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941.
Recent studies have used comparisons of mitochondrial DNA (mtDNA) sequence divergence among populations and species to test existing hypotheses about avian evolution during the Pleistocene epoch. In 1998, Avise and Walker concluded that the Pleistocene was an important time for avian evolution, including the initiation of phylogeographic separations and the completion of speciation events that began in the Pliocene. The study implied that these conclusions conflicted with the study, in 1997, by Klicka and Zink, which concluded that most species pairs previously thought to have originated in the past 250 000 years were much older. The two studies are complementary in the sense that Avise and Walker dealt primarily with phylogeographic (intraspecific) separations. Furthermore, Klicka and Zink concentrated on the inception of divergences whereas the Avise and Walker focused on the timing of the completion of speciation. To accomplish this, Avise and Walker analysed ''phylogroups'', geographically coherent subsets of biological species in which mtDNA haplotypes exhibit reciprocal monophyly. The study used the average interphylogroup mtDNA distance (0.027), calibrated at 2% per million years, to conclude that speciation required on average one million years to complete. Hence, speciation events begun in the Late Pliocene would have been completed in the mid- to late Pleistocene. Although we appreciate the extended nature of the speciation process and Avise and Walker''s insightful attempt to estimate its duration, we conclude that their value was an overestimate by a factor of two. In particular we question whether phylogroups can be used in the novel evolutionary role that Avise and Walker envisioned, because of the vagaries of taxonomic practices and lack of consensus regarding species concepts. To extend their analysis of intraspecific, phylogeographic separations, we compiled previously analysed and newly available data for divergence times for North American songbird (order Passeriformes) phylogroups. More than 80% were initiated at least one million years ago, which is inconsistent with the late Pleistocene origins model previously rejected by Klicka and Zink mentioned above. Although some divergence events can be traced to the late Pleistocene, the significance of the distribution must be judged with reference to a null model. Whether the Pleistocene was a profound time for avian phylogeographic differentiation is at present unknown. 相似文献
942.
943.
Halldis Hellebust Mathias Uhlén Sven-Olof Enfors 《Applied microbiology and biotechnology》1988,28(3):258-262
Summary Fermentation of the fused protein staphylococcal protein A-human insulin-like growth factor I (SpA-IGF-I) was investigated. The fused protein was expressed in Staphylococcus aureus and secreted to the culture medium. The production of SpA-IGF-I was growth related and started after a short lag phase. Examination of the product quality by SDS-PAGE after IgG affinity purification showed that the product was partially degraded. Exoproteases appeared later than SpA-IGF-I and were responsible for some, but probably not all, of the degradation of the product. It was possible to influence the exoprotease activity and thereby the product degradation by varying the cultivation conditions. 相似文献
944.
Kristen L. Hollands Trudy A. Pelton Andrew Wimperis Diane Whitham Wei Tan Sue Jowett Catherine M. Sackley Alan M. Wing Sarah F. Tyson Jonathan Mathias Marianne Hensman Paulette M. van Vliet 《PloS one》2015,10(10)
Objectives
Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke.Design
This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation servicesParticipants
Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairmentsIntervention
Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks.Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up.Results
Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms.Conclusions
Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention.Trial Registration
Clinicaltrials.gov NCT01600391 相似文献945.
