first experiment compared the effectiveness of VUV photolysis reactor with the standard fruit industry adsorbent (potassium permanganate, KMnO4) on the removal of ethylene from mixed-fruit loading of apples, banana, and pears stored at ambient temperature (16 °C) for 6 days. Second study evaluated the impact of direct VUV radiation on quality attributes of apples stored at 10 °C for 21 days. Results showed that ethylene produced in mixed-fruit loading storage significantly (p < 0.05) reduced by 86.9% in the storage chamber connected to VUV modular reactor compared to 25.4% for storage under potassium permanganate. Direct exposure of apples to VUV radiation successfully reduced both ethylene and respiration rate but damaged the skin of the apples. Hue angle and lightness (L*) for apples exposed to VUV radiation declined significantly (p < 0.05) from 60.7 ± 1.09 to 33.5 ± 9.51 and 58.1 ± 3.60 to 50.4 ± 1.13, respectively. This study showed the potential of VUV photolysis as an innovative technique for removing ethylene from storage facility.

The transient character of mitochondrial uncoupling by the popular fungicide fluazinam is specific for liver

The popular fungicide fluazinam is known to exhibit an unusual cyclic pattern of the protonophoric uncoupling activity in isolated rat liver mitochondria (RLM), with membrane deenergization followed by spontaneous recoupling in the minute scale, which is associated with glutathione conjugation of fluazinam catalyzed by glutathione-S-transferase (GST). Here, we compare the fluazinam effect on RLM with that on rat kidney (RKM) and heart (RHM) mitochondria by monitoring three bioenergetic parameters: oxygen consumption rate, mitochondrial membrane potential and reduction of nucleotides. Only in RLM, the uncoupling activity of fluazinam was transient, i.e. disappeared in a few minutes, whereas in RKM and RHM it was stable in this time scale. We attribute this difference to the increased activity of mitochondrial GST in liver. We report data on the detection of glutathione-fluazinam conjugates by mass-spectrometry, thin layer chromatography and capillary electrophoresis after incubation of fluazinam with RLM but not with RKM, which supports the assumption of the tissue specificity of the conjugation.

Ozone micro-nano bubble water preserves the quality of postharvest parsley

The production and use of ozone micro-nano bubble water (O₃-MNBW) is an innovative technology that prolongs the reactivity of aqueous-phase ozone and maintains the freshness and quality of fruits and vegetables by removing pesticides, mycotoxins, and other contaminants. The quality of parsley treated with different concentrations of O₃-MNBW was investigated during storage at 20 ℃ for 5 d, and found that a ten-minute exposure of parsley to 2.5 mg·L^-1 O₃-MNBW effectively preserved the sensory quality of parsley, and resulted in lower weight loss, respiration rate, ethylene production, MDA levels, and a higher level of firmness, vitamin C, and chlorophyll content, relative to untreated parsley. The O₃-MNBW treatment also increased the level of total phenolics and flavonoids, enhanced peroxidase and ascorbate peroxidase activity, and inhibited polyphenol oxidase activity in stored parsley. Five volatile signatures identified using an electronic nose (W1W, sulfur-compounds; W2S, ethanol; W2W, aromatic- and organic- sulfur compounds; W5S, oxynitride; W1S, methane) exhibited a significant decrease in response to the O₃-MNBW treatment. A total of 24 major volatiles were identified. A metabolomic analysis identified 365 differentially abundant metabolites (DMs). Among them, 30 and 19 DMs were associated with characteristic volatile flavor substance metabolism in O₃-MNBW and control groups, respectively. The O₃-MNBW treatment increased the abundance of most DMs related to flavor metabolism and reduced the level of naringin and apigenin. Our results provide insight into the mechanisms that are regulated in response to the exposure of parsley to O₃-MNBW, and confirmed the potential use of O₃-MNBW as a preservation technology.

African jewel fish (Hemichromis bimaculatus) distinguish individual faces based on their unique iridophore patterns

Previous research has shown that African jewel fish (Hemichromis bimaculatus) recognize pair-bonded mates during their exchanges of egg-guarding duties. The current research examined the perceptual cues for face recognition by comparing two face models displaying anatomically realistic arrangements of blue iridophores derived from discriminant function analysis of distinct sibling groups. Four groups each consisting of 9 subadults were examined using a narrow compartment restraining lateral movement where face models were presented at eye level for eight trials. Because respiratory movement of the operculum can mechanically displace the eye thereby shifting the retinal image, jewel fish reduce their respiration rate during increased attention. When two experimental groups were presented with the same face models on four trials following initial model presentations, both groups exhibited stable respiration rates indicative of model habituation. When the habituated face models were switched to novel face models on the fifth trial, the rates of respiration decreased as measured by reliable increases in the elapsed times of opercular beats. Switching the models back to the habituated models on the sixth trial caused reliable decreases in the elapsed times of opercular beats, resembling the earlier trials for the habituated models. Switching the face models again to the formerly novel models on the seventh trial produced respiration rates that resembled those of the habituated models. The two control groups viewing the same models for all eight trials exhibited no substantial change in respiration rates. Together, these findings indicate that jewel fish can learn to recognize novel faces displaying unique arrangements of iridorphores after one trial of exposure.

Use of thermography and physiological rate to assess heat tolerance in cattle breeds

Thermography has grown in use in recent years. It is a valuable tool for measuring animal heat tolerance under heat stress conditions since it is a non-invasive, safe and practical methodology. Physiological variables such as respiration rate and eye temperature, and environmental variables such as air temperature and wet bulb temperature were analysed in animals from nine cattle breeds (Angus, Braford, Brangus, Canchim, Charolais, Hereford, Nelore, Simmental and Santa Gertrudis) and one bubaline (Mediterranean) at Rio Grande do Sul, Brazil. Positive correlations were observed between air temperature and respiration rate and eye temperature. Furthermore, the breed strongly influenced the eye temperature and respiration rate of the animals. Eye temperature showed strong correlation with air temperature and wet bulb temperature. Simmental and Nelore animals presented higher eye temperature values. Simmental presented alteration in respiratory rate before the other breeds and Nelore was the last breed to present this alteration. The inflection points in the broken line analysis indicated the environmental temperature limits at which breeds begin to change their respiration to compensate for environmental variation. The use of thermography has proven to be a technique with possible application to evaluate the temperature of animals. Logistic regression analysis allows us to observe how each breed behaves with the temperature change. Using respiration rates and eye temperatures it was possible to identify physiological limits for comfort in different breeds of bovine. In the future it would be interesting to conduct additional studies using other physiological variables and also other indices of climatic conditions.

The effects of kangaroo mother care on physiological parameters of premature neonates in neonatal intensive care unit: A systematic review

PURPOSE

The effects of Kangaroo mother care (KMC) on physiological parameters in preterm infants have been reported in the literature by experimental and quasi-experimental studies, and varying findings have been presented. The present study was conducted to determine the effects of KMC on the physiological parameters of premature newborns in the Neonatal Intensive Care Unit.

DESIGN AND METHOD

The review was conducted according to the specified keywords by scanning the EBSCO-host, Cochrane Library, Medline, PubMed, ScienceDirect, Web of Science, and TR index databases using the keywords "kangaroo care AND preterm AND vital signs." The pool mean differences (MDs) were calculated, adopting a 95% confidence interval (CIs) using the Stata 16 software for the meta-analysis [PROSPERO: CRD42021283475].

