• Sarco(endo)plasmic reticulum ATPase is a molecular partner of Wolfram syndrome 1 protein, which negatively regulates its expression.

      Zatyka, Malgorzatta; Xavier, Gabriela Da Silva; Bellomo, Elisa A.; Leadbeater, Wendy; Astuti, Dewi; Smith, Joel; Michelangeli, Francesco; Rutter, Guy A.; Barrett, Timothy G.; University of Birmingham, Imperial College London, (Oxford University Press, 2015-02-01)
      Wolfram syndrome is an autosomal recessive disorder characterized by neurodegeneration and diabetes mellitus. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER)-resident transmembrane protein that is involved in the regulation of the unfolded protein response (UPR), intracellular ion homeostasis, cyclic adenosine monophosphate production and regulation of insulin biosynthesis and secretion. In this study, single cell Ca(2+) imaging with fura-2 and direct measurements of free cytosolic ATP concentration ([ATP]CYT) with adenovirally expressed luciferase confirmed a reduced and delayed rise in cytosolic free Ca(2+) concentration ([Ca(2+)]CYT), and additionally, diminished [ATP]CYT rises in response to elevated glucose concentrations in WFS1-depleted MIN6 cells. We also observed that sarco(endo)plasmic reticulum ATPase (SERCA) expression was elevated in several WFS1-depleted cell models and primary islets. We demonstrated a novel interaction between WFS1 and SERCA by co-immunoprecipitation in Cos7 cells and with endogenous proteins in human neuroblastoma cells. This interaction was reduced when cells were treated with the ER stress inducer dithiothreitol. Treatment of WFS1-depleted neuroblastoma cells with the proteasome inhibitor MG132 resulted in reduced accumulation of SERCA levels compared with wild-type cells. Together these results reveal a role for WFS1 in the negative regulation of SERCA and provide further insights into the function of WFS1 in calcium homeostasis.
    • The sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase (SERCA) is the likely molecular target for the acute toxicity of the brominated flame retardant hexabromocyclododecane (HBCD).

      Al-Mousa, Fawaz; Michelangeli, Francesco; University of Birmingham, UK (Elsevier, 2014-01-01)
      Hexabromocyclododecane (HBCD) is a widely utilised brominated flame retardant (BFR). It has been shown to bio-accumulate within organisms, including man, and possibly cause neurological disorders. The acute neurotoxicity of HBCD, and six other unrelated BFRs, were assessed in SH-SY5Y human neuroblastoma cells by 24h viability assays and HBCD proved to be the most lethal (LC50, 3μM). In addition, the effects of these BFRs were also assessed for their potency at inhibiting the sarcoplasmic-endoplasmic reticulum Ca(2+) ATPase (SERCA) derived from the SH-SY5Y cells and again HBCD was the most potent (IC50, 2.7μM). The data for the other BFRs tested showed a direct correlation (coefficient 0.94) between the potencies of inducing cell death and inhibiting the Ca(2+) ATPase, indicating that SERCA is likely to be the molecular target for acute toxicity. Mechanistic studies of HBCD on the Ca(2+) ATPase suggest that it affects ATP binding, phosphorylation as well as the E2 to E1 transition step.
    • Scenario-Led Habitat Modelling of Land Use Change Impacts on Key Species

      Geary, Matthew; Fielding, Alan H.; McGowan, Philip J. K.; Marsden, Stuart J.; University of Chester, Manchester Metropolitan University; Newcastle University (PLOS, 2015-11-16)
      Accurate predictions of the impacts of future land use change on species of conservation concern can help to inform policy-makers and improve conservation measures. If predictions are spatially explicit, predicted consequences of likely land use changes could be accessible to land managers at a scale relevant to their working landscape. We introduce a method, based on open source software, which integrates habitat suitability modelling with scenario-building, and illustrate its use by investigating the effects of alternative land use change scenarios on landscape suitability for black grouse Tetrao tetrix. Expert opinion was used to construct five near-future (twenty years) scenarios for the 800 km2 study site in upland Scotland. For each scenario, the cover of different land use types was altered by 5–30% from 20 random starting locations and changes in habitat suitability assessed by projecting a MaxEnt suitability model onto each simulated landscape. A scenario converting grazed land to moorland and open forestry was the most beneficial for black grouse, and ‘increased grazing’ (the opposite conversion) the most detrimental. Positioning of new landscape blocks was shown to be important in some situations. Increasing the area of open-canopy forestry caused a proportional decrease in suitability, but suitability gains for the ‘reduced grazing’ scenario were nonlinear. ‘Scenario-led’ landscape simulation models can be applied in assessments of the impacts of land use change both on individual species and also on diversity and community measures, or ecosystem services. A next step would be to include landscape configuration more explicitly in the simulation models, both to make them more realistic, and to examine the effects of habitat placement more thoroughly. In this example, the recommended policy would be incentives on grazing reduction to benefit black grouse.
    • Seascape genomics reveals population isolation in the reef-building honeycomb worm, Sabellaria alveolata (L.)

