939 research outputs found

    Two’s company, three’s a crowd: fine-scale habitat partitioning by depth among sympatric species of marine mesopredator

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    A sympatric assemblage of morphologically similar predators is expected to exhibit fine-scale habitat segregation, or resource partitioning, to reduce the effects of direct competition. This principle has been well studied for predators in terrestrial ecosystems. In the marine environment, how sympatric species of large predators spatially segregate at the fine-scale is poorly understood because detailed movement and behavioural data is often not available across multiple species within the same timeframe. How co-occurring congeneric predators separate spatially is even less well understood. Medium sized species of skates (Genus Raja) co-occur in temperate habitats of the north-east Atlantic Ocean, share similar morphologies and have distributional ranges that overlap significantly in the western English Channel ecosystem. Here, detailed depth time series retrieved from 89 electronic data storage tags attached to four species of skate were analysed to determine preferred depth ranges. The four species were found to segregate spatially into two groups, with one group having a significantly shallower core annual depth range than the other. To our knowledge fine-scale segregation by depth has not been observed previously. Interestingly the members of each species group appeared complementary, each group comprising species having different dietary preferences and with a larger and smaller body size. An understanding of how core depth ranges differ and how these species utilise vertical habitat has potential to predict geographic ranges around the coast with important implications for how these species interact with fisheries and Marine Protected Areas

    A Bayesian palaeoenvironmental transfer function model for acidified lakes

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    A Bayesian approach to palaeoecological environmental reconstruction deriving from the unimodal responses generally exhibited by organisms to an environmental gradient is described. The approach uses Bayesian model selection to calculate a collection of probability-weighted, species-specific response curves (SRCs) for each taxon within a training set, with an explicit treatment for zero abundances. These SRCs are used to reconstruct the environmental variable from sub-fossilised assemblages. The approach enables a substantial increase in computational efficiency (several orders of magnitude) over existing Bayesian methodologies. The model is developed from the Surface Water Acidification Programme (SWAP) training set and is demonstrated to exhibit comparable predictive power to existing Weighted Averaging and Maximum Likelihood methodologies, though with improvements in bias; the additional explanatory power of the Bayesian approach lies in an explicit calculation of uncertainty for each individual reconstruction. The model is applied to reconstruct the Holocene acidification history of the Round Loch of Glenhead, including a reconstruction of recent recovery derived from sediment trap data.The Bayesian reconstructions display similar trends to conventional (Weighted Averaging Partial Least Squares) reconstructions but provide a better reconstruction of extreme pH and are more sensitive to small changes in diatom assemblages. The validity of the posteriors as an apparently meaningful representation of assemblage-specific uncertainty and the high computational efficiency of the approach open up the possibility of highly constrained multiproxy reconstructions

    Attachment, infidelity, and loneliness in college students involved in a romantic relationship: the role of relationship satisfaction, morbidity and prayer for partner

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    This study examined the mediating effects of relationship satisfaction, prayer for a partner, and morbidity in the relationship between attachment and loneliness, infidelity and loneliness, and psychological morbidity and loneliness, in college students involved in a romantic relationship. Participants were students in an introductory course on family development. This study examined only students (n = 345) who were involved in a romantic relationship. The average age of participants was 19.46 (SD = 1.92) and 25 % were males. Short-form UCLA Loneliness Scale (ULS-8), (Hays and DiMatteo in J Pers Assess 51:69–81, doi:10.1207/s15327752jpa5101_6, 1987); Relationship Satisfaction Scale (Funk and Rogge in J Fam Psychol 21:572–583, doi:10.1037/0893-3200.21.4.572, 2007); Rotterdam Symptom Checklist (De Haes et al. in Measuring the quality of life of cancer patients with the Rotterdam Symptom Checklist (RSCL): a manual, Northern Centre for Healthcare Research, Groningen, 1996); Prayer for Partner Scale, (Fincham et al. in J Pers Soc Psychol 99:649–659, doi:10.1037/a0019628, 2010); Infidelity Scale, (Drigotas et al. in J Pers Soc Psychol 77:509–524, doi:10.1037/0022-3514.77.3.509, 1999); and the Experiences in Close Relationship Scale-short form (Wei et al. in J Couns Psychol 52(4):602–614, doi:10.1037/0022-0167.52.4.602, 2005). Results showed that relationship satisfaction mediated the relationship between avoidance attachment and loneliness and between infidelity and loneliness. Physical morbidity mediated the relationship between anxious attachment and psychological morbidity. Psychological morbidity mediated the relationship between anxious attachment and physical morbidity. The present results expand the literature on attachment by presenting evidence that anxious and avoidant partners experience loneliness differently. Implications for couple’s therapy are addressed. Future research should replicate these results with older samples and married couples.Acknowledgments This research was supported by Grant Number 90FE0022 from the United States Department of Health and Human Services awarded to the last author

    Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

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    Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, while infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with other disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harboring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit

    Regional variability in the atmospheric nitrogen deposition signal and its transfer to the sediment record in Greenland lakes