RESULTS

Eleven studies for systematic review and nine studies for meta-analysis, including 634 participants, were found eligible for inclusion. It was determined that the "temperature" (z = 3.21; p = 0.000) and "oxygen saturation" (z = 2.49; p = 0.000) values created a positive effect in general in the kangaroo care group; however, there was no sufficient evidence to state that it affected the "heart rate" (z = -0.60; p = 0.55) and "respiratory rate" (z = -1.45; p = 0.15) values. In the present study, the duration of KMC application had statistically different effects on temperature and oxygen saturation (SpO₂) (p < 0.05). One-hour or shorter applications of KMC had a higher effect on the temperature and oxygen saturation values (1.83; 1.62, respectively).

CONCLUSION

Our results provided references for clinical implications, and the "temperature" and "oxygen saturation (SpO₂)" values created a positive effect in general in the KMC group. However, there was no sufficient evidence to state that it affected the "heart rate" and "respiratory rate" values. The duration of KMC application had statistically different effects on temperature and oxygen saturation. One-hour or shorter applications of KMC had a higher effect on the temperature and SpO₂ values. Longitudinal, randomized, controlled studies examining the effects of KMC on vital signs in premature newborns with vital parameters outside the normal reference range are recommended.

PRACTICE IMPLICATIONS

The goal of the NICU nurse is to improve the infant's well-being. The application of KMC is a unique care for the nurse in maintaining the newborn's well-being. The vital signs of newborns hospitalized in the NICU with critical problems may be out of normal limits. KMC is an essential developmental care practice that ensures that the neonate's vital signs are kept within normal limits by relaxing the neonate, reducing stress, increasing comfort, and supporting interventions and treatments. KMC application is unique for each mother‑neonate pair. Depending on the tolerance of the mother and infant in terms of duration, it is recommended to perform KMC in the NICU under the supervision of a nurse. Neonatal nurses should support mothers in giving KMC in the NICU since KMC has ameliorative effects on the vital signs of premature neonates.

Selective feeding protects moon jellyfish (Aurelia aurita s.l.) from overloading with microplastics

Jellyfish blooms may be important bioindicators for marine ecosystem degradation, including the accumulation of microplastics in pelagic food webs. Here we show growth, respiration and filtration rates of the moon jellyfish (Aurelia aurita s.l.) when fed high concentrations (350 L^-1) of zooplankton prey (Artemia salina nauplii) and polystyrene (PS) or reference particles (charcoal; size range 50-500 μm). Our controlled feeding experiments reveal that inedible particles are ingested less efficiently compared to prey (retention efficiency ~60 % for PS) and actively removed from the gastrovascular system of ephyrae and medusae. Increased metabolic demands for excretion of inedible material (up to 76.7 ± 3.1 % of ingested prey biomass) suggest that overloading with microplastics can decelerate growth (observed maxima 26.1 % d^-1 and 12.6 % d^-1, respectively) and reproductive rates when food is limited. Possible consequences of this selective feeding strategy in response to proceeding microplastic pollution in the world's future oceans are discussed.

A closer look at yoga nidra- early randomized sleep lab investigations

OBJECTIVES

We aimed to examine trial feasibility plus physiological and psychological effects of a guided meditation practice, Yoga Nidra, in adults with self-reported insomnia.

METHODS

Twenty-two adults with self-reported insomnia were recruited to attend two visits at our research center. At Visit 1 (V1), participants were asked to lie quietly for ninety minutes. The primary outcome was change in electroencephalography (EEG). Heart rate variability (HRV), respiratory rate and self-reported mood and anxiety were also measured. At Visit 2 (V2), the same protocol was followed, except half of participants were randomized to practice Yoga Nidra for the first 30-min.

RESULTS

There were no between-group changes (V1-V2) in alpha EEG power at O1 (Intervention: 13 ± 70%; Control: -20 ± 40%), HRV or sleep onset latency in response to Yoga Nidra. Respiratory rate, however, showed statistically significant difference between groups (Yoga Nidra -1.4 breaths per minute (bpm) change during and - 2.1 bpm afterwards vs. Control +0.2 bpm during and + 0.4 bpm after; p = .03 for both during and after). The intervention displayed good acceptability (well-tolerated) and credibility (perceived benefit ratings) with implementation success (target sample size reached; 5% dropout rate).

CONCLUSIONS

This preliminary clinical trial provides early evidence that Yoga Nidra is a well-tolerated, feasible intervention for adults reporting insomnia. Decreased respiratory rate in response to Yoga Nidra needs to be confirmed in more definitive studies.

TRIAL REGISTRATION INFORMATION

This trial was registered on ClinicalTrials.gov as "A Closer Look at Yoga Nidra: Sleep Lab Analyses" (NCT#03685227).

Gene expression differences consistent with water loss reduction underlie desiccation tolerance of natural Drosophila populations

BACKGROUND

Climate change is one of the main factors shaping the distribution and biodiversity of organisms, among others by greatly altering water availability, thus exposing species and ecosystems to harsh desiccation conditions. However, most of the studies so far have focused on the effects of increased temperature. Integrating transcriptomics and physiology is key to advancing our knowledge on how species cope with desiccation stress, and these studies are still best accomplished in model organisms.

RESULTS

Here, we characterized the natural variation of European D. melanogaster populations across climate zones and found that strains from arid regions were similar or more tolerant to desiccation compared with strains from temperate regions. Tolerant and sensitive strains differed not only in their transcriptomic response to stress but also in their basal expression levels. We further showed that gene expression changes in tolerant strains correlated with their physiological response to desiccation stress and with their cuticular hydrocarbon composition, and functionally validated three of the candidate genes identified. Transposable elements, which are known to influence stress response across organisms, were not found to be enriched nearby differentially expressed genes. Finally, we identified several tRNA-derived small RNA fragments that differentially targeted genes in response to desiccation stress.

CONCLUSIONS

Overall, our results showed that basal gene expression differences across individuals should be analyzed if we are to understand the genetic basis of differential stress survival. Moreover, tRNA-derived small RNA fragments appear to be relevant across stress responses and allow for the identification of stress-response genes not detected at the transcriptional level.

Spatiotemporal variability of oxygen concentration in coral reefs of Gorgona Island (Eastern Tropical Pacific) and its effect on the coral Pocillopora capitata

Dissolved oxygen concentration (DO) is one of the main factors limiting benthic species distribution. Due to ocean warming and eutrophication, the ocean is deoxygenating. In the Eastern Tropical Pacific (ETP), deep waters with low DO (<1 mg L^-1) may reach coral reefs, because upwelling will likely intensify due to climate change. To understand oxygen variability and its effects on corals, we characterize the Spatio-temporal changes of DO in coral reefs of Gorgona Island and calculate the critical oxygen tension (P _crit) to identify the DO concentration that could represent a hypoxic condition for Pocillopora capitata, one of the main reef-building species in the ETP. The mean (±SD) DO concentration in the coral reefs of Gorgona Island was 4.6 ± 0.89 mg L^-1. Low DO conditions were due to upwelling, but hypoxia (<3.71 mg L^-1, defined as a DO value 1 SD lower than the Mean) down to 3.0 mg O₂ L^-1 sporadically occurred at 10 m depth. The P _crit of P. capitata was 3.7 mg L^-1 and lies close to the hypoxic condition recorded on coral reefs during the upwelling season at 10 m depth. At Gorgona Island oxygen conditions lower than 2.3 mg L^-1 occur at >20 m depth and coincide with the deepest bathymetric distribution of scattered colonies of Pocillopora. Because DO concentrations in coral reefs of Gorgona Island were comparably low to other coral reefs in the Eastern Tropical Pacific, and the hypoxic threshold of P. capitata was close to the minimum DO record on reefs, hypoxic events could represent a threat if conditions that promote eutrophication (and consequently hypoxia) increase.