      Dubois, Stanislas; Muir, Anna P; orcid: 0000-0002-6896-6915; Ross, Rebecca; Firth, Louise; Knights, Antony; Lima, Fernando; Seabra, Rui; Corre, Erwan; Le Corguillé, Gildas; Nunes, Flavia; et al. (BMC, 2020-08-10)
      Background: Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried out RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. Results: We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. Conclusions: As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.
    • Seascape genomics reveals population isolation in the reef-building honeycomb worm, Sabellaria alveolata (L.)

      Muir, Anna P.; orcid: 0000-0002-6896-6915; email: a.muir@chester.ac.uk; Dubois, Stanislas F.; Ross, Rebecca E.; Firth, Louise B.; Knights, Antony M.; Lima, Fernando P.; Seabra, Rui; Corre, Erwan; Le Corguillé, Gildas; Nunes, Flavia L. D. (BioMed Central, 2020-08-10)
      Abstract: Background: Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried out RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. Results: We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. Conclusions: As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.
    • Seasonality in birth rate in two 19th century North Wales parishes

      Lewis, Stephen J.; Glenn, Janine; Chester College of Higher Education (2000)
      An understanding of the basic patterns in the seasonality of birth rate may be useful in certain fertility techniques. The use of artificial birth control, however, has had the effect of masking the influence of underlying biometeriological factors. To elucidate trends in birth seasonality in the absence of current social factors, a study useing nineteenth-century parish records was undertaken. Analysis of 5,905 births recorded in the baptismal records of the parishes of Hawarden and Northop between the years 1837 and 1886 revealed significant seasonal trend with a peak occuring in the spring. Further analysis showed a significant positive correlation occuring between the (standardized) numbers of births in each month and the mean day length (hours between sunrise and sunset) of the pulative month of conception.
    • Seasonality of Plasmodium falciparum transmission: a systematic review

      Reiner, Robert C.; Geary, Matthew; Atkinson, Peter M.; Smith, David L.; Gething, Peter W.; 1 Fogarty International Center, National Institutes of Health, Bethesda, MD, USA 2 Department of Epidemiology and Biostatistics, Indiana University School of Public Health, Bloomington, IN, USA 3 Department of Entomology, University of California, Davis, CA, USA 4 Department of Biological Sciences, University of Chester, Chester, UK 5 Faculty of Science and Technology, Engineering Building, Lancaster University, Lancaster LA1 4YR, UK 6 Faculty of Geosciences, University of Utrecht, Heidelberglaan 2, Utrecht, 3584 CS, The Netherlands 7 School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, Belfast BT7 1NN, Northern Ireland, UK 8 Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK 9 Center for Disease Dynamics, Economics and Policy, Washington, DC, USA 10 Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK (BioMed Central, 2015-09-15)
      Background Although Plasmodium falciparum transmission frequently exhibits seasonal patterns, the drivers of malaria seasonality are often unclear. Given the massive variation in the landscape upon which transmission acts, intra-annual fluctuations are likely influenced by different factors in different settings. Further, the presence of potentially substantial inter-annual variation can mask seasonal patterns; it may be that a location has “strongly seasonal” transmission and yet no single season ever matches the mean, or synoptic, curve. Accurate accounting of seasonality can inform efficient malaria control and treatment strategies. In spite of the demonstrable importance of accurately capturing the seasonality of malaria, data required to describe these patterns is not universally accessible and as such localized and regional efforts at quantifying malaria seasonality are disjointed and not easily generalized. Methods The purpose of this review was to audit the literature on seasonality of P. falciparum and quantitatively summarize the collective findings. Six search terms were selected to systematically compile a list of papers relevant to the seasonality of P. falciparum transmission, and a questionnaire was developed to catalogue the manuscripts. Results and discussion 152 manuscripts were identified as relating to the seasonality of malaria transmission, deaths due to malaria or the population dynamics of mosquito vectors of malaria. Among these, there were 126 statistical analyses and 31 mechanistic analyses (some manuscripts did both). Discussion Identified relationships between temporal patterns in malaria and climatological drivers of malaria varied greatly across the globe, with different drivers appearing important in different locations. Although commonly studied drivers of malaria such as temperature and rainfall were often found to significantly influence transmission, the lags between a weather event and a resulting change in malaria transmission also varied greatly by location. Conclusions The contradicting results of studies using similar data and modelling approaches from similar locations as well as the confounding nature of climatological covariates underlines the importance of a multi-faceted modelling approach that attempts to capture seasonal patterns at both small and large spatial scales. Keywords: Plasmodium falciparum ; Seasonality; Climatic drivers
    • Sex and age-specific survival and life expectancy in a free ranging population of Indri indri (Gmelin, 1788).

