419 research outputs found
Anisotropy in the dielectric spectrum of hydration water and its relation to water dynamics
Proteins, molecules, and macromolecular assemblies in water are surrounded by
a nanometer-sized hydration layer with properties very different from bulk
water. Here, we use classical molecular dynamics simulations to study the
dielectric response of hydration water next to hydrophobic and hydrophilic
planar surfaces. We find the interfacial dielectricabsorption of water to be
strongly anisotropic: compared to bulk water, which shows a broad
dielectricabsorption maximum around 15 GHz in the imaginary part of the
dielectric function, the absorption for electric fields parallel to the
surface is of similar strength and shows a slight redshift, while for
perpendicular electric fields it is strongly attenuated and blueshifted. This
anisotropy is generic for hydrophobic and hydrophilic surfaces. From our
spatially resolved dielectric functions and a modified Maxwell-Garnett theory
that accounts for anisotropic hydration layers around spherical particles, the
dielectricabsorption of solutions of organic molecules and micelles is derived
to exhibit the experimentally known attenuation in combination with a
redshift. These two features are traced back to the subtle interplay of
interfacial depolarization effects and the dielectricanisotropy in the
hydration layer. By a detailed analysis of the individual water molecule
dynamics the perpendicular blueshift is shown not to be linked to accelerated
water reorientation, but rather to dielectric boundary effects. Carefully
conducted angularly resolved experiments at planar aqueous interfaces will be
able to resolve this dielectricanisotropy and thus to confirm the subtle
connection between spectralabsorption features and the molecular water
dynamics in hydration layers
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F.J. Turnerâs âfrontier thesisâ: the ruse of American âcharacter'
American society was transformed by the expansion of capital Westward and the explosion in opportunities that ensued for land grabbing and agricultural and industrial investment. In Turnerâs (1961) frontier thesis this was portrayed as resulting in the emergence of âthe new manâ i.e. the fulfilment of American character. The frontier thesis is a neo-Darwinian contribution. It posits exceptionalism and transcendence as the keys to American character. The gene pool of the Americans, thriving in a new geographical and social environment, is depicted as achieving a higher level of development than the stratified societies of Old Europe. What the thesis ignores is the importance of orthodox Eurocentric strategies of colonization and land appropriation. Turner portrays pioneer/settler society as a heroic departure, but in many ways, it is a continuation of European precedents. Analogously, the proposition that the push West crystallized American character obscures the role of personality, especially in urban-industrial settings, in establishing the parameters of American life. Turner conceived of character as emerging from a struggle with the spatial frontier. But the struggles of personality with the social frontier of repression and establishment values is no less significant. The paper examines the tensions between character and personality by using some ideas developed by Carl Schmitt on the significance of âthe opportunityâ in competitive advantage. The importance of the opportunity and personality in developing the American way of life are examined by the vaudeville and celebrity traditions. The exploitation of contingency for personal advantage, the use of melodrama to engineer social impact, the social validation of forthright behaviour are examined in the context of the careers of the film actress Mae West and the comedian Bob Hope
Biosafety level-2 laboratory diagnosis of Zaire Ebola virus disease imported from Liberia to Nigeria
Introduction: Global travel is an efficient route of transmission for highly infectious pathogens and increases the chances of such pathogens moving from high disease-endemic areas to new regions. We describe the rapid and safe identification of the first imported case of Ebola virus disease in a traveler to Lagos, Nigeria, using conventional reverse transcription polymerase chain reaction (RT-PCR) in a biosafety level (BSL)-2 facility.
Case presentation: On 20 July 2014, a traveler arrived from Liberia at Lagos International Airport and was admitted to a private hospital in Lagos, with clinical suspicion of Ebola virus disease.
Methodology and Outcome: Blood and urine specimens were collected, transported to the Virology Unit Laboratory at the College of Medicine, University of Lagos, and processed under stringent biosafety conditions for viral RNA extraction. RT-PCR was set-up to query the Ebola, Lassa and Dengue fever viruses. Amplicons for pan-filoviruses were detected as 300 bp bands on a 1.5% agarose gel image; there were no detectable bands for Lassa and Dengue viral RNA. Nucleotide BLAST and phylogenetic analysis of sequence data of the RNA-dependent RNA polymerase (L) gene confirmed the sequence to be Zaire ebolavirus (EBOV/Hsap/ NGA/2014/LIB-NIG 01072014; Genbank: KM251803.1).
