Changes in the reflex excitability of the soleus spinal center in humans performing various motor tasks

The reflex excitability of the soleus spinal motoneurons was assessed in healthy subjects performing different types of motor tasks: voluntary contraction of the flexor (dorsal flexion) and extensor (plantar flexion) muscles of the foot. The effect of the contraction strength of these muscles was also evaluated. During dorsal flexion of the ipsi-and contralateral feet, changes in the reflex ecitability of the soleus motoneurons were unidirectional: the excitability decreased. The decrease in the reflex excitability was more profound during dorsal flexion with the maximum strength than with the half-maximum strength. During the plantar flexion of the ipsi-and contralateral feet, the excitability of the soleus motoneurons changed in opposite directions: in some subjects it increased, while in the others it decreased. The reflex excitability of the soleus motoneurons changed to a greater extent during dorsal or plantar flexion of the ipsilateral foot. In the case of plantar flexion, the soleus motor center is possibly affected by a broader spectrum of influences than in the case of dorsal flexion, which can explain the variations in the reflex excitability changes during plantar flexion. © Pleiades Publishing, Inc., 2006

Low energy kaon photoproduction from nuclei

We study $K^+$-meson production in $\gamma{A}$ interaction at energies below the reaction threshold in free space. The Thomas-Fermi and spectral function approaches are used for the calculations of the production process. It is found that the measurement of the differential spectra may allow to reconstruct the production mechanism and to investigate the dispersion relations entering the production vertex. It is shown that the contribution from secondary pion induced reactions to the total kaon photoproduction is negligible for $E_\gamma{<}$1.2 GeV so that strangeness production at low energies is sensitive to the nuclear spectral function.Comment: 20 pages, espcrc1, including 12 figures, to appear in Nucl. Phys.

Branching ratio change in K- absorption at rest and the nature of the Lambda(1405)

We investigate in-medium corrections to the branching ratio in K- absorption at rest and their effect on the (positively and negatively) charged pion spectrum. The in-medium corrections are due to Pauli blocking, which arises if the Lambda(1405) is assumed to be a $\bar{K}$-nucleon bound state and leads to a density and momentum dependent mass shift of the Lambda(1405). Requiring that the optical potential as well as the branching ratio are derived from the same elementary T-matrix, we find that the in-medium corrected, density dependent T-matrix gives a better description of the K- absorption reaction than the free, density-independent one. This result suggests that the dominant component of the Lambda(1405) wave function is the $\bar{K}N$ bound state.Comment: 8 Pages, Revtex with epsf, and embedded 8 ps figure

Heterologous reporter expression in the planarian Schmidtea mediterranea through somatic mRNA transfection

Planarians have long been studied for their regenerative abilities. Moving forward, tools for ectopic expression of non-native proteins will be of substantial value. Using a luminescent reporter to overcome the strong autofluorescence of planarian tissues, we demonstrate heterologous protein expression in planarian cells and live animals. Our approach is based on the introduction of mRNA through several nanotechnological and chemical transfection methods. We improve reporter expression by altering untranslated region (UTR) sequences and codon bias, facilitating the measurement of expression kinetics in both isolated cells and whole planarians using luminescence imaging. We also examine protein expression as a function of variations in the UTRs of delivered mRNA, demonstrating a framework to investigate gene regulation at the post-transcriptional level. Together, these advances expand the toolbox for the mechanistic analysis of planarian biology and establish a foundation for the development and expansion of transgenic techniques in this unique model system

Gestão Participativa e a interface com trabalhadores do Sistema Único de Saúde: uma revisão integrativa

Trata-se de uma revisão integrativa de literatura com objetivo de integrar o conhecimento produzido acerca da Gestão Participativa e a interface dos trabalhadores do SUS. Para seleção dos artigos foram consultadas três bases de dados – Scielo, LiLACS e MEDLINE  - sendo incluídos doze artigos. Os resultados mostram estudos qualitativos, todos publicados entre 2008 a 2012. Identificou-se nos artigos que a Gestão Participativa é vivenciada por trabalhadores de saúde, muito embora haja dificuldades para a mesma. Os resultados evidenciaram um maior número de estudos nas regiões sul e sudeste brasileiro. Conclui-se que a Gestão Participativa é importante para o desenvolvimento do SUS e que é possível superar desafios e fazer com que o trabalhador de saúde participe mais do processo de decisões

Simplified method of analysis, control and forecast of high water pollution by separate components

Assessing the risks and predicting the increased pollution of natural water bodies is especially important in the industrial regions where the instability of the monitored indicators is most significant. This article proposes methods of this activity with the use of non-parametric and more accurate parametric methods of hydro-monitoring data analysis. The results of using these methods for the Ural region have been obtained, and it has been shown that the analytical description of the “tail” parts of the probability distribution in the studied water quality indicators with the use of the Pareto distribution allows to identify the appropriate indicators for the limited volume samples and to give the projected estimates in the unobserved parts of the distributions. It has been noted that the risk of significant water pollution exists even if the situation is relatively favorable according to the hydro-monitoring. In this regard, a methodology of estimating the upper limit of the confidence interval covering the value of the monitored index with the acceptable reliability has been proposed. Practical examples show the effectiveness of this method. The special significance of the application of the proposed approaches to the predicting aspect is due to the possibility of assessing the small risks of the appearance of extreme unit values of the investigated random variables.Оценка риска и прогноз повышенного загрязнения природных вод особенно важны в промышленных регионах, где нестабильность контролируемых показателей наиболее высока. Поскольку риск является вероятностной характеристикой степени загрязнения воды отдельными компонентами, для решения этой задачи необходимо привлечение статистических методов. В статье предложена практическая методика такой оценки с использованием непараметрических, основанных на теории порядковых статистик, и более точных параметрических методов статистического анализа данных гидромониторинга, требующих аналитического описания функции распределения концентрации загрязняющих веществ. Результаты использования методики апробированы для уральского региона, для чего обосновано и показано, что аналитическое описание «хвостовых» частей функций распределения вероятностей при больших значениях исследуемых показателей качества воды распределением Парето позволяет по выборкам ограниченного объема определять соответствующие показатели в ненаблюдаемых частях распределений, т.е. давать прогнозные оценки. Отмечено, что риск высокого загрязнения воды существует, даже если ситуация по данным гидромониторинга относительно благополучна. В связи с этим предложена методика оценки доверительного интервала, покрывающего значения контролируемого показателя с заданной доверительной вероятностью, в том числе наиболее важной его верхней доверительной границы. На практических демонстрационных примерах показана эффективность разработанной методики. Особая значимость применения предложенных подходов к прогнозной задаче обусловлена возможностью оценивания малых рисков появления экстремальных единичных значений исследуемых случайных величин

Advancing stem cell technologies for conservation of wildlife biodiversity.

Wildlife biodiversity is essential for healthy, resilient and sustainable ecosystems. For biologists, this diversity also represents a treasure trove of genetic, molecular and developmental mechanisms that deepen our understanding of the origins and rules of life. However, the rapid decline in biodiversity reported recently foreshadows a potentially catastrophic collapse of many important ecosystems and the associated irreversible loss of many forms of life on our planet. Immediate action by conservationists of all stripes is required to avert this disaster. In this Spotlight, we draw together insights and proposals discussed at a recent workshop hosted by Revive &amp; Restore, which gathered experts to discuss how stem cell technologies can support traditional conservation techniques and help protect animal biodiversity. We discuss reprogramming, in vitro gametogenesis, disease modelling and embryo modelling, and we highlight the prospects for leveraging stem cell technologies beyond mammalian species