      Rolle, Francesca; Torti, Valeria; Valente, Daria; De Gregorio, Chiara; Giacoma, Cristina; von Hardenberg, Achaz; University of Turin; University of Chester (Taylor & Francis, 2021-07-22)
      The critically endangered indri (Indri indri) is the largest extant lemur species and its population size is projected to decline over the next three generations due to habitat loss, hunting and climate change. Accurate information on the demographic parameters driving the population dynamics of indri is urgently needed to help decision-making regarding the conservation of this iconic species. We monitored and followed the life histories of 68 individually recognizable indris in 10 family groups in the Maromizaha New Protected Area (Madagascar) for 12 years. We estimated age and sex-specific survival trajectories using a Bayesian hierarchical survival model and found that the survival curves for male and female indris show a similar pattern, consistent with what found typically in primates; i.e., a high infant mortality rate which declines with age in the juvenile phase and increases again for adults. Also, life expectancies at 2 years of age (e2), were found to be similar between the sexes (e2 females = 7.8 years; e2 males = 7.5 years). We suggest that the lack of strong differences in the survival patterns for male and female indris are related to the strictly monogamous mating system and the lack of sexual dimorphism in this species. Our study provides, for the first time, robust estimates for demographic parameters of indris and one of the very few datasets on survival trajectories available for primates.
    • Shock wave lithotripsy, for the treatment of kidney stones, results in changes to routine blood tests and novel biomarkers: a prospective clinical pilot-study

      Hughes, Stephen F.; orcid: 0000-0001-6558-9037; email: Stephen.hughes6@wales.nhs.uk; Jones, Nathan; Thomas-Wright, Samantha J.; Banwell, Joseph; Moyes, Alyson J.; Shergill, Iqbal (BioMed Central, 2020-06-01)
      Abstract: Background: The number of patients undergoing shock wave lithotripsy (SWL) for kidney stones is increasing annually, and as such the development of post-operative complications, such as haematuria and acute kidney injury (AKI) following SWL, is likely to increase. The aim of the study was to evaluate changes in routine blood and novel biomarkers following SWL, for the treatment of kidney stones. Methods: Twelve patients undergoing SWL for solitary unilateral kidney stones were recruited. From patients (8 males and 4 females) aged between 31 and 72 years (median 43 years), venous blood samples were collected pre-operatively (baseline), at 30, 120 and 240 min post-operatively. Routine blood tests were performed using a Sysmex XE-5000, and Beckman Coulter AU5800 and AU680 analysers. NGAL, IL-18, IL-6, TNF-α, IL-10 and IL-8 concentrations were determined using commercially available ELISA kits. Results: Significant (p ≤ 0.05) changes were observed in several blood parameters following SWL. NGAL concentration significantly increased, with values peaking at 30 min post-treatment (p = 0.033). Although IL-18 concentration increased, these changes were not significant (p = 0.116). IL-6 revealed a statistically significant rise from pre-operative up to 4 h post-operatively (p < 0.001), whilst TNF-α significantly increased, peaking at 30 min post-SWL (p = 0.05). There were no significant changes to IL-10 and IL-8 concentrations post-SWL (p > 0.05). Conclusions: Changes to routine blood tests and specific biomarkers, in the future, may be more useful for clinicians. In turn, identification of a panel of biomarkers could provide valuable data on “normal” physiological response after lithotripsy. Ultimately, studies could be expanded to identify or predict those patients at increased risk of developing post-operative complications, such as acute kidney injury or. These studies, however, need validating involving larger cohorts.
    • A simple procedure for investigating differences in sexual dimorphism between populations

