465 research outputs found
Metazoan-protozoan parasite co-infections and host body weight in St Kilda Soay sheep
For hundreds of years, the unmanaged Soay sheep population on St Kilda has survived despite enduring presumably deleterious co-infections of helminth, protozoan and arthropod parasites and intermittent periods of starvation. Important parasite taxa in young Soay sheep are strongyles (Trichostrongylus axei, Trichostrongylus vitrinus and Teladorsagia circumcincta), coccidia (11 Eimeria species) and keds (Melophagus ovinus) and in older animals, Teladorsagia circumcincta. In this research, associations between the intensity of different parasite taxa were investigated. Secondly, the intensities of different parasite taxa were tested for associations with variation in host weight, which is itself a determinant of over-winter survival in the host population. In lambs, the intensity of strongyle eggs was positively correlated with that of Nematodirus spp. eggs, while in yearlings and adults strongyle eggs and coccidia oocysts were positively correlated. In lambs and yearlings, of the parasite taxa tested, only strongyle eggs were significantly and negatively associated with host weight. However, in adult hosts, strongyles and coccidia were independently and negatively associated with host weight. These results are consistent with the idea that strongyles and coccidia are exerting independent selection on Soay sheep.</p
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Sediment structure and physicochemical changes following tidal inundation at a large open coast managed realignment site
Managed realignment (MR) schemes are being implemented to compensate for the loss of intertidal saltmarsh habitats by breaching flood defences and inundating the formerly defended coastal hinterland. However, studies have shown that MR sites have lower biodiversity than anticipated, which has been linked with anoxia and poor drainage resulting from compaction and the collapse of sediment pore space caused by the site's former terrestrial land use. Despite this proposed link between biodiversity and soil structure, the evolution of the sediment sub-surface following site inundation has rarely been examined, particularly over the early stages of the terrestrial to marine or estuarine transition. This paper presents a novel combination of broad- and intensive-scale analysis of the sub-surface evolution of the Medmerry Managed Realignment Site (West Sussex, UK) in the three years following site inundation. Repeated broad-scale sediment physiochemical datasets are analysed to assess the early changes in the sediment subsurface and the preservation of the former terrestrial surface, comparing four locations of different former land uses. Additionally, for two of these locations, high-intensity 3D-computed X-ray microtomography and Itrax micro-X-ray fluorescence spectrometry analyses are presented. Results provide new data on differences in sediment properties and structure related to the former land use, indicating that increased agricultural activity leads to increased compaction and reduced porosity. The presence of anoxic conditions, indicative of poor hydrological connectivity between the terrestrial and post-inundation intertidal sediment facies, was only detected at one site. This site has experienced the highest rate of accretion over the terrestrial surface (ca. 7 cm over 36 months), suggesting that poor drainage is caused by the interaction (or lack of) between sediment facies rather than the former land use. This has significant implications for the design of future MR sites in terms of preparing sites, their anticipated evolution, and the delivery of ecosystem services
Evolutionary tradeoffs in cellular composition across diverse bacteria
One of the most important classic and contemporary interests in biology is the connection between cellular composition and physiological function. Decades of research have allowed us to understand the detailed relationship between various cellular components and processes for individual species, and have uncovered common functionality across diverse species. However, there still remains the need for frameworks that can mechanistically predict the tradeoffs between cellular functions and elucidate and interpret average trends across species. Here we provide a comprehensive analysis of how cellular composition changes across the diversity of bacteria as connected with physiological function and metabolism, spanning five orders of magnitude in body size. We present an analysis of the trends with cell volume that covers shifts in genomic, protein, cellular envelope, RNA and ribosomal content. We show that trends in protein content are more complex than a simple proportionality with the overall genome size, and that the number of ribosomes is simply explained by cross-species shifts in biosynthesis requirements. Furthermore, we show that the largest and smallest bacteria are limited by physical space requirements. At the lower end of size, cell volume is dominated by DNA and protein content—the requirement for which predicts a lower limit on cell size that is in good agreement with the smallest observed bacteria. At the upper end of bacterial size, we have identified a point at which the number of ribosomes required for biosynthesis exceeds available cell volume. Between these limits we are able to discuss systematic and dramatic shifts in cellular composition. Much of our analysis is connected with the basic energetics of cells where we show that the scaling of metabolic rate is surprisingly superlinear with all cellular components
