1,388 research outputs found
Applied Linguistics Theory and Application
Applied linguistics is an interdisciplinary field that identifies, investigates, and offers solutions to language-related real-life problems. Some of the academic fields related to applied linguistics are education, psychology, communication research, anthropology, and sociology. Theoretical Linguistics focuses on the examination of the structure of English in all its manifestations (phonetics, phonology, morphology, syntax, grammar at large). Other branches of Applied linguistics offered are, for instance, the acquisition of a second language and sociolinguistics. applied linguistics is a branch of linguistics where the primary concern is the application of linguistic theories, methods and findings to the elucidation of language problems that have arisen in other areas of experience. Today the governing board of AILA describes applied linguistics 'as a means to help solve specific problems in society. Applied linguistics focuses on the numerous and complex areas in society in which language plays a role.
Collusion through Joint R&D: An Empirical Assessment
This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors – created through firms being members in several RJVs at the same time – are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing
Determination of free 25(OH)D concentrations and their relationships to total 25(OH)D in multiple clinical populations
Context : The optimal measure of vitamin D(D) status is unknown.
Objective : Directly measure circulating free 25(OH)D concentrations and relationships to total 25(OH)D in a clinically diverse sample of humans.
Design : Cross-sectional analysis
Setting : Seven academic sites
Patients : 1661 adults: (healthy(n=211), pre-diabetic(n=479), outpatients(n=783), cirrhotic(n=90), pregnant(n=20), nursing home(n=79))
Interventions : Merge research data on circulating free 25(OH)D (directly measured immunoassay), total 25(OH)D (LC/MS/MS), D binding protein (DBP by radial (polyclonal) immunodiffusion assay)), albumin, creatinine, iPTH and DBP haplotype
Main outcome measures : Distribution of free 25(OH)D (ANOVA with Bonferroni correction for post hoc comparisons) and relationships between free and total 25(OH)D (mixed effects modeling incorporating clinical condition, DBP haplotype with sex, race, eGFR, BMI and other covariates).
Results : Free 25(OH)D was 4.7±1.8 pg/mL (mean ±SD) in healthy and 4.3 ±1.9 pg/mL in outpatients with 0.5-8.1 pg/mL and 0.9-8.1 pg/mL encompassing 95% of healthy and outpatients, respectively. Free 25(OH)D was higher in cirrhotics (7.1 ±3.0 pg/mL, pnursing home>prediabetic > outpatient > pregnant), and BMI (lesser effect) as covariates affecting relationships but not eGFR, sex, race or DBP haplotype.
Conclusions : Total 25(OH)D, health condition, race and DBP haplotype affected free 25(OH)D, but only health conditions and BMI affected relationships between total and free 25(OH) D. Clinical importance of free 25(OH)D needs to be established in studies assessing outcomes
Subclinical thyroid dysfunction and cognitive decline in old age
<p>Background: Subclinical thyroid dysfunction has been implicated as a risk factor for cognitive decline in old age, but results are inconsistent. We investigated the association between subclinical thyroid dysfunction and cognitive decline in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).</p>
<p>Methods: Prospective longitudinal study of men and women aged 70–82 years with pre-existing vascular disease or more than one risk factor to develop this condition (N = 5,154). Participants taking antithyroid medications, thyroid hormone supplementation and/or amiodarone were excluded. Thyroid function was measured at baseline: subclinical hyper- and hypothyroidism were defined as thyroid stimulating hormones (TSH) <0.45 mU/L or >4.50 mU/L respectively, with normal levels of free thyroxine (FT4). Cognitive performance was tested at baseline and at four subsequent time points during a mean follow-up of 3 years, using five neuropsychological performance tests.</p>
<p>Results: Subclinical hyperthyroidism and hypothyroidism were found in 65 and 161 participants, respectively. We found no consistent association of subclinical hyper- or hypothyroidism with altered cognitive performance compared to euthyroid participants on the individual cognitive tests. Similarly, there was no association with rate of cognitive decline during follow-up.</p>
<p>Conclusion: We found no consistent evidence that subclinical hyper- or hypothyroidism contribute to cognitive impairment or decline in old age. Although our data are not in support of treatment of subclinical thyroid dysfunction to prevent cognitive dysfunction in later life, only large randomized controlled trials can provide definitive evidence.</p>
Subclinical thyroid dysfunction and cognitive decline in old age
<p>Background: Subclinical thyroid dysfunction has been implicated as a risk factor for cognitive decline in old age, but results are inconsistent. We investigated the association between subclinical thyroid dysfunction and cognitive decline in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).</p>
<p>Methods: Prospective longitudinal study of men and women aged 70–82 years with pre-existing vascular disease or more than one risk factor to develop this condition (N = 5,154). Participants taking antithyroid medications, thyroid hormone supplementation and/or amiodarone were excluded. Thyroid function was measured at baseline: subclinical hyper- and hypothyroidism were defined as thyroid stimulating hormones (TSH) <0.45 mU/L or >4.50 mU/L respectively, with normal levels of free thyroxine (FT4). Cognitive performance was tested at baseline and at four subsequent time points during a mean follow-up of 3 years, using five neuropsychological performance tests.</p>