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    Disruption of the nitrogen cycle is a major component of global environmental change. δ15N in lake sediments is increasingly used as a measure of reactive nitrogen input but problematically, the characteristic depleted δ15N signal is not recorded at all sites. We used a regionally replicated sampling strategy along a precipitation and N-deposition gradient in SW Greenland to assess the factors determining the strength of δ15N signal in lake sediment cores. Analyses of snowpack N and δ15N-NO3 and water chemistry were coupled with bulk sediment δ15N. Study sites cover a gradient of snowpack δ15N (ice sheet: −6‰; coast −10‰), atmospheric N deposition (ice sheet margin: ∼ 0.2 kg ha−1 yr−1; coast: 0.4 kg ha−1 yr−1) and limnology. Three 210Pb-dated sediment cores from coastal lakes showed a decline in δ15N of ca.−1‰ from ∼ 1860, reflecting the strongly depleted δ15N of snowpack N, lower in-lake total N (TN) concentration (∼ 300 μg N L−1) and a higher TN-load. Coastal lakes have 3.7–7.1× more snowpack input of nitrate than inland sites, while for total deposition the values are 1.7–3.6× greater for lake and whole catchment deposition. At inland sites and lakes close to the ice-sheet margin, a lower atmospheric N deposition rate and larger in-lake TN pool resulted in greater reliance on N-fixation and recycling (mean sediment δ15N is 0.5–2.5‰ in most inland lakes; n = 6). The primary control of the transfer of the atmospheric δ15N deposition signal to lake sediments is the magnitude of external N inputs relative to the in-lake N-pool

    Lake Acidification in the United Kingdom II. A preliminary report to the Department of the Environment under Contract PECD 7/10/167

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    This report summarises progress made in Department of the Environment project PECD 7/10/167 - "causes and extent of lake acidification in the United Kingdom". It includes data and results available at the present time and indicates where work is still in progress. We expect that all work will be completed on schedule and that a final report will be issued shortly after completion of the contract (March 31st 1990)

    Individual, social and area level factors associated with older people\u27s walking: analysis of a UK household panel study (Understanding Society)

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    BackgroundAmong older people, walking is a popular and prevalent activity and is key to increasing physical activity levels and resulting physical and mental health. In the context of rapidly ageing populations, it is important to better understand what factors are associated with walking among older people, based on the socioecological model of health.MethodsWe used data from Understanding Society (n:6450), a national panel survey of UK adults aged 65 years and over living in Great Britain. Slope Indices of Inequality (SII) were calculated for weekly walking hours for those according to individual, social and area characteristics. These include health, loneliness and social isolation, previous walking and activity, residential self-selection, contact with neighbours, number of close friends and social activity, and spatial area-level data describing local area crime, walkability, and proximity to retail, greenspace, and public transport amenities.ResultsResults from multivariable models indicated that poor health, particularly requiring help with walking, was the strongest predictor of weekly walking hours (SII (95% CI) comparing those needing help vs. no help: -3.58 (-4.30, -2.87)). However, both prior sporting activity (most vs. least active: 2.30 (1.75, 2.88)) and walking for pleasure (yes vs. no: 1.92 (1.32, 2.53)) were strongly associated with increased walking several years later. Similarly having close friends (most vs. fewest, 1.18 (0.72, 1.77)) and local retail destinations (any vs. none: 0.93 (0.00, 1.86)) were associated with more weekly walking.ConclusionsPast engagement in physical activity and walking for pleasure are strong predictors of walking behaviour in older people, underscoring the importance of implementing and sustaining walking interventions across the lifespan to ensure continued engagement in later years and the associated health benefits. However, poor health significantly impedes walking in this demographic, emphasising the need for interventions that offer both physical assistance and social support to promote this activity

    Social network characteristics associated with mid-to-older aged adults\u27 co-engagement in physical activity

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    Objectives: Physical activity is associated with a greater quantity and quality of social connections. Participating in physical activity with others (co-engagement) has dual physical and social benefits that can promote healthy ageing. We aimed to understand the social network characteristics of mid-to-older aged adults associated with co-engagement in physical activity. Methods: Adults aged 55–75 years completed a social network survey (3679 social contacts reported by 140 participants). Multilevel modelling was used to identify the characteristics of participants, social contacts, and relationships that were predictive of co-engagement in physical activity. Results: Network size and relationship quality were not associated with co-engagement. Similarity in age, greater interaction frequency, closer geographic proximity, and shorter relationship length were associated with higher odds of co-engagement. Discussion: For co-engagement, the quality and quantity of relationships were less important than the convenience and accessibility of relationships, particularly newer relationships. As such, co-engagement ties can be understood as part of a dynamic social convoy which fulfil a specific function at a specific life stage. An understanding of naturally occurring tendencies for co-engagement may be utilised to identify leverage points for the development of interventions

    Mitochondria function associated genes contribute to Parkinson’s Disease risk and later age at onset

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    Mitochondrial dysfunction has been implicated in the etiology of monogenic Parkinson’s disease (PD). Yet the role that mitochondrial processes play in the most common form of the disease; sporadic PD, is yet to be fully established. Here, we comprehensively assessed the role of mitochondrial function-associated genes in sporadic PD by leveraging improvements in the scale and analysis of PD GWAS data with recent advances in our understanding of the genetics of mitochondrial disease. We calculated a mitochondrial-specific polygenic risk score (PRS) and showed that cumulative small effect variants within both our primary and secondary gene lists are significantly associated with increased PD risk. We further reported that the PRS of the secondary mitochondrial gene list was significantly associated with later age at onset. Finally, to identify possible functional genomic associations we implemented Mendelian randomization, which showed that 14 of these mitochondrial function-associated genes showed functional consequence associated with PD risk. Further analysis suggested that the 14 identified genes are not only involved in mitophagy, but implicate new mitochondrial processes. Our data suggests that therapeutics targeting mitochondrial bioenergetics and proteostasis pathways distinct from mitophagy could be beneficial to treating the early stage of P
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