A horizon scan of global biological conservation issues for 2024

We present the results of our 15th horizon scan of novel issues that could influence biological conservation in the future. From an initial list of 96 issues, our international panel of scientists and practitioners identified 15 that we consider important for societies worldwide to track and potentially respond to. Issues are novel within conservation or represent a substantial positive or negative step-change with global or regional extents. For example, new sources of hydrogen fuel and changes in deep-sea currents may have profound impacts on marine and terrestrial ecosystems. Technological advances that may be positive include benchtop DNA printers and the industrialisation of approaches that can create high-protein food from air, potentially reducing the pressure on land for food production.

Evidence of Antineutrinos from Distant Reactors Using Pure Water at SNO

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.

Correlation with a limited set of behavioral niches explains the convergence of somatic morphology in mygalomorph spiders

Understanding the drivers of morphological convergence requires investigation into its relationship with behavior and niche space, and such investigations in turn provide insights into evolutionary dynamics, functional morphology, and life history. Mygalomorph spiders (trapdoor spiders and their kin) have long been associated with high levels of morphological homoplasy, and many convergent features can be intuitively associated with different behavioral niches. Using genus-level phylogenies based on recent genomic studies and a newly assembled matrix of discrete behavioral and somatic morphological characters, we reconstruct the evolution of burrowing behavior in the Mygalomorphae, compare the influence of behavior and evolutionary history on somatic morphology, and test hypotheses of correlated evolution between specific morphological features and behavior. Our results reveal the simplicity of the mygalomorph adaptive landscape, with opportunistic, web-building taxa at one end, and burrowing/nesting taxa with structurally modified burrow entrances (e.g., a trapdoor) at the other. Shifts in behavioral niche, in both directions, are common across the evolutionary history of the Mygalomorphae, and several major clades include taxa inhabiting both behavioral extremes. Somatic morphology is heavily influenced by behavior, with taxa inhabiting the same behavioral niche often more similar morphologically than more closely related but behaviorally divergent taxa, and we were able to identify a suite of 11 somatic features that show significant correlation with particular behaviors. We discuss these findings in light of the function of particular morphological features, niche dynamics within the Mygalomorphae, and constraints on the mygalomorph adaptive landscape relative to other spiders.

A global biological conservation horizon scan of issues for 2023

We present the results of our 14th horizon scan of issues we expect to influence biological conservation in the future. From an initial set of 102 topics, our global panel of 30 scientists and practitioners identified 15 issues we consider most urgent for societies worldwide to address. Issues are novel within biological conservation or represent a substantial positive or negative step change at global or regional scales. Issues such as submerged artificial light fisheries and accelerating upper ocean currents could have profound negative impacts on marine or coastal ecosystems. We also identified potentially positive technological advances, including energy production and storage, improved fertilisation methods, and expansion of biodegradable materials. If effectively managed, these technologies could realise future benefits for biological diversity.

A horizon scan of global biological conservation issues for 2022

We present the results of our 13th annual horizon scan of issues likely to impact on biodiversity conservation. Issues are either novel within the biological conservation sector or could cause a substantial step-change in impact, either globally or regionally. Our global panel of 26 scientists and practitioners identified 15 issues that we believe to represent the highest priorities for tracking and action. Many of the issues we identified, including the impact of satellite megaconstellations and the use of long-distance wireless energy transfer, have both elements of threats and emerging opportunities. A recent state-sponsored application to commence deep-sea mining represents a significant step-change in impact. We hope that this horizon scan will increase research and policy attention on the highlighted issues.

Annual abundance of common Kestrels (Falco tinnunculus) is negatively associated with second generation anticoagulant rodenticides

Rats and mice can damage food and agricultural products as well as transmit diseases, thereby requiring control of their numbers. Application of Second Generation Anticoagulant Rodenticides (SGARs) often reduces rodent numbers locally. However, predators eating rodents, including non-target species, that have consumed SGARs may be secondarily exposed and potentially lethally poisoned. Here we study whether SGARs may have contributed to the widespread population declines of a rodent-eating raptor, the Common Kestrel (Falco tinnunculus) in the UK. We show that 161 (66.8%) of the 241 Kestrels submitted for ecotoxicology tests between 1997 and 2012 had detectable levels of at least one SGAR in their livers. Adult Kestrels had significantly higher prevalence of SGARs than juveniles, suggesting accumulation of SGARs through time. The prevalence and concentrations of individual SGARs in Kestrels were significantly higher in England than in Scotland. SGAR prevalence in Kestrels were positively associated with some land cover types, primarily arable cereals and broad-leaved woodland, and negatively associated with mainly mean elevation, probably reflecting variation in SGAR usage across land cover types. By using volunteer-collected data on national Kestrel abundance 1997-2012, we show that there is a negative correlation between the Kestrel population index in a specific year and the concentration of bromadialone as well as the total SGAR concentration in the same year. Although correlative, this is the first study to provide evidence for a potential population-limiting effect of SGARs on a raptor.

