2,097 research outputs found
An effective method for extraction and polymerase chain reaction (PCR) amplification of DNA from formalin preserved tissue samples of snow leopard
Formalin-preserved biological samples obtained from endangered species are valuable in assessing genetic diversity. To make use of snow leopard samples preserved in formalin over a period of two to seven years, we optimized the method of extracting DNA from these samples. We used (a) phenol chloroform : isoamyl alcohol, (b) the Qiagen DNeasy Blood and Tissue Kit (Qiagen, Germany), (c) the Qiagen DNeasy Blood and Tissue Kit after treating the samples with NaOH for three days and (d) the Qiagen DNeasy Blood and Tissue Kit after treating the samples with phosphate buffered saline (PBS) for three days. The usefulness of the extracted DNA was assessed on the basis of mitochondrial (150 to 550 bp) and nuclear (95 to 229 bp) markers. There was no PCR amplification with the first two methods. The PCR amplification with the NaOH and PBS treatment had a success rate of 30 to 100% for both mitochondrial and nuclear markers. The PBS method is the best method for extraction of DNA from formalin-preserved samples of longer period (two to seven years) because of higher success rate in amplifying mitochondrial gene of ca. 550 bp (60%) than the NaOH method (28%). The overall amplification of microsatellite markers in such samples was also higher in samples treated with PBS (43 to 100%) than NaOH (0 to 100%). The PCR products obtained were confirmed through DNA sequencing to be of snow leopard origin. The optimized protocol will enable genetic studies to be conducted on tissue samples of other species that have been preserved in formalin. The protocol will be particularly useful for species that are elusive and from which it is difficult to collect fresh tissue samples.Keywords: Formalin, polymerase chain reaction (PCR), mtDNA, microsatellites, snow leopardAfrican Journal of Biotechnology Vol. 12(22), pp. 3399-340
Shiny app to predict agricultural tire dimensions
The main objective of this project, carried out in an industrial context, was to apply a multivariate analysis to variables related to the specifications required for the production of an agricultural tire and the dimensional test results. With the exploratory data analysis, it was possible to identify strong correlations between predictor variables and with the response variables of each test. In this project, the principal component analysis (PCA) serves to eliminate the effects of multicollinearity. The use of regression analysis was intended to predict the behavior of the agricultural tire considering the selected variables of each test. In the case of Test 1, when applying the Stepwise methods to select the variables, the model with the lowest value of Akaike Information Criterion (AIC) was achieved with the technique “Both”. However, the lowest value of AIC for Test 2 was achieved with “Backward”. Regarding the validation of assumptions, both Test 1 and Test 2 were validated. Therefore, all the quantitative variables are important, both in Test 1 and Test 2, because they are a linear combination that determines the principal components. In order to make it easier to compute predictions for future agricultural tires, an application that was developed in Shiny allows the company to know the behavior of the tire before it was produced. Using the application, it is possible to reduce the industrialization time, materials and resources, thus increasing efficiency and profits.This work has been supported by FCT – Fundação para a Ciˆencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020
Hepatolithiasis with biliary ascariasis – a case report
BACKGROUND: Biliary ascariasis is regarded as possible etiological factor for hepatolithiasis. Here we report one case of a patient with hepatolithiasis with biliary ascariasis who developed a liver abscess, which was treated with partial hepatectomy. CASE PRESENTATION: A young adult female presented with epigastric pain and vomiting with repeated attacks of cholangitis. ERCP showed evidence of multiple intrahepatic calculi with the development of abscess in the left lobe of liver. The patient underwent partial hepatectomy and was found to have biliary ascariasis on histology. She was treated with antihelmenthic therapy and has had an uneventful postoperative period of 2 years. CONCLUSION: Biliary ascariasis with hepatolithiasis, although rare, should be considered in endemic countries
The role of childhood social position in adult type 2 diabetes: Evidence from the English Longitudinal Study of Ageing