<p>Results: Subclinical hyperthyroidism and hypothyroidism were found in 65 and 161 participants, respectively. We found no consistent association of subclinical hyper- or hypothyroidism with altered cognitive performance compared to euthyroid participants on the individual cognitive tests. Similarly, there was no association with rate of cognitive decline during follow-up.</p>
<p>Conclusion: We found no consistent evidence that subclinical hyper- or hypothyroidism contribute to cognitive impairment or decline in old age. Although our data are not in support of treatment of subclinical thyroid dysfunction to prevent cognitive dysfunction in later life, only large randomized controlled trials can provide definitive evidence.</p>
The effect of high-dose vitamin D3 supplementation on bone mineral density in subjects with prediabetes
Purpose: Type 2 diabetes mellitus is associated with increased fracture risk and recent studies show crosstalk between bone and glucose metabolism. Few studies have investigated the effect of vitamin D supplementation on bone without additional calcium. In the present study, we aimed to determine whether a high dose of vitamin D3 could improve bone mass density (BMD) in prediabetic subjects. Methods: The current study was conducted as a secondary research on a previously performed trial, in which five hundred and eleven subjects with prediabetes were randomized to vitamin D3 (20 000 IU per week) versus placebo for five years. BMD was measured using dual-energy X-ray absorptiometry (DEXA). Results: Two hundred and fifty-six subjects were randomized to vitamin D and 255 to placebo. Mean baseline serum 25-hydroxyvitamin D (25(OH)D) level was 60 nmol/L. Two hundred and two and 214 in the vitamin D and placebo groups, respectively, completed BMD measurements, whereas one in each group was excluded due to use of bisphosphonates. Males given vitamin D had significantly less reduction in BMD at the femoral neck measurement site compared to the controls (0.000 g/cm2 versus -0.010 g/cm2, p=0.008). No significant differences between intervention groups were seen at the total hip measurement site, regarding both males and females. Conclusions: Vitamin D3 supplementation alone may be beneficial in males with prediabetes, but confirmatory studies are needed
Effect of Intraduodenal Bile and Na-Taurodeoxycholate on Exocrine Pancreatic Secretion and on Plasma Levels of Secretin, Pancreatic Polypeptide, and Gastrin in Man
The effect of intraduodenally administered cattle bile (CB) and Na-taurodeoxycholate (TDC) on basal pancreatic secretion and plasma levels of secretin, pancreatic polypeptide (PP), and gastrin were investigated on two separate days in 10 fasting volunteers. Doses of 2-6 g CB and 20&600 mg TDC were given intraduodenally at 65-min intervals. Volume, bicarbonate, lipase, trypsin, amylase, and bilirubin were measured in 10-min fractions of duodenal juice, and GI peptides determined by radioimmunoassay. CB and TDC enhanced significantly and dose-dependently volume, bicarbonate and enzyme secretion, and plasma secretin and PP levels. In contrast, plasma gastrin showed only a marginal increase. We conclude that the hydrokinetic effect of intraduodenal CB and TDC is at least partially mediated by secretin. Gastrin could be ruled out as a mediator of the ecbolic effect, whereas other GI peptides, primarily CCK, and/or neural mechanisms must be considered possible mediators. Both pathways may also play a role in the PP release
Autism as a disorder of neural information processing: directions for research and targets for therapy
The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
Empirical Distributions of F-ST from Large-Scale Human Polymorphism Data
Studies of the apportionment of human genetic variation have long established that most human variation is within population groups and that the additional variation between population groups is small but greatest when comparing different continental populations. These studies often used Wright’s FST that apportions the standardized variance in allele frequencies within and between population groups. Because local adaptations increase population differentiation, high-FST may be found at closely linked loci under selection and used to identify genes undergoing directional or heterotic selection. We re-examined these processes using HapMap data. We analyzed 3 million SNPs on 602 samples from eight worldwide populations and a consensus subset of 1 million SNPs found in all populations. We identified four major features of the data: First, a hierarchically FST analysis showed that only a paucity (12%) of the total genetic variation is distributed between continental populations and even a lesser genetic variation (1%) is found between intra-continental populations. Second, the global FST distribution closely follows an exponential distribution. Third, although the overall FST distribution is similarly shaped (inverse J), FST distributions varies markedly by allele frequency when divided into non-overlapping groups by allele frequency range. Because the mean allele frequency is a crude indicator of allele age, these distributions mark the time-dependent change in genetic differentiation. Finally, the change in mean-FST of these groups is linear in allele frequency. These results suggest that investigating the extremes of the FST distribution for each allele frequency group is more efficient for detecting selection. Consequently, we demonstrate that such extreme SNPs are more clustered along the chromosomes than expected from linkage disequilibrium for each allele frequency group. These genomic regions are therefore likely candidates for natural selection
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