Changes in the pattern of heat waves and the impacts on Holstein cows in a subtropical region

This study aimed to evaluate the change in the air temperature and the impacts of heat waves using Climate Change Indexes on the physiological and productive responses of lactating Holstein cows. Daily data of maximum and minimum air temperature for 1981-2021 were used. Heat waves were determined using six Climate Change Indexes. Individual data on respiratory rate, rectal temperature, and milk yield were collected in the summers of 2018, 2019, and 2021. The temperature trend analysis showed a significant (p < 0.0001) increase in maximum temperature, minimum temperature, and days in a heat wave. All six indexes increased significantly (p > 0.01). The increase in warm nights (> 20 °C) and the hottest days (> 35 °C) was the highest since 2010. Heat waves were classified into short (< 5 days) and long (> 5 days) of greater (> 36 °C) or lesser (< 36 °C) intensity. During the long and short heat waves of greater intensity, the respiratory rate increased (p < 0.05) until the fourth day. On the other hand, rectal temperature was higher (p < 0.05) from the fourth day until the end of the long heat waves. Therefore, the decrease in milk yield was significantly greater from the fourth or fifth day onwards. Finally, the evaluation method based on indexes was efficient to demonstrate the negative effects on physiological parameters and milk yield and can be indicated to evaluate heat stress in lactating cows.

A survey on vital signs monitoring based on Wi-Fi CSI data

The COVID-19 pandemic further highlighted the need to use low-cost remote monitoring procedures for medical patients. Since the results reported in the literature have shown that the use of Channel State Information (CSI) from Wi-Fi networks to remotely monitor patients can provide means to obtain a powerful medical information package in a non-invasive way and at low cost, a consistent review and analysis of the state of the art on this applied technique is developed in the present work. Initially, a mathematical overview of the CSI technology and its functional model is done. Subsequently, details about the technical approach necessary to use CSI in medical applications and a summary of the studies reported in the literature with such applications are presented. Based on the analyses and discussions carried out throughout this work, a better understanding of the current state of the art is achieved. Challenges and perspectives for future research are also highlighted.

How should the respiration rate be counted in cattle?

Respiration rate (RR) is a proficient indicator to measure the health status of cattle. The common method of measurement is to count the number of respiratory cycles each minute based on flank movements. However, there is no consistent method of execution. In previous studies, various methods have been described, including counting flank movements for 15 s, 30 s or 60 s as well as stopping the time for 5 or 10 breaths. We assume that the accuracy of the aforementioned methods differs. Therefore, we compared their precision with an RR sensor, which was used as the reference method in this study. Five scientists from the fields of agricultural science and veterinary medicine quantified the flank movement according to each of the five methods mentioned above. The results showed that with an average RR of 30 breaths per minute (bpm), all methods showed a high correlation to the values of the RR sensor. However, counting breaths for 60 s had the highest level of conformity with the RR sensor (Lin`s concordance correlation coefficient: 0.96) regardless of the level of RR. With rising RR, the inaccuracy increased significantly for the other four investigated methods, especially when counting 5 and 10 breaths. Therefore, we would recommend that counting for 60 s should be used as the standard method for future studies due to its high precision regardless of the level of RR.

Polyethylene microplastics reduce filtration and respiration rates in the Mediterranean sponge Petrosia ficiformis

Microplastic (MP) pollution represents a distinctive mark of the Anthropocene. Despite the increasing efforts to determine the ecological impacts of MP on marine biodiversity, our understanding of their toxicological effects on invertebrate species is still limited. Despite their key functional roles, sponges (Phylum Porifera) are particularly understudied in MP research. These filter-feeders extract and retain particles from the water column, across a broad size range. In this study, we carried out a laboratory experiment to assess the uptake of MPs (polyethylene, PE) by the Mediterranean sponge Petrosia ficiformis, how MPs influence key biological process after different times of exposure (24h and 72h) and whether they can be subsequently eliminated. MP uptake increased with time of exposure, with 30.6% of the inoculated MP particles found in sponge samples after 72h. MPs impaired filtration and respiration rates and these effects were still evident 72h after sponges had been transferred in uncontaminated water. Our study shows that time of exposure represents a key factor in determining MP toxicity in sponges. In addition, our results suggest that sponges are able to incorporate foreign particles and may thus be a potential bioindicator for MP pollutants.

Near-future extreme temperatures affect physiology, morphology and recruitment of the temperate sponge Crella incrustans

Current rates of greenhouse gas emissions are leading to a rapid increase in global temperatures and a greater occurrence of extreme climatic events such as marine heatwaves. In this study, we assessed the effects of thermal conditions predicted to occur within the next 40 years (SSP3-7.0 scenario of IPCC, 2021) on the respiration rate, buoyant weight, morphology and recruitment of the temperate model sponge Crella incrustans. Under predicted average temperatures (+ 2.5 °C, over the local mean), C. incrustans did not show any physiological and morphological changes compared to current conditions. However, when exposed to a simulated marine heatwave (16 days duration and a thermal peak at 22 °C), there was a large increase in sponge respiration rate, significant weight loss resulting from tissue regression, and sponge mortality. The simulated marine heatwave resulted also in a shorter period of recruitment, lower recruitment rate and higher mortality of settlers. Despite the tissue regression, the majority of sponges that survived the extreme temperatures showed respiration rates similar to controls 13 days after the thermal peak, indicating some resilience of C. incrustans to extreme thermal events. Our study shows that marine heatwaves will significantly impact the physiology, morphology, and recruitment of temperate sponges under near-future conditions, but that these sponges are likely to persist in warmer oceans.

Contactless monitoring of human respiration using infrared thermography and deep learning

OBJECTIVE

To monitor the human respiration rate (RR) using infrared thermography (IRT) and artificial intelligence, in a completely non-invasive and automated manner.

APPROACH

The human breathing signals (BS) were obtained using IRT. The RR was monitored under extreme conditions, by developing a deep learning (DL) based "Residual network 50+Facial landmark detection" (ResNet 50+FLD) model. This model was built and evaluated on 10,000 thermograms and is the first work that documents the use of a DL classifier on a large thermal dataset for nostril tracking. Further, the acquired BS were filtered using the Moving average filter (MAF), and the Butterworth filter (BF). The novel "Breathing signal characterization algorithm (BSCA)" was proposed to obtain the RR in an automated manner. This algorithm is the first work that identifies the breaths in the thermal BS as regular, prolonged, or rapid, using machine learning (ML). The "Exploratory data analysis" was performed to choose an appropriate ML algorithm for the BSCA. The performance of the "BSCA" was evaluated for both "Decision tree (DT)" and "Support vector machine(SVM)" models.

MAIN RESULTS

The "ResNet 50+FLD model" had Validation and Testing accuracy, of 99.5 %, and 99.4 % respectively. The Precision, Sensitivity, Specificity, F-measure, and G- mean values were computed as well. The comparative analysis of the filters revealed that the BF performed better than the MAF. The "BSCA" performed better with the SVM classifier, than the DT classifier, with Validation accuracy, and Testing accuracy of 99.5%, and 98.83%, respectively.

