539 research outputs found

    Salt-Enrichment Impact on Biomass Production in a Natural Population of Peatland Dwelling Arcellinida and Euglyphida (Testate Amoebae)

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    This is the final version. Available on open access from Springer Verlag via the DOI in this recordUnicellular free-living microbial eukaryotes of the order Arcellinida (Tubulinea; Amoebozoa) and Euglyphida (Cercozoa; SAR), commonly termed testate amoebae, colonise almost every freshwater ecosystem on Earth. Patterns in the distribution and productivity of these organisms are strongly linked to abiotic conditions—particularly moisture availability and temperature—however, the ecological impacts of changes in salinity remain poorly documented. Here, we examine how variable salt concentrations affect a natural community of Arcellinida and Euglyphida on a freshwater sub-Antarctic peatland. We principally report that deposition of wind-blown oceanic salt-spray aerosols onto the peatland surface corresponds to a strong reduction in biomass and to an alteration in the taxonomic composition of communities in favour of generalist taxa. Our results suggest novel applications of this response as a sensitive tool to monitor salinisation of coastal soils and to detect salinity changes within peatland palaeoclimate archives. Specifically, we suggest that these relationships could be used to reconstruct millennial scale variability in salt-spray deposition—a proxy for changes in wind-conditions—from sub-fossil communities of Arcellinida and Euglyphida preserved in exposed coastal peatlands.Natural Environment Research Council (NERC

    Plantar heel pain in middle-aged and older adults: population prevalence, associations with health status and lifestyle factors, and frequency of healthcare use

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    Background The objectives of this study were to estimate the population prevalence and distribution of plantar heel pain in mid-to-older age groups, examine associations with selected health status and lifestyle factors, and report the frequency of healthcare use. Methods Adults aged ≥50 years registered with four general practices were mailed a health survey (n = 5109 responders). Plantar heel pain in the last month was defined by self-reported shading on a foot manikin, and was defined as disabling if at least one of the function items of the Manchester Foot Pain and Disability Index were also reported. Population prevalence estimates and associations between plantar heel pain and demographic characteristics, health status measures and lifestyle factors were estimated using multiple imputation and weighted logistic regression. Healthcare professional consultation was summarised as the 12-month period prevalence of foot pain-related consultation. Results The population prevalence of plantar heel pain was 9.6% (95% CI: 8.8, 10.5) and 7.9% (7.1, 8.7) for disabling plantar heel pain. Occurrence was slightly higher in females, comparable across age-groups, and significantly higher in those with intermediate/routine and manual occupations. Plantar heel pain was associated with physical and mental impairment, more anxiety and depression, being overweight, a low previous use of high-heeled footwear, and lower levels of physical activity and participation. The 12-month period prevalence of foot pain-related consultation with a general practitioner, physiotherapist or podiatrist/chiropodist was 43.0, 15.1 and 32.8%, respectively. Conclusions Plantar heel pain is a common, disabling symptom among adults aged 50 years and over. Observed patterns of association indicate that in addition to focused foot-specific management, primary care interventions should also target more general physical and psychological factors that could potentially act as barriers to treatment adherence and recovery

    Fluctuation scaling in complex systems: Taylor's law and beyond

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    Complex systems consist of many interacting elements which participate in some dynamical process. The activity of various elements is often different and the fluctuation in the activity of an element grows monotonically with the average activity. This relationship is often of the form "fluctuationsconst.×averageαfluctuations \approx const.\times average^\alpha", where the exponent α\alpha is predominantly in the range [1/2,1][1/2, 1]. This power law has been observed in a very wide range of disciplines, ranging from population dynamics through the Internet to the stock market and it is often treated under the names \emph{Taylor's law} or \emph{fluctuation scaling}. This review attempts to show how general the above scaling relationship is by surveying the literature, as well as by reporting some new empirical data and model calculations. We also show some basic principles that can underlie the generality of the phenomenon. This is followed by a mean-field framework based on sums of random variables. In this context the emergence of fluctuation scaling is equivalent to some corresponding limit theorems. In certain physical systems fluctuation scaling can be related to finite size scaling.Comment: 33 pages, 20 figures, 2 tables, submitted to Advances in Physic

    Cerebral cavernous malformations associated to meningioma: High penetrance in a novel family mutated in the PDCD10 gene

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    Multiple familial meningiomas occur in rare genetic syndromes, particularly neurofibromatosis type 2. The association of meningiomas and cerebral cavernous malformations (CCMs) has been reported in few patients in the medical literature. The purpose of our study is to corroborate a preferential association of CCMs and multiple meningiomas in subjects harbouring mutations in the PDCD10 gene (also known as CCM3). Three members of an Italian family affected by seizures underwent conventional brain Magnetic Resonance Imaging (MRI) with gadolinium contrast agent including gradient echo (GRE) imaging. The three CCM-causative genes were sequenced by Sanger method. Literature data reporting patients with coexistence of CCMs and meningiomas were reviewed. MRI demonstrated dural-based meningioma-like lesions associated to multiple parenchymal CCMs in all affected individuals. A disease-causative mutation in the PDCD10 gene (p.Gln112PhefsX13) was identified. Based on neuroradiological and molecular data as well as on literature review, we outline a consistent association between PDCD10 mutations and a syndrome of CCMs with multiple meningiomas. This condition should be considered in the differential diagnosis of multiple/familial meningioma syndromes. In case of multiple/familial meningioma the use of appropriate MRI technique may include GRE and/or susceptibility-weighted imaging (SWI) to rule out CCM. By contrast, proper post-gadolinium scans may aid defining dural lesions in CCM patients and are indicated in PDCD10-mutated individuals

    Patients' experience of shoulder disorders: a systematic review of qualitative studies for the OMERACT Shoulder Core Domain Set.

