520 research outputs found
Blood pressure control among hypertensive subjects in Dutse, Northwestern Nigeria
Background: High blood pressure is an independent risk factor for cerebrovascular, renal and cardiovascular disease. According to World Health Organization treatment to target Blood Pressure (BP) of <140/90 mmHg has been associated with decrease in morbidity and mortality. Despite this BP control has been very poor even in developed economies.Objective: We set to assess level of BP control among hypertensive patients on treatment in Dutse, Jigawa state, and to identify treatable causes of failure to achieve target for better management.Methods: It is a cross sectional study of all hypertensives for more than one year attending medical out patients clinic who have consented. An interviewer administered questionnaire was used to obtain information from the patients.Results: A total of 123 patients of which 45% were females with mean age, duration of hypertension of 51.9 and 5.9 years respectively and BMI of 40.9Kg/m2. Eighty-three per cent, 91% and 94% were aware of salt restriction, cessation of smoking and alcohol moderation as lifestyle modifications respectively. The mean Systolic and Diastolic BP were 142mmHg and 86mmHg respectively. Fifty-two per cent were on two drugs combination including a diuretic while 4.87% were on three drugs or more. Less than a third (27.6%) had their BP controlled at <140/90mmHg. There was no significant difference in the demographic and clinical data between patients with controlled and uncontrolled BP.Conclusion: This study found that control of BP is still poor in our setting. This could be due to physician inertia in the treatment, use of inappropriate combination of anti hypertensives or failure to reinforce lifestyle modifications.Keywords: Blood pressure, Hypertensives, Control, Black
Optimization of Absorber Layer and Operating Temperature of Copper Indium Gallium Selenide Solar Cells Using Different Metal Contacts
Device simulation was employed to investigate the effect of metal back contact electrodes on the performance of n-type CdS/p-CIGS thin film solar cells using varying thicknesses of absorber layer at operating temperature of 300K. The effect of working temperatures was also studied from 300K to 400K in steps of 10K. The simulations were carried out using standard solar cell capacitance simulator (SCAPS) 3.3.03 version software. The results showed better efficiencies at the optimized thickness of 3µm for all the back contact electrodes under study. The maximum efficiencies of 17.5 %, 15.5 %, 11.5 %, 3.5 % and 3 % were estimated for CIGS thin film solar cell at 300 K for platinum, gold, cobalt, silver and copper back contact electrodes respectively. The efficiency decreases as the operating temperatures increases from 300 K to 400 K. It is recommended that the optimized thickness of 3 µm is appropriate as absorber layer for efficient and cost effective CIGS thin film solar cells for economic reasons
Scaling and Intermittency in Animal Behavior
Scale-invariant spatial or temporal patterns and L\'evy flight motion have
been observed in a large variety of biological systems. It has been argued that
animals in general might perform L\'evy flight motion with power law
distribution of times between two changes of the direction of motion. Here we
study the temporal behaviour of nesting gilts. The time spent by a gilt in a
given form of activity has power law probability distribution without finite
average. Further analysis reveals intermittent eruption of certain periodic
behavioural sequences which are responsible for the scaling behaviour and
indicates the existence of a critical state. We show that this behaviour is in
close analogy with temporal sequences of velocity found in turbulent flows,
where random and regular sequences alternate and form an intermittent sequence.Comment: 10 page
Global shape aftereffects in composite radial frequency patterns
YesIndividual radial frequency (RF) patterns are generated by modulating a circle's radius as a sinusoidal function of polar angle and have been shown to tap into global shape processing mechanisms. Composite RF patterns can reproduce the complex outlines of natural shapes and examining these stimuli may allow us to interrogate global shape mechanisms that are recruited in biologically relevant tasks. We present evidence for a global shape aftereffect in a composite RF pattern stimulus comprising two RF components. Manipulations of the shape, location, size and spatial frequency of the stimuli revealed that this aftereffect could only be explained by the attenuation of intermediate-level global shape mechanisms. The tuning of the aftereffect to test stimulus size also revealed two mechanisms underlying the aftereffect; one that was tuned to size and one that was invariant. Finally, we show that these shape mechanisms may encode some RF information. However, the RF encoding we found was not capable of explaining the full extent of the aftereffect, indicating that encoding of other shape features such as curvature are also important in global shape processing.This research was supported by a Biotechnology and Biological Sciences Research Council (BBSRC) grant #BB/L007770/1
What lies beneath: predicting seagrass below-ground biomass from above-ground biomass, environmental conditions and seagrass community composition
Seagrass condition, resilience and ecosystem services are affected by the below-ground tissues (BGr) but these are rarely monitored. In this study we compiled historical data across northern Australia to investigate biomass allocation strategies in 13 tropical seagrass species. There was sufficient data to undertake statistical analysis for five species: Cymodocea serrulata, Halophila mutts, Halodule uninervis, Thalassia hemprichii, and Zostera muelleri. The response of below-ground biomass (BGr) to above-ground biomass (AGr) and other environmental and seagrass community composition predictor variables were assessed using Generalized Linear Models. Environmental data included: region, season, sediment type, water depth, proximity to land-based sources of pollution, and a light stress index. Seagrass community data included: species diversity and dominant species class (colonising, opportunistic or persistant) based on biomass. The predictor variables explained 84-97% of variance in BGr on the log-scale depending on the species. Multi-species meadows showed a greater investment into BGr than mono-specific meadows and when dominated by opportunistic or persistent seagrass species. This greater investment into BGr is likely to enhance their resistance to disturbances if carbohydrate storage reserves also increase with biomass. Region was very important for the estimation of BGr from AGr in four species (not in C. serrulata). No temporally changing environmental features were included in the models, therefore, they cannot be used to predict local-scale responses of BGr to environmental change. We used a case study for Cairns Harbour to predict BGr by applying the models to AGr measured at 362 sites in 2017. This case study demonstrates how the model can be used to estimate BGr when only AGr is measured. However, the general approach can be applied broadly with suitable calibration data for model development providing a more complete assessment of seagrass resources and their potential to provide ecosystem services
Provision of straw as a foraging substrate reduces the development of excessive chain and bar manipulation in food restricted sows.