SIGNIFICANCE

The ever-increasing number of critical cases and the limited availability of skilled medical attendants, advocates in favor of an automated and harmless health monitoring system. The proposed methodology eliminates the risk of infections that spread through contact. It can be used in darkness, and in remote areas as well, where there is a lack of medical attendants.

The effect of tree shade on ambient conditions and heat stress indicator traits of new-born South African Mutton Merino and Dormer lambs: Preliminary results

This preliminary study investigated the provision of shade on heat stress indicators of South African Mutton Merino (SAMM) and Dormer lambs shortly after birth, during the autumn 2017 and 2018 lambing seasons. Newborn lambs were assessed to determine whether welfare, as assessed by respiratory response and rectal temperature as heat stress indicators, survival and early growth benefitted from the provision of shade. Groups consisting of 4-17 pregnant SAMM and Dormer ewes were randomly allocated to 5-10 paddocks with natural shade from trees and 5-9 paddocks that were directly in the sun with no shade available. The lambs were recorded within 24 h of birth at noon. Climate data were obtained from a nearby weather station. The lambs were also weighed at 12 (SD = 2) days of age at tail-docking. Tree shade had a moderating effect on temperature, resulting in lower maximum daytime and higher minimum night-time temperatures. There was an interaction between a temperature-humidity index (THI) and the treatments (access to shade or no access to shade) for respiration and rectal temperature (P < 0.01). Both traits were relatively unaffected by the THI at values below 77. Unshaded lambs exhibited a pronounced upwards trend following a THI-threshold of 77-78. Tailing weight tended to be higher while lamb survival of live-born lambs to tail-docking was lower in lambs born in shaded paddocks but these trends did not persist to weaning. Shade is needed to enhance animal welfare by alleviating the effect of high THI-values on hot days in an autumn lambing season.

Effects of the toxic dinoflagellate Alexandrium catenella on the behaviour and physiology of the blue mussel Mytilus edulis

The effects of harmful algae on bivalve physiology are complex and involve both physiological and behavioural responses. Studying those responses is essential to better describe and predict their impact on shellfish aquaculture and health risk for humans. In this study we recorded for two months the physiological response of the blue mussel Mytilus edulis from Eastern Canada to a one-week exposure to a paralytic shellfish poisoning producing dinoflagellate strain of Alexandrium catenella, isolated from the St Lawrence estuary, Canada. Mussels in a 'control' treatment were fed continuously with a non-toxic diet, while mussels in a 'starvation' treatment were fed the same non-toxic diet the first week and subsequently starved for seven weeks. Mussels in a 'toxic' treatment received A. catenella for one week before being starved until the end of the experiment. Over a two-month experiment we monitored shell and tissue growth, filtration capacity, respiration rate, byssal attachment strength, valve opening behaviour, and toxin content in tissues. Mussels fed normally on the toxic dinoflagellate and accumulated an average of 51.6 µg STXeq 100 g^-1 after one week of exposure. After seven weeks of depuration, about half of the specimen showed levels around 18 µg STXeq 100 g^-1. The condition index of exposed mussels ('toxic' treatment) decreased rapidly from the start as compared to mussels that received a one-week non-toxic diet ('starvation' treatment). Oxygen consumption rates increased in the 'toxic' treatment before leveling out with that of mussels from the 'starvation' treatment. Valve opening amplitude was lower in the 'toxic' treatment during and following the exposure. Average valve closure duration was higher right after the exposure, during the peak of mussel tissue intoxication. No significant change in byssal thread strength was observed through time in each treatment but less force was required to detach mussels from the 'toxic' and 'starvation' treatments. The number of byssus threads produced by mussels exposed to the toxic dinoflagellate was also lower than in the control group. These results represent advancements in our understanding of the impacts of harmful algae on bivalves and contribute to the development of mitigation measures necessary to both the safety of consumers and the sustainability of aquaculture operations.

Early identification and treatment of COPD exacerbation using remote respiratory monitoring

Remote patient monitoring (RPM) is increasingly more accessible and accurate. The optimal utilization of RPM requires medical conditions which have predictive physiologic changes and effective outpatient therapies. Respiratory rate elevation has been shown to be predictive of impending chronic obstructive pulmonary disease (COPD) exacerbation and treatment often focuses on home-based medical therapies. In this case, we report the successful treatment of a patient with an exacerbation of COPD based on pre-identification via respiratory RPM.

Respiration Measurements of Individual Tardigrades of the Species Richtersius cf coronifer as a Function of Temperature and Salinity and Termination of Anhydrobiosis

Numerous studies have demonstrated that tardigrades in a resting state (tun state) are very resistant to exceptional stress levels in comparison with the resistance observed in multicellular organisms in general. The types of stress include desiccation and radiation, which are also relevant in astrobiological research, and therefore, tardigrades are used as multicellular model organisms. For example, tardigrades have been investigated in the TARSE, TARDIS, RoTaRad, and TARDIKISS projects; their survival has been evaluated according to stressful conditions that prevail in low earth orbit, including the effects of cosmic radiation and microgravity. Despite this interest, the study of tardigrade biology has been severely hampered by the sparsity of appropriate quantitative techniques that inform at the single-organism level. In this study, we present results on mass-specific respiration rates as a function of termination of anhydrobiosis and variations in temperature and salinity, including Mars-analog perchlorate solutions, by using microsensor technology to measure respiration. Based on our results for Richtersius cf coronifer, we estimated the activation energy (50.8 kJ/mole O₂) for its metabolism as well as Q10 for selected temperature intervals. Q10 was constant-∼1.5-between 2°C and 33°C, except for the interval 11-16°C, where Q10 was 5.5. The steady-state mass-specific respiration rate of individuals of Richtersius cf coronifer increased with increasing salinity below the lethal limit, likely representing the energy requirements of its osmoregulatory response. We report the first quantitative data of a tardigrade's metabolic dynamics during the termination of anhydrobiosis, revealing significant variation between individuals. However, we observed a general trend, that is, a high initial metabolic rate after exposure to water. Our approach would allow us to carry out quantitative physiological studies of tardigrades on board of the International Space Station, and thus significantly extend the possibility of studying the response of multicellular organisms in space. Summary statement This article reports on first measurements of mass-specific respiration rates of individual tardigrades of the species Richtersius cf coronifer during termination of anhydrobiosis as well as measurements of the impact of temperature and salinity on oxygen uptake rates.

