1,736 research outputs found

    Influence of Spartina alterniflora invasion stages on macrobenthic communities on a tidal flat in Wenzhou Bay, China

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    Muitos habitats costeiros vêm sendo alterados substancialmente pela invasão de Spartina alterniflora no leste da China. Em 2007, em uma planície de maré situada em Wenzhou Bay, foram analisadas riqueza de espécies, densidade e diversidade da macrofauna bêntica em relação a diferentes estágios da invasão da gramínea e à estação do ano. Para as medidas de diversidade foram usados os índices de Margalef (R) e de Shannon (H'). Foram detectados efeitos significativos do estágio de invasão e época do ano sobre a macrofauna. As comunidades macrofaunais foram mais complexas nas manchas onde a invasão de S. alterniflora estava no seu início, quando considerados os locais onde as manchas estavam em estágios mais avançados. Através das análises de agrupamento e ordenação as comunidades puderam ser classificadas pelo tipo de habitat formado em cada estágio de invasão da Spartina. Os resultados indicaram que a biodiversidade aumentou no estágio de invasão inicial (idade de invasão de 1 a 2 anos), mas diminuiu gradativamente com os estágios intermediário (idade de invasão de 3 a 4 anos) e completo (idade de invasão de 5 a 6 anos), mostrando assim o efeito deletério de S. alterniflora sobre a estrutura da macrofauna presente no local.Many coastal habitats in eastern China are being substantially altered by the invasion of Spartina alterniflora. The species richness, density, Margalef's diversity index (R) and Shannon's diversity index (H') of macrobenthic communities on a tidal flat in Wenzhou Bay, China, were analyzed with the factors of invasion stage and season, in 2007. A significant effect of invasion stage, season, and the interaction between them on communities was detected. The macrobenthic community was more complex in the patch of initial S. alterniflora invasion than in the patches of some other invasion stages. Macrobenthic communities were classified by cluster and ordination in accordance with the habitat character of the S. alterniflora invasion stage. Our research demonstrated that the S. alterniflora invasion stage affected the macrobenthic communities significantly. The results indicated that biodiversity increased in the initial stage of invasion (invasion age 1-2 years) and then decreased in the stage of invasion underway (invasion age 3-4 years) and in the stage of invasion completed (invasion age 5-6 years); this phenomenon was related to the change in the S. alterniflora canopy which accompanied the invasion stages

    PO-170 Epidemiology of children's febrile seizures and prospects for health education

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    Objective  In this paper, through the epidemiological characteristics of febrile seizures (FS) and the status quo of health education, the non-drug prevention system based on scientific physical activity intervention is gradually formed in the future, so as to establish "knowledge, pr34evention, medical, nursing ,sports nutrition” The protection and maintenance of the five-in-one sports promotion health network lays the theoretical foundation. Methods Through domestic and foreign literatures, CNKI, Pubmed, Web of science and other databases are reviewed. Results (1) The exclusion criteria of FS are similar at home and abroad, only the definitions of onset age are different, the disease has age dependence.(2) The index of FS prognosis health assessment is single. There are few reports on the post-exercise ability and physical changes of FS children. And there is a lack of preventive health care related to exercise and brain health.(3) The descriptive study of FS in China lacks the incidence rate based on large-scale population samples, and the interventional research is limited to the clinic. The prevention and prognosis interventions for this disease lack relevant health education guidelines and intervention programs for kindergartens, schools and communities.(4) In the process of continuous seizures, hypoxia can cause transient or long-term organ damage in the body, affecting the development of the nervous system. The effects of FS on physical fitness are mainly concentrated on balance ability, systemic coordination ability and motor discrimination ability. Balance, sensitivity and coordination quality are related to nervous system, skeletal muscle and sensory organs. Conclusions The research on the epidemiological characteristics of FS in China needs to be further improved. Prognosis and health assessment should be complementary to physical health and medical health. For children with history of febrile seizures, exercise as a simple, convenient, non-burden, drug-free effective way to promote central nervous system and brain health, has a positive effect on improving the immune level of children with FS and improving the prognosis of brain damage. Provide new ideas for prognosis and prevention, and promote health education and health communication of febrile seizures

    Impact of combinations of time-delay interferometry channels on stochastic gravitational wave background detection

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    The method of time delay interferometry (TDI) is proposed to cancel the laser noise in space-borne gravitational-wave detectors. Among all different TDI combinations, the most commonly used ones are the orthogonal channels A, E and T, where A and E are signal-sensitive and T is signal-insensitive. Meanwhile, for the detection of stochastic gravitational-wave background, one needs to introduce the overlap reduction function to characterize the correlation between channels. For the calculation of overlap reduction function, it is often convenient to work in the low-frequency approximation, and assuming the equal-arm Michelson channels. However, if one wishes to work on the overlap reduction function of A/E\rm A/E channels, then the low-frequency approximation fails. We derive the exact form of overlap reduction function for A/E\rm A/E channels. Based on the overlap reduction function, we calculate the sensitivity curves of TianQin, TianQin I+II and TianQin + LISA. We conclude that the detection sensitivity calculated with A/E\rm A/E channels is mostly consistent with that obtained from the equal-arm Michelson channels.Comment: 18 pages,10 figure

    Developments of a 2D Position Sensitive Neutron Detector

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    Chinese Spallation Neutron Source (CSNS), one project of the 12th five-year-plan scheme of China, is under construction in Guangdong province. Three neutron spectrometers will be installed at the first phase of the project, where two-dimensional position sensitive thermal neutron detectors are required. Before the construction of the neutron detector, a prototype of two-dimensional 200 mmx200 mm Multi-wire Proportional Chamber (MWPC) with the flowing gas of Ar/CO2 (90/10) has been constructed and tested with the 55Fe X-Ray using part of the electronics in 2009, which showed a good performance. Following the test in 2009, the neutron detector has been constructed with the complete electronics and filled with the 6atm.3He + 2.5atm.C3H8 gas mixture in 2010. The neutron detector has been primarily tested with an Am/Be source. In this paper, some new developments of the neutron detector including the design of the high pressure chamber, the optimization of the gas purifying system and the gas filling process will be reported. The results and discussion are also presented in this paper.Comment: 5 page

    Poly[[aqua­tris­(μ-benzene-1,4-dicarboxyl­ato)tricobalt(II)] methanol monosolvate monohydrate]

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    The asymmetric unit of the title compound, {[Co3(C8H4O4)3(H2O)]·CH3OH·H2O}n, consists of four crystallographically independent Co cations, four benzene-1,4-dicarboxyl­ate (bdc) anions, two water and one methanol solvent mol­ecule. Two of the Co cations and two of the bdc anions are located on centres of inversion, whereas all other atoms are located in general positions. In the crystal, two Co atoms are only fourfold coordinated by three O atoms from three bdc ligands and by one O atom from one coordinated water mol­ecule, while a third Co atom is coordinated by four O atoms from four bdc ligands within a strongly distorted tetra­hedral geometry. The other two Co cations are octa­hedrally coordinated by six O atoms from six bdc anions. The Co cations are linked by the bdc anions into a three-dimensional framework. From this arrangement, cavities are formed in which additional methanol and water mol­ecules are embedded
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