The Faculty of Life Sciences is predominantly based on the Chester Campus, with sports-related and computer-related courses also delivered at Warrington. A number of specialist courses are also delivered at our partner associate college at Reaseheath in Cheshire, as well as some delivery outside the UK. The Faculty also supports several research centres.

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Recent Submissions

  • Female clustering in cockroach aggregations – a case of social niche construction?

    Stanley, Christina; Preziosi, Richard F.; Liddiard Williams, H.; University of Chester, University of Manchester, Manchester Metropolitan University (Wiley, 2018)
    Individuals in groups can suffer costs through interactions with adversarial or unknown conspecifics. Social niche construction allows individuals to buffer such potential costs by only engaging in preferred associations. This may be particularly beneficial in insect aggregations, which are often large and highly fluid. However, little is known regarding the structuring of such aggregations. Here we use social network analyses to test for fine-scale social structure in resting aggregations of the sub-social cockroach Diploptera punctata and to explore the social pressures that contribute towards such structure. We showed that females were significantly more gregarious than males and formed the core of the proximity network, thus demonstrating a higher level of social integration. This fine-scale structure is likely to result from females displacing males; females initiated most displacements whilst males received the majority. We explain this behaviour in terms of social niche construction by showing that females received significantly fewer approaches and investigations at more female-biased local sex ratios. We therefore suggest that female social clustering occurs in this, and presumably other, species to reduce potential costs associated with male harassment. This demonstrates how social niche construction can lead to higher level social structure; we suggest this approach could be used across a range of species in order to improve our understanding of the evolution of sociality.
  • Musculoskeletal Disorders in the Workplace: An examination of the underlying causes and contributory risk factors

    Fallows, Stephen; Gellatly, Pamela (University of Chester, 2018-05-16)
    Introduction The incidence of musculoskeletal disorders remain the most common single condition, by incidence, affecting the working population. This remains true even though the apparent historic causation of manual handling, has reduced significantly. Back pain alone has been termed a 20thcentury medical disaster, which has reverberated into the 21stcentury, with 85% of low back pain having no clear clinical diagnosis yet individuals continue to seek a clinical solution. Understanding pain remains as complex as ever with very little evidence to suggest progress. The overall scale and cost of MSDs in the workplace are not easily identifiable as objective and accurate data are rare. Other workplace incidence and costs are either, not recorded or not published, in documents or grey literature, that are generally only accessible to individual organisations on a regular basis. Objectives The epistemology of this thesis is complexity and the extent to which this influences outcomes. The trilogy of complexity considered includes: 1. The issues facing organisations in how they prevent and manage MSDs; 2. The individual’s perspective and what they understand about possible causation, their beliefs, fears and expectations; 3. The interface with clinical and non-clinical practitioners, and whether interventions provided, are beneficial to the individual. Consideration of the multiple perspectives that arise from the various influences affecting the organisation, the employees within that organisation and the practitioners, has been possible by the metaphoric use of a “bricolage” methodology, and suggests that the current medical model is no longer appropriate. Methods A mixed method research design comprising four studies was undertaken. Firstly, a retrospective quantitative study of data (n = 21,092) from benefits provided by four organisations followed by a qualitative case example study (n = 21) of supporting documents and clinical information. These studies then informed the need for a qualitative study (n= 9) symptomatic individuals who participated in a focus group and (n= 6) face-to-face interviews and finally a qualitative study of practitioners involved in the provision of treatment services to the participating organisations. The data from each study informed the others and the data merged with the findings from the literature review and common interventions. Conclusions A disparity was found between what has been identified in literature and what actually is considered in clinical practice. The healthcare industry operates in “silos” and this separation of disciplines is reflected in organisational management. The range of underlying risk factors, evident in modern society, which are affecting or may affect an individual’s future musculoskeletal health are not being addressed by the medical model, and practitioners require training, or need to work in a multidisciplinary team, if they are to improve long-term outcomes. This thesis discusses the complexity of the multifactorial nature of musculoskeletal health, and provides a framework to challenge current practice and promote a fundamental change in the way in we assess, and treat the range of MSDs including a move towards educating individuals to take personal responsibility.
  • Visualisation of xanthan conformation by atomic force microscopy

