61 research outputs found
Early-life telomere dynamics differ between the sexes and predict growth in the barn swallow (Hirundo rustica)
Telomeres are conserved DNA-protein structures at the termini of eukaryotic chromosomes which contribute to maintenance of genome integrity, and their shortening leads to cell senescence, with negative consequences for organismal functions. Because telomere erosion is influenced by extrinsic and endogenous factors, telomere dynamics may provide a mechanistic basis for evolutionary and physiological trade-offs. Yet, knowledge of fundamental aspects of telomere biology under natural selection regimes, including sex- and context-dependent variation in early-life, and the covariation between telomere dynamics and growth, is scant. In this study of barn swallows (Hirundo rustica) we investigated the sex-dependent telomere erosion during nestling period, and the covariation between relative telomere length and body and plumage growth. Finally, we tested whether any covariation between growth traits and relative telomere length depends on the social environment, as influenced by sibling sex ratio. Relative telomere length declined on average over the period of nestling maximal growth rate (between 7 and 16 days of age) and differently covaried with initial relative telomere length in either sex. The frequency distribution of changes in relative telomere length was bimodal, with most nestlings decreasing and some increasing relative telomere length, but none of the offspring traits predicted the a posteriori identified group to which individual nestlings belonged. Tail and wing length increased with relative telomere length, but more steeply in males than females, and this relationship held both at the within- and among-broods levels. Moreover, the increase in plumage phenotypic values was steeper when the sex ratio of an individual's siblings was female-biased. Our study provides evidence for telomere shortening during early life according to subtly different dynamics in either sex. Furthermore, it shows that the positive covariation between growth and relative telomere length depends on sex as well as social environment, in terms of sibling sex ratio
Biophysical interactions in tropical agroforestry systems
sequential systems, simultaneous systems Abstract. The rate and extent to which biophysical resources are captured and utilized by the components of an agroforestry system are determined by the nature and intensity of interac-tions between the components. The net effect of these interactions is often determined by the influence of the tree component on the other component(s) and/or on the overall system, and is expressed in terms of such quantifiable responses as soil fertility changes, microclimate modification, resource (water, nutrients, and light) availability and utilization, pest and disease incidence, and allelopathy. The paper reviews such manifestations of biophysical interactions in major simultaneous (e.g., hedgerow intercropping and trees on croplands) and sequential (e.g., planted tree fallows) agroforestry systems. In hedgerow intercropping (HI), the hedge/crop interactions are dominated by soil fertility improvement and competition for growth resources. Higher crop yields in HI than in sole cropping are noted mostly in inherently fertile soils in humid and subhumid tropics, and are caused by large fertility improvement relative to the effects of competition. But, yield increases are rare in semiarid tropics and infertile acid soils because fertility improvement does not offse
Pathogenetic mechanisms in vascular dementia
Vascular dementia accounts for approximately 20% of all cases of dementia and for about 50% in subjects over 80 years. Thromboembolism with multiple cerebral infarcts was considered to be almost the only pathogenetic pathway of vascular dementia, with multi-infarct dementia as its clinical manifestation. However, there is a great heterogeneity of vascular dementia syndromes and pathological subtypes, as documented by the number of pathogenetic mechanisms now known to underlie the clinical picture. They include thromboembolism and extracerebral and cerebral factors. Among the extracerebral factors are ischemic hypoxic dementia (i.e., dementia due to hypoperfusion), vasculitis, hyperviscosity and abnormalities of hemostasis. Among the cerebral factors are lipohyalinosis, cerebral amyloid angiopathy, disruption of the blood-brain barrier and altered regulation of cerebral blood flow. Therefore, the approach to vascular dementia should take the heterogeneity into account. In this context, the importance of non-infarct type should be considered; subcortical white matter disorder seems to be a noteworthy common pathway of vascular dementia produced by various vascular mechanisms. Finally, the heterogeneity of the vascular mechanisms involved in vascular dementia-namely hypoperfusion-might be a factor that can be positively influenced by targeted therapeutic intervention
Alternative medicine and herbal remedies in the treatment of erectile dysfunction: A systematic review
Objectives: To systematically review and discuss the current evidence from placebo-controlled
clinical trials that investigated the use of alternative medicines and herbal remedies in the
management of erectile dysfunction (ED).
