996 resultados para Transient Wave Groups


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This study assesses the decline in second birth rates for men and women across different skill levels in transitional Russia. Changes within educational groups and occupational classes are observed over three distinct time periods: the Soviet era, economic crisis, and economic recovery. The most remarkable finding is the similarity in the extent second birth rates declined within educational groups and occupational classes during the economic crisis. Although further decline occurred in the recovery period, more variation emerged across groups.

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The genetic characterization of Native Mexicans is important to understand multiethnic based features influencing the medical genetics of present Mexican populations, as well as to the reconstruct the peopling of the Americas. We describe the Y-chromosome genetic diversity of 197 Native Mexicans from 11 populations and 1,044 individuals from 44 Native American populations after combining with publicly available data. We found extensive heterogeneity among Native Mexican populations and ample segregation of Q-M242* (46%) and Q-M3 (54%) haplogroups within Mexico. The northernmost sampled populations falling outside Mesoamerica (Pima and Tarahumara) showed a clear differentiation with respect to the other populations, which is in agreement with previous results from mtDNA lineages. However, our results point toward a complex genetic makeup of Native Mexicans whose maternal and paternal lineages reveal different narratives of their population history, with sex-biased continental contributions and different admixture proportions. At a continental scale, we found that Arctic populations and the northernmost groups from North America cluster together, but we did not find a clear differentiation within Mesoamerica and the rest of the continent, which coupled with the fact that the majority of individuals from Central and South American samples are restricted to the Q-M3 branch, supports the notion that most Native Americans from Mesoamerica southwards are descendants from a single wave of migration. This observation is compatible with the idea that present day Mexico might have constituted an area of transition in the diversification of paternal lineages during the colonization of the Americas.

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Induced pluripotent stem (iPS) cells have generated keen interestdue to their potential use in regenerative medicine. They havebeen obtained from various cell types of both mice and humans byexogenous delivery of different combinations of Oct4, Sox2, Klf4,c-Myc, Nanog, and Lin28. The delivery of these transcription factorshas mostly entailed the use of integrating viral vectors (retrovirusesor lentiviruses), carrying the risk of both insertional mutagenesisand oncogenesis due to misexpression of these exogenousfactors. Therefore, obtaining iPS cells that do not carry integratedtransgene sequences is an important prerequisite for their eventualtherapeutic use. Here we report the generation of iPS cell linesfrom mouse embryonic fibroblasts with no evidence of integrationof the reprogramming vector in their genome, achieved by nucleofectionof a polycistronic construct coexpressing Oct4, Sox2, Klf4,and c-Myc

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BACKGROUND: CODIS-STRs in Native Mexican groups have rarely been analysed for human identification and anthropological purposes. AIM:To analyse the genetic relationships and population structure among three Native Mexican groups from Mesoamerica.SUBJECTS AND METHODS: 531 unrelated Native individuals from Mexico were PCR-typed for 15 and 9 autosomal STRs (Identifiler™ and Profiler™ kits, respectively), including five population samples: Purépechas (Mountain, Valley and Lake), Triquis and Yucatec Mayas. Previously published STR data were included in the analyses. RESULTS:Allele frequencies and statistical parameters of forensic importance were estimated by population. The majority of Native groups were not differentiated pairwise, excepting Triquis and Purépechas, which was attributable to their relative geographic and cultural isolation. Although Mayas, Triquis and Purépechas-Mountain presented the highest number of private alleles, suggesting recurrent gene flow, the elevated differentiation of Triquis indicates a different origin of this gene flow. Interestingly, Huastecos and Mayas were not differentiated, which is in agreement with the archaeological hypothesis that Huastecos represent an ancestral Maya group. Interpopulation variability was greater in Natives than in Mestizos, both significant.CONCLUSION: Although results suggest that European admixture has increased the similarity between Native Mexican groups, the differentiation and inconsistent clustering by language or geography stresses the importance of serial founder effect and/or genetic drift in showing their present genetic relationships.