Pregnant sows fed at commercial levels remain highly food motivated for most of the day. The inability to express this behaviour appropriately may, under certain conditions, result in the development of abnormal oral activities such as stereotypic chain and bar manipulation. Ninety-six gilts, all between 1 and 3 weeks post service, were entered into a 2X2 factorial design comparing food level (low, 1.8 kg/23 MJ day(-1) (L); high, 3.2 kg/40 MJ day(-1) (H)) and the provision of a foraging substrate (S, straw; N, no straw). The gilts were loose housed in groups of six with individual stalls. A 70 cm chain loop was attached to the front of each stair. The sows were fed at 09:00 h, during which time S sows received straw (approximately 1.5 kg per sow). Behaviour was recorded over the first two parities, by time sampling for the 2 and 6 h after the start of feeding and over 24 h using video recordings. Activity levels were highest just after feeding, with L sows being more active than H sows (L vs. H, 79% vs. 49% for the second hour after the start of feeding, F-1,F-12 = 41.5, P <0.001). Most of the postprandial activity consisted of manipulating substrates. In LN sows, particularly in Parity 2, this behaviour was mainly directed towards chains and bars, resulting in levels three to four times higher than in other groups (26%, 7%, 4% and 4% for the second hour after feeding for LN, LS, HN and HS respectively; Tukey's HSD, P <0.05). LS sows directed their foraging behaviour mainly towards the straw. It is concluded that in food-restricted pregnant sows, abnormally high levels of chain and bar manipulation can be prevented by providing straw which apparently acts as a foraging substrate
Bulk perturbations of N=2 branes
The evolution of supersymmetric A-type D-branes under the bulk
renormalization group flow between two different N=2 minimal models is studied.
Using the Landau-Ginzburg description we show that a specific set of branes
decouples from the infrared theory, and we make detailed predictions for the
behavior of the remaining branes. The Landau-Ginzburg picture is then checked
against a direct conformal field theory analysis. In particular we construct a
natural index pairing which is preserved by the RG flow, and show that the
branes that decouple have vanishing index with the surviving branes.Comment: 35 pages (30 pages plus title and references), 8 figure
The frequency of transforming growth factor-TGF-B gene polymorphisms in a normal southern Iranian population
Several single nucleotide polymorphisms (SNPs) of the transforming growth factor-β1 gene (TGFB1) have been reported. Determination of TGFB1 SNPs allele frequencies in different ethnic groups is useful for both population genetic analyses and association studies with immunological diseases. In this study, five SNPs of TGFB1 were determined in 325 individuals from a normal southern Iranian population using polymerase chain reaction-restriction fragment length polymorphism method. This population was in Hardy-Weinberg equilibrium for these SNPs. Of the 12 constructed haplotypes, GTCGC and GCTGC were the most frequent in the normal southern Iranian population. Comparison of genotype and allele frequencies of TGFB SNPs between Iranian and other populations (meta-analysis) showed significant differences, and in this case the southern Iranian population seems genetically similar to Caucasoid populations. However, neighbour-joining tree using Nei's genetic distances based on TGF-β1 allele frequencies showed that southern Iranians are genetically far from people from the USA, Germany, UK, Denmark and the Czech Republic. In conclusion, this is the first report of the distribution of TGFB1 SNPs in an Iranian population and the results of this investigation may provide useful information for both population genetic and disease studies. © 2008 The Authors
Dimensions and Global Twist of Single-Layer DNA Origami Measured by Small-Angle X-ray Scattering
The
rational design of complementary DNA sequences can be used
to create nanostructures that self-assemble with nanometer precision.
DNA nanostructures have been imaged by atomic force microscopy and
electron microscopy. Small-angle X-ray scattering (SAXS) provides
complementary structural information on the ensemble-averaged state
of DNA nanostructures in solution. Here we demonstrate that SAXS can
distinguish between different single-layer DNA origami tiles that
look identical when immobilized on a mica surface and imaged with
atomic force microscopy. We use SAXS to quantify the magnitude of
global twist of DNA origami tiles with different crossover periodicities:
these measurements highlight the extreme structural sensitivity of
single-layer origami to the location of strand crossovers. We also
use SAXS to quantify the distance between pairs of gold nanoparticles
tethered to specific locations on a DNA origami tile and use this
method to measure the overall dimensions and geometry of the DNA nanostructure
in solution. Finally, we use indirect Fourier methods, which have
long been used for the interpretation of SAXS data from biomolecules,
to measure the distance between DNA helix pairs in a DNA origami nanotube.
Together, these results provide important methodological advances
in the use of SAXS to analyze DNA nanostructures in solution and insights
into the structures of single-layer DNA origami
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