Diversification of the mygalomorph spider genus Aname (Araneae: Anamidae) across the Australian arid zone: Tracing the evolution and biogeography of a continent-wide radiation

The assembly of the Australian arid zone biota has long fascinated biogeographers. Covering over two-thirds of the continent, Australia's vast arid zone biome is home to a distinctive fauna and flora, including numerous lineages which have diversified since the Eocene. Tracing the origins and speciation history of these arid zone taxa has been an ongoing endeavour since the advent of molecular phylogenetics, and an increasing number of studies on invertebrate animals are beginning to complement a rich history of research on vertebrate and plant taxa. In this study, we apply continent-wide genetic sampling and one of the largest phylogenetic data matrices yet assembled for a genus of Australian spiders, to reconstruct the phylogeny and biogeographic history of the open-holed trapdoor spider genus Aname L. Koch, 1873. This highly diverse lineage of Australian mygalomorph spiders has a distribution covering the majority of Australia west of the Great Dividing Range, but apparently excluding the high rainfall zones of eastern Australia and Tasmania. Original and legacy sequences were obtained for three mtDNA and four nuDNA markers from 174 taxa in seven genera, including 150 Aname specimen terminals belonging to 102 species-level operational taxonomic units, sampled from 32 bioregions across Australia. Reconstruction of the phylogeny and biogeographic history of Aname revealed three radiations (Tropical, Temperate-Eastern and Continental), which could be further broken into eight major inclusive clades. Ancestral area reconstruction revealed the Pilbara, Monsoon Tropics and Mid-West to be important ancestral areas for the genus Aname and its closest relatives, with the origin of Aname itself inferred in the Pilbara bioregion. From these origins in the arid north-west of Australia, our study found evidence for a series of subsequent biome transitions in separate lineages, with at least eight tertiary incursions back into the arid zone from more mesic tropical, temperate or eastern biomes, and only two major clades which experienced widespread (primary) in situ diversification within the arid zone. Based on our phylogenetic results, and results from independent legacy divergence dating studies, we further reveal the importance of climate-driven biotic change in the Miocene and Pliocene in shaping the distribution and composition of the Australian arid zone biota, and the value of continent-wide studies in revealing potentially complex patterns of arid zone diversification in dispersal-limited invertebrate taxa.

Systematics of the Australian golden trapdoor spiders of the Euoplos variabilis-group (Mygalomorphae : Idiopidae : Euoplini): parapatry and sympatry between closely related species in subtropical Queensland

The Australian golden trapdoor spiders of the tribe Euoplini (family Idiopidae) are among the most abundant and diverse of mygalomorph lineages in subtropical eastern Australia. Throughout this highly populated area, species in the monophyletic Euoplos variabilis-group are largely ubiquitous; however, species delimitation has long proven difficult in the group because species are morphologically very similar and have parapatric or even sympatric distributions. We address these challenges in the variabilis-group, and explore the phylogeny and taxonomy of species using an integrative systematic approach. In doing so, we apply a conservative, pragmatic methodology, naming only species for which adequate data are available (namely sequence data and unequivocally linked male specimens), and explicitly stating and mapping material that could not be linked to a species, to aid future research on the group. We describe five new species from south-eastern Queensland –E. booloumba sp. nov., E. jayneae sp. nov., E. raveni sp. nov., E. regalis sp. nov. and E. schmidti sp. nov.; we redescribe two previously named species – E. similaris (Rainbow & Pulleine, 1918) and E. variabilis (Rainbow & Pulleine, 1918); and we reillustrate the recently described E. grandis Wilson & Rix, 2019. The nominate species, E. variabilis, is shown to have a far smaller distribution than previously thought, and E. similaris is given a modern taxonomic description for the first time. A key to adult male specimens is also provided. This study further reveals a case of sympatry between two species within the variabilis-group; both E. raveni sp. nov. and E. schmidti sp. nov. occur in the Brisbane Valley, south of the Brisbane River – a notable result given that closely related mygalomorph species usually occur allopatrically. This work updates what is currently known of the phylogeny and diversity of one of the dominant mygalomorph lineages of subtropical eastern Australia, resolving a complex and highly endemic fauna. http://zoobank.org/urn:lsid:zoobank.org:pub:A4FB92F6-EFFF-4468-B1D8-000D69923996