    Moffat, Jonathan; Morris, Victor J.; Al-Assaf, Saphwan; Gunning, A. Patrick; Asylum Research an Oxford Instruments Company; Norwich Research Park; University of Chester (Elsevier, 2016-04-20)
    Direct visual evidence obtained by atomic force microscopy demonstrates that when xanthan is adsorbed from aqueous solution onto the heterogeneously charged substrate mica, its helical conformation is distorted. Following adsorption it requires annealing for several hours to restore its ordered helical state. Once the helix state reforms, the AFM images obtained showed clear resolution of the periodicity with a value of 4.7 nm consistent with the previously predicted models. In addition, the images also reveal evidence that the helix is formed by a double strand, a clarification of an ambiguity of the xanthan ultrastructure that has been outstanding for many years.
  • Effects of temperature and solvent condition on phase separation induced molecular fractionation of gum arabic/hyaluronan aqueous mixtures

    Hu, Bing; Han, Lingyu; Gao, Zhiming; Zhang, Ke; Al-Assaf, Saphwan; Nishinari, Katsuyoshi; Phillips, Glyn O.; Yang, Jixin; Fang, Yapeng; Hubei University of Technology; Wrexham Glyndwr University (Elsevier, 2018-05-14)
    Effects of temperature and solvent condition on phase separation-induced molecular fractionation of gum arabic/hyaluronan (GA/HA) mixed solutions were investigated. Two gum arabic samples (EM10 and STD) with different molecular weights and polydispersity indices were used. Phase diagrams, including cloud and binodal curves, were established by visual observation and GPC-RI methods. The molecular parameters of control and fractionated GA, from upper and bottom phases, were measured by GPC-MALLS. Fractionation of GA increased the content of arabinogalactan-protein complex (AGP) from ca. 11% to 18% in STD/HA system and 28% to 55% in EM10/HA system. The phase separation-induced molecular fractionation was further studied as a function of temperature and solvent condition (varying ionic strength and ethanol content). Increasing salt concentration (from 0.5 to 5 mol/L) greatly reduced the extent of phase separation-induced fractionation. This effect may be ascribed to changes in the degree of ionization and shielding of the acid groups. Increasing temperature (from 4oC to 80oC) also exerted a significant influence on phase separation-induced fractionation. The best temperature for GA/HA mixture system was 40oC while higher temperature negatively affected the fractionation due to denaturation and possibly degradation in mixed solutions. Increasing the ethanol content up to 30% showed almost no effect on the phase separation induced fractionation.
  • The concurrent validity of a rugby-specific Yo-Yo Intermittent Recovery Test (Level 1) for assessing match-related running performance

    Dobbin, Nick; Highton, Jamie M.; Moss, Samantha L.; Hunwicks, Richard; Twist, Craig; University of Chester; Rugby Football League, Leeds (Lippincott, Williams & Wilkins, 2018-06-01)
    This study investigated the concurrent validity of a rugby-specific high-intensity intermittent running test (HIIR) against the internal, external and perceptual responses to simulated match-play. Thirty-six rugby league players (age 18.5 ± 1.8 years; stature 181.4 ± 7.6 cm; body mass 83.5 ± 9.8 kg) completed the prone Yo-Yo IR1, of which sixteen also completed the Yo-Yo IR1, and 2 x ~20 min bouts of a simulated match-play (RLMSP-i). Most likely reductions in relative total, low-speed and high-speed distance, mean speed and time above 20 W·kg-1 (HMP) were observed between bouts of the RLMSP-i. Likewise, rating of perceived exertion (RPE) and percentage of peak heart rate (%HRpeak) were very likely and likely higher during the second bout. Pearson’s correlations revealed a large relationship for the change in relative distance (r = 0.57-0.61) between bouts with both Yo-Yo IR1 tests. The prone Yo-Yo IR1 was more strongly related to the RLMSP-i for change in repeated sprint speed (r = 0.78 cf. 0.56), mean speed (r = 0.64 cf. 0.36), HMP (r = 0.48 cf. 0.25), fatigue index (r = 0.71 cf. 0.63), %HRpeak (r = -0.56 cf. -0.35), RPEbout1 (r = -0.44 cf. -0.14), and RPEbout2 (r = -0.68 cf. -0.41) than the Yo-Yo IR1, but not for blood lactate concentration (r = -0.20 to -0.28 cf. -0.35 to -0.49). The relationships between prone Yo-Yo IR1 distance and measure of load during the RLMSP-i suggests it possesses concurrent validity and is more strongly associated with measures of training or match load than the Yo-Yo IR1 using rugby league players.
  • Extraction, identification and biological activities of saponins in sea cucumber Pearsonothuria graeffei