Bacteria are more sensitive than fungi to moisture in eroded soil by natural grass vegetation restoration on the Loess Plateau

Community composition and respiration rates of bacterial and fungal communities from grass-covered eroded soils of the Loess Plateau responded differently to constant and increasing soil moisture (SM) regimes. The soils were incubated with SM contents of 5%, 30%, and 45% and with wetting processes in the SM ranges from 5% to 30% (5-30%), from 5% to 30% to 45% (5-30-45%) and from 30% to 45% (30-45%); high-throughput sequencing and co-occurrence network analyses were applied to investigate the different responses of the bacterial and fungal communities to changed SM. Our results showed that bacteria were more sensitive than fungi to changes in SM. The dominant bacterial communities converted from Actinobacterial to Proteobacteria and Acidobacteria in 5-30-45% wetting procedure. Firmicutes preferred wet condition and exhibited slow resilience. However, no difference was observed for the Chloroflexi communities across any sample. The obvious difference in fungal composition was found between the wetting process of 5-30-45% and constant 45% SM. During the 5-30-45% procedure, the respiration rate was higher than that at 30-45% procedure after incubation for 24 days. The respiration rate in 5-30% procedure was lower than that of 5-30-45% process after incubation for 16-27 days. The larger effects on bacterial response than on fungi were verified in network analysis. Multiple stepwise regression analysis showed that 84.40% of the variation in bacterial richness and diversity as well as fungal diversity can be explained by changes in soil respiration rate in response to wetting procedure. Understanding the response of difference between bacterial and fungal community composition, phylum-levels networks and respiration rate to changes in SM is essential for the management of plant-soil-water relationship in the ecosystem after natural vegetation restoration on the Loess Plateau.

Appropriate THI model and its threshold for goats in semi-arid regions of India

The present study was attempted to identify an appropriate THI model and threshold THI for goats of semi-arid regions of India. Sixty non-pregnant goats each from Jamunapari and Barbari breeds were selected for the study. The study was conducted from last week of February to first week of June, during which average THI ranged between 53 and 92. Pulse rate (PR), respiration rate (RR) and rectal temperature (RT) were recorded at 1430 h on alternate days from six goats of each breed randomly during the experiment. Nine THI models were used to calculate THI. An appropriate THI model was predicted on the basis of correlation between THIs calculated from each model and physiological responses. The data of physiological parameters were linked to the THI calculated from identified THI model and threshold THI for each parameter was determined using segmented regression analysis (SegReg Software). The THI models; THI₁{(1.8 × Tdb+32)-[(0.55-0.0055 × RH) × (1.8 × Tdb-26.8)]} and THI₈{(0.8 × Tdb)+[(RH/100) × (Tdb-14.4)]+46.4)} were found to be equally appropriate for assessing environmental heat stress. Threshold THIs with respect to PR, RR and RT in Jamunapari goat were 71.78, 75.14 and 85.94, respectively and in Barbari goats, threshold THIs for PR and RR were 79.48 and 84.40, respectively. A threshold THI could not be identified for RT in Barbari goats. It can be concluded that THI₁ and THI₈ were the appropriate THI models for measuring environmental heat stress in goats. Results suggested that PR is the first physiological parameter which alters after the onset of heat stress and is followed by changes in RR and RT. On the basis of differential threshold THIs, it can be concluded that Barbari is better adapted than Jamunapari goats in semi-arid regions of India.

Efficacy of postharvest sodium nitroprusside application to extend storability by regulating physico-chemical quality of pear fruit

Quality loss in pear fruit during storage reduces its marketability for long run. To increase its storability, the efficacy of postharvest dip treatment donor sodium nitroprusside (SNP) 0.000, 0.001, 0.002 and 0.003 mol L^-1 were investigated on pear fruit cv. Patharnakh under storage conditions (low temperature 0-1 °C and relative humidity (90-95%). SNP effectively lowered fruit mass loss, retained colour and higher firmness, suppressed browning and respiration rate and sustained soluble solids content, titratable acidity, total phenol content and ascorbic acid thus conserved the fruit quality for longer period. SNP treatments suppressed the activity of polyphenol oxidase and increased activity of superoxide dismutase enzyme. Additionally, the SNP treated fruit exhibited lesser activities of fruit softening enzymes like pectin methylesterase, polygalacturonase and cellulase. Among all, 0.002 mol L^-1 SNP concentration was superior to lengthen storability and sensory quality of pear up to 60 d under cold storage.

Pre-harvest application of hexanal formulations for improving post-harvest life and quality of mango (Mangifera indica L.) cv. Dashehari

The highly perishable nature of the mango fruit which leads to quick deterioration in quality is the major limiting factor for mango growers of north India. Studies were, therefore, planned to determine the role of 'enhanced freshness formulation' (EFF) having hexanal as the main component in extending the storage life and quality of mango fruits of cultivar Dashehari. Aqueous formulations of hexanal are known to retard the activity of phospholipase-D thereby increasing the shelf-life and quality of stored fruits. Mango trees were given pre-harvest sprays of hexanal @800 µM, 1200 µM, 1600 µM and 2000 µM at 30 and 15 days before harvesting of the fruit. After harvest at physiologically mature stage, fruits were stored in walk-in-cool chambers at a temperature of 12 ± 2 °C and 85-90% relative humidity. These fruits were analysed for different physiological and biochemical parameters at weekly intervals till the stipulated storage period of 35 days. The results of the research revealed that the hexanal treatments widened the storage period of fruits while maintaining their freshness in comparison to the untreated mango fruits. Hexanal formulation @1600 µM significantly reduced the decay incidence, pectin methyl esterase activity and respiratory rate of mango fruits. These fruits also exhibited increased firmness, total soluble solids, acidity and maintained acceptable palatability up to 28 days of storage. The lower doses of EFF did not showed significant effect in expanding the storage span of fruits beyond 21 days while the higher dose of hexanal @2000 µM did not showed a significant enhancement in quality and storage life of mango fruits in comparison to hexanal @1600 µM.

Sows' responses to increased heat load - A review

There is a comprehensive body of literature on how increased air temperature affects the physiology, production and behaviour of sows, while very few studies consider the thermal effects of air humidity and air velocity. This review summarises studies that have investigated effects of air temperature by reviewing published literature in which sows were exposed to at least two different levels of air temperature ranging from 15 °C to 39 °C. Increased rectal temperature was investigated in the majority of the studies (26) and on average, the rectal temperature increased by 0.099 °C per °C increased air temperature above 25 °C. The increase was smaller at lower air temperatures, and it was suggested that rectal temperature is practically unaffected by air temperatures in the range of 15 °C-21 °C. This review elucidates how air temperature also affects performance indicators such as respiration rate, vaginal temperature, skin temperature, feed intake, milk yield, body weight loss during lactation, mortality, litter daily weight gain during lactation and sow behaviour. One study reported how respiration rate, rectal temperature, vaginal temperature and skin temperature were affected by both air temperature and air humidity, and the results suggest that the relative significance of air temperature and humidity may be similar for sows and finishing pigs (e.g. an increase of 40% relative humidity at an air temperature of 30 °C has a similar effect as a 1.9 °C increase in temperature). Studies on mitigation methods against the effects of high temperature and humidity such as snout cooling, drip cooling and floor cooling were reviewed to extract knowledge related to the effects of air velocity, temperatures of surrounding surfaces and the opportunity for sows to moisten their skin.

Respiratory properties of fresh black carrot (Dacus Carota L.) based upon non-linear enzyme kinetics approach

The present work was undertaken with an objective to evaluate the impact of temperature on respiration rate of fresh black carrot using a non-linear enzyme kinetics approach. Two different models viz. Arrhenius equation (temperature effect) and enzyme kinetics (effect of temperature and headspace concentration) have been compared for predicting the respiration rate of black carrot. The respiratory behavior of black carrot was assessed using closed system technique at 5, 10 and 15 °C (± 1 °C) temperature and constant relative humidity (RH) of 85%. The O₂ consumption and CO₂ evolution rate values were 39.17, 58.88 and 68.08 ml kg^-1 h^-1; 22.15, 34.63 and 41.86 ml kg^-1 h^-1 after the attainment of steady-state condition at 5, 10 and 15 °C, respectively. The inhibition by evolved CO₂ was found to be predominantly competitive at all temperatures. The average absolute deviation in O₂ consumption and CO₂ evolution rate for Arrhenius model was 3.5% and 5.3% while for enzyme kinetics model was 8.8% and 6.3%, respectively. Dependency of respiration rate of black carrot on temperature was well defined by Arrhenius model. The outcomes of the study can be further utilized to design the MAP (modified atmosphere packages) for fresh black carrot storage at 5 °C with 85% RH.

