896 resultados para 0.044-0.04 µm


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Estudos de comunidades de esponjas marinhas são escassos no Brasil, sendo este trabalho pioneiro nessa abordagem para a Ilha Grande - RJ, um local de alta diversidade biológica. A estrutura das assembleias de esponjas marinhas e da comunidade bentônica marinha séssil foi avaliada, a partir de índices descritores de diversidade, em seis pontos da Ilha Grande e ilhas próximas, sendo três do lado continental e três do lado oceânico. As assembleias foram comparadas entre os diferentes lado e profundidade, através da contagem do número de indivíduos e área de cobertura por foto-quadrados. Paralelamente, as esponjas foram coletadas, fixadas e posteriormente identificadas através de metodologia e literatura especializada. Foi encontrado um total de 5.457 indivíduos, representando as Classes Demospongiae e Calcarea, distribuídos em 41 espécies e nove morfotipos, indicando maior diversidade para Lagoa Azul e menor para Parnaióca, sendo o local com maior riqueza a Ilha do Abraão. Dentre as espécies identificadas, quatro dominaram mais de 50% do total e 26 não alcançaram nem 5% da abundância absoluta. Análises de variância por GLM só evidenciaram diferença significativa para profundidade com substratos diferentes (F= 2,79; p<0,04), enquanto o fator lado (F= 2,23; p>0,16) e a interação entre os fatores (F= 1,17; p>0,38) não tiveram diferença estatística. As análises multivariadas de ordenação Cluster e MDS indicaram a formação de quatro assembleias de esponjas: 1) quatro locais com substrato não consolidado; 2) Lagoa Azul com substrato não consolidado; 3) locais oceânicos de substrato rochoso; e 4) locais continentais de substrato consolidado. Já para a comunidade geral, 49 espécies foram encontradas, sendo o Filo Porifera o de maior representatividade específica, apesar das macroalgas terem formado o grupo mais abundante. A comunidade bentônica foi dominada por quatro espécies, que juntas alcançaram média de 50% da cobertura bentônica: alga calcária incrustante, algas formadoras de tapete de turf, a esponja Iotrochota arenosa e o zoantídeo Palythoacaribaeorum. Estatisticamente, o lado continental se mostrou diferente do oceânico, o qual possui maior riqueza, diversidade e uniformidade de espécies, muito provavelmente pelo menor número de espécies dominantes e aliado a isso maior heterogeneidade de habitats, o que promove o aumento da diversidade. Quinze novas espécies estão sendo registradas para a Baía da Ilha Grande, sendo três novas espécies, as quais estão sendo descritas por especialistas, e 12 são novos registros de espécies ou gêneros para a região, evidenciando que a diversidade de esponjas marinhas na BIG é alta e ainda pouco conhecida e que a formação de assembleias pode ser devida a singularidade de cada local, implicando na necessidade de conservação dos costões rochosos da Ilha Grande e cercanias, a qual pode ser manejada através da realização de rápidos levantamentos sobre a riqueza e o número de indivíduos da espécie na região

