3,011 research outputs found
Measuring fitness of Kenyan children with polyparasitic infections using the 20-meter shuttle run test as a morbidity metric.
BACKGROUND: To date, there has been no standardized approach to the assessment of aerobic fitness among children who harbor parasites. In quantifying the disability associated with individual or multiple chronic infections, accurate measures of physical fitness are important metrics. This is because exercise intolerance, as seen with anemia and many other chronic disorders, reflects the body's inability to maintain adequate oxygen supply (VO(2) max) to the motor tissues, which is frequently linked to reduced quality-of-life in terms of physical and job performance. The objective of our study was to examine the associations between polyparasitism, anemia, and reduced fitness in a high risk Kenyan population using novel implementation of the 20-meter shuttle run test (20mSRT), a well-standardized, low-technology physical fitness test.
METHODOLOGY/PRINCIPAL FINDINGS: Four villages in coastal Kenya were surveyed during 2009-2010. Children 5-18 years were tested for infection with Schistosoma haematobium (Sh), malaria, filaria, and geohelminth infections by standard methods. After anthropometric and hemoglobin testing, fitness was assessed with the 20 mSRT. The 20 mSRT proved easy to perform, requiring only minimal staff training. Parasitology revealed high prevalence of single and multiple parasitic infections in all villages, with Sh being the most common (25-62%). Anemia prevalence was 45-58%. Using multiply-adjusted linear modeling that accounted for household clustering, decreased aerobic capacity was significantly associated with anemia, stunting, and wasting, with some gender differences.
CONCLUSIONS/SIGNIFICANCE: The 20 mSRT, which has excellent correlation with VO(2), is a highly feasible fitness test for low-resource settings. Our results indicate impaired fitness is common in areas endemic for parasites, where, at least in part, low fitness scores are likely to result from anemia and stunting associated with chronic infection. The 20 mSRT should be used as a common metric to quantify physical fitness and compare sub-clinical disability across many different disorders and community settings
Role of the gut microbiota in nutrient competition and protection against intestinal pathogen colonization.
The human gut microbiota can restrict the growth of pathogens to prevent them from colonizing the intestine ('colonization resistance'). However, antibiotic treatment can kill members of the gut microbiota ('gut commensals') and reduce competition for nutrients, making these nutrients available to support the growth of pathogens. This disturbance can lead to the growth and expansion of pathogens within the intestine (including antibiotic-resistant pathogens), where these pathogens can exploit the absence of competitors and the nutrient-enriched gut environment. In this review, we discuss nutrient competition between the gut microbiota and pathogens. We also provide an overview of how nutrient competition can be harnessed to support the design of next-generation microbiome therapeutics to restrict the growth of pathogens and prevent the development of invasive infections
Geochemistry and geobarometry of Eocene dykes intruding the Ladakh Batholith
We present further distinguishing characteristics among Eocene dykes found along the Southern margin of the Ladakh batholith (NW-India). Coupled evidence from field structures and Nd-Sr isotope data showed that there are two broad dyke provinces extending over 50 km: between Leh and Tunglung, an 'eastern', ENE-trending family with higher crustal assimilation; between Tunglung and Hemis Shugpachan, the ...postprin
Polarization fields in nitride nanostructures: ten points to think about
Macroscopic polarization, both of intrinsic and piezoelectric nature, is
unusually strong in III-V nitrides, and the built in electric fields in the
layers of nitride-based nanostructures, stemming from polarization changes at
heterointerfaces, have a major impact on the properties of single and multiple
quantum wells, high mobility transistors, and thin films. The concepts involved
in the theory and applications of polarization in nitrides have encountered
some resistance in the field. Here we discuss critically ten ``propositions''
aimed at clarifying the main controversial issues.Comment: RevTeX 5 pages, 2 embedded figure
The Cosmic Lens All-Sky Survey: statistical strong lensing, cosmological parameters, and global properties of galaxy populations
Extensive analyses of statistical strong gravitational lensing are performed
based on the final Cosmic Lens All Sky Survey (CLASS) well-defined statistical
sample of flat spectrum radio sources and current estimates of galaxy
luminosity functions per morphological type. The analyses are done under the
assumption that galactic lenses are well-approximated by singular isothermal
ellipsoids and early-type galaxies evolved passively since redshift .