Biochemical and physiological responses of two clam species to Triclosan combined with climate change scenario

Ocean acidification and warming are among the man-induced factors that most likely impact aquatic wildlife worldwide. Besides effects caused by temperature rise and lowered pH conditions, chemicals of current use can also adversely affect aquatic organisms. Both climate change and emerging pollutants, including toxic impacts in marine invertebrates, have been investigated in recent years. However, less information is available on the combined effects of these physical and chemical stressors that, in nature, occur simultaneously. Thus, this study contrasts the effects caused by the antimicrobial agent and plastic additive, Triclosan (TCS) in the related clams Ruditapes philippinarum (invasive) and Ruditapes decussatus (native) and evaluates if the impacts are influenced by combined temperature and pH modifications. Organisms were acclimated for 30 days at two conditions (control: 17 °C; pH 8.1 and climate change scenario: 21 °C, pH 7.7) in the absence of the drug (experimental period I) followed by a 7 days exposure under the same water physical parameters but either in absence (unexposed) or presence of TCS at 1 μg/L (experimental period II). Biochemical responses covering metabolic, oxidative defences and damage-related biomarkers were contrasted in clams at the end of experimental period II. The overall picture showed a well-marked antioxidant activation and higher TCS bioaccumulation of the drug under the forecasted climate scenario despite a reduction on respiration rate and unaltered metabolism in the exposed clams. Since clams are highly consumed shellfish, the consequences for higher tissue bioaccumulation of anthropogenic chemicals to final consumers should be alerted not only at present conditions but more significantly under predicted climatic conditions for humans but also for other components of the marine trophic chain.

Redefining physiological responses of moose (Alces alces) to warm environmental conditions

We tested the concept that moose (Alces alces) begin to show signs of thermal stress at ambient air temperatures as low as 14 °C. We determined the response of Alaskan female moose to environmental conditions from May through September by measuring core body temperature, heart rate, respiration rate, rate of heat loss from exhaled air, skin temperature, and fecal and salivary glucocorticoids. Seasonal and daily patterns in moose body temperature did not passively follow the same patterns as environmental variables. We used large changes in body temperature (≥1.25 °C in 24hr) to indicate days of physiological tolerance to thermal stressors. Thermal tolerance correlated with high ambient air temperatures from the prior day and with seasonal peaks in solar radiation (June), ambient air temperature and vapor pressure (July). At midday (12:00hr), moose exhibited daily minima of body temperature, heart rate and skin temperature (difference between the ear artery and pinna) that coincided with daily maxima in respiration rate and the rate of heat lost through respiration. Salivary cortisol measured in moose during the morning was positively related to the change in air temperature during the hour prior to sample collection, while fecal glucocorticoid levels increased with increasing solar radiation during the prior day. Our results suggest that free-ranging moose do not have a static threshold of ambient air temperature at which they become heat stressed during the warm season. In early summer, body temperature of moose is influenced by the interaction of ambient temperature during the prior day with the seasonal peak of solar radiation. In late summer, moose body temperature is influenced by the interaction between ambient temperature and vapor pressure. Thermal tolerance of moose depends on the intensity and duration of daily weather parameters and the ability of the animal to use physiological and behavioral responses to dissipate heat loads.

Integrated approach for data acquisition, visualization and processing of analog polarographic systems for bioenergetics studies

Bioenergetic function is characterized with assays obtained by polarographic systems. Analog systems without data acquisition, visualization, and processing tools are used but require cumbersome operations to derive respiration rate and ADP to oxygen stoichiometry of oxidative phosphorylation (ADP/O ratio). The analog signal of a polarograhic system (YSI-5300) was digitized and a graphical user interface (GUI) was developed in MATLAB to integrate visualization, recording, calibration and processing of bioenergetic data. With the GUI, the signal is continuously visualized during the experiment and respiratory rates and ADP/O ratios can be determined. The integrated system was tested to evaluate bioenergetic function of subpopulations of mitochondria isolated from rat skeletal muscle (n = 10). Signal processing was applied to denoise data recorded at the sampling rate of 1000Hz, and maximize data decimation for computational applications. The error in calculating the bioenergetic outputs using decimated data is negligible when data are denoised. The estimate of respiration rate, ADP/O ratio and RCR obtained with denoised data at sampling rate as low as 5Hz was similar to that obtained with raw data recorded at sampling rate of 1000Hz. In summary, the integrated tools of the GUI overcome the limitations of data processing, accuracy, and utilization of analog polarographic systems.

The influence of climate change related factors on the response of two clam species to diclofenac

Diclofenac (DIC) is one of the non-steroidal anti-inflammatory drugs (NSAID) with higher consumption rates, used in both human and veterinary medicine. Previous studies already demonstrated the presence of this drug in aquatic environments and adverse effects towards inhabiting organisms. However, with the predictions of ocean acidification and warming, the impacts induced by DIC may differ from what is presently known and can be species-dependent. Thus, the present study aimed to comparatively assess the effects caused by DIC in the clams Ruditapes philippinarum and Ruditapes decussatus and evaluate if these impacts were influenced by pH and temperature. For this, organisms were acclimated for 30 days at two different temperature and pH (control conditions: pH 8.1, 17 °C; climate change forecasted scenario: pH 7.7, 20 °C) in the absence of drugs (experimental period I) followed by 7 days exposure under the same water physical parameters but in absence or presence of the pharmaceutical drug (at 1 μg/L, experimental period II). Biochemical responses covering metabolic capacity, oxidative stress and damage-related biomarkers were contrasted in clams at the end of the second experimental period. The results showed that under actual conditions, R. philippinarum individuals exposed to DIC presented enhanced antioxidant activities and reduced their respiration rate compared with non-contaminated clams. When exposed to the predicted climate change conditions, a similar response was observed in contaminated clams, but in this case clams increased their metabolic activities probably to fight the stress caused by the combination of both stressors. When R. decussatus was exposed to DIC, even at actual pH and temperature conditions, their antioxidant defences were also elevated but their baseline enzymatic activities were also naturally higher in respect to R. philippinarum. Although clams may use different strategies to prevent DIC damage, both clam species showed under low pH and high temperature limited oxidative stress impacts in line with a lower DIC bioaccumulation. The present findings reveal that predicted climate change related factors may not enhance the impacts of DIC in Ruditapes clams in a species-dependent manner although both displayed particular mechanisms to face stress.

Modeling respiration rates of Ipomoea batatas (sweet potato) under hermetic storage system

The sweet potato respiration rate versus gas composition was mathematically modeled, as required to design an effective modified atmosphere packaging (MAP) system. Storage tests of sweet potato were conducted at 15-30 °C. The O₂ and CO₂ concentrations were measured over time in a closed system. The respiration rate was estimated to be a derivative of the quadratic function of gas concentration over time and decreased with decreasing O₂ and increasing CO₂. The model of the uncompetitive inhibition enzyme reaction rate fitted well with the experimental results. The temperature dependency of the equation parameters (V_m, K_m, and K_i) followed the Arrhenius relationships. The use of the proposed models to simulate the respiration rates as a function of temperature revealed less temperature dependence in low O₂ and high CO₂ concentrations. This gas composition, more desirable in practice, also agreed with the typical gas composition of MAP.