The open-holed trapdoor spiders (Mygalomorphae: Anamidae: Namea) of Australia's D'Aguilar Range: revealing an unexpected subtropical hotspot of rainforest diversity

The D'Aguilar Range of subtropical south-eastern Queensland (Australia), harbours an upland rainforest biota characterised by high levels of endemic diversity. Following recent phylogenetic and biogeographic research into the open-holed trapdoor spiders of the genus Namea Raven, 1984 (family Anamidae), remarkable levels of sympatry for a single genus of mygalomorph spiders were recorded from the D'Aguilar Range. It is now known that eight different species in the genus can be found in the D'Aguilar uplands, with five apparently endemic to rainforest habitats. In this paper we present a phylogenetic and taxonomic synopsis of the remarkable anamid fauna of the D'Aguilar Range: a key to the eight species is provided, and four new species of Namea are described (N. gloriosa sp. nov., N. gowardae sp. nov., N. nebo sp. nov. and N. nigritarsus sp. nov.). In shining a spotlight on the mygalomorph spiders of this region, we highlight the D'Aguilar Range as a hotspot of subtropical rainforest diversity, and an area of considerable conservation value.

Clinging on to alpine life: Investigating factors driving the uphill range contraction and population decline of a mountain breeding bird

Climate change and anthropogenic nitrogen deposition are widely regarded as important drivers of environmental change in alpine habitats. However, due to the difficulties working in high-elevation mountain systems, the impacts of these drivers on alpine breeding species have rarely been investigated. The Eurasian dotterel (Charadrius morinellus) is a migratory wader, which has been the subject of uniquely long-term and spatially widespread monitoring effort in Scotland, where it breeds in alpine areas in dwindling numbers. Here we analyse data sets spanning three decades, to investigate whether key potential drivers of environmental change in Scottish mountains (snow lie, elevated summer temperatures and nitrogen deposition) have contributed to the population decline of dotterel. We also consider the role of rainfall on the species' wintering grounds in North Africa. We found that dotterel declines-in both density and site occupancy of breeding males-primarily occurred on low and intermediate elevation sites. High-elevation sites mostly continued to be occupied, but males occurred at lower densities in years following snow-rich winters, suggesting that high-elevation snow cover displaced dotterel to lower sites. Wintering ground rainfall was positively associated with densities of breeding males two springs later. Dotterel densities were reduced at low and intermediate sites where nitrogen deposition was greatest, but not at high-elevation sites. While climatic factors explained variation in breeding density between years, they did not seem to explain the species' uphill retreat and decline. We cannot rule out the possibility that dotterel have increasingly settled on higher sites previously unavailable due to extensive snow cover, while changes associated with nitrogen deposition may also have rendered lower lying sites less suitable for breeding. Causes of population and range changes in mountain-breeding species are thus liable to be complex, involving multiple anthropogenic drivers of environmental change acting widely across annual and migratory life cycles.

Implications of the prevalence and magnitude of sustained declines for determining a minimum threshold for favourable population size

We propose a new approach to quantifying a minimum threshold value for the size of an animal population, below which that population might be categorised as having unfavourable status. Under European Union law, the concept of Favourable Conservation Status requires assessment of populations as having favourable or unfavourable status, but quantitative methods for such assessments have not yet been developed. One population threshold that is well established in conservation biology is the minimum viable population (MVP) defined as the size of a small but stable population with an acceptably low risk of extinction within a specified period. Our approach combines this small-population paradigm MVP concept with a multiplier, which is a factor by which the MVP is multiplied to allow for the risk of a sustained future decline. We demonstrate this approach using data on UK breeding bird population sizes. We used 43-year time-series data for 189 species and a qualitative assessment of population trends over almost 200 years for 229 species to examine the prevalence, duration and magnitude of sustained population declines. Our study addressed the problem of underestimation of the duration and magnitude of declines caused by short runs of monitoring data by allowing for the truncation of time series. The multiplier was derived from probability distributions of decline magnitudes within a given period, adjusted for truncation. Over a surveillance period of 100 years, we estimated that there was a 10% risk across species that a sustained population decline of at least sixteen-fold would begin. We therefore suggest that, in this case, a factor of 16 could be used as the multiplier of small-population MVPs to obtain minimum threshold population sizes for favourable status. We propose this 'MVP Multiplier' method as a new and robust approach to obtaining minimum threshold population sizes which integrates the concepts of small-population and declining-population paradigms. The minimum threshold value we propose is intended for use alongside a range of other measures to enable overall assessments of favourable conservation status.