    Khattaba, Rafat A.; Elbandy, Mohamed; Lawrence, Andrew; Paget, Tim; Rae-Rho, Jung; Binnasera, Yaser S.; Alih, Imran; Taibah University; Suez Canal University; Jizan University; Alarish University; University of Chester; Sunderland University; Kunsan National University; Central University, New Delhi (Bentham Science, 2018-04-01)
    Secondary metabolism in marine organisms produced a diversity of biological important natural compounds which are unpresented in terrestrial species. Sea cucumbers belong to the invertebrate Echinodermata and are famous for their nutraceutical, medical and food values. They are known for possession triterpenoid glycosides (saponins) with various ecological roles. The current work aimed to separate, identify and test various biological activities (anti-bacterial, antifungal, antileishmanial and anticancer properties) of saponins produced by the holothurian Pearsonothuria graeffei from the Red Sea, Egypt.
  • Two independent proteomic approaches provide a comprehensive analysis of the synovial fluid proteome response to Autologous Chondrocyte Implantation

    Hulme, Charlotte H.; Wilson, Emma L.; Fuller, Heidi R.; Roberts, Sally; Richardson, James B.; Gallacher, Pete; Peffers, Mandy J.; Shirran, Sally L.; Botting, Catherine H.; Wright, Karina T.; Keele University; Robert Jones and Agnes Hunt Orthopaedic Hospital; University of Chester; University of Liverpool; University of St Andrews (BioMed Central, 2018-05-02)
    Background: Autologous chondrocyte implantation (ACI) has a failure rate of approximately 20%, but it is yet to be fully understood why. Biomarkers are needed that can pre-operatively predict in which patients it is likely to fail, so that alternative or individualised therapies can be offered. We previously used label-free quantitation (LF) with a dynamic range compression proteomic approach to assess the synovial fluid (SF) of ACI responders and non-responders. However, we were able to identify only a few differentially abundant proteins at baseline. In the present study, we built upon these previous findings by assessing higher-abundance proteins within this SF, providing a more global proteomic analysis on the basis of which more of the biology underlying ACI success or failure can be understood. Methods: Isobaric tagging for relative and absolute quantitation (iTRAQ) proteomic analysis was used to assess SF from ACI responders (mean Lysholm improvement of 33; n = 14) and non-responders (mean Lysholm decrease of 14; n = 13) at the two stages of surgery (cartilage harvest and chondrocyte implantation). Differentially abundant proteins in iTRAQ and combined iTRAQ and LF datasets were investigated using pathway and network analyses. Results: iTRAQ proteomic analysis confirmed our previous finding that there is a marked proteomic shift in response to cartilage harvest (70 and 54 proteins demonstrating ≥ 2.0-fold change and p < 0.05 between stages I and II in responders and non-responders, respectively). Further, it highlighted 28 proteins that were differentially abundant between responders and non-responders to ACI, which were not found in the LF study, 16 of which were altered at baseline. The differential expression of two proteins (complement C1s subcomponent and matrix metalloproteinase 3) was confirmed biochemically. Combination of the iTRAQ and LF proteomic datasets generated in-depth SF proteome information that was used to generate interactome networks representing ACI success or failure. Functional pathways that are dysregulated in ACI non-responders were identified, including acute-phase response signalling. Conclusions: Several candidate biomarkers for baseline prediction of ACI outcome were identified. A holistic overview of the SF proteome in responders and non-responders to ACI  has been profiled, providing a better understanding of the biological pathways underlying clinical outcome, particularly the differential response to cartilage harvest in non-responders.
  • The influence of music genre on explosive power, repetitions to failure and mood responses during resistance exercise

