897 resultados para SPATIO-TEMPORAL DISTRIBUTION
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In this project, have been studied to determine the appropriate model to spatial, temporal and diversity of demersal fishes in the Sea of Oman, including Trichiuridae, Nemipteridae, Haemulidae, Arridae, Synodontidae, Batoidfishes, Carangidae, Scianidae, Carchariniformes and Serranidae. This research became operational from catch data during 2003 to 2013 (in 2007, due to the lack of ship failed). Processing and calculations was evaluated by using the software Excel, SPSS, Arc GIS and table curve 3D highest biomass and abundance was showed in strata A and C and 10-30 m depth layers was showed the best condition biomass. In other words, highest biomass was showed in the eastern region in the Oman Sea than the central and western regions. Batoidfishes and Trichiuridae had the highest biomass .Depth factors was showed a significant correlation with the biomass. Scianidae, Serranidae and Haemulidae were showed a large decline. Synodontidae was showed a very large increase. The largest of Shannon index belong to central and western region of the Oman Sea. The highest Shannon index was showed 10-20 and 50-100 m, respectively. The Distribution maps based on the biomass was analyzed by using Arc GIS software. So that were identified in the first time in a ten-year period and carefully catch stations any economic of aquatic group. In conclusion, the depth can be found in the pattern of distribution, abundance and diversity of fish from away the beach so that follow specific pattern.
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Spatio-temporal modelling is an area of increasing importance in which models and methods have often been developed to deal with specific applications. In this study, a spatio-temporal model was used to estimate daily rainfall data. Rainfall records from several weather stations, obtained from the Agritempo system for two climatic homogeneous zones, were used. Rainfall values obtained for two fixed dates (January 1 and May 1, 2012) using the spatio-temporal model were compared with the geostatisticals techniques of ordinary kriging and ordinary cokriging with altitude as auxiliary variable. The spatio-temporal model was more than 17% better at producing estimates of daily precipitation compared to kriging and cokriging in the first zone and more than 18% in the second zone. The spatio-temporal model proved to be a versatile technique, adapting to different seasons and dates.
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A exposição gestacional ao etanol produz um amplo espectro de defeitos neurocomportamentais que podem persistir ao longo da vida. Dentre os distúrbios mais comumente observados estão o transtorno do déficit de atenção e hiperatividade (TDAH) e os déficits de aprendizado e memória. Apesar da grande quantidade de estudos, os mecanismos envolvidos com a manifestação destes transtornos permanecem pouco conhecidos. Estudos em roedores vêm demonstrando que o período equivalente ao terceiro trimestre de gestação é critico para o aparecimento destas alterações comportamentais. Durante este período, que é caracterizado por intensa sinaptogênese, a neurotoxicidade do etanol vem sendo atribuída ao bloqueio dos receptores glutamatérgicos do tipo N-metil-D-aspartato (NMDA) e hiperativação dos receptores do ácido gama-aminobutírico do subtipo A (GABAA). Tendo em vista que ao longo do desenvolvimento estes receptores diferem em relação a função e distribuição espaço-temporal, neste estudo avaliamos a contribuição relativa do bloqueio dos receptores NMDA e hiperativação dos receptores GABAA durante o período equivalente ao terceiro trimestre de gestação para a manifestação da hiperatividade locomotora e para os distúrbios de aprendizado e memória de camundongos pré-púberes. Para tanto, este estudo foi realizado em duas etapas. Na primeira, investigamos os efeitos da exposição isolada ao bloqueador NMDA MK801 (MK) e ao agonista GABAA muscimol (MU). Para tanto, em dias alternados do segundo dia pós-natal (PN2) a PN8, os animais receberam uma injeção intraperitoneal de Salina (SAL), MK nas doses de 0,1, 0,3 ou 0,5 mg/kg ou de MU nas doses de 0,1 0,3 ou 0,5 mg/kg. Na segunda etapa investigamos os efeitos da administração simultânea de MK (0,1mg/kg) e MU (doses 0,02, 0,1 ou 0,5 mg/kg). Em PN25, a atividade locomotora foi automaticamente avaliada por 15 min no teste de campo aberto. Em PN31 e PN32, o aprendizado e memória foi avaliado no teste da esquiva passiva inibitória. Em relação aos resultados da exposição isolada a cada uma das drogas, apenas o tratamento com MK promoveu um aumento dose dependente na atividade locomotora. No teste da esquiva passiva inibitória, os animais expostos as maiores doses de MK e MU apresentaram déficits de aprendizado e memória. Em relação aos resultados da exposição combinada de MK e MU, não foram observadas diferenças significativas entre os grupos na atividade locomotora. Na esquiva passiva inibitória, a administração simultânea de MK e MU, em doses que administradas isoladamente não tiveram efeito, promoveu prejuízos de aprendizado e memória. Nossos resultados sugerem que, enquanto a hiperatividade locomotora está associada apenas com o bloqueio dos receptores NMDA, os déficits de aprendizado e memória podem ser produto de uma ação sinergista do etanol nos dois receptores.