Annet Nanvubya Julius Ssempiira Juliet Mpendo Ali Ssetaala Annet Nalutaaya Mathias Wambuzi Paul Kitandwe Bernard S. Bagaya Sabrina Welsh Stephen Asiimwe Leslie Nielsen Fredrick Makumbi Noah Kiwanuka 《PloS one》2015,10(10)
Introduction
Fishing communities (FCs) in Uganda have high HIV infection rates but poor access to health services including family planning (FP). Although FP is a cost-effective public health intervention, there is a paucity of data on knowledge and use of modern FP in FCs. This study determined knowledge and use of modern FP methods in FCs of Uganda.Methods
Data were accrued from a 12-month follow up of 1,688 HIV-uninfected individuals, 18–49 years from 8 FCs along Lake Victoria, between September 2011 and March 2013. Data on knowledge and use of modern FP were collected through a semi-structured questionnaire. Prevalence Risk Ratios with corresponding 95% CIs were used to determine factors associated with Modern FP knowledge and use.Results
The mean age was 31.4 years, with nearly half (48.8%) being females while more than half (58.6%) had attained up to primary education level. Knowledge of modern FP was high, 87.5% (1477/1688); significantly higher among females [adj. PRR = 4.84 (95% CI; 3.08, 7.61)], among older respondents (25–29 years) [adj. PRR = 1.83 (95% CI; 1.12, 2.99)] compared to younger ones (18–24 years) and among those conducting business [adj. PRR = 2.42(95% CI; 1.02, 5.74)] relative to those primarily in fishing. Just over a third (35.2%, 595/1688) reported use of at least one modern FP method. Use of modern FP methods was significantly higher among females [adj. PRR = 2.04 (95% CI; 1.56, 2.65, and among those reporting multiple sexual partnerships [adj. PRR = 2.12, 95% CI; 1.63, 2.76)]. Nonuse of modern methods was mostly due to desire for more children (30.6%), fear of side effects (12.2%) and partner refusal (5.2%).Conclusion
Despite their high knowledge of FP, FCs have low use of modern FP methods. Key barriers to use of modern FP methods were high fertility desires, fear of perceived side effects and partner refusal of methods. 相似文献946.
Marta Garcia-Miralles Janaky Coomaraswamy Karina H?big Martin C. Herzig Natalja Funk Frank Gillardon Martina Maisel Mathias Jucker Thomas Gasser Dagmar Galter Saskia Biskup 《PloS one》2015,10(4)
Mutations within the LRRK2 gene have been identified in Parkinson’s disease (PD) patients and have been implicated in the dysfunction of several cellular pathways. Here, we explore how pathogenic mutations and the inhibition of LRRK2 kinase activity affect cytoskeleton dynamics in mouse and human cell systems. We generated and characterized a novel transgenic mouse model expressing physiological levels of human wild type and G2019S-mutant LRRK2. No neuronal loss or neurodegeneration was detected in midbrain dopamine neurons at the age of 12 months. Postnatal hippocampal neurons derived from transgenic mice showed no alterations in the seven parameters examined concerning neurite outgrowth sampled automatically on several hundred neurons using high content imaging. Treatment with the kinase inhibitor LRRK2-IN-1 resulted in no significant changes in the neurite outgrowth. In human fibroblasts we analyzed whether pathogenic LRRK2 mutations change cytoskeleton functions such as cell adhesion. To this end we compared the adhesion characteristics of human skin fibroblasts derived from six PD patients carrying one of three different pathogenic LRRK2 mutations and from four age-matched control individuals. The mutant LRRK2 variants as well as the inhibition of LRRK2 kinase activity did not reveal any significant cell adhesion differences in cultured fibroblasts. In summary, our results in both human and mouse cell systems suggest that neither the expression of wild type or mutant LRRK2, nor the inhibition of LRRK2 kinase activity affect neurite complexity and cellular adhesion. 相似文献
947.
Elisabeth Kleppa Kari F. Klinge Hashini Nilushika Galaphaththi-Arachchige Sigve D. Holmen Kristine Lilleb? Mathias Onsrud Svein Gunnar Gundersen Myra Taylor Patricia Ndhlovu Eyrun F. Kjetland 《PloS one》2015,10(3)
Schistosoma (S.) haematobium causes urogenital schistosomiasis and has been hypothesized to adversely impact HIV transmission and progression. On the other hand it has been hypothesized that HIV could influence the manifestations of schistosomiasis. In this cross-sectional study, we explored the association between urogenital S. haematobium infection and CD4 cell counts in 792 female high-school students from randomly selected schools in rural KwaZulu-Natal, South Africa. We also investigated the association between low CD4 cell counts in HIV positive women and the number of excreted schistosome eggs in urine. Sixteen percent were HIV positive and 31% had signs of urogenital schistosomiasis (as determined by genital sandy patches and / or abnormal blood vessels on ectocervix / vagina by colposcopy or presence of eggs in urine). After stratifying for HIV status, participants with and without urogenital schistosomiasis had similar CD4 cell counts. Furthermore, there was no significant difference in prevalence of urogenital schistosomiasis in HIV positive women with low and high CD4 cell counts. There was no significant difference in the number of eggs excreted in urine when comparing HIV positive and HIV negative women. Our findings indicate that urogenital schistosomiasis do not influence the number of circulating CD4 cells. 相似文献
948.
