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Shaun P. Wilkinson Stefanie Pontasch Paul L. Fisher Simon K. Davy 《Coral reefs (Online)》2016,35(2):565-576
The symbiotic dinoflagellates of corals and other marine invertebrates (Symbiodinium) are essential to the development of shallow-water coral reefs. This genus contains considerable genetic diversity and a corresponding range of physiological and ecological traits. Most genetic variation arises through the accumulation of somatic mutations that arise during asexual reproduction. Yet growing evidence suggests that occasional sexual reproductive events also occur within, and perhaps between, Symbiodinium lineages, further contributing to the pool of genetic variation available for evolutionary adaptation. Intra-genomic variation can therefore arise from both sexual and asexual reproductive processes, making it difficult to discern its underlying causes and consequences. We used quantitative PCR targeting the ITS2 locus to estimate proportions of genetically homogeneous symbionts and intra-genomically variable Symbiodinium (IGV Symbiodinium) in the reef-building coral Pocillopora damicornis at Lord Howe Island, Australia. We then sampled colonies through time and at a variety of spatial scales to find out whether the distribution of these symbionts followed patterns consistent with niche partitioning. Estimated ratios of homogeneous to IGV Symbiodinium varied between colonies within sites (metres to tens of metres) and between sites separated by hundreds to thousands of metres, but remained stable within colonies through time. Symbiont ratios followed a temperature gradient, with the local thermal maximum emerging as a negative predictor for the estimated proportional abundance of IGV Symbiodinium. While this pattern may result from fine-scale spatial population structure, it is consistent with an increased susceptibility to thermal stress, suggesting that the evolutionary processes that generate IGV (such as inter-lineage recombination and the accumulation of somatic mutations at the ITS2 locus) may have important implications for the fitness of the symbiont and that of the coral host. 相似文献
94.
Diabetes mellitus in people with schizophrenia,bipolar disorder and major depressive disorder: a systematic review and large scale meta‐analysis 下载免费PDF全文
Davy Vancampfort Christoph U. Correll Britta Galling Michel Probst Marc De Hert Philip B. Ward Simon Rosenbaum Fiona Gaughran John Lally Brendon Stubbs 《World psychiatry》2016,15(2):166-174
Type 2 diabetes mellitus (T2DM) is highly predictive of cardiovascular diseases and can have particularly deleterious health impacts in people with severe mental illness (SMI), i.e. schizophrenia, bipolar disorder or major depressive disorder. This meta‐analysis aimed: a) to describe pooled frequencies of T2DM in people with SMI; b) to analyze the influence of demographic, illness and treatment variables as well as T2DM assessment methods; and c) to describe T2DM prevalence in studies directly comparing persons with each specific SMI diagnosis to general population samples. The trim and fill adjusted pooled T2DM prevalence among 438,245 people with SMI was 11.3% (95% CI: 10.0%‐12.6%). In antipsychotic‐naïve participants, the prevalence of T2DM was 2.9% (95% CI: 1.7%‐4.8%). There were no significant diagnostic subgroup differences. A comparative meta‐analysis established that multi‐episode persons with SMI (N=133,470) were significantly more likely to have T2DM than matched controls (N=5,622,664): relative risk, RR=1.85, 95% CI: 1.45‐2.37, p<0.001. The T2DM prevalence was consistently elevated in each of the three major diagnostic subgroups compared to matched controls. Higher T2DM prevalences were observed in women with SMI compared to men (RR=1.43, 95% CI: 1.20‐1.69, p<0.001). Multi‐episode (versus first‐episode) status was the only significant predictor for T2DM in a multivariable meta‐regression analysis (r2=0.52, p<0.001). The T2DM prevalence was higher in patients prescribed antipsychotics, except for aripriprazole and amisulpride. Routine screening and multidisciplinary management of T2DM is needed. T2DM risks of individual antipsychotic medications should be considered when making treatment choices. 相似文献
95.