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辽东栎是我国暖温带落叶阔叶林地带的优势乔木树种之一。通过26年的定位监测,对子午岭辽东栎林种子质量消减、种子萌发与环境条件、实生苗时空分布动态以及对其森林更新的影响等方面进行了初步探讨。结果表明:辽东栎林在子午岭半阳坡、半阴坡和阴坡3种类型中,平均完好种子占种子总数的26.65%;霉变种子占18.72%;动物取食虫蛀种子在阴坡远高于半阴坡和半阳坡,占到种子总数的26.32%;已发芽的种子占其总数的28.31%,且半阴坡>半阳坡>阴坡。每年均有大量种子生产,但在生境与动物的共同作用下,种子数量和质量受到很大影响,多达73.35%的种子失去生命力,直接影响实生苗的形成;地表覆盖物虽能促进种子的快速发芽,但对成苗却是一个物理障碍,影响是负作用的,主要影响因子是地表覆盖物的厚度和含水量;在辽东栎林下虽有一定的实生幼苗分布,但数量极少,平均密度仅为140~120株/hm2,且不同立地条件差异显著,严重影响森林的天然更新。
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Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant-Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.
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研究胶州湾浮游植物的物种组成与时空分布的特点,对于了解该湾生态系统的现状与历史变化趋势以及生态系统对自然条件变化和人类干扰的响应具有重要意义。 本文根据2004年每月一次采集的浮游植物样品,分析了胶州湾浮游植物的物种组成和优势种的时空分布情况。调查发现浮游植物共142种,分属于6门53属,其中硅藻门40属113种,占总物种数的79.6%;甲藻门10属24种,占总物种数的16.9%;其它为金藻门1属2种,裸藻1属1种,绿藻1属2种。浮游植物丰度周年波动范围为11.12-14602.39×104cells/m3,全年平均为1857.55×104cells/m3。全年丰度最高的藻为环纹劳德藻(Lauderia annulata),出现在2月份,而全年的丰度最高值也出现在2月份。在胶州湾中,硅藻所占比例最大,平均为97.44%,最高为99.95%,最低为82.55%。浮游植物的丰度的周年变化:有两个高峰,分别出现在2月份和10月份,是典型的温带海域双高峰的分布形式。 胶州湾浮游植物的优势种分析,采用Kikvidze等(2002)提出的确定优势种数量的计算方法,再依据各物种的优势度排序最终确定优势种。其中在多样性最低的6月和10月,优势种数目均为1种,分别为丹麦细柱藻(Leptocylindrus danicus)和中肋骨条藻(Skeletonema costatum)。而在多样性指数较低的1月、2月,优势种数目分别为2和3;而在物种多样性比较高的5月、7月、11月,由于分布相对比较分散,所以优势种数量较多。这说明这个方法可以较好地完成对胶州湾浮游植物群落分析时确定优势种的目标。优势种出现频率较多的种类为中肋骨条藻(1、3、4、5、8、10、11、12月)、洛氏角毛藻(Chaetoceros lorenzianus)(7、8、9、11、12月)、尖刺拟菱形藻(Pseudonitzschia pungens)(2、3、5、7月)、加拉星杆藻(Asteronella kariana)(1、2、3、5月)、密联角毛藻(Chaetoceros densus)(5、11、12月)、扭鞘藻(Streptothece thamesis)(7、8、9月)、夜光藻(Noctiluca scintillancs)(4、5、7月)、奇异菱形藻(Nitzschia paradoxa)(5、11、12月),对这些种的时空分布进行了分析。 对2004年胶州湾的浮游植物数据进行分层聚类分析后,发现可以将胶州湾划分为三个海区:湾南与湾外海区、湾中西部海区、湾东海区。
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浮游动物作为海洋食物链中承上启下的一环,其群落结构和动态变化直接影响着海洋生态系统能流、物流的方向和效率。胶州湾作为一个受自然环境和人类活动双重影响的海湾,是研究人为活动对自然生态系统影响的模式港湾。因此,深入研究胶州湾浮游动物的群落特征及时空分布特点对了解该海湾生态系统的现状与历史变化趋势以及生态系统对自然条件变化和人类干扰的响应具有重要意义,也可为其他海区的研究提供参考资料。 本文根据2004年1月-12月用浅水I型和浅水II型浮游生物网在胶州湾每月一次的垂直拖网采集的浮游动物样品,分析了胶州湾浮游动物的物种组成和优势种的时空分布特征。2004年胶州湾浮游动物共74个种,分属于暖温带近岸种和暖温带近海种。浮游动物丰度周年波动范围1006-15571 ind./m3,全年平均5187 ind./m3。在胶州湾体长<1mm的浮游动物丰度和生物量最大。浮游动物的丰度和物种多样性季节变化明显,春夏大(高),秋冬小(低)。多数月份浮游动物丰度在湾内大于湾外。物种多样性在湾北和湾南较低,在湾中心和湾外较高。 胶州湾浮游动物优势种为双刺纺锤水蚤、小拟哲水蚤、太平洋纺锤水蚤、中华哲水蚤、拟长腹剑水蚤、近缘大眼剑水蚤、长尾住囊虫、强壮箭虫、短角长腹剑水蚤、八斑芮氏水母和小介穗水母等。双刺纺锤水蚤全年都是优势种,小拟哲水蚤除了4月其余月份都是优势种。其他优势种季节更替明显,冬、春季(12月、1-5月)优势种为中华哲水蚤、拟长腹剑水蚤、近缘大眼剑水蚤、长尾住囊虫等;夏季(6-8月)太平洋纺锤水蚤代替中华哲水蚤、拟长腹剑水蚤成为优势种;秋季(9-11月)优势种更替频繁,9月为短角长腹剑水蚤和太平洋纺锤水蚤,10月为太平洋纺锤水蚤、拟长腹剑水蚤和长尾住囊虫,11月为拟长腹剑水蚤、长尾住囊虫、近缘大眼剑水蚤和强壮箭虫。 双刺纺锤水蚤与中华哲水蚤在4月达到数量高峰,丰度分别为5604ind./m3和493 ind./m3。长尾住囊虫6月丰度1809 ind./m3为全年最大。小拟哲水蚤、太平洋纺锤水蚤和近缘大眼剑水蚤在7月达到数量高峰,丰度分别为1667 ind./m3、4000 ind./m3、775 ind./m3。短角长腹剑水蚤和强壮箭虫在8月丰度最大,分别为389ind./m3和192 ind./m3。八斑芮氏水母和小介穗水母分别在3、8月大量出现,丰度分别为194 ind./m3、358 ind./m3。拟长腹剑水蚤全年有7、10月两个高峰。双刺纺锤水蚤、小拟哲水蚤、太平洋纺锤水蚤、短角长腹剑水蚤、八斑芮氏水母和小介穗水母主要在湾北密集;中华哲水蚤密集区趋向于湾中心和湾外;近缘大眼剑水蚤、拟长腹剑水蚤、异体住囊虫和强壮箭虫等分布广泛,不同月份密集区不同。 从目前我们所掌握的资料来看,近30年来,胶州湾浮游动物的种类组成和优势种群没有发生大的变化。与70年代相比,2004年的物种数基本不变,但物种组成稍有不同;优势种丰度大大降低。与90年代相比,2004年物种数有所增加,其中水母类增加了15种,八斑芮氏水母成为冬季优势种;浮游动物的丰度和优势种的水平分布格局基本不变。胶州湾浮游动物的生态类型与渤海相似,但与黄海有所差异;胶州湾优势种的丰度大于渤海,且高峰期比渤海提前一个月。