    Moss, Samantha L.; Enright, Kevin; Cushman, Simon; University of Chester; Liverpool John Moores University (Elsevier, 2018-05-04)
    Objectives: To investigate the influence of different music genres on the psychological, psychophysical and psychophysiological responses during power-based and strength-based resistance exercises. Design: Repeated-measures counterbalanced design. Method: Sixteen resistance-trained participants completed an explosive power test in the squat and bench exercises at 30% 1RM across no music, electronic dance music, metal and self-selected conditions. Peak and mean values were recorded for power and velocity. A progressive loading protocol assessed the impact of condition on repetitions to failure at 60, 70 and 80% 1RM in the squat and bench exercises. For all tests, recording of heart rate and rating of perceived exertion were completed after every set, blood lactate after protocol completion, and mood states before and after. Results: Using magnitude-based inferences, music either had no effect or a small detrimental effect on power and velocity, depending on the exercise. Repetitions to failure increased by a small to moderate amount for all music conditions compared to no music at low but not high intensities. Self-selected music provided additional small benefits in repetitions than other music conditions. Rating of perceived exertion was similar between self-selected, metal and no music conditions, whereas electronic dance music revealed higher responses. Vigour increased after all music conditions but remained unchanged in no music. Conclusions: Explosive power exercises either remain unchanged or are disadvantaged when completed to music. Various music genres could improve repetition to failure training at low to moderate intensities, although individuals might expect greatest improvements using self-selected music, without concomitant increases in perceived effort.
  • An examination of a modified Yo-Yo test to measure intermittent running performance in rugby players

    Dobbin, Nick; Moss, Samantha; Highton, Jamie M.; Twist, Craig; University of Chester (Taylor & Francis, 2018-06-17)
    This study examined how starting each shuttle in the prone position altered the internal, external and perceptual responses to the Yo-Yo Intermittent Recovery Test Level 1. Using a randomized crossover design, 17 male rugby players completed the Yo-Yo IR1 and prone Yo-Yo IR1 on two separate occasions. External loads (via microtechnology), V ̇O2, heart rate (HR), rating of perceived exertion (RPE) were measured at 160, 280 and 440 m (sub-maximal) and when the test was terminated (peak). The pre-to-post change in blood lactate concentration (∆[La]b) was determined for both tests. All data were analysed using effect sizes and magnitude-based inferences. Between-trial differences (ES  90%CL) indicated total distance was most likely lower (-1.87  0.19), whereas other measures of peak external load were likely to very likely higher during the prone Yo-Yo IR1 (0.62-1.80). Sub-maximal RPE was likely to most likely higher (0.40-0.96) and peak RPE very likely higher (0.63  0.41) in the prone Yo-Yo IR1. The change in [La]b was likely higher after the prone Yo-Yo IRl. Mean HR was possibly lower at 440 m (-0.25  0.29) as was peak HR (-0.26  0.25) in the prone Yo-Yo IR1. "V" ̇E, "V" ̇O2 and "V" ̇CO2 were likely to very likely higher at 280 and 440 m (ES = 0.36-1.22), while peak values were possibly to likely higher (ES = 0.23-0.37) in the prone Yo-Yo IR1. Adopting a prone position during the Yo-Yo IR1 increases the internal, perceptual and external responses, placing greater emphasis on metabolically demanding actions typical of rugby.
  • The influence of preseason training phase and training load on body composition and its relationship with physical qualities in professional junior rugby league players

    Dobbin, Nick; Gardner, Adrian; Daniels, Matthew; Twist, Craig; University of Chester (Taylor & Francis, 2018-05-08)
    This study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = -0.73 to -1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = -0.05 to -0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = -0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.
  • Metabolic demands of elite rugby competition after 36 hours of a high (6 g·kg-1) or low (3 g·kg-1) carbohydrate diet: implications for dietary recommendations.