The effect of active coating and refrigerated storage on the quality of avocado cultivar, Quintal

Postharvest technologies, such as the application of coatings, could contribute to the extension of the shelf life of avocado fruit. The objective of the present research was to evaluate the effects of coating, based on agro-industrial co-products (citrus pectin, broken rice grain flour, and cellulosic rice skin nanofiber), sorbitol and potassium sorbate, on the quality of avocado (cultivar 'Quintal') stored under refrigeration. The coating contributed to a longer conservation of the green color of avocado, both peel and pulp, and significantly reducing the respiration rate of the coated fruit, which was 35% lower than that of the control fruit. The coated fruit was firmer and, possibly, the addition of cellulosic nanofiber contributed to the maintenance of this firmness. Regarding the bioactive compounds, there was no difference (p > 0.05) among the coated and control fruit. During refrigerated storage, total phenolic compounds content increased (p < 0.05) from 311.44 ± 25.89 to 800.25 ± 160.74 mg kg^-1 gallic acid equivalents (GAE) in the control fruit, and from 242.86 ± 52.33 to 584.75 ± 125.57 mg kg^-1 GAE in the coated fruit. It was concluded that the shelf life of avocado (cultivar 'Quintal') could be extended and ripening delayed by a minimum of 8 days, by applying a coating formulated with rice flour, pectin, sorbitol, potassium sorbate, and cellulosic rice skin nanofiber.

Critical THI thresholds based on the physiological parameters of lactating dairy cows

The severity of heat stress conditions in high-yielding dairy cows is currently underestimated. The present study aimed to determine the heat load threshold of the temperature-humidity index (THI) on physiological parameters of lactating Holstein-Friesian cows under a continental climatic zone in Germany. Physiological parameter measurements, such as respiration rate (RR), measured hourly, and heart rate (HR) and rectal temperature (RT), both measured twice daily, were performed in a total of 139 multiparous cows on three randomly chosen measurement days per week. In addition, the ambient temperature and relative humidity of the barn were recorded every 5 min to calculate the current THI. The physiological parameter data were linked to the THI, and the heat load thresholds were determined using the broken-stick model. The heat load duration effect of each physiological parameter was obtained by regression analysis. Considering the increases in the physiological parameters, our study provided reliable data to determine heat load thresholds for lactating high-yielding dairy cows in a moderate climatic zone. The heat load threshold could be determined for RR in standing cows (THI = 70) and lying cows (THI = 65) and for HR (THI = 72) and RT (THI = 70) in standing cows. The heat load duration also demonstrated a significant effect on the increases in physiological parameters among dairy cows. In particular, the present study enabled a strategy to be devised to initiate heat mitigation in high-yielding dairy cows when they are exposed to THIs above 65.

Hemoglobin in Arthropods-Daphnia as a Model

Hemoglobin is the respiratory protein of many arthropods, enhancing the oxygen transport capacity of the hemolymph. One example, that has been subject of extensive studies, is the hemoglobin of the crustacean genus Daphnia. Here the characteristics of this oxygen binding protein are reviewed. The genetic structure is the result of repeated duplication events in the evolution, leading to a variety of di-domain isoforms. Adjustments to environmental changes thus result from differential expression of these paralogs. The biochemical properties, including spectral characteristics, concentration ranges, molecular mass of monomers and native oligomers, are compared. Structural differences between isoforms can be correlated to functional properties of oxygen binding characteristics. The mechanism of hemoglobin induction via hypoxia-inducible factor 1 allows the response to altered oxygen and temperature conditions. Changes of the hemoglobin suite in quantity and functional quality can be linked to their benefits for the animals' physiological performance. However, there is a large inter- and intra-specific variability of this induction potential. The consequences of altered hemoglobin characteristics for the animals' success within their habitat are discussed.

Extracting physiological information in experimental biology via Eulerian video magnification

BACKGROUND

Videographic material of animals can contain inapparent signals, such as color changes or motion that hold information about physiological functions, such as heart and respiration rate, pulse wave velocity, and vocalization. Eulerian video magnification allows the enhancement of such signals to enable their detection. The purpose of this study is to demonstrate how signals relevant to experimental physiology can be extracted from non-contact videographic material of animals.

RESULTS

We applied Eulerian video magnification to detect physiological signals in a range of experimental models and in captive and free ranging wildlife. Neotenic Mexican axolotls were studied to demonstrate the extraction of heart rate signal of non-embryonic animals from dedicated videographic material. Heart rate could be acquired both in single and multiple animal setups of leucistic and normally colored animals under different physiological conditions (resting, exercised, or anesthetized) using a wide range of video qualities. Pulse wave velocity could also be measured in the low blood pressure system of the axolotl as well as in the high-pressure system of the human being. Heart rate extraction was also possible from videos of conscious, unconstrained zebrafish and from non-dedicated videographic material of sand lizard and giraffe. This technique also allowed for heart rate detection in embryonic chickens in ovo through the eggshell and in embryonic mice in utero and could be used as a gating signal to acquire two-phase volumetric micro-CT data of the beating embryonic chicken heart. Additionally, Eulerian video magnification was used to demonstrate how vocalization-induced vibrations can be detected in infrasound-producing Asian elephants.

CONCLUSIONS

Eulerian video magnification provides a technique to extract inapparent temporal signals from videographic material of animals. This can be applied in experimental and comparative physiology where contact-based recordings (e.g., heart rate) cannot be acquired.

The role of ROS-induced change of respiratory metabolism in pulp breakdown development of longan fruit during storage

Compared to the control longans, hydrogen peroxide (H₂O₂)-treated longans exhibited higher index of pulp breakdown, higher fruit respiration rate, higher activities of pulp phosphohexose isomerase (PGI), succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), ascorbic acid oxidase (AAO) and polyphenol oxidase (PPO), but lower activity of pulp nicotinamide adenine dinucleotide kinase (NADK). H₂O₂-treated longans also exhibited lower total activities of pulp glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH), lower levels of pulp NADP(H), but higher levels of pulp NAD(H). These data indicated that H₂O₂-stimulated longan pulp breakdown was owing to a decreased proportion of pentose phosphate pathway (PPP), the increased proportions of Embden-Meyerhof-Parnas pathway (EMP), tricarboxylic acid (TCA) cycle and cytochrome pathway (CCP) in total respiratory pathways. These findings further revealed that H₂O₂ could enhance respiration rate, and thus accelerate pulp breakdown occurrence and shorten the shelf life of longan fruit.

Potential survival of the lichen Caloplaca flavovirescens under high helium-beam doses

Testing the limits of survivability in space is the primary focus in astrobiological research. Although a number of previous studies have examined terrestrial life survival in an extraterrestrial environment, only a few have investigated how life systems respond to high doses of alpha cosmic ray, the main component of cosmic rays. We used respiration and photosynthetic rates as indicators of the vital signs of the lichen Caloplaca flavovirescens, which is a symbiotic life form including fungi and algae. Our experiment demonstrated that the photosynthetic rate decreased with increased helium-beam doses, whereas the respiration rate was relatively unaffected. Specifically, under a helium-beam dose greater than 10 Gy, the respiration rate remained nearly constant regardless of further increases in the radiation rate. Our results indicate that the different metabolic systems of terrestrial life forms might exhibit different survival characteristics when they are in space.