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    OBJECTIVES:To describe the experiences (including symptoms and perceived impacts on daily living) of people with a shoulder disorder. METHODS:Systematic review of qualitative studies. We searched for eligible qualitative studies indexed in Ovid MEDLINE, Ovid Embase, CINAHL (EBSCO), SportDiscus (EBSCO) and Ovid PsycINFO up until November 2017. Two authors independently screened studies for inclusion, appraised their methodological quality using the Critical Appraisal Skills Programme checklist, used thematic synthesis methods to generate themes describing the experiences reported by participants and assessed the confidence in the findings using the Grading of Recommendations Assessment, Development and Evaluation Confidence in Evidence from Reviews of Qualitative research (GRADE-CERQual) approach. RESULTS:The inclusion criteria were met by eight studies, which included 133 participants (49 females and 84 males) with either rotator cuff disease, adhesive capsulitis, proximal humeral fracture, shoulder instability or unspecified shoulder pain. We generated seven themes to describe what people in the included studies reported experiencing: pain; physical function/activity limitations; participation restriction; sleep disruption; cognitive dysfunction; emotional distress; and other pathophysiological manifestations (other than pain). There were interactions between the themes, with particular experiences impacting on others (e.g. pain leading to reduced activities and sleep disruption). Following grading of the evidence, we considered it likely that most of the review findings were a reasonable representation of the experiences of people with shoulder disorders. CONCLUSION:Patients with shoulder disorders contend with considerable disruption to their life. The experiences described should be considered by researchers seeking to select the most appropriate outcomes to measure in clinical trials and other research studies in people with shoulder disorders

    Host Genetic Factors and Vaccine-Induced Immunity to Hepatitis B Virus Infection

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    BACKGROUND: Vaccination against hepatitis B virus infection (HBV) is safe and effective; however, vaccine-induced antibody level wanes over time. Peak vaccine-induced anti-HBs level is directly related to antibody decay, as well as risk of infection and persistent carriage despite vaccination. We investigated the role of host genetic factors in long-term immunity against HBV infection based on peak anti-HBs level and seroconversion to anti-HBc. METHODS: We analyzed 715 SNP across 133 candidate genes in 662 infant vaccinees from The Gambia, assessing peak vaccine-induced anti-HBs level and core antibody (anti-HBc) status, whilst adjusting for covariates. A replication study comprised 43 SNPs in a further 393 individuals. RESULTS: In our initial screen we found variation in IFNG, MAPK8, and IL10RA to affect peak anti-HBs level (GMTratio of 1.5 and P < or = 0.001) and lesser associations in other genes. Odds of core-conversion was associated with variation in CD163. A coding change in ITGAL (R719V) with likely functional relevance showed evidence of association with increased peak anti-HBs level in both screens (1st screen: s595_22 GMTratio 1.71, P = 0.013; 2nd screen: s595_22 GMTratio 2.15, P = 0.011). CONCLUSION: This is to our knowledge the largest study to date assessing genetic determinants of HBV vaccine-induced immunity. We report on associations with anti-HBs level, which is directly related to durability of antibody level and predictive of vaccine efficacy long-term. A coding change in ITGAL, which plays a central role in immune cell interaction, was shown to exert beneficial effects on induction of peak antibody level in response to HBV vaccination. Variation in this gene does not appear to have been studied in relation to immune responses to viral or vaccine challenges previously. Our findings suggest that genetic variation in loci other than the HLA region affect immunity induced by HBV vaccination

    Use of genetically modified bacteria for drug delivery in humans: Revisiting the safety aspect

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    The use of live, genetically modified bacteria as delivery vehicles for biologics is of considerable interest scientifically and has attracted significant commercial investment. We have pioneered the use of the commensal gut bacterium Bacteroides ovatus for the oral delivery of therapeutics to the gastrointestinal tract. Here we report on our investigations of the biological safety of engineered B. ovatus bacteria that includes the use of thymineless death as a containment strategy and the potential for the spread of transgenes in vivo in the mammalian gastrointestinal tract. We demonstrate the ability of GM-strains of Bacteroides to survive thymine starvation and overcome it through the exchange of genetic material. We also provide evidence for horizontal gene transfer in the mammalian gastrointestinal tract resulting in transgene-carrying wild type bacteria. These findings sound a strong note of caution on the employment of live genetically modified bacteria for the delivery of biologics

    A mutation in the viral sensor 2'-5'-oligoadenylate synthetase 2 causes failure of lactation.

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    We identified a non-synonymous mutation in Oas2 (I405N), a sensor of viral double-stranded RNA, from an ENU-mutagenesis screen designed to discover new genes involved in mammary development. The mutation caused post-partum failure of lactation in healthy mice with otherwise normally developed mammary glands, characterized by greatly reduced milk protein synthesis coupled with epithelial cell death, inhibition of proliferation and a robust interferon response. Expression of mutant but not wild type Oas2 in cultured HC-11 or T47D mammary cells recapitulated the phenotypic and transcriptional effects observed in the mouse. The mutation activates the OAS2 pathway, demonstrated by a 34-fold increase in RNase L activity, and its effects were dependent on expression of RNase L and IRF7, proximal and distal pathway members. This is the first report of a viral recognition pathway regulating lactation
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