Copyright @ 2014 Pikhartova et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article has been made available through the Brunel Open Access Publishing Fund.Background: Socioeconomic circumstances in childhood and early adulthood may influence the later onset of chronic disease, although such research is limited for type 2 diabetes and its risk factors at the different stages of life. The main aim of the present study is to examine the role of childhood social position and later inflammatory markers and health behaviours in developing type 2 diabetes at older ages using a pathway analytic approach. Methods. Data on childhood and adult life circumstances of 2,994 men and 4,021 women from English Longitudinal Study of Ageing (ELSA) were used to evaluate their association with diabetes at age 50 years and more. The cases of diabetes were based on having increased blood levels of glycated haemoglobin and/or self-reported medication for diabetes and/or being diagnosed with type 2 diabetes. Father's job when ELSA participants were aged 14 years was used as the measure of childhood social position. Current social characteristics, health behaviours and inflammatory biomarkers were used as potential mediators in the statistical analysis to assess direct and indirect effects of childhood circumstances on diabetes in later life. Results: 12.6 per cent of participants were classified as having diabetes. A disadvantaged social position in childhood, as measured by father's manual occupation, was associated at conventional levels of statistical significance with an increased risk of type 2 diabetes in adulthood, both directly and indirectly through inflammation, adulthood social position and a risk score constructed from adult health behaviours including tobacco smoking and limited physical activity. The direct effect of childhood social position was reduced by mediation analysis (standardised coefficient decreased from 0.089 to 0.043) but remained statistically significant (p = 0.035). All three indirect pathways made a statistically significantly contribution to the overall effect of childhood social position on adulthood type 2 diabetes. Conclusions: Childhood social position influences adult diabetes directly and indirectly through inflammatory markers, adulthood social position and adult health behaviours. © 2014Pikhartova et al.; licensee BioMed Central Ltd.Economic and Social Research Council-funded International Centre for Life Course Studies in Society and Health (RES-596-28-0001)
Unconfined Aquifer Flow Theory - from Dupuit to present
Analytic and semi-analytic solution are often used by researchers and
practicioners to estimate aquifer parameters from unconfined aquifer pumping
tests. The non-linearities associated with unconfined (i.e., water table)
aquifer tests makes their analysis more complex than confined tests. Although
analytical solutions for unconfined flow began in the mid-1800s with Dupuit,
Thiem was possibly the first to use them to estimate aquifer parameters from
pumping tests in the early 1900s. In the 1950s, Boulton developed the first
transient well test solution specialized to unconfined flow. By the 1970s
Neuman had developed solutions considering both primary transient storage
mechanisms (confined storage and delayed yield) without non-physical fitting
parameters. In the last decade, research into developing unconfined aquifer
test solutions has mostly focused on explicitly coupling the aquifer with the
linearized vadose zone. Despite the many advanced solution methods available,
there still exists a need for realism to accurately simulate real-world aquifer
tests
Effect of arsenic-phosphorus interaction on arsenic-induced oxidative stress in chickpea plants
Arsenic-induced oxidative stress in chickpea was investigated under glasshouse conditions in response to application of arsenic and phosphorus. Three levels of arsenic (0, 30 and 60 mg kg−1) and four levels of P (50, 100, 200, and 400 mg kg−1) were applied to soil-grown plants. Increasing levels of both arsenic and P significantly increased arsenic concentrations in the plants. Shoot growth was reduced with increased arsenic supply regardless of applied P levels. Applied arsenic induced oxidative stress in the plants, and the concentrations of H2O2 and lipid peroxidation were increased. Activity of superoxide dismutase (SOD) and concentrations of non-enzymatic antioxidants decreased in these plants, but activities of catalase (CAT) and ascorbate peroxidase (APX) were significantly increased under arsenic phytotoxicity. Increased supply of P decreased activities of CAT and APX, and decreased concentrations of non-enzymatic antioxidants, but the high-P plants had lowered lipid peroxidation. It can be concluded that P increased uptake of arsenic from the soil, probably by making it more available, but although plant growth was inhibited by arsenic the P may have partially protected the membranes from arsenic-induced oxidative stress
Social factors and obesity: an investigation of the role of health behaviours
