De novo origins of multicellularity in response to predation

The transition from unicellular to multicellular life was one of a few major events in the history of life that created new opportunities for more complex biological systems to evolve. Predation is hypothesized as one selective pressure that may have driven the evolution of multicellularity. Here we show that de novo origins of simple multicellularity can evolve in response to predation. We subjected outcrossed populations of the unicellular green alga Chlamydomonas reinhardtii to selection by the filter-feeding predator Paramecium tetraurelia. Two of five experimental populations evolved multicellular structures not observed in unselected control populations within ~750 asexual generations. Considerable variation exists in the evolved multicellular life cycles, with both cell number and propagule size varying among isolates. Survival assays show that evolved multicellular traits provide effective protection against predation. These results support the hypothesis that selection imposed by predators may have played a role in some origins of multicellularity

Les Espèces vègètales de couverture du sol destinées à la culture du coton en semis direct.

bitstream/item/142514/1/Les-especes-vegetables-de-couverture-du-sol....pdfCOTON-4

Alterations of cardiorespiratory and motor profile of paralympic 5-a-side football athletes during 14-week in-season training

The aim of this study was to characterize the cardiorespiratory and motor performance characteristics of blind 5-a-side footballers from the Brazilian Paralympic Team. Seven male athletes were evaluated at before and after 14-week in-season training (weekly volume between 6.5 hours to 10.8 hours), through cardiorespiratory fitness test, Agility test (5x10), Running-based Anaerobic Sprint Test (RAST) and Standing Long Jump Test (SLJT). The VO2max ranged from 51.9 (±3.8) to 54.3 (±5.0) mL.kg-1.min-1.VO2 at ventilatory threshold ranged from 48.4 (±4.4) to 41.1 (±6.8) mL.kg-1.min-1. Heart rate at ventilatory threshold ranged from 94.7 (±2.3) to 89.9 (±3.7) bpm. Regarding motor performance the values of medium Power Output ranged from 442 (± 63) to 421.9 (±66) Watts and Fatigue Index ranged from 63.1 (±9.4) to 53.9 (±14.8) W/s. Overall, our results show that while the performance of these athletes is inferior to that of professional players, their cardiorespiratory and motor performance is superior to that typical of semi-professional futsal athletes and, this study which can potentially suggest and contribute to the prescription of future training programs

Influência do espaçamento entre linhas e da relação entre espaçamento-altura na podridão de maçãs do algodoeiro.

A podridão de maçãs é um dos problemas fitossanitários mais importantes para a cultura do algodoeiro no Brasil. Sob condições de elevada umidade e precipitação pluviométrica no período de abertura ou formação das maçãs, essa enfermidade provoca prejuízos expressivos. A podridão de maçãs pode ocorrer tanto antes como após sua abertura, e é caracterizada pela ação de um complexo de agentes patogênicos primários e secundários, sendo registra dos mais de uma centena de microrganismos associados

Estabilidade de produção do algodoeiro cultivado sob diferentes palhadas para cobertura do solo.

Nos últimos anos, a região oeste da Bahia vem enfrentando problemas sérios de veranicos prolongados com quedas de produtividade do algodoeiro. Quando e stes veranicos ocorrem em estádios de alta demanda de agua pela planta, os prejuízos são ainda maiores. Alternativas como o uso de cobertura do solo com biomassa podem minimizar estes problemas, pois podem diminuir as perdas de água por evaporação, e consequentemente aumentar a eficiência do uso da água do solo pelas culturas. Frente a esta realidade, o objetivo deste trabalho foi de avaliar a estabilidade de produção do algodoeiro cultivado sob diferentes condições de cobertura do solo com biomassa seca

ВЛИЯНИЕ РАЗЛИЧНЫХ МЕТОДОВ ПОСЛЕОПЕРАЦИОННОГО ОБЕЗБОЛИВАНИЯ НА СИСТЕМУ ГЕМОСТАЗА ПРИ ЭНДОПРОТЕЗИРОВАНИИ ТАЗОБЕДРЕННОГО СУСТАВА

120 patients were examined using instrumental methods, such as hemocoagulography and agregatography. It has been various methods of postoperative anesthesia have different effect on the functional status of haemostasis system following hip replacement. Optimization of postoperative anesthesia provides a way of preventing thrombohemorrhagic complications Проведено обследование 120 пациентов с помощью инструментальных методов – гемокоагулографии и агрегатографии. Выявлено, что различные методы послеоперационного обезболивания по-разному влияют на функциональное состояние системы гемостаза при эндопротезировании тазобедренного сустава. Оптимизация послеоперационного обезболивания ведет к возможности профилактики тромбогеморрагических осложнений

Differences in lateral gene transfer in hypersaline versus thermal environments

<p>Abstract</p> <p>Background</p> <p>The role of lateral gene transfer (LGT) in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles.</p> <p>Results</p> <p>We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei) and a halophilic class of Archaea (Halobacteria). We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles.</p> <p>Conclusions</p> <p>Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.</p