Joshua D. Eikenberg Jyoti Savla Elaina L. Marinik Kevin P. Davy John Pownall Mary E. Baugh Kyle D. Flack Soheir Boshra Richard A. Winett Brenda M. Davy 《PloS one》2016,11(2)
Purpose
To determine if prediabetes phenotype influences improvements in glucose homeostasis with resistance training (RT).Methods
Older, overweight individuals with prediabetes (n = 159; aged 60±5 yrs; BMI 33±4 kg/m2) completed a supervised RT program twice per week for 12 weeks. Body weight and composition, strength, fasting plasma glucose, 2-hr oral glucose tolerance, and Matsuda-Defronza estimated insulin sensitivity index (ISI) were assessed before and after the intervention. Participants were categorized according to their baseline prediabetes phenotype as impaired fasting glucose only (IFG) (n = 73), impaired glucose tolerance only (IGT) (n = 21), or combined IFG and IGT (IFG/IGT) (n = 65).Results
Chest press and leg press strength increased 27% and 18%, respectively, following the 12-week RT program (both p<0.05). Waist circumference (-1.0%; pre 109.3±10.3 cm, post 108.2±10.6 cm) and body fat (-0.6%; pre 43.7±6.8%, post 43.1±6.8%) declined, and lean body mass (+1.3%; pre 52.0±10.4 kg, post 52.7±10.7 kg) increased following the intervention. Fasting glucose concentrations did not change (p>0.05) following the intervention. However, 2-hr oral glucose tolerance improved in those with IGT (pre 8.94±0.72 mmol/l, post 7.83±1.11 mmol/l, p<0.05) and IFG/IGT (pre 9.66±1.11mmol/l, post 8.60±2.00 mmol/l) but not in those with IFG (pre 6.27±1.28mmol/l, post 6.33± 1.55 mmol/l). There were no significant changes in ISI or glucose area under the curve following the RT program.Conclusions
RT without dietary intervention improves 2-hr oral glucose tolerance in individuals with prediabetes. However, the improvements in glucose homeostasis with RT appear limited to those with IGT or combined IFG and IGT.Trial Registration
ClinicalTrials.gov: NCT01112709相似文献96.
Nucleotide sequence analysis of the lemur beta-globin gene family: evidence for major rate fluctuations in globin polypeptide evolution 总被引:1,自引:0,他引:1
Lemur beta-related globin genes have been isolated and sequenced. Orthology
of prosimian and human epsilon-, gamma-, and beta-related globin genes was
established by dot-matrix analysis. All of these lemur globin genes
potentially encode functional beta-related globin polypeptides, though
precisely when the gamma-globin gene is expressed remains unknown. The
organization of the 18-kb brown lemur beta-globin gene cluster (5'
epsilon-gamma-[psi eta-delta]-beta 3') is consistent with its evolution by
contraction via unequal crossing-over from the putative ancestral mammalian
beta-globin gene cluster (5' epsilon-gamma- eta-delta-beta 3'). The dwarf
lemur nonadult globin genes are arranged as in the brown lemur. Similar
levels of synonymous (silent) nucleotide substitutions and noncoding DNA
sequence differences have accumulated between species in all of these
genes, suggesting a uniform rate of noncoding DNA divergence throughout
primate beta-globin gene clusters. These differences are comparable with
those observed in the nonfunctional psi eta pseudogene and have therefore
accumulated at the presumably maximal neutral rate. In contrast,
nonsynonymous (replacement) nucleotide substitutions show a significant
heterogeneity in distribution for both the same gene in different lineages
and different genes in the same lineage. These major fluctuations in
replacement but not silent substitution rates cannot be attributed to
changes in mutation rate, suggesting that changes in the rate of globin
polypeptide evolution in primates is not governed solely by variable
mutation rates.
相似文献
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The purpose of this investigation was to examine the effects of the Ca2+ agonist BAY K 8644 and the Ca2+ antagonist nifedipine on halothane- and caffeine-induced twitch potentiation of mammalian skeletal muscle. Muscle fiber bundles were taken from normal Landrace pigs and exposed to BAY K 8644 (10 microM), nifedipine (1 microM), and low Ca2+ media administered alone and in combination with halothane (3%) or with increasing concentrations of caffeine (0.5-8.0 mM). Both BAY K 8644 and halothane potentiated twitches by approximately 80%; when they were administered in combination, twitch potentiation was nearly double that caused by either drug alone. In the presence of nifedipine, halothane increased twitches by less than 30%. Low Ca2+ significantly depressed twitches by approximately 25% but also inhibited halothane's inotropic effect. BAY K 8644 augmented caffeine potentiation but only at low caffeine concentrations (0.5-2.0 mM). Nifedipine and low Ca2+ failed to inhibit caffeine's inotropic effects. These results suggest that halothane potentiates twitches via a mechanism that involves or is influenced by extracellular Ca2+. 相似文献
99.
Reference intervals for some clinical chemistry parameters in the marmoset were calculated. The effects of age (250-300 days compared with 500-550 days) and sex on the values found was investigated. Alkaline phosphatase levels decreased with age, young males having higher plasma levels than young females, but no sex differences were discernible for older animals. Levels of gamma-glutamyl transpeptidase and sorbitol dehydrogenase were higher in older males than in younger females. Higher plasma iron levels were found in the males with increasing age. Age and sex effects for protein and albumin were interactive and further interpretation was therefore difficult. No significant age or sex effects were seen for cholinesterase, acetylcholinesterase, isocitrate dehydrogenase, malate dehydrogenase, lactate dehydrogenase, glutamate dehydrogenase, aspartate amino transferase, alanine aminotransferase or bilirubin. 相似文献
100.