Impact of co-digestion on existing salt and nutrient mass balances for a full-scale dairy energy project

Anaerobic digestion of manure and other agricultural waste streams with subsequent energy production can result in more sustainable dairy operations; however, importation of digester feedstocks onto dairy farms alters previously established carbon, nutrient, and salinity mass balances. Salt and nutrient mass balance must be maintained to avoid groundwater contamination and salination. To better understand salt and nutrient contributions of imported methane-producing substrates, a mass balance for a full-scale dairy biomass energy project was developed for solids, carbon, nitrogen, sulfur, phosphorus, chloride, and potassium. Digester feedstocks, consisting of thickened manure flush-water slurry, screened manure solids, sudan grass silage, and feed-waste, were tracked separately in the mass balance. The error in mass balance closure for most elements was less than 5%. Manure contributed 69.2% of influent dry matter while contributing 77.7% of nitrogen, 90.9% of sulfur, and 73.4% of phosphorus. Sudan grass silage contributed high quantities of chloride and potassium, 33.3% and 43.4%, respectively, relative to the dry matter contribution of 22.3%. Five potential off-site co-digestates (egg waste, grape pomace, milk waste, pasta waste, whey wastewater) were evaluated for anaerobic digestion based on salt and nutrient content in addition to bio-methane potential. Egg waste and wine grape pomace appeared the most promising co-digestates due to their high methane potentials relative to bulk volume. Increasing power production from the current rate of 369 kW to the design value of 710 kW would require co-digestion with either 26800 L d(-1) egg waste or 60900 kg d(-1) grape pomace. However, importation of egg waste would more than double nitrogen loading, resulting in an increase of 172% above the baseline while co-digestion with grape pomace would increase potassium by 279%. Careful selection of imported co-digestates and management of digester effluent is required to manage salt and nutrient mass loadings and reduce groundwater impacts.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

Synthesis, characterization, and CO2 capture study of micro-nano carbonaceous composites

The micro-nano carbonaceous composite activated carbon fiber/carbon nanotube (ACF/CNTs) was obtained by chemical vapor deposition technology with CNTs growth on the substrate ACF, and the composite was further modified by branched polyethyleneimine (PEI). The morphological features of the as-grown ACF/CNTs and PEI-modified samples were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermal gravimetric analysis respectively. Physical properties of the samples were recorded by conducting N2 adsorption/desorption at 77K. CO2 capture tests indicated that both the presence of CNTs and PEI increased the CO2 adsorption capacity, due to the unique hollow tubular structure of CNTs and poly amino groups of PEI. The CO2 adsorption capacities of ACF/CNTs and ACF/CNTs-PEI were tested to be 66.2 mg/g and 98.8 mg/g, respectively at 30°C, which were much higher than that of unmodified ACF (42.4 mg/g). Increasing adsorption temperature up to 60°C further promoted the CO2 adsorption capacity of ACF/CNTs-PEI (121.2 mg/g) due to the maximum equilibrium adsorption between the chemical and physical adsorption at this temperature. Cyclic CO2 adsorption tests via thermal desorption proved that ACF/CNTs-PEI had a good regenerability of 96.2%, suggesting this material is a promising CO2 adsorbent for practical applications.

MRNA and miRNA expression patterns associated to pathways linked to metal mixture health effects

Metals are a threat to human health by increasing disease risk. Experimental data have linked altered miRNA expression with exposure to some metals. MiRNAs comprise a large family of non-coding single-stranded molecules that primarily function to negatively regulate gene expression post-transcriptionally. Although several human populations are exposed to low concentrations of As, Cd and Pb as a mixture, most toxicology research focuses on the individual effects that these metals exert. Thus, this study aims to evaluate global miRNA and mRNA expression changes induced by a metal mixture containing NaAsO2, CdCl2, Pb(C2H3O2)2·3H2O and to predict possible metal-associated disease development under these conditions. Our results show that this metal mixture results in a miRNA expression profile that may be responsible for the mRNA expression changes observed under experimental conditions in which coding proteins are involved in cellular processes, including cell death, growth and proliferation related to the metal-associated inflammatory response and cancer.

