53 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
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
A cost-benefit analysis of hedgerow intercropping in the Philippine uplands using the SCUAF model
Soil erosion in the Philippine uplands is severe. Hedgerow intercropping is widely advocated as an effective means of controlling soil erosion from annual cropping systems in the uplands. However, few farmers adopt hedgerow intercropping even in areas where it has been vigorously promoted. This may be because farmers find hedgerow intercropping to be uneconomic compared to traditional methods of farming. This paper reports a cost-benefit analysis comparing the economic returns from traditional maize farming with those from hedgerow intercropping in an upland community with no past adoption of hedgerows. A simple erosion/productivity model, Soil Changes Under Agroforestry (SCUAF), is used to predict maize yields over 25 years. Economic data were collected through key informant surveys with experienced maize farmers in an upland community. Traditional methods of open-field farming of maize are economically attractive to farmers in the Philippine uplands. In the short term, establishment costs are a major disincentive to the adoption of hedgerow intercropping. In the long term, higher economic returns from hedgerow intercropping compared to open-field farming are realised, but these lie beyond farmers' limited planning horizons
The decline in joint replacement surgery in rheumatoid arthritis is associated with a concomitant increase in the intensity of anti-rheumatic therapy
BACKGROUND AND PURPOSE: Drug-based treatment of rheumatoid arthritis (RA) has evolved markedly over the past 2 decades. Using nationwide register data, we studied how this has affected the rates of hip, knee, shoulder, and elbow replacement from 1995 to 2010. METHODS: The number of primary joint replacements was obtained from the Finnish Arthroplasty Register. To test the hypothesis that improvements in medical treatment of RA reduce the need for joint replacements, we also collected data about purchases of different disease-modifying anti-rheumatic agents (DMARDs) and biological drugs from the nationwide drug registers. RESULTS: The annual incidence of primary joint replacements for RA declined from 19 per 10(5) in 1995 to 11 per 10(5) in 2010. The decline was greater for upper-limb operations than for lower-limb operations. At the same time, the numbers of individuals using methotrexate, hydroxychloroquine, and sulfasalazine (the most commonly used DMARDs) increased 2- to 4-fold. INTERPRETATION: Our results are in accordance with observations from other countries, and indicate that the use of joint replacements in RA has decreased dramatically. Our data suggest that effective medical therapy is the most likely explanation for this favorable development
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