First phylogenetic assessment and taxonomic synopsis of the open-holed trapdoor spider genus Namea (Mygalomorphae: Anamidae): a highly diverse mygalomorph lineage from Australia’s tropical eastern rainforests

The tropical and subtropical rainforests of Australia’s eastern mesic zone have given rise to a complex and highly diverse biota. Numerous old endemic, niche-conserved groups persist in the montane rainforests south of Cooktown, where concepts of serial allopatric speciation resulting from the formation of xeric interzones have largely driven our biogeographic understanding of the region. Among invertebrate taxa, studies on less vagile arachnid lineages now complement extensive research on vertebrate taxa, and phylogenetic studies on mygalomorph spiders in particular are revealing significant insights about the biogeographic history of the Australian continent since the Eocene. One mygalomorph lineage entirely endemic to Australia’s tropical and subtropical eastern rainforests is the open-holed trapdoor spider genus Namea Raven, 1984 (family Anamidae). We explore, for the first time, the phylogenetic diversity and systematics of this group of spiders, with the aims of understanding patterns of rainforest diversity in Namea, of exploring the relative roles of lineage overlap versus in situ speciation in driving predicted high levels of congeneric sympatry, and of broadly reconciling morphology with evolutionary history. Original and legacy sequences were obtained for three mtDNA and four nuDNA markers from 151 specimens, including 82 specimens of Namea. We recovered a monophyletic genus Namea sister to the genus Teyl Main, 1975, and monophyletic species clades corresponding to 30 morphospecies OTUs, including 22 OTUs nested within three main species-complex lineages. Remarkable levels of sympatry for a single genus of mygalomorph spiders were revealed in rainforest habitats, with upland subtropical rainforests in south-eastern Queensland often home to multiple (up to six) congeners of usually disparate phylogenetic affinity living in direct sympatry or close parapatry, likely the result of simultaneous allopatric speciation in already co-occurring lineages, and more recent dispersal in a minority of taxa. In situ speciation, in contrast, appears to have played a relatively minor role in generating sympatric diversity within rainforest ‘islands’. At the population level, changes in the shape and spination of the male first leg relative to evolutionary history reveal subtle but consistent interspecific morphological shifts in the context of otherwise intraspecific variation, and understanding this morphological variance provides a useful framework for future taxonomic monography. Based on the phylogenetic results, we further provide a detailed taxonomic synopsis of the genus Namea, formally diagnosing three main species-complexes (the brisbanensis-complex, the dahmsi-complex and the jimna-complex), re-illustrating males of all 15 described species, and providing images of live spiders and burrows where available. In doing so, we reveal a huge undescribed diversity of Namea species from tropical and subtropical rainforest habitats, and an old endemic fauna that is beginning to shed light on more complex patterns of rainforest biogeography.

Systematics of the palisade trapdoor spiders (Euoplos) of south-eastern Queensland (Araneae : Mygalomorphae : Idiopidae): four new species distinguished by their burrow entrance architecture

Within the spiny trapdoor spider genus Euoplos Rainbow exists a group of species from south-eastern Queensland that create unusual ‘palisade’ burrow entrances. Despite their intriguing burrows, the group was only recently circumscribed, and all species within it were undescribed. In this study, by undertaking a molecular phylogenetic analysis of two mitochondrial markers and seven nuclear markers, we confirm that the palisade trapdoor spiders, here formally named the ‘turrificus-group’, are monophyletic. We further recognise four species based on morphological, molecular and behavioural characters: E. crenatus, sp. nov., E. goomboorian, sp. nov., E. thynnearum, sp. nov. and E. turrificus, sp. nov. Morphological taxonomic data for each species are presented alongside information on their distribution, habitat preferences and burrow architecture. A key to species within the turrificus-group is also provided. The unusual burrow entrances of these spiders, which project out from the surrounding substrate, are found to exhibit structural autapomorphies, which allow species-level identification. Consequently, we include features of burrow architecture in our key and species diagnoses. This provides a non-intrusive method for distinguishing species in the field. Finally, we conclude that all species within the turrificus-group are likely to represent short-range endemic taxa. http://zoobank.org/urn:lsid:zoobank.org:pub:F2E042DC-DA14-4751-A48B-A367ABC272D9

A review of predation as a limiting factor for bird populations in mesopredator-rich landscapes: a case study of the UK