The Acceptability of Diagnostic Tests in the United Kingdom
Babu Karavadra,1 Dharani K Hapangama,2,3 Nicola Tempest2,3 1University of Liverpool, Department of Primary Care and Mental Health, Liverpool, UK; 2Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of the Liverpool Health Partnership, Liverpool, UK; 3Liverpool Women’s Hospital NHS Foundation Trust, Member of the Liverpool Health Partnership, Liverpool, UKCorrespondence: Nicola Tempest, Department of Women’s and Children’s Health, Institute of Life Course and Medical Sciences, University of Liverpool, Member of the Liverpool Health Partnership, Liverpool, UK, Tel +441517089988, Email [email protected]: It is increasingly acknowledged that public acceptability should be considered when designing, evaluating, and implementing healthcare interventions; especially for vulnerable groups.Patients and Methods: A voluntary, self-reported, anonymous questionnaire with ethical approval and patient and public involvement was distributed online through social media over a 6-month period to explore acceptability of diagnostic tests.Results: Ninety-three individuals replied to the questionnaire, of which the majority were female (89.2%) heterosexual (92.4%) white (81.6%) and resided in England (94.6%). The most encountered diagnostic test was an X-ray (92.4%) and the least encountered test was a bone marrow biopsy with local anaesthetic (0%). A sputum sample test was the most perfectly acceptable investigation (83.8%). One percent of participants felt that the cervical smear test was perfectly acceptable With reference to hysteroscopy, 44% felt a hysteroscopy was perfectly acceptable under general anaesthesia, compared to no participants with local anaesthetic or sedation. Forty one percent of participants felt a diagnostic laparoscopy was perfectly acceptable.Conclusion: The findings from this study provide insight into the acceptability of medical tests from a patient perspective and will inform a more explorative qualitative study to ensure researchers are aiming to produce tests that are sensitive, specific and importantly acceptable.Plain Language Summary: The development of a medical test should always acknowledge the views of the public in terms of its acceptability. We conducted an online questionnaire-based study that explored the view of the public, in the United Kingdom (UK), regarding a series of non-invasive and invasive medical tests. Ninety-three individuals replied to the questionnaire and the majority were female (89.2%) and most resided in England (94.6%). The most encountered diagnostic test was an X-ray (92.4%) and the least encountered test was a bone marrow biopsy (test to remove soft tissue inside a bone through a needle) with local anaesthetic (0%). A sputum sample test was the most perfectly acceptable investigation (83.8%). Participants also explained that if the test was looking for cancer, or if the reason for the test was due to pain symptoms, then they were more likely to have the test. We will explore our findings further through our next study by interviewing participants and ensuring the patient and public voice is represented for the different medical tests.Keywords: medical investigations, tolerability, patient centered, investigation
Integrated Ugi-Based Assembly of Functionally, Skeletally, and Stereochemically Diverse 1,4-Benzodiazepin-2-ones
A practical, integrated and versatile U-4CR-based assembly of 1,4-benzodiazepin-2-ones exhibiting functionally, skeletally, and stereochemically diverse substitution patterns is described. By virtue of its convergence, atom economy, and bond-forming efficiency, the methodology documented herein exemplifies the reconciliation of structural complexity and experimental simplicity in the context of medicinal chemistry projects.This work was financially supported by the Galician Government (Spain), Projects: 09CSA016234PR and GPC-2014-PG037. J.A. thanks FUNDAYACUCHO (Venezuela) for a predoctoral grant and Deputación da Coruña (Spain) for a postdoctoral research grant. A.N.-V. thanks the Spanish government for a Ramón y Cajal research contract
Comparative genomics in chicken and Pekin duck using FISH mapping and microarray analysis
BACKGROUND:
The availability of the complete chicken (Gallus gallus) genome sequence as well as a large number of chicken probes for fluorescent in-situ hybridization (FISH) and microarray resources facilitate comparative genomic studies between chicken and other bird species. In a previous study, we provided a comprehensive cytogenetic map for the turkey (Meleagris gallopavo) and the first analysis of copy number variants (CNVs) in birds. Here, we extend this approach to the Pekin duck (Anas platyrhynchos), an obvious target for comparative genomic studies due to its agricultural importance and resistance to avian flu.