Conclusion: Our BSL-2 facility in Lagos, Nigeria, was able to safely detect Ebola virus disease using molecular techniques, supporting the reliability of molecular detection of highly infectious viral pathogens under stringent safety guidelines in BSL-2 laboratories. This is a significant lesson for the many under-facilitated laboratories in resource-limited settings, as is predominantly found in sub-Saharan Africa
An introduction to violence against women as a human rights and public health problem
O objetivo deste artigo Ă© apresentar Ă queles(as) que se iniciam no estudo da violĂȘncia praticada contra as mulheres uma breve contextualização histĂłrica do modo como, gradualmente, este se tornou um tema do campo dos Direitos Humanos e da SaĂșde PĂșblica. Partimos da Declaração Universal dos Direitos dos Homens para, em seguida, discutirmos sua importĂąncia para o campo dos Direitos Humanos e analisarmos a polĂȘmica entre direitos humanos versus direitos das mulheres. Posteriormente, apresentamos as diversas convençÔes e tratados internacionais de proteção dos direitos das mulheres e sua importĂąncia para a conscientização da SaĂșde PĂșblica, com relação ao fenĂŽmeno da violĂȘncia. Inicialmente abordada como "causas externas" de morbidade e mortalidade, devido Ă grande incidĂȘncia e aos elevados prejuĂzos sociais, econĂŽmicos e de saĂșde (fĂsica e psicolĂłgica), atualmente a violĂȘncia Ă© reconhecida como um campo especĂfico e urgente de intervenção sob a perspectiva da SaĂșde PĂșblica. De modo particular, a violĂȘncia praticada contra as mulheres Ă© um problema de proporçÔes mundiais, que atinge pessoas de todas as classes sociais, religiĂ”es e etnias. Afirmamos que, a partir da inclusĂŁo da violĂȘncia contra as mulheres na arena dos direitos humanos e da SaĂșde PĂșblica, começaram a ocorrer transformaçÔes mais efetivas nas polĂticas legais de muitos paĂses, como a criação de programas de intervenção e outros suportes. Por fim, apresentamos a situação do Brasil com relação Ă igualdade de gĂȘnero.The aim of this paper is to show to those who are beginning to study the subject of violence against women a brief historical overview of the way it gradually became a theme of the fields of Human Rights and Public Health. We start with the Universal Declaration of Human Rights to discuss its importance for the field of Human Rights and to analyze the polemic between human rights versus women's rights. After that, we present the international treaties and conventions that protect women's rights and their importance to raise the awareness of the Public Health field about violence. Initially seen as "external causes" of morbidity and mortality, because of its high incidence and several social, economic and health (physical and psychological) damages, nowadays violence is seen as a specific domain of the Public Health field that needs urgent intervention. In particular, violence against women is a global problem that reaches people of all social classes, religions and ethnic groups. We claim that, since the inclusion of violence against women in the fields of Human Rights and Public Health, more effective transformations in the legal policies of several countries have begun to occur, like the creation of interventional programs and other supports. At the end, we show Brazil's position about gender equality.info:eu-repo/semantics/publishedVersio
Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei)
The final publication is available at Springer via http://dx.doi.org/10.1007/s00265-016-2066-6Weaning marks an important milestone during life history in mammals indicating nutritional independence from the mother. Age at weaning is a key measure of maternal investment and care, affecting female reproductive rates, offspring survival and ultimately the viability of a population. Factors explaining weaned age variation in the endangered mountain gorilla are not yet well understood. This study investigated the impact of group size, group type (one-male versus multi-male), offspring sex, as well as maternal age, rank, and parity on weaned age variation in the Virunga mountain gorilla population. The status of nutritional independence was established in 69 offspring using long-term suckling observations. A Cox-regression with mixed effects was applied to model weaned age and its relationship with covariates. Findings indicate that offspring in one-male groups are more likely to be weaned earlier than offspring in multi-male groups, which may reflect a female reproductive strategy to reduce higher risk of infanticide in one-male groups. Inferior milk production capacity and conflicting resource allocation between their own and offspring growth may explain later weaning in primiparous mothers compared to multiparous mothers. Sex-biased weaned age related to maternal condition defined by parity, rank, and maternal age will be discussed in the light of the Trivers-Willard hypothesis. Long-term demographic records revealed no disadvantage of early weaning for mother or offspring. Population growth and two peaks in weaned age within the Virunga population encourage future studies on the potential impact of bamboo shoots as a weaning food and other environmental factors on weaning
Sixty-four new records for the flora of Peru from rapid biological inventories in the Peruvian Amazon
Durante el perĂodo 2000 â 2016, se llevaron a cabo 15 inventarios biolĂłgicos en ĂĄreas remotas en el pie de monte andino y el llano amazĂłnico del PerĂș. En estos inventarios, 27 botĂĄnicos colectaron un total de 9397 especĂmenes de plantas vasculares fĂ©rtiles. Hasta finales del 2017, mĂĄs de la mitad de estos especĂmenes se han identificado a nivel de especie, de los cuales 64 especies y 2 gĂ©neros (Dicorynia y Monopteryx) representan nuevos registros para la flora del PerĂș. Si esta tasa de novedades se mantiene, el nĂșmero de registros nuevos en el material de los inventarios podrĂa aumentar, lo cual nos indica que aĂșn queda mucho por descubrir en la flora andino-amazĂłnica del PerĂș.Between 2000 and 2016 we carried out 15 rapid biological inventories in remote areas of the Andean foothills and Amazon basin in Peru. During these inventories, 27 botanists collected 9397 fertile vascular plant specimens. By the end of 2017, more than half of these specimens had been identified to species. Of the 2303 species identified to date, 64 species and 2 genera (Dicorynia and Monopteryx) are new records for the flora of Peru. If this rate of discovery proves typical, the number of new records for Peru in the rapid inventory material could increase, which indicates that there is still much to discover in the Peruvian flora
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