      Lewis, Stephen J.; Chester College of Higher Education (Oxbow Books (for The Osteoarchaeological Research Group), 1997-12-01)
      Although sexual dimorphism has a strong genetic component in many animals, external factors may alter its expression - enhancing or diminishing it depending on the parameter measured and the type of influence experienced. A measure of sexual dimorphism may be used, therefore, to characterise a whole population and the factors acting upon it. Differences between populations for such factors may then be investigated by comparing sexual dimorphisms and may be more informative than merely comparing population means. A quick and relatively simple technique which provides a coefficient of the relationship between a continuous variable and another which is dichotomous, such as sex, is the point biserial correlation. This is a less frequently described extension of the commonly used Pearson product-moment correlation. The point-biserial correlation coefficients can be calculated for a given parameter and compared to determine whether the same sexual dimorphism is evident in different samples. If it is not, some factor influencing one or other population, as a whole, may require further investigation. The full procedure, which can be performed without the need for statistical tables, and the necessary formulae are described. This method, in its generalised form, may also be applied to the study of bilateral asymmetry.
    • A simple procedure for testing for differences in sexual dimorphism between populations

      Lewis, Stephen J.; Chester College of Higher Education (InterStat, 2004)
      Using point bi-serial correlation, an approach to the biological problem of comparing differences in sexual dimorphism between populations is presented. In particular, a way of deriving the point bi-serial correlation coefficient from summary statistics (means, standard deviations and sample sizes) is given. This bypasses the need for access to raw data.
    • Skeletal changes during catch-up growth - suggestions from a rat model

      Lewis, Stephen J.; Chester College of Higher Education (2001)
      The removal of a growth limiting influence, such as undernutrition, is frequently followed by a period of growth at a rate greater than normally expected for chronological age. This, so called 'catch-up growth', tends to return affected individuals to their original growth trajectory. How catch-up growth is controlled or regulated remains unclear. Histological studies of the proximal tibial growth plate in rats which had been undernourished by half-feeding between the 56th and 70th days (post partum) showed them to be thinner than those of controls. Upon inspection, the chondrocytes also appeared to be flatter in profile and less numerous. However, during the catch-up period, when food was again allowed ad libitum, previously undernourished rats showed wider growth plates with rounder and more numerous chondrocytes than controls. It was noted that such changes were similar to those that accompany sectioning of the periosteum and the release of growth restraint that results. A study of the flexibility of the sacro-iliac joint in the same animals suggested that it was less flexible following undernutrition but more so during the catch-up period, by comparison with controls. This was in contrast to a progressive loss of flexibility shown by controls during the same period and would appear to result from changes in the characteristics of the fibrous connective tissues associated with the joint. If this reflects a more generalized change in such connective tissues, but particularly the periosteum, ligaments and joint capsules, this may represent a means whereby skeletal growth rate during the catch-up period may be influenced in a co-ordinated manner.
    • Social Experience of Captive Livingstone’s Fruit Bats (Pteropus livingstonii)

      Stanley, Christina R; Smith, Tessa; Welch, Morgan J; Hosie, Charlotte; Wormell, Dominic; Price, Eluned; University of Chester; Jersey Zoo (MDPI, 2020-07-30)
      Social network analysis has been highlighted as a powerful tool to enhance the evidence-based management of captive-housed species through its ability to quantify the social experience of individuals. We apply this technique to explore the social structure and social roles of 50 Livingstone’s fruit bats (Pteropus livingstonii) housed at Jersey Zoo, Channel Islands, through the observation of associative, affiliative, and aggressive interactions over two data collection periods. We implement binomial mixture modelling and characteristic-based assortment quantification to describe the complexity and organisation of social networks, as well as a multiple regression quadratic assignment procedural (MRQAP) test to analyse the relationship between network types. We examine the effects of individual characteristics (i.e., sex, age, and dominance rank) on social role by fitting models to explain the magnitude of node metrics. Additionally, we utilize a quadratic assignment procedural (QAP) test to assess the temporal stability of social roles over two seasons. Our results indicate that P. livingstonii display a non-random network structure. Observed social networks are positively assorted by age, as well as dominance rank. The frequency of association between individuals correlates with a higher frequency of behavioural interactions, both affiliative and aggressive. Individual social roles remain consistent over ten months. We recommend that, to improve welfare and captive breeding success, relationships between individuals of similar ages and dominance levels should be allowed to persist in this group where possible, and separating individuals that interact frequently in an affiliative context should be avoided.
    • Social network analysis of small social groups: Application of a hurdle GLMM approach in the Alpine marmot ( Marmota marmota )