The impact of increasing vertebrate predator numbers on bird populations is widely debated among the general public, game managers and conservationists across Europe. However, there are few systematic reviews of whether predation limits the population sizes of European bird species. Views on the impacts of predation are particularly polarised in the UK, probably because the UK has a globally exceptional culture of intensive, high-yield gamebird management where predator removal is the norm. In addition, most apex predators have been exterminated or much depleted in numbers, contributing to a widely held perception that the UK has high numbers of mesopredators. This has resulted in many high-quality studies of mesopredator impacts over several decades. Here we present results from a systematic review of predator trends and abundance, and assess whether predation limits the population sizes of 90 bird species in the UK. Our results confirm that the generalist predators Red Fox (Vulpes vulpes) and Crows (Corvus corone and C. cornix) occur at high densities in the UK compared with other European countries. In addition, some avian and mammalian predators have increased numerically in the UK during recent decades. Despite these high and increasing densities of predators, we found little evidence that predation limits populations of pigeons, woodpeckers and passerines, whereas evidence suggests that ground-nesting seabirds, waders and gamebirds can be limited by predation. Using life-history characteristics of prey species, we found that mainly long-lived species with high adult survival and late onset of breeding were limited by predation. Single-brooded species were also more likely to be limited by predation than multi-brooded species. Predators that depredate prey species during all life stages (i.e. from nest to adult stages) limited prey numbers more than predators that depredated only specific life stages (e.g. solely during the nest phase). The Red Fox and non-native mammals (e.g. the American Mink Neovison vison) were frequently identified as numerically limiting their prey species. Our review has identified predator-prey interactions that are particularly likely to result in population declines of prey species. In the short term, traditional predator-management techniques (e.g. lethal control or fencing to reduce predation by a small number of predator species) could be used to protect these vulnerable species. However, as these techniques are costly and time-consuming, we advocate that future research should identify land-use practices and landscape configurations that would reduce predator numbers and predation rates.

Spiny trapdoor spiders (Euoplos) of eastern Australia: Broadly sympatric clades are differentiated by burrow architecture and male morphology

Spiders of the infraorder Mygalomorphae are fast becoming model organisms for the study of biogeography and speciation. However, these spiders can be difficult to study in the absence of fundamental life history information. In particular, their cryptic nature hinders comprehensive sampling, and linking males with conspecific females can be challenging. Recently discovered differences in burrow entrance architecture and male morphology indicated that these challenges may have impeded our understanding of the trapdoor spider genus Euoplos in Australia's eastern mesic zone. We investigated the evolutionary significance of these discoveries using a multi-locus phylogenetic approach. Our results revealed the existence of a second, previously undocumented, lineage of Euoplos in the eastern mesic zone. This new lineage occurs in sympatry with a lineage previously known from the region, and the two are consistently divergent in their burrow entrance architecture and male morphology, revealing the suitability of these characters for use in phylogenetic studies. Divergent burrow entrance architecture and observed differences in microhabitat preferences are suggested to facilitate sympatry and syntopy between the lineages. Finally, by investigating male morphology and plotting it onto the phylogeny, we revealed that the majority of Euoplos species remain undescribed, and that males of an unnamed species from the newly discovered lineage had historically been linked, erroneously, to a described species from the opposite lineage. This paper clarifies the evolutionary relationships underlying life history diversity in the Euoplos of eastern Australia, and provides a foundation for urgently needed taxonomic revision of this genus.

Differences in the Contribution of CD4+ T Cells to Proislet and Islet Allograft Rejection Correlate with Constitutive Class II MHC Alloantigen Expression

Allografts of BALB/c (H-2d) fetal proislets facilitated long-term (>100 days) reversal of streptozotocin-induced diabetes in CBA/H (H-2k) mice treated with a combination of anti-CD4 and anti-CD8 mAbs. Anti-CD8 monotherapy was partially effective in restoring normoglycemia but anti-CD4 mAb treatment of host animals failed to promote allograft function. In contrast, allografts of BALB/c adult islets demonstrated indefinite reversal of diabetes in recipient mice treated only with anti-CD8 mAb. Anti-CD4 monotherapy resulted in only transient restoration of normoglycemia. These findings clearly demonstrate (1) a critical role for CD8 T cells in the acute rejection of pancreatic islet tissue allografts and (2) tissue-specific differences in the participation of CD4 T cells as primary effectors in the rejection reaction. Immunohistochemical studies showed that the capacity for CD4 T cells to initiate the rejection of proislet but not adult islet allografts correlates with the presence/absence, respectively, of graft parenchymal cells that constitutively express Class II MHC alloantigens. Proislet grafts, unlike transplants of purified adult islets, contain heterogeneous tissue components including Class II MHC+ve duct epithelium. Thus, the participation of CD8 and CD4 T cells as primary effectors of graft rejection depends on which class or classes of MHC antigens are constitutively expressed on graft parenchymal cells and are available for recognition. Islet tissue in both rejecting proislet and islet allografts showed de novo induction of Class II MHC alloantigens only after severe disruption to islet architecture had been achieved by infiltrating mononuclear cells. Thus, at this stage of advanced allograft injury, CD4 T cells have the potential to act as secondary effectors, possibly by amplifying the inflammatory reaction and thus accelerating graft destruction. The capacity for antirejection mAb therapy to establish transplant tolerance was facilitated in the islet allograft model where it was necessary to target only the CD8 T cell subpopulation.