A panting score index for sheep

When exposed to hot conditions, heat dissipation via an increase in respiration rate (RR) is an important thermoregulatory mechanism for sheep. However, evaluating RR under field conditions is difficult. In cattle, a viable alternative has been to assess panting score (PS); therefore, the objective of this study was to evaluate the relationship between RR and PS to determine if a PS index can be used to evaluate heat load in sheep. One hundred and forty-four Merino wethers (44.02 ± 0.32 kg) were used within a climate-controlled study. The study was replicated twice over 29 days, where each replicate consisted of two treatments: (1) thermoneutral (TN) and (2) hot (HOT). Ambient temperature (T_A) and relative humidity (RH) were maintained between 18 and 20 °C and 60 and 70% respectively for the TN treatment. For the HOT treatment, heat load increased steadily over the 29 days. Minimum T_A was 22.5 °C and maximum was 38.5 °C, while RH decreased (60 to 30%) as T_A increased in the HOT treatment. A comprehensive PS classification was developed by enhancing the current sheep PS index and aligning the descriptors with the current PS index utilized in beef cattle studies. Respiration rate and PS were obtained for each animal at 3-h intervals between 0800 h and 1700 h daily. These data were used to determine the mean RR for each PS, across the study and within the TN and HOT treatments. The relationship between PS and RR was evaluated using a Pearson's correlation coefficient. Data were also analyzed using a general linear model to determine the impact of PS, posture and animal identification (animal ID) on RR within each PS. Unsurprisingly, RR increased as PS increased, and PS, 0 and RR, 2.5 were 30.7 ± 0.59 and 246.8 ± 12.20 bpm respectively. There was a strong relationship between RR and PS (r = 0.71; P < 0.0001). As RR increased, sheep were more likely to be observed standing (P < 0.001). Mean PS of sheep within the HOT treatment (1.49 ± 0.02) were greater (P = 0.0085) when compared to the TN (1.17 ± 0.02) sheep. Individual animal ID accounted for approximately 7-37% of the variation observed for RR across PS, indicating that animal ID and climatic conditions were influencing RR and PS. These results suggest that the comprehensive PS index described here can be used as a visual appraisal of the heat load status of sheep.

Chlorantraniliprole-mediated effects on survival, walking abilities, and respiration in the coffee berry borer, Hypothenemus hampei

Hypothenemus hampei Ferrari (Coleoptera: Curculionidae) is the main pest of coffee crops, and effective methods for pest management are needed urgently. Bioassays were conducted to assess the effects of the insecticide chlorantraniliprole on H. hampei adults. Toxicity, survivorship, larval production, respiration rate, and behavioral responses to six concentrations of chlorantraniliprole were evaluated. Chlorantraniliprole was toxic to H. hampei (LD₅₀ = 0.49 mg mL^-1 and LD₉₀ = 1.21 mg mL^-1). Survivorship was 98% in adults not exposed to chlorantraniliprole, decreasing to 52% in insects exposed to LD₅₀ and 2% in insects treated with LD₉₀. H. hampei showed reduced mobility on insecticide-treated surfaces. The insecticide promoted a decrease in the respiration rate of H. hampei for up to 3 h after exposure, altering behavioral responses and locomotor activity. Chlorantraniliprole was shown to have lethal and sublethal effects on H. hampei and, thus, can be used rotationally in integrated pest management programs to control of this pest in coffee crops and retard of insect resistance.

Combined effect of heat and nutritional stress on superovulation of Malpura ewes in a semi-arid region

Sheep reared in hot semi-arid environments are generally exposed to heat and nutritional stress in some seasons of the year, which affects both production and reproduction. To assess the effect of high ambient temperature and feed scarcity on superovulation, 16 adult Malpura ewes were randomly divided into two groups of 8 animals each. G1 (control) was kept under a shed and offered a maintenance diet, and G2 (combined stress) was subjected to both nutritional (30% less of maintenance diet) and heat (38-44 °C for 6 h/day) stress. Ewes were superovulated without estrus synchronization by a combination of single injection of 200 IU eCG and 8 injections of FSH (Folltropin-V) at 12-h intervals in tapering doses of 5 mg/kg body weight, starting from the day 7 of natural estrus. eCG was given with the first injection and PGF2α (10 mg) was given with the second last FSH injection. G2 increased respiration rate and rectal temperature (P < 0.01), and blood urea level (P < 0.05), whereas it decreased average daily gain, plasma T4 concentration (P < 0.01) and body weight (P < 0.05). Plasma estradiol level was lower (P < 0.05) in G2 ewes as compared to control (G1) ewes. However, the number of ewes showed a superovulatory response (88 vs 66% ewes ≥ 3 corpus luteum), ovulation rate (8.75 vs 5.88) and embryo production (5.5 vs 3.9) decreased, and the number of large follicles (anovulation) increased (1.0 vs 2.14) in G2 ewes. G2 had a comparable effect on the superovulatory response compared to control ewes although physiological changes occurred as an adaptive mechanism to stress. Therefore, the well-adapted cyclic sheep of the semi-arid region may be used for superovulation despite the stressful condition of heat exposure and nutritional insufficiency.

Photoplethysmographic determination of the respiratory rate in acutely ill patients: validation of a new algorithm and implementation into a biomedical device

Background

Respiratory rate is among the first vital signs to change in deteriorating patients. The aims of this study were to evaluate the accuracy of respiratory rate measurements using a specifically dedicated reflection-mode photoplethysmographic signal analysis in a pathological condition (PPG-RR) and to validate its implementation within medical devices.

Methods

This study is derived from a data mining project, including all consecutive patients admitted to our ICU (ReaSTOC study, ClinicalTrials.gov identifier: NCT02893462). During the evaluation phase of the algorithm, PPG-RR calculations were retrospectively performed on PPG waveforms extracted from the data warehouse and compared with RR reference values. During the prospective phase, PPG-RR calculations were automatically and continuously performed using a dedicated device (FreeO₂, Oxynov, Québec, QC, Canada). In all phases, reference RR was measured continuously using electrical thoracic impedance and chronometric evaluation (Manual-RR) over a 30-s period.

Results

In total, 201 ICU patients’ recordings (SAPS II 51.7 ± 34.6) were analysed during the retrospective evaluation phase, most of them being admitted for a respiratory failure and requiring invasive mechanical ventilation. PPG-RR determination was available in 95.5% cases, similar to reference (22 ± 4 vs. 22 ± 5 c/min, respectively; p = 1), and well correlated with reference values (R = 0.952; p < 0.0001), with a low bias (0.1 b/min) and deviation (± 3.5 b/min). Prospective estimation of the PPG-RR on 30 ICU patients’ recordings was well correlated with the reference method (Manual-RR; r = 0.78; p < 0.001). Comparison of the methods depicted a low bias (0.5 b/min) and acceptable deviation (< ± 5.5 b/min).

Conclusion

According to our results, PPG-RR is an interesting approach for ventilation monitoring, as this technique would make simultaneous monitoring of respiratory rate and arterial oxygen saturation possible, thus minimizing the number of sensors attached to the patient.

Trial registry number ClinicalTrials.gov identifier NCT02893462