    Bradley, Warren J.; Morehen, James C.; Haigh, Julian; Clarke, Jon; Donovan, Timothy F.; Twist, Craig; Cotton, Caroline; Shepherd, Sam; Cocks, Matthew; Sharma, Asheesh; Impey, Samuel G.; MacLaren, Don P. M.; Morton, James P.; Close, Graeme L.; Liverpool John Moores University; Widnes Vikings Rugby; Glyndwr University; University of Chester; Aintree University Hospital; Royal Liverpool Hospital; University of Liverpool (Elsevier, 2016-04-22)
    Objectives: Although the physical demands of Rugby League (RL) match-play are well-known, the fuel sources supporting energy-production are poorly understood. We therefore assessed muscle glycogen utilisation and plasma metabolite responses to RL match-play after a relatively high (HCHO) or relatively low CHO (LCHO) diet. Design: Sixteen (mean ± SD age; 18 ± 1 years, body-mass; 88 ± 12 kg, height 180 ± 8 cm) professional players completed a RL match after 36-h consuming a non-isocaloric high carbohydrate (n = 8; 6 g kg day−1) or low carbohydrate (n = 8; 3 g kg day−1) diet. Methods: Muscle biopsies and blood samples were obtained pre- and post-match, alongside external and internal loads quantified using Global Positioning System technology and heart rate, respectively. Data were analysed using effects sizes ±90% CI and magnitude-based inferences. Results: Differences in pre-match muscle glycogen between high and low carbohydrate conditions (449 ± 51 and 444 ± 81 mmol kg−1 d.w.) were unclear. High (243 ± 43 mmol kg−1 d.w.) and low carbohydrate groups (298 ± 130 mmol kg−1 d.w.) were most and very likely reduced post-match, respectively. For both groups, differences in pre-match NEFA and glycerol were unclear, with a most likely increase in NEFA and glycerol post-match. NEFA was likely lower in the high compared with low carbohydrate group post-match (0.95 ± 0.39 mmol l−1 and 1.45 ± 0.51 mmol l−1, respectively), whereas differences between the 2 groups for glycerol were unclear (98.1 ± 33.6 mmol l−1 and 123.1 ± 39.6 mmol l−1) in the high and low carbohydrate groups, respectively. Conclusions: Professional RL players can utilise ∼40% of their muscle glycogen during a competitive match regardless of their carbohydrate consumption in the preceding 36-h.
  • Playing exposure does not affect movement characteristics or physiological responses of elite youth footballers during an intensified period of competition.

    Gibson, Neil; McCunn, Robert; MacNay, Sophie; Mullen, Thomas; Twist, Craig; Heriot-Watt University; University of Chester (Taylor & Francis, 2018-05-08)
    This study investigated the effect of playing time on physiological and perceptual responses to six, 60 min matches played over five days. Thirty youth football players (age = 14.1 ± 0.4 years; body mass = 57.4 ± 12.9 kg; stature 169.3 ± 7.7 cm) were grouped into low (<250 min; LPG, n = 18) and high (≥250 min; HPG, n = 12) match exposure groups and monitored daily for lower body power and perceived wellness. GPS technology was used to assess match running demands in total distance (m•min-1), low (<13 km•h-1) and high (≥13 km•h-1) speed running categories. Hypothesis based testing and effect sizes (ES) were used to analyse data. The HPG performed moderately more total distance (103.7 ± 10.4 cf. 90.2 ± 19.7 m•min-1, P = 0.03; ES=0.74 ± 0.63) and high speed running (26.7 ± 6.6 cf. 20.3 ± 6.5 m•min-1, P = 0.01; ES=0.87 ± 0.6) than the LPG across all six matches. Differences of a small magnitude were observed between groups for lower body power (P = 0.08; ES =0.59 ± 0.8) and perceived wellness (P = 0.09; ES=0.42 ± 0.4) which were both higher in the HPG. Youth football players appear well equipped to deal with intensified period of competition, such as those experienced in tournaments, irrespective of match exposure.
  • Movement characteristics, physiological and perceptual responses of elite standard youth football players to different high intensity running drills