Sustained delivery of dbcAMP by poly(propylene carbonate) micron fibers promotes axonal regenerative sprouting and functional recovery after spinal cord hemisection

This study describes the use of poly(propylene carbonate) (PPC) electrospun fibers as vehicle for the sustained delivery of dibutyryl cyclic adenosine monophosphate (dbcAMP) to the hemisected spinal cord. The dbcAMP and PPC were uniformly mixed with acetonitrile; then, electrospinning was used to generate micron fibers. The release of dbcAMP was assessed by ELISA in vitro. Our results showed that the encapsulation of dbcAMP in the fibers led to stable and prolonged release in vitro. The PPC micron fibers containing dbcAMP and the PPC micron fibers without dbcAMP were then implanted into the hemisected thoracic spinal cord, followed by testing of the functional recovery and immunohistochemistry. Compared with the control group, sustained delivery of dbcAMP promoted axonal regenerative sprouting and functional recovery and reduced glial scar formation, and the PPC micron fibers without dbcAMP did not have these effects. Our findings demonstrated the feasibility of using PPC electrospun fibers containing dbcAMP for spinal cord injury. The approach described here also will provide a platform for the potential delivery of other axon-growth-promoting or scar-inhibiting agents.

Chemosensory signals and their receptors in the olfactory neural system

Chemical communication is widely used among various organisms to obtain essential information from their environment required for life. Although a large variety of molecules have been shown to act as chemical cues, the molecular and neural basis underlying the behaviors elicited by these molecules has been revealed for only a limited number of molecules. Here, we review the current knowledge regarding the signaling molecules whose flow from receptor to specific behavior has been characterized. Discussing the molecules utilized by mice, insects, and the worm, we focus on how each organism has optimized its reception system to suit its living style. We also highlight how the production of these signaling molecules is regulated, an area in which considerable progress has been recently made.

Partial venom gland transcriptome of a Drosophila parasitoid wasp, Leptopilina heterotoma, reveals novel and shared bioactive profiles with stinging Hymenoptera

Analysis of natural host-parasite relationships reveals the evolutionary forces that shape the delicate and unique specificity characteristic of such interactions. The accessory long gland-reservoir complex of the wasp Leptopilina heterotoma (Figitidae) produces venom with virus-like particles. Upon delivery, venom components delay host larval development and completely block host immune responses. The host range of this Drosophila endoparasitoid notably includes the highly-studied model organism, Drosophila melanogaster. Categorization of 827 unigenes, using similarity as an indicator of putative homology, reveals that approximately 25% are novel or classified as hypothetical proteins. Most of the remaining unigenes are related to processes involved in signaling, cell cycle, and cell physiology including detoxification, protein biogenesis, and hormone production. Analysis of L. heterotoma's predicted venom gland proteins demonstrates conservation among endo- and ectoparasitoids within the Apocrita (e.g., this wasp and the jewel wasp Nasonia vitripennis) and stinging aculeates (e.g., the honey bee and ants). Enzyme and KEGG pathway profiling predicts that kinases, esterases, and hydrolases may contribute to venom activity in this unique wasp. To our knowledge, this investigation is among the first functional genomic studies for a natural parasitic wasp of Drosophila. Our findings will help explain how L. heterotoma shuts down its hosts' immunity and shed light on the molecular basis of a natural arms race between these insects.