OBJECTIVES: This study evaluated a behavioural model of the relation between social factors and obesity, in which differences in body mass index (BMI) across sociodemographic groups were hypothesized to be attributable to social group differences in health behaviours affecting energy expenditure (physical activity, diet and alcohol consumption and weight control). METHODS: A total of 8667 adults who participated in the 1995 Australian National Health and Nutrition Surveys provided data on a range of health factors including objectively measured height and weight, health behaviours, and social factors including family status, employment status, housing situation and migration status. RESULTS: Social factors remained significant predictors of BMI after controlling for all health behaviours. Neither social factors alone, nor health behaviours alone, adequately explained the variance in BMI. Gender-specific interactions were found between social factors and individual health behaviours. CONCLUSIONS: These results suggest that social factors moderate the relation between BMI and weight-related behaviours, and that the mechanisms underlying sociodemographic group differences in obesity may vary among men and women. Additional factors are likely to act in conjunction with current health behaviours to explain variation in obesity prevalence across sociodemographic groups.<br /
Personal Drug Selection: Problem-Based Learning in Pharmacology: Experience from a Medical School in Nepal
BACKGROUND: At the Manipal College of Medical Sciences, Pokhara, Nepal, Pharmacology is taught during the first four semesters of the undergraduate medical course. Personal or P-drug selection is an important exercise. The present study was carried out to obtain student opinion about the P-drug learning sessions, the assessment examinations, and on the small group dynamics. METHOD: The practical sessions on P-drug selection are carried out in small groups. Student feedback about the session was obtained using focus group discussions. The focus groups were selected to represent both genders and the three main nationalities, Nepalese, Indians, and Sri Lankans. There were four Nepalese, five Indians, and three Sri Lankans. Within each nationality and gender category the students were randomly selected. The respondents were explained the objectives of the study and were invited to participate. Written informed consent was obtained. The discussion lasted around two hours and was conducted in the afternoon in two groups of six students each. The first author (PRS) acted as a facilitator. The responses were recorded and analyzed qualitatively. RESULTS: The overall student opinion was positive. Around 25% (3 respondents) of respondents were confused about whether P-drugs were for a disease or a patient. Group consensus was commonly used to give numerical values for the different criteria. The large number of brands created problems in calculating cost. The students wanted more time for the exercise in the examination. Formative assessment during the learning sessions may be considered. The group members usually got along well. Absenteeism was a problem and not all members put in their full effort. The physical working environment should be improved. CONCLUSIONS: Based on what the students say, the sessions on P-drugs should be continued and strengthened. Modifications in the sessions are required. Sessions during the clinical years and internship training can be considered
Effect of temperature anisotropy on various modes and instabilities for a magnetized non-relativistic bi-Maxwellian plasma
Using kinetic theory for homogeneous collisionless magnetized plasmas, we
present an extended review of the plasma waves and instabilities and discuss
the anisotropic response of generalized relativistic dielectric tensor and
Onsager symmetry properties for arbitrary distribution functions. In general,
we observe that for such plasmas only those electromagnetic modes whose
magnetic field perturbations are perpendicular to the ambient magneticeld,
i.e.,B1 \perp B0, are effected by the anisotropy. However, in oblique
propagation all modes do show such anisotropic effects. Considering the
non-relativistic bi-Maxwellian distribution and studying the relevant
components of the general dielectric tensor under appropriate conditions, we
derive the dispersion relations for various modes and instabilities. We show
that only the electromagnetic R- and L- waves, those derived from them and the
O-mode are affected by thermal anisotropies, since they satisfy the required
condition B1\perpB0. By contrast, the perpendicularly propagating X-mode and
the modes derived from it (the pure transverse X-mode and Bernstein mode) show
no such effect. In general, we note that the thermal anisotropy modifies the
parallel propagating modes via the parallel acoustic effect, while it modifies
the perpendicular propagating modes via the Larmor-radius effect. In oblique
propagation for kinetic Alfven waves, the thermal anisotropy affects the
kinetic regime more than it affects the inertial regime. The generalized fast
mode exhibits two distinct acoustic effects, one in the direction parallel to
the ambient magnetic field and the other in the direction perpendicular to it.
In the fast-mode instability, the magneto-sonic wave causes suppression of the
firehose instability. We discuss all these propagation characteristics and
present graphic illustrations
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