Recurrent bacterial vaginosis: the use of maintenance acidic vaginal gel following treatment

Bacterial vaginosis (BV) frequently recurs after treatment. One option in the management of recurrences is to keep the vaginal pH at 4.5 or less, in order to prevent overgrowth of bacteria, until the normal lactobacilli are re-established. We report the outcome of using maintenance acetic acid vaginal gel, after treatment of BV, in a sample of 49 women with frequent recurrences. Half of the women had no further recurrences, and in those who did there was a significant increase in time to first recurrence (4.8 months) after commencing the gel compared with the previous recurrence (2.1 months). Prior to using acidic gel, the mean recurrence rate in 49 women was 4.4 per woman/year, and this was reduced to 0.6 recurrences per woman/year. As there are few effective therapies for women with recurrent BV, we feel this offers an option that can currently be used in clinical practice.

Haemangioma of the uterine cervix

We describe a rare cause of irregular vaginal bleeding due to a haemangioma of the uterine cervix. Clinical, ultrasound and MRI appearances are shown and options for management discussed.

A computer-aided approach to detect the fetal behavioral states using multi-sensor Magnetocardiographic recordings

We propose a novel computational approach to automatically identify the fetal heart rate patterns (fHRPs), which are reflective of sleep/awake states. By combining these patterns with presence or absence of movements, a fetal behavioral state (fBS) was determined. The expert scores were used as the gold standard and objective thresholds for the detection procedure were obtained using Receiver Operating Characteristics (ROC) analysis. To assess the performance, intraclass correlation was computed between the proposed approach and the mutually agreed expert scores. The detected fHRPs were then associated to their corresponding fBS based on the fetal movement obtained from fetal magnetocardiogaphic (fMCG) signals. This approach may aid clinicians in objectively assessing the fBS and monitoring fetal wellbeing.

Glucose: Detection and analysis

Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also plays a major role in modern food products, particularly where flavor and or structure are concerned. Over the years, many diverse methods for detecting and quantifying glucose have been developed; this review presents an overview of the most widely employed and historically significant, including copper iodometry, HPLC, GC, CZE, and enzyme based systems such as glucose meters. The relative strengths and limitations of each method are evaluated, and examples of their recent application in the realm of food chemistry are discussed.

Development of a 96-well plate iodine binding assay for amylose content determination

Cereal starch amylose/amylopectin (AM/AP) is critical in functional properties for food and industrial applications. Conventional methods of AM/AP are time consuming and labor intensive making it difficult to screen the large sample sets necessary for evaluating breeding samples and investigating environmental impact on starch development. The objective was to adapt and optimize the iodine binding assay in a 96-well plate format for measurement at both λ 620 nm and λ 510 nm. The standard curve for amylose content was scaled to a 96-well plate format and demonstrated R(2) values of 0.999 and 0.993 for single and dual wavelengths, respectively. The plate methods were applicable over large ranges of amylose contents: high amylose maize starch at 61.7±2.3%, normal wheat starch at 29.0±0.74%, and a waxy maize starch at 1.2±0.9%. The method exhibited slightly greater amylose content values than the Concanavalin A method for normal type starches; but is consistent with cuvette scale iodine binding assays.

Effect of nitrogen fertilization and cover cropping systems on sorghum grain characteristics

Cover crop treatments and nitrogen (N) fertilization rates were investigated for their impact on sorghum grain quality attributes. Sorghum was planted in field plots treated with differing cover cropping systems and fertilization rates. The size (weight and diameter) and hardness of the kernels were influenced by both the cover crop and N rates. The protein content increased as the N rate increased and also with the addition of cover crops to the system. The protein digestibility values and starch granule size distributions were not affected by N rate or the cover cropping treatments. Soil properties were tested to determine relationships with grain quality attributes. The utilization of cover crops appears to increase the protein content without causing a deleterious effect on protein digestibility. The end-product quality is not hampered by the use of beneficial cropping systems necessary for sustainable agriculture.