      editor: Ebensperger, Luis; Panaccio, Matteo; orcid: 0000-0002-1903-154X; email: matteo.panaccio01@universitadipavia.it; Ferrari, Caterina; Bassano, Bruno; Stanley, Christina R.; orcid: 0000-0002-5053-4831; von Hardenberg, Achaz; orcid: 0000-0002-9899-1687; email: a.vonhardenberg@chester.ac.uk (2021-03-24)
      Abstract: Social network analysis (SNA) has recently emerged as a fundamental tool to study animal behavior. While many studies have analyzed the relationship between environmental factors and behavior across large, complex animal populations, few have focused on species living in small groups due to limitations of the statistical methods currently employed. Some of the difficulties are often in comparing social structure across different sized groups and accounting for zero‐inflation generated by analyzing small social units. Here, we use a case study to highlight how Generalized Linear Mixed Models (GLMMs) and hurdle models can overcome the issues inherent to study of social network metrics of groups that are small and variable in size. We applied this approach to study aggressive behavior in the Alpine marmot (Marmota marmota) using an eight‐year long dataset of behavioral interactions across 17 small family groups (7.4 ± 3.3 individuals). We analyzed the effect of individual and group‐level factors on aggression, including predictors frequently inferred in species with larger groups, as the closely related yellow‐bellied marmot (Marmota flaviventris). Our approach included the use of hurdle GLMMs to analyze the zero‐inflated metrics that are typical of aggressive networks of small social groups. Additionally, our results confirmed previously reported effects of dominance and social status on aggression levels, thus supporting the efficacy of our approach. We found differences between males and females in terms of levels of aggression and on the roles occupied by each in agonistic networks that were not predicted in a socially monogamous species. Finally, we provide some perspectives on social network analysis as applied to small social groups to inform subsequent studies.
    • Social Network Analysis of small social groups: application of a hurdle GLMM approach in the Alpine marmot (Marmota marmota)

      Stanley, Christina; von Hardenberg, Achaz; Panaccio, Matteo; Ferrari, Caterina; Bassano, Bruno; University of Chester; University of Turin; Alpine Wildlife Research Centre, Gran Paradiso National Park
      Social Network Analysis (SNA) has recently emerged as a fundamental tool to study animal behavior. While many studies have analyzed the relationship between environmental factors and behavior across large, complex animal populations, few have focused on species living in small groups due to limitations of the statistical methods currently employed. Some of the difficulties are often in comparing social structure across different sized groups and accounting for zero-inflation generated by analyzing small social units. Here we use a case study to highlight how Generalized Linear Mixed Models (GLMMs) and hurdle models can overcome the issues inherent to study of social network metrics of groups that are small and variable in size. We applied this approach to study aggressive behavior in the Alpine marmot (Marmota marmota) using an eight-year long dataset of behavioral interactions across 17 small family groups (7.4 ± 3.3 individuals). We analyzed the effect of individual and group-level factors on aggression, including predictors frequently inferred in species with larger groups, as the closely related yellow-bellied marmot (Marmota flaviventris). Our approach included the use of hurdle GLMMs to analyze the zero-inflated metrics that are typical of aggressive networks of small social groups. Additionally, our results confirmed previously reported effects of dominance and social status on aggression levels, thus supporting the efficacy of our approach. We found differences between males and females in terms of levels of aggression and on the roles occupied by each in agonistic networks that were not predicted in a socially monogamous species. Finally, we provide some perspectives on social network analysis as applied to small social groups to inform subsequent studies.
    • Social roles influence cortisol levels in captive Livingstone's fruit bats (Pteropus livingstonii)