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The field observation of this study was carried out in the Changjiang Estuary from May 19 to 26,2003, just a few days before the Three Gorges Dam began to store water. A total of 29 stations, including 2 anchor stations, were distributed through almost the whole salinity gradient Based on the data gained from these stations, the biogeochemical characteristics of dissolved oxygen (DO) were examined. Spatial distribution of DO concentrations showed the pattern that it increased in a downriver direction. DO concentration generally varied within a narrow range of 733-8.10 mg l(-1) in the freshwater region and the west part of the mixed water region, and after that it increased rapidly. In vertical direction, the differences in DO concentrations between surface and 2 m above the bottom were big at the stations with water depths exceeding 20 m; DO concentration up to 14.88 mg l(-1) was recorded at the sea surface, while at 2 m above the bottom its concentration was only about 4 mg l(-1). The fluctuation in DO concentrations was small during a period of 48 h in the mixed water region and 2 m above the bottom of the seawater region; while it was large during the same period in the seawater region for surface and 5 m below the surface layer, and a maximum variation from 8.77 to 12.66 mg l(-1) in 4 h was recorded. Oxygen fluxes also showed a marked spatio-temporal variation. As a whole, the freshwater region and mixed water region were an oxygen sink while the seawater region was a source. Relationships between dissolved oxygen and some biogeochemical parameters which could markedly influence its spatio-temporal distribution were discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.
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Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.
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Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.
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Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity
Resumo:
Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.
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Synoptic wind events in the equatorial Pacific strongly influence the El Niño/Southern Oscillation (ENSO) evolution. This paper characterizes the spatio-temporal distribution of Easterly (EWEs) and Westerly Wind Events (WWEs) and quantifies their relationship with intraseasonal and interannual large-scale climate variability. We unambiguously demonstrate that the Madden–Julian Oscillation (MJO) and Convectively-coupled Rossby Waves (CRW) modulate both WWEs and EWEs occurrence probability. 