800 research outputs found
Assumptions for long-term stochastic population forecasts in 18 European countries: Hypothèses de projections stochastiquesàlong terme des populations de 18 pays européens
The aim of the ‘Uncertain Population of Europe’(UPE) project was to compute long-term stochastic (probabilistic) population forecasts for 18 European countries. We developed a general methodology for constructing predictive distributions for fertility, mortality and migration. The assumptions underlying stochastic population forecasts can be assessed by analysing errors in past forecasts or model-based estimates of forecast errors, or by expert judgement. All three approaches have been used in the project. This article summarizes and discusses the results of the three approaches. It demonstrates how the—sometimes conflicting—results can be synthesized into a consistent set of assumptions about the expected levels and the uncertainty of total fertility rate, life expectancy at birth of men and women, and net migration for 18 European countries
Contaminação por mercúrio em sedimento e moluscos da Bacia do rio Bento Gomes, MT.
Os níveis de mercúrio total detectados no sedimento e tecidos moles de moluscos gastrópodos provenientes da bacia hidrográfica do rio Bento Gomes, embora baixos, mostraram indícios de contaminação. De um total de 69 amostras de sedimento analisadas, 26% apresentaram níveis de mercúrio total variando de 0,01 a 0,25 µg.g-1 de mercúrio (peso úmido). Os níveis de mercúrio obtidos em 54 amostras dos moluscos Ampullaria scalaris; A. canaliculata e Marisa planogira evidenciaram que 39% estavam contaminadas com níveis variando de 0,02 a 1,6 µg.g-1 de peso úmido. Estes resultados indicam que o mercúrio utilizado na extração de ouro de aluvião está atingindo o ambiente aquático e contaminado o sedimento e os organismos bentônicos desta área do Pantanal.bitstream/item/37304/1/BP58.pd
Managing arbuscular mycorrhizal fungi for bioprotection: Mn toxicity
We investigated whether an intact extraradical mycelium (ERM) is more effective than other forms of propagule from indigenous arbuscular mycorrhizal fungi (AMF) in providing protection against stress to a host plant. The response of wheat (Triticum aestivum L.) to Mn toxicity was studied in a two-phase greenhouse experiment. In Phase 1, four Mn tolerant species from the natural vegetation, ranging from strongly mycotrophic to non- or weakly mycotrophic, were grown to develop different amounts of ERM. Wheat was then planted (Phase 2) with the ERM fragmented by sieving (Disturbed Treatment) or kept intact with no prior soil disturbance (Undisturbed Treatment). The growth of wheat was doubled by earlier and faster mycorrhizal colonization (AC) in the presence of an intact ERM at planting. There was a positive correlation between plant growth and the reduction of Mn and enhancement of P and S uptake into shoots. However, the growth of plants in undisturbed soil was significantly affected by the ERM developer species, which was not explained by differences in AC. Colonization starting from an intact ERM greatly enhanced the potential of AMF for protection against Mn toxicity. However, the degree of protection depended on the plant previously grown to develop the ERM, suggesting that there may be functional diversity within the ERM developed by mycotrophic plants of the natural vegetation
Interaction between Arbuscular Mycorrhizal Fungi and rhizobia on the growth of subclover under Mn toxicity: The role of Extraradical Mycelium.
When Arbuscular Mycorrhizal (AM) colonization started from an intact extraradical mycelium (ERM) its bioprotective effect on subclover was enhanced in comparison with other sources of inoculum. The presence in the soil of an intact ERM, developed previously on mycotrophic plants tolerant to Mn toxicity, resulted in the earlier colonization of subclover, reduced Mn concentration in the roots, improved development and activity of root nodules, and enhanced N acquisition
Ageing of a giant: a stochastic population forecast for China, 2006-2060
This paper presents a stochastic population forecast for China with a special emphasis on population ageing. The so-called scaled model for error was used to quantify the uncertainty attached to the population predictions. Data scarcity was a major problem in the specification of the expected error of the population forecast. Therefore, the error structures estimated for European countries were used with some modifications, taking into account the large size and heterogeneity of the Chinese population. The stochastic forecast confirms the expectation of extremely rapid population ageing during the first half of the twenty-first century in China. The old age dependency ratio (OADR) will certainly increase. Simply maintaining the current demographic rates (no international migration) would drive the OADR to 0.42 in 2060, four times the current level. Including expected declines in mortality and net outmigration in the projection would increase the median OADR in 2060 to 0.59, with a 80% prediction interval of [0.47, 0.75]. In particular, the oldest-old population will grow much faster than any other age group. This development has
major implications for policy-making in China.
Keywords: Stochastic population forecast Predictive distribution Uncertainty Scaled model for error China Population ageing Low fertility Mortality decline
Influence of body odors and gender on perceived genital arousal
Olfaction is often linked to mating behavior in nonhumans. Additionally, studies in mating behavior have shown that women seem to be more affected by odor cues than men. However, the relationship between odor cues and sexual response—specifically, sexual arousal—has not been studied yet. The aim of this study was to evaluate the impact of the exposure to human body odors (from individuals of the opposite gender) on perceived genital arousal, while these were presented concomitantly to sexually explicit video clips. Eighty university students (40 women) rated their perceived genital arousal (perceived degree of erection/genital lubrication) in response to an audiovisual sexual stimulus, while simultaneously exposed to a body odor from an opposite-gender donor or no odor. Participants also rated each odor sample’s (body odor and no odor) perceived pleasantness, intensity, and familiarity. Findings indicated that odor condition had an effect on women’s (but not men’s) perceived genital arousal, with women showing higher levels of perceived genital arousal in the no odor condition. Also, results showed that women rated body odors as less pleasant than no odor. Notwithstanding, the odor ratings do not seem to explain the association between body odor and perceived genital arousal. The current results support the hypothesis that women, rather than men, are sensitive to odors in the context of sexual response. The findings of this study have relevance for the understanding of human sexuality with respect to chemosensory communicationinfo:eu-repo/semantics/acceptedVersio
Modulation of gamma-aminobutyric acid-mediated inhibitory synaptic currents in dissociated cortical cell cultures.
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