Optical property measurements establish the feasibility of photodynamic therapy as a minimally invasive intervention for tumors of the kidney

We measured the optical properties of freshly excised kidneys with renal parenchymal tumors to assess the feasibility of photodynamic therapy (PDT) in these patients. Kidneys were collected from 16 patients during surgical nephrectomies. Spatially resolved, white light, steady-state diffuse reflectance measurements were performed on normal and neoplastic tissue identified by a pathologist. Reflectance data were fit using a radiative transport model to obtain absorption (μa) and transport scattering coefficients (μs'), which define a characteristic light propagation distance, δ. Monte Carlo (MC) simulations of light propagation from cylindrical diffusing fibers were run using the optical properties extracted from each of the kidneys. Interpretable spectra were obtained from 14 kidneys. Optical properties of human renal cancers exhibit significant inter-lesion heterogeneity. For all diagnoses, however, there is a trend toward increased light penetration at longer wavelengths. For renal cell carcinomas (RCC), mean values of δ increase from 1.28 to 2.78 mm as the PDT treatment wavelength is increased from 630 to 780 nm. MC simulations of light propagation from interstitial optical fibers show that fluence distribution in tumors is significantly improved at 780 versus 630 nm. Our results support the feasibility of PDT in selected renal cancer patients, especially with photosensitizers activated at longer wavelengths.

Development of the penile urethra in the tammar wallaby

Hypospadias is increasingly common, and requires surgery to repair, but its aetiology is poorly understood. The marsupial tammar wallaby provides a unique opportunity to study hypospadias because penile differentiation occurs postnatally. Androgens are responsible for penile development in the tammar, but the majority of differentiation, in particular formation and closure of the urethral groove forming the penile urethra in males, occurs when there is no measurable sex difference in the concentrations of testosterone or dihydrotestosterone in either the gonads or the circulation [corrected]. Phalluses were examined morphologically from the sexually indifferent period (when androgens are high) to well after the time that the phallus becomes sexually dimorphic. We show that penile development and critical changes in the positioning of the urethra occur in the male phallus begin during an early window of time when androgens are high. Remodelling of the urethra in the male occurs between days 20-60. The critical period of time for the establishment urethral closure occurs during the earliest phases of penile development. This study suggests that there is an early window of time before day 60 when androgen imprinting must occur for normal penile development and closure of the urethral groove.

Bio-magnetic signatures of fetal breathing movement

The purpose of fetal magnetoencephalography (fMEG) is to record and analyze fetal brain activity. Unavoidably, these recordings consist of a complex mixture of bio-magnetic signals from both mother and fetus. The acquired data include biological signals that are related to maternal and fetal heart function as well as fetal gross body and breathing movements. Since fetal breathing generates a significant source of bio-magnetic interference during these recordings, the goal of this study was to identify and quantify the signatures pertaining to fetal breathing movements (FBM). The fMEG signals were captured using superconducting quantum interference devices (SQUIDs) The existence of FBM was verified and recorded concurrently by an ultrasound-based video technique. This simultaneous recording is challenging since SQUIDs are extremely sensitive to magnetic signals and highly susceptible to interference from electronic equipment. For each recording, an ultrasound-FBM (UFBM) signal was extracted by tracing the displacement of the boundary defined by the fetal thorax frame by frame. The start of each FBM was identified by using the peak points of the UFBM signal. The bio-magnetic signals associated with FBM were obtained by averaging the bio-magnetic signals time locked to the FBMs. The results showed the existence of a distinctive sinusoidal signal pattern of FBM in fMEG data.

To what degree is digital imaging reliable? Validation of femoral neck shaft angle measurement in the era of picture archiving and communication systems

OBJECTIVES

This study investigates the reliability of femoral neck shaft angle (NSA) measurements made with the software and images available in routine clinical practice.

METHODS

Using the Centricity Enterprise™ (GE Healthcare Pty Ltd Piscataway, NJ) picture archiving and communication system (PACS), the NSA of the proximal femur was measured from anteroposterior radiographs of adult hips. 3 independent observers, using a standardised technique, performed a total of 120 measurements.

RESULTS

The Pearson's correlation coefficient for the intraobserver agreement was 0.98 (p<0.01) and for interobserver measurements 0.86 (p<0.01). Bland-Altman plots revealed the limits of intraobserver agreement to be ±2.5°, but interobserver limits of agreement to be ±6°. The intraclass correlation coefficient (ICC) was also calculated. The interobserver ICC was 0.62 (0.42-0.78, 95% confidence interval (CI); p<0.001). The intraobserver ICC was 0.98 (0.95-0.99, 95% CI; p<0.001).