Recent progresses in data-driven analysis methods, including network-based approaches, are revolutionizing many classical disciplines. These techniques can also be applied to food and nutrition, which must be studied to design healthy diets. Using nutritional information from over 1,000 raw foods, we systematically evaluated the nutrient composition of each food in regards to satisfying daily nutritional requirements. The nutrient balance of a food was quantified and termed nutritional fitness; this measure was based on the food’s frequency of occurrence in nutritionally adequate food combinations. Nutritional fitness offers a way to prioritize recommendable foods within a global network of foods, in which foods are connected based on the similarities of their nutrient compositions. We identified a number of key nutrients, such as choline and α-linolenic acid, whose levels in foods can critically affect the nutritional fitness of the foods. Analogously, pairs of nutrients can have the same effect. In fact, two nutrients can synergistically affect the nutritional fitness, although the individual nutrients alone may not have an impact. This result, involving the tendency among nutrients to exhibit correlations in their abundances across foods, implies a hidden layer of complexity when exploring for foods whose balance of nutrients within pairs holistically helps meet nutritional requirements. Interestingly, foods with high nutritional fitness successfully maintain this nutrient balance. This effect expands our scope to a diverse repertoire of nutrient-nutrient correlations, which are integrated under a common network framework that yields unexpected yet coherent associations between nutrients. Our nutrient-profiling approach combined with a network-based analysis provides a more unbiased, global view of the relationships between foods and nutrients, and can be extended towards nutritional policies, food marketing, and personalized nutrition. 相似文献
949.
Rosana Rosseto de Oliveira Emiliana Cristina Melo Larissa Pereira Falavina Thais Aidar de Freitas Mathias 《PloS one》2015,10(11)
Background
Preterm birth is a serious public health problem, as it is linked to high rates of neonatal and child morbidity and mortality, with Brazil listed among the countries with the ten highest numbers of premature births. Nonetheless, knowledge is scarce regarding prematurity and associated factors in mid-sized cities. The objective of this study was to analyze the trend of preterm births and associated factors in a municipality located in the state of Paraná, Brazil.Methods
This was an ecological time series study of births recorded into the Live Birth Information System for residents of Maringá, Paraná, Brazil, between 2000 and 2013. The polynomial regression model was used for trend analysis of preterm birth, characteristics of the mother, gestation and delivery, and newborn. The association with preterm birth was analyzed using odds ratio (OR).Results
A total of 61,634 live births were analyzed, of which 5,632 were preterm births. Prematurity increased from 7.9% in 2000 to 11.2% in 2013 –an average increase of 0.54% per year (r2 = 0.93)–with a growing share of moderate preterm births (32 to <37 weeks), which rose from 7.0% in 2000 to 9.7% in 2013. Between 2011 and 2013, multiple pregnancy (OR = 16.64; CI = 13.24–20.92), inadequate number of prenatal visits (OR = 2.81; CI = 2.51–3.15), Apgar score below 7 at 1 (OR = 4.07; CI = 3.55–4.67) and 5 minutes (OR = 10.88; CI = 7.71–15.36), low birth weight (OR = 38.75; CI = 33.72–44.55) and congenital malformations (OR = 3.18; CI = 2.14–4.74) were associated with preterm birth. A growing trend was observed for multiple pregnancies, with an average annual increase of 0.32% (r2 = 0.90), as well as for C-section birth (2.38% yearly increase). Of all newborn characteristics, Apgar score below 7 at 5 minutes (-0.19% per year) and low birth weight (-1.43%) decreased, whereas congenital malformations rose (0.20% per year).Conclusions
Efforts are required to prevent premature delivery, particularly during the moderate period, as well as greater care during the prenatal period towards expectant mothers bearing multiple pregnancies, birth defects, in addition to reducing C-section birth as it may be linked to preterm birth. 相似文献950.
Sven-Erik Olofsson Bj?rn Nodin Alexander Gaber Jakob Eberhard Mathias Uhlén Karin Jirstr?m Mats Jerkeman 《PloS one》2015,10(3)