      Edwards, Morgan J.; Stanley, Christina R.; Hosie, Charlotte A.; Richdon, Sarah; Price, Eluned; Wormell, Dominic; Smith, Tessa E.; University of Chester; Bristol Zoological Society; Durrell Wildlife Conservation Trust (Elsevier, 2022-06-27)
      A critical component of conserving and housing species ex situ is an explicit scientific understanding of the physiological underpinnings of their welfare. Cortisol has been repeatedly linked to stress, and therefore used as an indicator of welfare for many species. In order to measure cortisol in the Livingstone's fruit bat (Pteropus livingstonii; a critically endangered keystone species) without disturbing the captive population, we have developed and validated a non-invasive, novel hormone extraction procedure and faecal glucocorticoid assay. A total of 92 faecal samples, 73 from the P. livingstonii breeding colony at Jersey Zoo, Channel Islands and 19 samples from P. livingstonii housed at Bristol Zoological Gardens, UK, have been collected and analyzed. Mixed-effect modelling of the influence of physiological state variables on cortisol concentration revealed that lactating females had higher cortisol levels than non-lactating females, indicating that our assay is measuring biologically relevant hormone concentrations. Males and older bats also had higher cortisol than non-lactating females and younger individuals. Further analysis applied social network methodology to compare the cortisol levels of bats with different social roles. We found that individuals that linked social groups possessed higher than average cortisol levels and conversely, individuals with high-quality, positive relationships had lower cortisol levels. These results demonstrate, for the first time in a bat species, social mediation of stress hormones. Lastly, the frequency of vocalisation was found to positively correlate with cortisol concentration in males, suggesting that this behaviour may be used by animal management as a visual indicator of a bat's hormonal status. Hence, this research has provided unique insights and empirical scientific knowledge regarding the relationship between the physiology and social behaviour of P. livingstonii, therefore allowing for recommendations to be made to optimise bat welfare at the individual level.
    • Social stability in semiferal ponies: networks show interannual stability alongside seasonal flexibility

      Stanley, Christina R.; Mettke-Hofmann, Claudia; Hager, Reinmar; Shultz, Susanne; University of Chester; University of Manchester; Liverpool John Moores University (Elsevier, 2017-06-23)
      Long-term relationships that underlie many stable mammalian groups often occur between philopatric kin. Although stable groups of nonrelatives appear to be less common, there is increasing evidence that social bonds between nonkin may confer sufficient intrinsic fitness benefits for these groups to persist. Here we evaluate whether social stability occurs in a bisexually dispersing species where social bonds have been shown to have reproductive benefits: the feral horse, Equus caballus. First, we quantified female social stability by applying a three-level framework to a 3-year data set of associations in semiferal ponies; this tested for stability at the individual, dyadic and subpopulation levels. Despite the relative weakness of these female bonds, we found significant social stability across all levels, as shown by stable association preferences, social networks and individual network positions. Second, we investigated how seasonality impacts on social bond strength and grouping patterns. We found seasonal fluctuations in female gregariousness, with a peak during the mating season. We therefore propose that significant social stability in female horses is coupled with a degree of flexibility that allows for effects of ecological fluctuations. Although social network analysis is widely used in behavioural ecological research, this is one of only a handful of studies to assess the temporal dynamics of networks over a significant timescale. Temporal stability in female relationships suggests that equid social structures are multifaceted: although bonds between stallions and mares are clearly strong, long-term relationships between mares underpin the social network structure. We suggest this framework could be used to assess social stability in other group-living species in order to improve our understanding of the nature of social bonds.
    • Solving the conundrum of health and disease

      Lewis, Stephen J.; Chester College of Higher Education (1997)
    • Some notes on crucifixion

      Lewis, Stephen J.; Chester College of Higher Education (1995)
      This article discusses the injuries caused by crucifixion, based on an adult male skeleton found in ossuary I:4 in north-east Jerusalem in 1968.
    • Some research possibilities in diagnostic radiography

      Lewis, Stephen J.; University College Chester (Elsevier, 1998)
      Although scientific method is usually viewed as starting with hypotheses which must then be exposed to experimental test, there are situations where this rigid scenario is inappropriate. Fortunately, the alternatives provide avenues for valuable investigative work in radiographic research. Research questions may be addressed by collecting data from existing sources in a way that not only provides fundamental information about human biology, but may improve the efficacy of radiographic practice while avoiding ethical problems about the use of patients. Among those involved in osteology, it is radiographers who see and store the most bone images. Subsequently, they have access to more osteological information than anyone else. All that remains is for this information to be extracted and put into a more accessible form. Since they are closely involved with the patients from whom their radiographs stem, there are research questions which radiographers are uniquely situated to raise.