CONCLUSION

PACS software has many advantages, but when using systems that can display angle measurements to one-tenth of a degree caution must be exercised to ensure that reliability of these measurements is not overestimated. We found that in the context of measuring the NSA of the proximal femur the reliability of the measurement, even under the best conditions, is only ±6° for different observers.

A novel approach to track fetal movement using multi-sensor magnetocardiographic recordings

Changes in fetal magnetocardiographic (fMCG) signals are indicators for fetal body movement. We propose a novel approach to reliably extract fetal body movements based on the field strength of the fMCG signal independent of its frequency. After attenuating the maternal MCG, we use a Hilbert transform approach to identify the R-wave. At each R-wave, we compute the center-of-gravity (cog) of the coordinate positions of MCG sensors, each weighted by the magnitude of the R-wave amplitude recorded at the corresponding sensor. We then define actogram as the distance between the cog computed at each R-wave and the average of the cog from all the R-waves in a 3-min duration. By applying a linear de-trending approach to the actogram we identify the fetal body movement and compare this with the synchronous occurrence of the acceleration in the fetal heart rate. Finally, we apply this approach to the fMCG recorded simultaneously with ultrasound from a single subject and show its improved performance over the QRS-amplitude based approach in the visually verified movements. This technique could be applied to transform the detection of fetal body movement into an objective measure of fetal health and enhance the predictive value of prevalent clinical testing for fetal wellbeing.

Female feathering in sebright cocks is due to conversion of testosterone to estradiol in skin

Sebright cocks develop a female feathering pattern but revert to normal male feathering after castration. Administration of testosterone to castrated cocks causes male comb development and reappearance of female feathering. Dihydrotes-tosterone treatment supports development of a male comb but does not induce female feathering. Since testosterone but not dihydrotestosterone is converted to estradiol in the skin of the Sebright, the female feathering appears to be the result of increased conversion of testosterone to estradiol.

Cholesterol synthesis in the squirrel monkey: relative rates of synthesis in various tissues and mechanisms of control

Cholesterol synthesis has been extensively investigated in various tissues of lower mammals; however, there is little specific information concerning cholesterologenesis in the primate. Furthermore, experiments in whole animals suggest that important differences may exist in the features of cholesterologenesis in the dog and rat versus the monkey and man. Using the new world squirrel monkey, therefore, we performed the present studies to determine the rates of cholesterologenesis in various tissues per unit weight, to define the relative rates of whole organ synthesis, and to evaluate the operation of control mechanisms in these tissues.In control animals fed a low cholesterol chow diet, the liver and ileum were the two most active sites for cholesterologenesis followed, in order, by the colon, esophagus, and proximal small bowel. Rates of synthesis in 10 other tissues tested were considerably lower than these found in the gastrointestinal tract. When rates of whole organ synthesis were calculated, three tissues, i.e., liver, bowel, and skin, accounted for 92% of the total demonstrable synthetic activity.Following cholesterol feeding utilizing either a solid chow or liquid formula diet, marked suppression of hepatic cholesterologenesis occurred while synthesis in other organs remained essentially unaltered. Similarly, fasting animals for periods up to 96 hr resulted in suppression of synthesis in the liver, but not in various levels of the intestine. Finally, biliary diversion for 48 hr caused a twofold increase in hepatic cholesterologenesis and a six- to eightfold increase in sterol synthesis in the small but not the large intestine.

Biosynthetic origin of serum cholesterol in the squirrel monkey: evidence for a contribution by the intestinal wall

The possibility that the intestinal wall serves as a biosynthetic site for serum cholesterol has been examined in two types of studies in the squirrel monkey. First, animals were fed cholesterol in order to inhibit cholesterol synthesis in the liver, and the intestinal lymph ducts were cannulated. After the administration of acetate-2-(14)C it was possible to demonstrate that cholesterol synthesized by the intestinal wall enters intestinal lymph and thereby in the intact animal enters the circulating pool. Second, an attempt to quantitate the significance of this intestinal contribution has been made in animals fed cholesterol-3-(3)H and injected with cholesterol-4-(14)C for long periods. By an application of the technique of analysis utilizing the isotopic steady state we estimated as a minimal value that in the squirrel monkey 1.5-2.0 mg of cholesterol synthesized in the intestinal wall reaches the circulation each day.