RESULTS:
We provide a detailed molecular cytogenetic map of the duck genome through FISH assignment of 155 chicken clones. We identified one inter- and six intrachromosomal rearrangements between chicken and duck macrochromosomes and demonstrated conserved synteny among all microchromosomes analysed. Array comparative genomic hybridisation revealed 32 CNVs, of which 5 overlap previously designated "hotspot" regions between chicken and turkey.
CONCLUSION:
Our results suggest extensive conservation of avian genomes across 90 million years of evolution in both macro- and microchromosomes. The data on CNVs between chicken and duck extends previous analyses in chicken and turkey and supports the hypotheses that avian genomes contain fewer CNVs than mammalian genomes and that genomes of evolutionarily distant species share regions of copy number variation ("CNV hotspots"). Our results will expedite duck genomics, assist marker development and highlight areas of interest for future evolutionary and functional studies
Powers of Romance: The Liminal Challenges of Managing Organizational Intimacy
© The Author(s) 2014 Problematic organizational relationships have recently been at the core of highly visible media coverage. Most analyses of sexual relations in organizations have been, however, simplistic and unidimensional, and have placed insufficient systematic emphasis on the role of governmentality in the social construction of organizational romance. In this article, we proceed in two theoretical steps. First, we elaborate a typology of organizational romance that covers different manifestations of this nuanced process. We think of these as organizational strategies of governmentality. Second, we elaborate and identify liminal cases that fall into the interstices of the four predominant ways of managing sexual relationships in organizations. We think of these as vases of liquid love and life that evade the border controls of regulation by governmentality. Finally, we relate these issues to debates about the nature of the civilizational process and suggest hypotheses for future research
Supermarket Transaction Records In Dietary Evaluation – The STRIDE study: validation against self-reported dietary intake
Objective:
Scalable methods are required for population dietary monitoring. The Supermarket Transaction Records In Dietary Evaluation (STRIDE) study compares dietary estimates from supermarket transactions with an online FFQ.
Design:
Participants were recruited in four waves, accounting for seasonal dietary variation. Purchases were collected for 1 year during and 1 year prior to the study. Bland–Altman agreement and limits of agreement (LoA) were calculated for energy, sugar, fat, saturated fat, protein and sodium (absolute and relative).
Setting:
This study was partnered with a large UK retailer.
Participants:
Totally, 1788 participants from four UK regions were recruited from the retailer’s loyalty card customer database, according to breadth and frequency of purchases. Six hundred and eighty-six participants were included for analysis.
Results:
The analysis sample were mostly female (72 %), with a mean age of 56 years (SD 13). The ratio of purchases to intakes varied depending on amounts purchased and consumed; purchases under-estimated intakes for smaller amounts on average, but over-estimated for larger amounts. For absolute measures, the LoA across households were wide, for example, for energy intake of 2000 kcal, purchases could under- or over-estimate intake by a factor of 5; values could be between 400 kcal and 10000 kcal. LoA for relative (energy-adjusted) estimates were smaller, for example, for 14 % of total energy from saturated fat, purchase estimates may be between 7 % and 27 %.
Conclusions:
Agreement between purchases and intake was highly variable, strongest for smaller loyal households and for relative values. For some customers, relative nutrient purchases are a reasonable proxy for dietary composition indicating utility in population-level dietary research
Exploring the Geographic Variation in Fruit and Vegetable Purchasing Behaviour Using Supermarket Transaction Data
The existence of dietary inequalities is well-known. Dietary behaviours are impacted by the food environment and are thus likely to follow a spatial pattern. Using 12 months of transaction records for around 50,000 ‘primary’ supermarket loyalty card holders, this study explores fruit and vegetable purchasing at the neighbourhood level across the city of Leeds, England. Determinants of small-area-level fruit and vegetable purchasing were identified using multiple linear regression. Results show that fruit and vegetable purchasing is spatially clustered. Areas purchasing fewer fruit and vegetable portions typically had younger residents, were less affluent, and spent less per month with the retailer
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