86 % of WWEs occur within convective MJO and/or CRW phases and 83 % of EWEs occur within the suppressed phase of MJO and/or CRW. 41 % of WWEs and 26 % of EWEs are in particular associated with the combined occurrence of a CRW/MJO, far more than what would be expected from a random distribution (3 %). Wind events embedded within MJO phases also have a stronger impact on the ocean, due to a tendency to have a larger amplitude, zonal extent and longer duration. These findings are robust irrespective of the wind events and MJO/CRW detection methods. While WWEs and EWEs behave rather symmetrically with respect to MJO/CRW activity, the impact of ENSO on wind events is asymmetrical. The WWEs occurrence probability indeed increases when the warm pool is displaced eastward during El Niño events, an increase that can partly be related to interannual modulation of the MJO/CRW activity in the western Pacific. On the other hand, the EWEs modulation by ENSO is less robust, and strongly depends on the wind event detection method. The consequences of these results for ENSO predictability are discussed.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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With the need to deploy management and monitoring systems of natural resources in areas susceptible to environmental degradation, as is the case of semiarid regions, several works have been developed in order to find effective models and technically and economically viable. Therefore, this study aimed to estimate the daily actual evapotranspiration (ETr) through the application of the Surface Energy Balance Algorithm for Land (SEBAL), from remote sensing products, in a semiarid region, Seridó of the Rio Grande do Norte, and do the validation of these estimates using ETr values obtained by the Penman-Monteith (standard method of the Food and Agriculture Organization-FAO). The SEBAL is based on energy balance method, which allows obtaining the vertical latent heat flux (LE) with orbital images and, consequently, of the evapotranspiration through the difference of flows, also vertical, of heat in the soil (G), sensitive heat (H) and radiation balance (Rn). The study area includes the surrounding areas of the Dourado reservoir, located in the Currais Novos/RN city. For the implementation of the algorithm were used five images TM/Landsat-5. The work was divided in three chapters in order to facilitate a better discussion of each part of the SEBAL processing, distributed as follows: first chapter addressing the spatio-temporal variability of the biophysical variables; second chapter dealing with spatio-temporal distribution of instant and daily radiation balance; and the third chapter discussing the heart of the work, the daily actual evapotranspiration estimation and the validation than to the study area