Ion beam generated surface ripples: new insight in the underlying mechanism

A new hydrodynamic mechanism is proposed for the ion beam induced surface patterning on solid surfaces. Unlike the standard mechanisms based on the ion beam impact generated erosion and mass redistribution at the free surface (proposed by Bradley-Harper (BH) and its extended theories), the new mechanism proposes that the ion beam induced saltation and creep processes, coupled with incompressible solid flow in amorphous layer, leads to the formation of ripple patterns at the amorphous/crystalline (a/c) interface and hence at the free surface. Ion beam stimulated solid flow inside the amorphous layer controls the wavelength, where as the amount of material transported and re-deposited at a/c interface control the amplitude of ripples. The new approach is verified by designed experiments and supported by the discrete simulation method.Comment: 12 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1206.082

Comparative genomics of Pseudomonas fluorescens subclade III strains from human lungs

Abstract Background While the taxonomy and genomics of environmental strains from the P. fluorescens species-complex has been reported, little is known about P. fluorescens strains from clinical samples. In this report, we provide the first genomic analysis of P. fluorescens strains in which human vs. environmental isolates are compared. Results Seven P. fluorescens strains were isolated from respiratory samples from cystic fibrosis (CF) patients. The clinical strains could grow at a higher temperature (>34 °C) than has been reported for environmental strains. Draft genomes were generated for all of the clinical strains, and multi-locus sequence analysis placed them within subclade III of the P. fluorescens species-complex. All strains encoded type- II, −III, −IV, and -VI secretion systems, as well as the widespread colonization island (WCI). This is the first description of a WCI in P. fluorescens strains. All strains also encoded a complete I2/PfiT locus and showed evidence of horizontal gene transfer. The clinical strains were found to differ from the environmental strains in the number of genes involved in metal resistance, which may be a possible adaptation to chronic antibiotic exposure in the CF lung. Conclusions This is the largest comparative genomics analysis of P. fluorescens subclade III strains to date and includes the first clinical isolates. At a global level, the clinical P. fluorescens subclade III strains were largely indistinguishable from environmental P. fluorescens subclade III strains, supporting the idea that identifying strains as ‘environmental’ vs ‘clinical’ is not a phenotypic trait. Rather, strains within P. fluorescens subclade III will colonize and persist in any niche that provides the requirements necessary for growth.http://deepblue.lib.umich.edu/bitstream/2027.42/116129/1/12864_2015_Article_2261.pd

Evidências sobre o suporte durante o trabalho de parto/parto: uma revisão da literatura Evidence on support during labor and delivery: a literature review

Os efeitos do suporte à mulher durante o trabalho de parto/parto por profissionais de saúde, mulheres leigas e doulas, sobre os resultados maternos e neonatais têm sido avaliados em vários ensaios clínicos randomizados, metanálises e revisões sistemáticas. Este artigo apresenta a revisão desses estudos, enfocando as principais características, o provedor de suporte, a simultaneidade na presença ou não do companheiro/familiares da parturiente durante o trabalho de parto e parto, e os resultados obtidos. Foram incluídos os estudos publicados entre os anos de 1980 e 2004, que contemplam explicitamente os aspectos avaliados. De maneira geral, os resultados do suporte são favoráveis, destacando-se redução da taxa de cesarianas, da analgesia/medicamentos para alívio da dor, da duração do trabalho de parto, da utilização de ocitocina e produzindo aumento na satisfação materna com a experiência vivida. Quando o provedor de suporte não é um profissional de saúde, os benefícios têm sido mais acentuados. Os estudos disponíveis não avaliam o acompanhante escolhido pela parturiente como um provedor de suporte, o que constitui lacuna de conhecimento a ser preenchida.<br>The effects of support for women during labor and delivery provided by health professionals, lay women, and doulas on the maternal and neonatal outcomes have been evaluated through randomized clinical trials, meta-analyses, and systematic reviews. This article presents a review of these studies, focusing on the principal characteristics, support provider, simultaneous presence of the woman's spouse and/or family members during labor and delivery and the outcomes. The analysis included studies published from 1980 to 2004 which explicitly approached these aspects. In general, the results of such support were favorable, highlighting a reduction in the cesarean rate, analgesia/ medication for pain relief, duration of labor, and utilization of oxytocin and an increase in maternal satisfaction with the experience. The benefits were greater when the support provider was not a health professional. The available studies did not evaluate the specific companion chosen by the woman as a support provider, which constitutes a gap in the knowledge that should be filled by future research