Methods: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-
based systematic review using specific keyword combinations was conducted on the PubMed
and Scopus databases. Randomised controlled trials investigating herbal medicine in at least
one group and using the International Index of Erectile Function (IIEF) as an outcome in
patients primarily diagnosed with ED were included for review.
Results: Following the literature search, screening and eligibility analysis, a total of 42 articles
were included. The 42 articles were categorised as single herb extractions (n = 14), combination
herbal formula (n = 5), combination of herbal formula and non-herbal nutraceuticals (n = 7),
non-herbal nutraceuticals (n = 5), acupuncture and moxibustion (n = 2), diet and nutrition
(n = 3), exercise (n = 5), and topical treatments (n = 1). Based on the results, Korean ginseng,
Pygnogenol and Prelox, Tribulus terrestris, Lepidium meyenii, L-arginine, acupuncture and lifestyle
interventions were the more predominantly investigated treatments interventions for ED.
Conclusions: Panax ginseng, Pygnogenol, Prelox and Tribulus terrestris have promising evidence
as herbal products, alongside L-arginine as a nutritional supplement, for ED based on
IIEF outcomes, and warrant further clinical investigation. The mechanisms of action remain
unclear, but each of these appears to in part increase nitric oxide synthesis. Importantly,
improved diet and exercise should be considered, particularly in patients with obesity or
diabetes mellitus
Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period
This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated. New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and from ghost charge are analysed with improved methods, showing that ghost charge in individual radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulations and to the fake jet rates from beam background. A thorough analysis of a particular LHC fill, where abnormally high background was observed, is presented. Correlations between backgrounds and beam intensity losses in special fills with very high β* are studied
Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period
This paper discusses various observations on beam-induced and cosmic-ray backgrounds
in the ATLAS detector during the LHC 2012 proton-proton run. Building on published
results based on 2011 data, the correlations between background and residual pressure of the beam
vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated.
New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC
abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and
from ghost charge are analysed with improved methods, showing that ghost charge in individual
radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated
cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates
are compared to Monte Carlo simulations and to the fake jet rates from beam background. A
thorough analysis of a particular LHC fill, where abnormally high background was observed, is
presented. Correlations between backgrounds and beam intensity losses in special fills with very
high β∗ are studied
ARFID InitiativE Sweden (ARIES): study protocol for a large-scale genetic and registry-linked cohort study on avoidant/restrictive food intake disorder
IntroductionThe ARFID InitiativE Sweden (ARIES) investigates the genetic and environmental factors contributing to avoidant/restrictive food intake disorder (ARFID) in children and adolescents aged 6-14 years. ARIES will establish a national biobank and research registry. It aims to provide data for immediate research and track ARFID outcomes and clarify genetic links between ARFID and other conditions and analyse the gut microbiome to guide nutrition interventions.Methods and analysisThe study will involve 1500 Swedish children and adolescents with ARFID and a control group of 500 Swedish children and adolescents without ARFID. Parents/guardians and their children will complete online questionnaires assessing ARFID and other eating disorder (ED) pathology, co-occurring conditions, quality of life and parental stress and ED pathology. All participants will provide a saliva sample for comprehensive genetic analyses. Additionally, a subset of participants will provide a stool sample to investigate the gut microbiome in ARFID.Ethics and disseminationARIES was approved by the Swedish Ethical Review Authority (Dnr 2023-04638). All participants will give assent and their parents will complete informed consent. Data will be made available by the authors on reasonable request. Findings will be published in scientific journals and shared with the public and stakeholders in accessible ways, for example, via social media
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