Divergences in morphological changes and antioxidant responses in salt-tolerant and salt-sensitive rice seedlings after salt stress

Salinization plays a primary role in soil degradation and reduced agricultural productivity. We observed that salt stress reversed photosynthesis and reactive oxygen scavenging responses in leaves or roots of two rice cultivars, a salt-tolerant cultivar Pokkali and a salt-sensitive cultivar IR-29. Salt treatment (100 mM NaCl) on IR-29 decreased the maximum photochemical efficiency (Fv/Fm) and the photochemical quenching coefficient (qP), thereby inhibiting photosynthetic activity. By contrast, the salt treatment on Pokkali had the converse effect on Fv/Fm and qP, while increasing the nonphotochemical quenching coefficient (NPQ), thereby favoring photosynthetic activity. Notably, chloroplast or root cells in Pokkali maintained their ultrastructures largely intact under the salt stress, but, IR-29 showed severe disintegration of existing grana stacks, increase of plastoglobuli, and swelling of thylakoidal membranes in addition to collapsed vascular region in adventitious roots. Pokkali is known to have higher hydrogen peroxide (H2O2)-scavenging enzyme activities in non-treated seedlings, including ascorbate peroxidase, catalase, and peroxidase activities. However, these enzymatic activities were induced to a greater extent in IR-29 by the salt stress. While the level of endogenous H2O2 was lower in Pokkali than in IR-29, it was reversed upon the salt treatment. Nevertheless, the decreased amount of H2O2 in IR-29 upon the salt stress didn't result in a high scavenging activity of total cell extracts for H2O2, as well as O2(·-) and (·)OH species. The present study suggests that the tolerance to the moderate salinity in Pokkali derives largely from the constitutively maintained antioxidant enzymatic activities as well as the induced antioxidant enzyme system.

Methane emissions and contaminant degradation rates at sites affected by accidental releases of denatured fuel-grade ethanol

The recent increase in the use of denatured fuel-grade ethanol (DFE) has enhanced the probability of its environmental release. Due to the highly labile nature of ethanol (EtOH), it is expected to rapidly biodegrade, increasing the potential for inducing methanogenic conditions in the subsurface. As environmental releases of DFE can be expected to occur at the ground surface or in the vadose zone (e.g., due to surficial spills from rail lines or tanker trucks and leaking underground storage tanks), the potential for methane (CH4) generation at DFE spill sites requires evaluation. An assessment is needed because high CH4 generation rates may lead to CH4 fluxes towards the ground surface, which is of particular concern if spills are located close to human habitation-related to concerns of soil vapor intrusion (SVI). This work demonstrates, for the first time, the measurement of surficial gas release rates at large volume DFE spill sites. Two study sites, near Cambria and Balaton, in MN are investigated. Total carbon emissions at the ground surface (summing carbon dioxide (CO2) and CH4 emissions) are used to quantify depth-integrated DFE degradation rates. Results from both sites demonstrate that substantial CO2 and CH4 emissions do occur-even years after a spill. However, large total carbon fluxes, and CH4 emissions in particular, were restricted to a localized area within the DFE source zone. At the Balaton site, estimates of total DFE carbon losses in the source zone ranged between 5 and 174 μmol m(-2) s(-1), and CH4 effluxes ranged between non-detect and 9 μmol m(-2) s(-1). At the Cambria site estimates of total DFE carbon losses in the source zone ranged between 8 and 500 μmol m(-2) s(-1), and CH4 effluxes ranged between non-detect and 393 μmol m(-2) s(-1). Substantial CH4 accumulation, coupled with oxygen (O2) depletion, measured in samples collected from custom-designed gas collection chambers at the Cambria site suggests that the development of explosion or asphyxiation hazards is possible in confined spaces above a rapidly degrading DFE release. However, the results also indicate that the development of such hazards is locally constrained, will require a high degree of soil moisture, close proximity to the source zone, a good connection between the soil and the confined space, and poorly aerated conditions.

Unraveling microalgal molecular interactions using evolutionary and structural bioinformatics

Microalgae are unicellular microorganisms indispensible for environmental stability and life on earth, because they produce approximately half of the atmospheric oxygen, with simultaneously feeding on the harmful greenhouse gas carbon dioxide. Using gene fusion analysis, a series of five fusion/fission events was identified, that provided the basis for critical insights to their evolutionary history. Moreover, the three-dimensional structures of both the fused and the component proteins were predicted, allowing us to envisage putative protein-protein interactions that are invaluable for the efficient usage, handling and exploitation of microalgae. Collectively, our proposed approach on the five fusion/fission alga protein events contributes towards the expansion of the microalgae knowledgebase, bridging protein evolution of the ancient microalgal species and the rapidly evolving, modern, bioinformatics field.