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Dialogic learning and interactive groups have proved to be a useful methodological approach appliedin educational situations for lifelong adult learners. The principles of this approach stress theimportance of dialogue and equal participation also when designing the training activities. This paperadopts these principles as the basis for a configurable template that can be integrated in runtimesystems. The template is formulated as a meta-UoL which can be interpreted by IMS Learning Designplayers. This template serves as a guide to flexibly select and edit the activities at runtime (on the fly).The meta-UoL has been used successfully by a practitioner so as to create a real-life example, withpositive and encouraging results

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The present study constitutes an investigation of tobacco consumption, related attitudes and individual differences in smoking or non-smoking behaviors in a sample of adolescents of different ages in the French-speaking part of Switzerland. We investigated three school-age groups (7th-grade, 9th-grade, and the second-year of high school) for differences in attitude and social and cognitive dimensions. We present both descriptive and inferential statistics. On an inferential level, we present a binary logistic regression-based model predicting risk of smoking. The resulting model most importantly suggests a strong relationship between smoking and alcohol consumption (both regular and sporadic). We interpret this result in terms of both the impact of the actual campaigns and the cognitive processes associated with adolescence.

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Whether maximal surgical resection of glioblastoma improves patient survival has been controversial, as it is difficult to perform an unbiased assessment of extent of resection (EOR) independent of other patient-specific prognostic factors. Recently, glioblastoma has been sub-classified into 4 distinct molecular risk groups (RGs), which have been validated as prognostic biomarkers in the randomized clinical trial of temozolomide dosing in glioblastoma: the Radiation Therapy Oncology Group 0525 (RTOG-0525) trial. We sought to perform exploratory analyses examining gross total resection (GTR) versus sub-total resection (STR) within these RGs in RTOG-0525 patients. Across all randomized patients, n ¼ 354 had STR and n ¼ 450 had GTR as determined by neurosurgeon operative report. GTR was not significantly associated with survival across the overall study group. A total of 725 patients had sufficient tissue for determination of molecular RG. There were no significant differences in percentage of GTR between each of the 4 RGs (P ¼ 0.64). In exploratory subgroup analyses, GTR was associated with improved survival only for patients with tumors from RG4. Hazard ratios (95% confidence intervals) were 0.52 (0.08-2.07) for RG1 (n ¼ 28, 68% GTR), 1.74 (0.75-4.05) for RG2 (n ¼ 39, 56% GTR), 1.09 (0.84-1.42) for RG3 (n ¼ 284, 56% GTR), and 1.26 (1.01-1.56) for RG4 (n ¼ 374, 55% GTR). In univariate analysis within RG4, GTR was associated with a median survival of 14.6 months vs 12.7 months for STR (P ¼ 0.0352. In a Cox model adjusting for age, KPS, and neurologic function (NF), surgery remained an independent factor within RG4: GTR (P ¼ 0.0331), age (P ¼ 0.0014), KPS (P ¼ .3289), and NF (P ¼ 0.3804). There are important cautions in the interpretation of these data, including lack of MRI confirmation of EOR, and inclusion of a range of STR (from biopsy to near-total resection). However, these exploratory results raise the possibility that upfront characterization of tumor molecular profile may allow for personalized therapeutic strategies to improve outcomes for patients with glioblastoma.

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The measurement of rigidity and perseveration respectively gets increasing importance in clinical psychodiagnostics. Recently we have developed a computer-assisted technique which allows to get information about inadequate persisting in psychic processes and behaviour within shortest time and to differentiate between psychopathological groups. 257 patients of both sexes who came for elucidation of their disorders to the department of clinical psychodiagnostics were investigated. The most significant differences between the groups were found in redundance of second degree (the patient has to press 10 buttons indiscriminately according to the beat of a metronom--standard condition) and in personal speed (the patient has to press 10 buttons as fast as possible--speed condition). Furthermore the psychopathological groups were ranged in the particular variables of rigidity according to their mean values and their average ranges the schizophrenics and effective psychoses were characterized by a high tendency of perseveration while the neurotics, patients with organic brain syndrome and alcohol and drug dependents showed more flexibility.