Depending on how the late-type galaxy population is treated (i.e., whether its
characteristic velocity dispersion is constrained or not), we find for a flat
universe with a cosmological constant that the present matter fraction of the
present critical density (68%) for the
unconstrained case or (68%) for the constrained case,
with an additional systematic uncertainty of arising from the
present uncertainty in the distribution of CLASS sources in redshift and flux
density. For a flat universe with a constant equation of state for dark energy
w = (pressure)/(energy density), we find that (68%) for the unconstrained case or (68%) for the constrained case. For the equal
frequencies of oblates and prolates, we find that km s (68%) for a `steep' or
km s (68%) for a `shallow'
. Finally, from the relative frequencies of doubly-imaged
sources and quadruply-imaged sources, we find that a mean projected mass
ellipticity of early-type galaxies with a
68% lower limit of 0.28. (Abridged)Comment: 31 pages, 12figures, 6 tables, to appear in MNRAS (referee comments
incorporated, a section on future prospects added
Understanding suicide attempts among gay men from their self-perceived causes
Gay men are at higher risk of suicidality. This paper describes the causes of suicide attempts as perceived by the men themselves and analyzes their impact on severity and recidivism. Mental health surveys conducted among gay men in Geneva, Switzerland, from two probability-based time-space samples in 2007 and 2011, were merged to yield a combined sample N = 762. Suicide ideation, plans, and attempts were assessed, and respondents who had ever attempted suicide answered open questions about perceived causes which were coded and categorized for analysis within the framework of cultural epidemiology. In all, 16.7% of the respondents reported a suicide attempt in their lifetime (59.5% of them with multiple attempts). At their latest attempt, over two thirds asserted intent to die, and half required medical assistance. There was a wide variety of perceived causes, with most individuals reporting multiple causes and many of the most common causes cited at both the first and most recent subsequent attempts. Social/inter-personal problems constitute the most prominent category. Problems with love/relationship and accepting one's homosexuality figure consistently among the top three causes. Whereas the former tend to be associated with weaker intent to die, the latter are associated with the strongest intent to die and reported at multiple attempts. Problems with family are among the most common perceived causes at first attempt but not at the most recent subsequent attempt. Nevertheless, they tend to be related to the strongest intent to die and the greatest medical severity of all the perceived causes. Ten percent of men attempting suicide cited depression as a cause. Although it tended to be associated with weaker intent to die, depression was most likely to be reported at multiple attempts. Respondent-driven assessment yielded both common and idiosyncratic causes of suicide and their distinct effects. Some of these perceived causes are not prominent in the curren literature, yet they have important implications for understanding risk and preventing suicide among gay men
So Small, So Loud: Extremely High Sound Pressure Level from a Pygmy Aquatic Insect (Corixidae, Micronectinae)
To communicate at long range, animals have to produce intense but intelligible signals. This task might be difficult to achieve due to mechanical constraints, in particular relating to body size. Whilst the acoustic behaviour of large marine and terrestrial animals has been thoroughly studied, very little is known about the sound produced by small arthropods living in freshwater habitats. Here we analyse for the first time the calling song produced by the male of a small insect, the water boatman Micronecta scholtzi. The song is made of three distinct parts differing in their temporal and amplitude parameters, but not in their frequency content. Sound is produced at 78.9 (63.6–82.2) SPL rms re 2.10−5 Pa with a peak at 99.2 (85.7–104.6) SPL re 2.10−5 Pa estimated at a distance of one metre. This energy output is significant considering the small size of the insect. When scaled to body length and compared to 227 other acoustic species, the acoustic energy produced by M. scholtzi appears as an extreme value, outperforming marine and terrestrial mammal vocalisations. Such an extreme display may be interpreted as an exaggerated secondary sexual trait resulting from a runaway sexual selection without predation pressure
Bioassay-guided isolation and identification of antimicrobial compounds from thyme essential oil by means of overpressured layer chromatography, bioautography and GC-MS
A simple method is described for efficient isolation of compounds having an antibacterial effect.
Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as
prospective materials likely to feature several bioactive components when examined by thin layer
chromatography coupled with direct bioautography as a screening method. The newly developed
infusion overpressured layer chromatographic separation method coupled with direct
bioautography assured that only the active components were isolated by means of overrun
overpressured layer chromatography with online detection and fractionation. Each of the 5
collected fractions represented one of the five antimicrobial essential oil components designated
at the screening. The purity and the activity of the fractions were confirmed with chromatography
coupled various detection methods (UV, vanillin-sulphuric acid reagent, direct bioautography).
The antibacterial components were identified with GC-MS as thymol, carvacrol, linalool, diethylphthalate,
and alpha-terpineol. The oil component diethyl-phthalate is an artificial compound,
used as plasticizer or detergent bases in the industry. Our results support that exploiting its
flexibility and the possible hyphenations, overpressured layer chromatography is especially
attractive for isolation of antimicrobial components from various matrixes
A novel case of MSTO1 gene related congenital muscular dystrophy with progressive neurological involvement
Recessive mutations in the MSTO1 gene, encoding for a mitochondrial distribution and morphology regulator, have been recently described in a very limited number of patients with multisystem involvement, mostly characterized by myopathy or dystrophy, cerebellar ataxia, pigmentary retinopathy and raised creatine kinase levels. Here we report an additional patient with recessive MSTO1-related muscular dystrophy (MSTO1-RD), and clinical and radiological evidence of progressive cerebellar involvement. Whole-exome sequencing identified two novel MSTO1 missense variants, c.766C > T (p. (Arg256Trp) and c.1435C > T (p. (Pro479Ser), predicted as damaging by in silico tools. We also report a distinct pattern of selective involvement on muscle MRI in MSTO1-RD. This case confirms a consistent MSTO1-related neuromuscular phenotype and in addition suggests a progressive neurological component at least in some patients, in keeping with the mitochondrial role of the defective protein
Non-invasive MR imaging of inflammation in a patient with both asymptomatic carotid atheroma and an abdominal aortic aneurysm: a case report.
Inflammation is a recognized risk factor for the vulnerable atherosclerotic plaque. USPIO-enhanced MRI imaging is a promising non-invasive method to identify high-risk atheromatous plaque inflammation in vivo in humans, in which areas of focal signal loss on MR images have been shown to correspond to the location of activated macrophages, typically at the shoulder regions of the plaque. This is the first report in humans describing simultaneous USPIO uptake within atheroma in two different arterial territories and again emphasises that atherosclerosis is a truly systemic disease. With further work, USPIO-enhanced MR imaging may be useful in identifying inflamed vulnerable atheromatous plaques in vivo, so refining patient selection for intervention and allowing appropriate early aggressive pharmacotherapy to prevent plaque rupture.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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