Physiologic underpinnings of negative BOLD cerebrovascular reactivity in brain ventricles

With a growing need for specific biomarkers in vascular diseases, there has been a surging interest in mapping cerebrovascular reactivity (CVR) of the brain. This index can be measured by conducting a hypercapnia challenge while acquiring blood-oxygenation-level-dependent (BOLD) signals. A BOLD signal increase with hypercapnia is the expected outcome and represents the majority of literature reports; in this work we report an intriguing observation of an apparently negative BOLD CVR response at 3T, during inhalation of 5% CO2 with balance medical air. These "negative-CVR" clusters were specifically located in the ventricular regions of the brain, where CSF is abundant and results in an intense baseline signal. The amplitude of the CVR response was -0.51±0.44% (N=14, age 26±4 years). We hypothesized that this observation might not be due to a decrease in oxygenation but rather a volume effect in which bright CSF signal is replaced by a less intensive blood signal as a result of vasodilation. To test this, we performed an inversion-recovery (IR) experiment to suppress the CSF signal (N=10, age 27±5 years). This maneuver in imaging sequence reversed the sign of the signal response (to 0.66±0.25%), suggesting that the volume change was the predominant reason for the apparently negative CVR in the BOLD experiment. Further support of this hypothesis was provided by a BOLD hyperoxia experiment, in which no voxels showed a negative response, presumably because vasodilation is not usually associated with this challenge. Absolute CBF response to hypercapnia was measured in a new group of subjects (N=8, age 29±7 years) and it was found that CBF in ventricular regions increased by 48% upon CO2 inhalation, suggesting that blood oxygenation most likely increased rather than decreased. The findings from this study suggest that CO2 inhalation results in the dilation of ventricular vessels accompanied by shrinkage in CSF space, which is responsible for the apparently negative CVR in brain ventricles.

Effects of changes in energy homeostasis and exposure of noxious insults on the expression of orexin (hypocretin) and its receptors in the brain

This review summarizes data regarding the brain expression of the orexin (hypocretin) system including: prepro-orexin (PPO), orexin A (OxA), orexin B (OxB) and the two orexin receptors 1 and 2 (OxR1, OxR2). Clinical data is limited to OxA and OxB in cerebral spinal fluid and serum/plasma, thus necessitating the development of animal models to undertake mechanistic studies. We focus on changes in animal models that were either exposed to a regime of altered sleep, metabolic energy homeostasis, exposed to drugs and noxious insults. Many more expressional studies are available for PPO, OxA and OxB levels, compared to studies of the receptors. Interestingly, the direction and pattern of change for PPO, OxA and OxB is inconsistent amongst studies, whereas for the receptors, there tends to be increased expression for both OxR1 and OxR2 after alterations in energy homeostasis, and an increased expression after noxious insults or exposure to some drugs. The clinical implications of these results from animal models are discussed in light of the findings from human studies, and future research directions are suggested to fill knowledge gaps with regard to the orexin system, particularly during early brain development.

Effect of different sintering methods on bioactivity and release of proteins from PLGA microspheres