    Gibson, Neil; Henning, Greig; Twist, Craig; Heriot-Watt University; University of Chester (Taylor & Francis, 2018-04-06)
    Purpose: To examine responses to high intensity running drills in youth football players. Methods: Seventeen players completed the YoYo Intermittent Recovery test level one (YYIR1) and a 15 m maximal sprint to quantify target running speeds. Players performed three conditions on separate occasions comprising: 12 x 15 s high intensity runs at 100% of the final YYIRT1 speed, 12 x ~4 s repeated sprints with ~26 s recovery, and combination running using both modalities. Heart rate was monitored continuously with PlayerLoadTM and movement characteristics using microtechnology. Ratings of perceived exertion and blood lactate responses were measured 2 min after the final repetition. The ratio of Flight:contraction time was calculated from a countermovement jump before and at 2 min and 14 hours after each condition. Data analysis used magnitude based inferences and effect sizes statistics. Results: Peak speed (1.1%; ES 0.23 ± 0.44) and mean speed over the initial 4s (6.3%; ES 0.45 ± 0.46) were possibly faster during combination compared to high intensity running with unclear differences when compared to repeated sprinting. This was despite most likely (21.6%; ES 7.65 ± 1.02) differences in prescribed speeds between conditions. There were likely reductions in F:C at 14 hours ratio after high intensity (-5.6%; ES –0.44 ± 0.32) and combination running (-6.8%; ES -0.53 ± 0.47). Changes in the repeated sprinting condition were unclear. Conclusions: Actual movement characteristics of high intensity running drills may not reflect those used to prescribe them whilst reductions in F:C ratio are still evident 14 hours after their completion.
  • Direct and indirect causal effects of heterozygosity on fitness-related traits in Alpine ibex

    Brambilla, Alice; Biebach, Iris; Bassano, Bruno; Bogliani, Giuseppe; von Hardenberg, Achaz; Università di Pavia, Italy; University of Zurich, Switzerland; Gran Paradiso National Park, Italy; University of Chester, UK (The Royal Society, 2015-01-07)
    Heterozygosity–fitness correlations (HFCs) are a useful tool to investigate the effects of inbreeding in wild populations, but are not informative in distinguishing between direct and indirect effects of heterozygosity on fitness-related traits. We tested HFCs in male Alpine ibex (Capra ibex) in a free-ranging population (which suffered a severe bottleneck at the end of the eighteenth century) and used confirmatory path analysis to disentangle the causal relationships between heterozygosity and fitness-related traits. We tested HFCs in 149 male individuals born between 1985 and 2009. We found that standardized multi-locus heterozygosity (MLH), calculated from 37 microsatellite loci, was related to body mass and horn growth, which are known to be important fitness-related traits, and to faecal egg counts (FECs) of nematode eggs, a proxy of parasite resistance. Then, using confirmatory path analysis, we were able to show that the effect of MLH on horn growth was not direct but mediated by body mass and FEC. HFCs do not necessarily imply direct genetic effects on fitness-related traits, which instead can be mediated by other traits in complex and unexpected ways.
  • Helpers influence on territory use and maintenance in Alpine marmot groups