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Cooperation among unrelated individuals can arise if decisions to help others can be based on reputation. While working for dyadic interactions, reputation-use in social dilemmas involving many individuals (e.g. public goods games) becomes increasingly difficult as groups become larger and errors more frequent. Reputation is therefore believed to have played a minor role for the evolution of cooperation in collective action dilemmas such as those faced by early humans. Here, we show in computer simulations that a reputation system based on punitive actions can overcome these problems and, compared to reputation system based on generous actions, (i) is more likely to lead to the evolution of cooperation in sizable groups, (ii) more effectively sustains cooperation within larger groups, and (iii) is more robust to errors in reputation assessment. Punishment and punishment reputation could therefore have played crucial roles in the evolution of cooperation within larger groups of humans.

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A simple variant of trait group selection, employing predators as the mechanism underlying group selection, supports contingent reproductive suicide as altruism (i.e., behavior lowering personal fitness while augmenting that of another) without kin assortment. The contingent suicidal type may either saturate the population or be polymorphic with a type avoiding suicide, depending on parameters. In addition to contingent suicide, this randomly assorting morph may also exhibit continuously expressed strong altruism (sensu Wilson 1979) usually thought restricted to kin selection. The model will not, however, support a sterile worker caste as such, where sterility occurs before life history events associated with effective altruism; reproductive suicide must remain fundamentally contingent (facultative sensu West Eberhard 1987; Myles 1988) under random assortment. The continuously expressed strong altruism supported by the model may be reinterpreted as probability of arbitrarily committing reproductive suicide, without benefit for another; such arbitrary suicide (a "load" on "adaptive" suicide) is viable only under a more restricted parameter space relative to the necessarily concomitant adaptive contingent suicide.

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OBJECTIVES: To compare the prevalence and management of cardiovascular risk factors (CVRFs) between immigrant groups and Swiss nationals. METHODS: The Swiss Health Surveys (SHS, N = 49,245) and CoLaus study (N = 6,710) were used. Immigrant groups from France, Germany, Italy, Portugal, Spain, former Yugoslavia, other European and other countries were defined. RESULTS: Immigrants from Italy, France, Portugal, Spain and former Yugoslavia presented a higher prevalence of smoking than Swiss nationals. Immigrants reported less hypertension than Swiss nationals, but the differences were reduced when blood pressure measurements were used. The prevalence of dyslipidaemia was similar between immigrants and Swiss nationals in the SHS. When eligibility for statin treatment was assessed, immigrants from Italy were more frequently eligible than Swiss nationals. Immigrants from former Yugoslavia presented a lower prevalence of diabetes in the SHS, but a higher prevalence in the CoLaus study. Most differences between immigrant groups and Swiss nationals disappeared after adjusting for age, leisure-time physical activity, being overweight/obesity and education. CONCLUSIONS: Most CVRFs are unevenly distributed among immigrant groups in Switzerland, but these differences are due to disparities in age, leisure-time physical activity, being overweight/obesity and education.

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We implemented Biot-type porous wave equations in a pseudo-spectral numerical modeling algorithm for the simulation of Stoneley waves in porous media. Fourier and Chebyshev methods are used to compute the spatial derivatives along the horizontal and vertical directions, respectively. To prevent from overly short time steps due to the small grid spacing at the top and bottom of the model as a consequence of the Chebyshev operator, the mesh is stretched in the vertical direction. As a large benefit, the Chebyshev operator allows for an explicit treatment of interfaces. Boundary conditions can be implemented with a characteristics approach. The characteristic variables are evaluated at zero viscosity. We use this approach to model seismic wave propagation at the interface between a fluid and a porous medium. Each medium is represented by a different mesh and the two meshes are connected through the above described characteristics domain-decomposition method. We show an experiment for sealed pore boundary conditions, where we first compare the numerical solution to an analytical solution. We then show the influence of heterogeneity and viscosity of the pore fluid on the propagation of the Stoneley wave and surface waves in general.