Macromolecule release from poly(d,l-lactide-co-glycolide) (PLGA) microspheres has been well-characterized, and is a popular approach for delivering bioactive signals from tissue-engineered scaffolds. However, the effect of some processing solvents, sterilization, and mineral incorporation (when used in concert) on long-term release and bioactivity has seldom been addressed. Understanding these effects is of significant importance for microsphere-based scaffolds, given that these scaffolds are becoming increasingly more popular, yet growth factor activity following sintering and/or sterilization is heretofore unknown. The current study evaluated the 6-week release of transforming growth factor (TGF)-β3 and bone morphogenetic protein (BMP)-2 from PLGA and PLGA/hydroxyapatite (HAp) microspheres following exposure to ethanol (EtOH), dense phase carbon dioxide (CO2), or ethylene oxide (EtO). EtO was chosen based on its common use in scaffold sterilization, whereas EtOH and CO2 were chosen given their importance in sintering microspheres together to create scaffolds. Release supernatants were then used in an accelerated cell stimulation study with human bone marrow stromal cells (hBMSCs) with monitoring of gene expression for major chondrogenic and osteogenic markers. Results indicated that in microspheres without HAp, EtOH exposure led to the greatest amount of delivery, while those treated with CO2 delivered the least growth factor. In contrast, formulations with HAp released almost half as much protein, regardless of EtOH or CO2 exposure. Notably, EtO exposure was not found to significantly affect the amount of protein released. Cell stimulation studies demonstrated that eluted protein samples performed similarly to positive controls in PLGA-only formulations, and ambiguously in PLGA/HAp composites. In conclusion, the use of EtOH, subcritical CO2, and EtO in microsphere-based scaffolds may have only slight adverse effects, and possibly even desirable effects in some cases, on protein availability and bioactivity.

Survival of Vibrio parahaemolyticus and Aeromonas hydrophila in sea bream (Sparus aurata) fillets packaged under enriched CO(2) modified atmospheres

The ability to survive of two pathogens (Vibrio parahaemolyticus and Aeromonas hydrophila) spread over sea bream fillets packaged under different modified atmospheres (MAPs) was studied at 0°C and 4°C under refrigerated storage. The atmospheres used were 60% CO2/40% N2, 70% CO2/30% N2 and 80% CO2/20% N2 and a control batch packaged in air. Head space gas analyses, microbial counts and confirming test of pathogenic bacteria were carried out during 16days. The results obtained showed that all the modified atmospheres studied were effective to reduce the microbial load of sea bream fillets when compared with air packaged samples although small differences were found among MAPs. Temperature storage was the main factor to reduce microbial growth. V. parahaemolyticus was unable to grow at both temperatures, 0°C and 4°C (except air batches) while A. hydrophila showed significant growth at 4°C and microbial inactivation at 0°C.

Suicide by carbon dioxide

Suicides by self-poisoning are common in all parts of the world. Among these intoxications, gases are rarely used, especially carbon dioxide (CO2). Very few cases of self-inflicted and deliberate carbon dioxide poisonings have been reported. This paper presents two uncommon suicides by carbon dioxide intoxication. In one case, a 53-year-old man tightly sealed a small bathroom and locked himself in it likely with dry ice. Warning notices were tagged to the door. In another case, a 48-year-old man working in a restaurant committed suicide by closing himself in a walk-in refrigerator and opening the stored carbon dioxide containers intended for the beverage dispensing equipment. The limited possibilities of proving lethal CO2 intoxications post-mortem necessitate a close cooperation of the involved parties during investigation. Only the synopsis of all findings permits a sound assessment regarding the manner and cause of death.

Anxiety, pCO2 and cerebral blood flow

This study examined the effect of anxiety on cerebral blood flow at different levels of pCO2 in healthy participants (N=29). Three types of breathing were used to manipulate pCO2 in a within-subject threat-of-shock paradigm: spontaneous breathing, CO2-inhalation and hyperventilation resulting in normo-, hyper- and hypocapnia. Transcranial Doppler ultrasonography was used to measure CBF velocity (CBFv) in the right middle cerebral artery, while breathing behavior and end-tidal pCO2 were monitored. During normocapnia, elevated anxiety was clearly associated with increased CBFv. Consistent with the cerebral vasoconstrictive and vasodilating effects of, respectively, hypo- and hypercapnia, we observed a positive linear association between CBFv and pCO2. The slope of this association became steeper with increasing anxiety, indicating that anxiety enhances the sensitivity of CBFv to changes in pCO2. The findings may elucidate conflicting findings in the literature and are relevant for brain imaging relying on regional cerebral blood flow.