    Pasquaretta, Cristian; Busia, Laura; Ferrari, Caterina; Bogliani, Giuseppe; Reale, Denis; von Hardenberg, Achaz; University of Pavia, Universiteé du Quebec a Montreal, Gran Paradiso National Park (2015-04-22)
    In social mammals, territory size and shape vary according to the number and strength of neighbour individuals competing for resources. Two main theories have been proposed to explain this variability: the Group Augmentation (GA) and the realized Resource Holding Potential (rRHP) hypotheses. The first states that the outcome of the interactions among groups depends on the total number of individuals in the group while the second states that only the number of animals directly involved in intergroup competition determines this outcome. We collected data on space use of individually tagged Alpine marmots ( Marmota marmota), a cooperative breeding species that overlaps part of its territory with neighbouring groups. In accordance with the rRHP hypothesis, we found that groups having higher proportion of helpers, rather than higher total number of individuals, had lower percentage of the territory overlapping with neighbouring groups and a larger area available for individual exclusive use.
  • Higher risk of gastrointestinal parasite infection at lower elevation suggests possible constraints in the distributional niche of Alpine marmots

    Zanet, Stefania; Miglio, Giacomo; Ferrari, Caterina; Bassano, Bruno; Ferroglio, Ezio; von Hardenberg, Achaz; Università di Torino; Gran Paradiso National Park; University of Chester (Public Library of Science, 2017-08-01)
    Alpine marmots Marmota marmota occupy a narrow altitudinal niche within high elevation alpine environments. For animals living at such high elevations where resources are limited, parasitism represents a potential major cost in life history. Using occupancy models, we tested if marmots living at higher elevation have a reduced risk of being infected with gastrointestinal helminths, possibly compensating the lower availability of resources (shorter feeding season, longer snow cover and lower temperature) than marmots inhabiting lower elevations. Detection probability of eggs and oncospheres of two gastro-intestinal helminthic parasites, Ascaris laevis and Ctenotaenia marmotae, sampled in marmot feces, was used as a proxy of parasite abundance. As predicted, the models showed a negative relationship between elevation and parasite detectability (i.e. abundance) for both species, while there appeared to be a negative effect of solar radiance only for C. marmotae. Site-occupancy models are used here for the first time to model the constrains of gastrointestinal parasitism on a wild species and the relationship existing between endoparasites and environmental factors in a population of free-living animals. The results of this study suggest the future use of site-occupancy models as a viable tool to account for parasite imperfect detection in ecoparasitological studies, and give useful insights to further investigate the hypothesis of the contribution of parasite infection in constraining the altitudinal niche of Alpine marmots.
  • Involvement of recreational anglers in the eradication of alien brook trout from high altitude lakes

    Tiberti, R.; Ottino, M.; Brighenti, S.; Iacobuzio, R.; Rolla, M.; von Hardenberg, Achaz; Bassano, B.; Gran Paradiso National Park, University of Pavia, Università degli studi di Trento, Fondazione E. Mach, Università degli Studi di Milano, Swansea University, University of Chester (Gran Paradiso National Park Agency, 2017)
    Stocking programmes for recreational angling are primarily responsible for the spread and ecological impact of introduced sh in high-altitude, originally shless lakes. In 2013, the Gran Paradiso National Park started an eradication campaign of brook trout by intensive gill-netting. Local anglers were invited to attend two angling sessions to start the eradication before gill-netting in an experimental lake, as part of an education action devoted to these critical stakeholders. The angling sessions turned out to be a valuable help for the eradication campaign and the aim of this study is to report on the outcomes of these angling sessions. Angling techniques were highly size-selective, removing a substantial part of the adult population and of the sh biomass, but their contribution to the eradication of small sh (<15cm) was irrelevant. Therefore, angling cannot completely eradicate age-structured populations. However, there is scope to use angling sessions as a support for eradication campaigns and as an emergency measure for recent sh introduc- tions. Similar actions should be considered whenever a sh eradication programme is planned. These ndings, however, do not imply a general endorsement for angling within protected areas.
  • Predicting the potential distribution of the Endangered huemul deer Hippocamelus bisulcus in North Patagonia

    Quevedo, Paloma; von Hardenberg, Achaz; Pastore, Hernan; Alvarez, Jose; Corti, Paulo; Ernst-Moritz-Arndt Universität, Greifswald, Germany; University of Chester; Administración de Parques Nacionales, Bariloche, Argentina;Corporación Nacional Forestal, Chile, Universidad Austral de Chile (2017-04)
    Habitat loss is one of the main threats to wildlife, particularly large mammals. Estimating the potential distribution of threatened species to guide surveys and conservation is crucial, primarily because such species tend to exist in small fragmented populations. The Endangered huemul deer Hippocamelus bisulcus is endemic to the southern Andes of Chile and Argentina. Although the species occurs in the Valdivian Ecoregion, a hotspot for biodiversity, we have no information on its occupancy and potential distribution in this region. We built and compared species distribution models for huemul using the maximum entropy approach, using 258 presence records and sets of bioclimatic and geographical variables as predictors, with the objective of assessing the potential distribution of the species in the Valdivian Ecoregion. Annual temperature range and summer precipitation were the predictive variables with the greatest influence in the best-fitting model. Approximately 12,360 km2 of the study area was identified as suitable habitat for the huemul, of which 30% is included in the national protected area systems of Chile and Argentina. The map of potential distribution produced by our model will facilitate prioritization of future survey efforts in other remote and unexplored areas in which huemul have not been recorded since the 1980s, but where there is a high probability of their occurrence.
  • Thermal niche predicts recent changes in range size for bird species

    Scridel, D.; Bogliani, G.; Pedrini, P.; Iemma, A.; von Hardenberg, Achaz; Brambilla, M.; Museo delle Scienze, Trento; University of Pavia, University of Chester, Fondzione Lombardia per l'Ambiente (Inter-Research Science Center (IR), 2017-08-30)
    Species’ distributions are strongly affected by climate, and climate change is affecting species and populations. Thermal niches are widely used as proxies for estimating thermal sensitivity of species, and have been frequently related to community composition, population trends and latitudinal/elevational shifts in distribution. To our knowledge, no work has yet explored the relationship between thermal niche and change in range size (changes in the number of occupied spatial units over time) in birds. In this study, we related a 30 yr change in range size to species thermal index (STI: average temperature at occurrence sites) and to other factors (i.e. birds’ associated habitats, body mass, hunting status) potentially affecting bird populations/range size. We analysed trends of breeding bird range in Italy for a suite of poorly studied cold-adapted animals potentially sensitive to global warming, and for a related group of control species taxonomically similar and with comparable mass but mainly occurring at lower/warmer sites. We found a strong positive correlation between change in range size and STI, confirming that recent climatic warming has favoured species of warmer climates and adversely affected species occupying colder areas. A model including STI and birds’ associated habitats was not so strongly supported, with forest species performing better than alpine open habitat and agricultural ones. In line with previous works highlighting effects of recent climate change on community composition, species’ population trends and poleward/upward distributional shifts, we found STI to be the most important predictor of change in range size variation in breeding birds.
  • MODIS time series contribution for the estimation of nutritional properties of alpine grassland

    Ranghetti, Luigi; Bassano, Bruno; Bogliani, Giuseppe; Polmonari, Alberto; Formigoni, Andrea; Stendardi, Laura; von Hardenberg, Achaz; Consiglio Nazionale delle Ricerche; Università di Pavia; Parco Nazionale Gran Paradiso; Università di Bologna; Università di Firenze; University of Chester (Taylor & Francis, 2017-02-17)
    Despite the Normalised Difference Vegetation Index (NDVI) has been used to make predictions on forage quality, its relationship with bromatological field data has not been widely tested. This relationship was investigated in alpine grasslands of the Gran Paradiso National Park (Italian Alps). Predictive models were built using remotely sensed derived variables (NDVI and phenological information computed from MODIS) in combination with geo-morphometric data as predictors of measured biomass, crude protein, fibre and fibre digestibility, obtained from 142 grass samples collected within 19 experimental plots every two weeks during the whole 2012 growing season. The models were both cross-validated and validated on an independent dataset (112 samples collected during 2013). A good predictability ability was found for the estimation of most of the bromatological measures, with a considerable relative importance of remotely sensed derived predictors; instead, a direct use of NDVI values as a proxy of bromatological variables appeared not to be supported.

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