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As doenças cardiovasculares são a principal causa de morte nos países ocidentais. Alguns estudos sugerem que o chá verde tem efeito benéfico sobre diferentes fatores de risco cardiovascular. No entanto, outros estudos não mostraram essa associação. Objetiva avaliar em mulheres pré-hipertensas obesas o efeito do consumo de chá verde sobre: a pressão arterial, a função endotelial, o perfil metabólico, a atividade inflamatória e a adiposidade corporal. Estudos clínico, randomizado, cruzado, duplo-cego e placebo-controlado. Durante 4 semanas as mulheres foram orientadas a ingerir 3 cápsulas de extrato de chá verde por dia (500mg extrato chá verde/cápsula) passando por 2 semanas de washout e posteriormente ingeriam por mais 4 semanas o placebo. As mulheres que iniciaram o estudo tomando placebo posteriormente utilizaram o chá verde. Ou seja, todas as pacientes receberam chá verde e placebo por um mesmo período. No início e final de cada tratamento foram analisadas as variáveis. Foram avaliadas 20 mulheres pré-hipertensas, obesidade grau I e II, idade entre 25 e 59 anos. O local do estudo foi o Laboratório da Disciplina de Fisiopatologia Clínica e Experimental Clinex. Universidade do Estado do Rio de Janeiro. As variáveis estudadas foram a pressão arterial, índice de hipertemia reativa (avaliada com Endo-PAT2000), proteína C reativa, interleucina-6, fator de necrose tumoral-α, molécula de adesão intercelular e molécula de adesão vascular celular, inibidor de ativador do plasminogênio, fator de crescimento endotelial vascular, E-selectina, adiponectina, colesterol total, LDL-colesterol, HDL-colesterol, triglicérides, glicemia, insulina, HOMA, índice de massa corporal, circunferência de cintura, circunferência de quadril, relação cintura quadril e percentual de gordura corporal. Como resultados, na avaliação da pressão arterial pela monitorização ambulatorial da pressão arterial, observou-se redução significativa da pressão arterial sistólica de 24 horas (pré 130,31,7 mmHg vs. pós 127,02,0 mmHg; p= 0,02), pressão arterial sistólica diurna (pré 134,01,7 mmHg vs. pós 130,72,0 mmHg; p= 0,04) e pressão arterial sistólica noturna (pré 122,21,8 mmHg vs. pós 118,42,2 mmHg; p= 0,02), após o consumo do chá verde, em comparação ao uso do placebo. Após o consumo do chá verde foi observado aumento, embora estatisticamente não significativo, no índice de hiperemia reativa (pré 1,980,10 vs. pós 2,220,14), além de redução expressiva na concentração da molécula de adesão intercelular (pré 91,88,0 ng/ml vs. pós 85,85,6 ng/ml) e do fator de crescimento endotelial vascular (pré 195,846,2 pg/ml vs. pós 158,638,7 pg/ml), porém sem significância estatística. As demais variáveis avaliadas não se modificaram de forma significativa após o consumo do chá verde, em comparação ao placebo. Foi observada forte correlação entre redução de pressão arterial sistólica e diastólica de 24hs, avaliada pela monitorização ambulatorial da pressão arterial, e o aumento do índice de hipertemia reativa (r= -0,47; r= -0,50, respectivamente). Os resultados do presente estudo sugerem que o chá verde tem efeito benéfico sobre a pressão arterial e possivelmente sobre a função endotelial.

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Estimulação transcraniana por corrente contínua (ETCC) sobre áreas corticais pré-selecionadas, tem aumentado o desempenho físico de diferentes populações. Porém, lacunas persistem no tocante aos mecanismos subjacentes à estes efeitos. Assim, a presente tese objetivou: a) investigar os efeitos da ETCC anódica (aETCC) e placebo (Sham) no córtex motor (CM) de indivíduos saudáveis sobre o desempenho de força máxima; b) comparar os efeitos da ETCC sobre a produção de força máxima e estabilidadade da força durante exercícios máximo e submáximo em sujeitos hemiparéticos e saudáveis; c) investigar o efeito da ETCC sobre a conectividade funcional inter-hemisférica (coerência eletroencefalográfica cEEG) do córtex pré-frontal (CPF), desempenho aeróbio e dispêndio energético (EE) durante e após exercício máximo e submáximo. No 1 estudo, 14 adultos saudáveis executaram 2 sessões de exercício máximo de força (EMF) dos músculos flexores e extensores do joelho dominante (3 séries de 10 rep máximas), precedidos por aETCC ou Sham (2mA; 20 mim). aETCC não foi capaz de aumentar o trabalho total e pico de torque (PT), resistência à fadiga ou atividade eletromiográfica durante o EMF. No 2 estudo, 10 hemiparéticos e 9 sujeitos saudáveis receberam aETCC e Sham no CM. O PT e a estabilidade da força (coeficiente de variação - CV) foram avaliados durante protocolo máximo e submáximo de extensão e flexão unilateral do joelho (1 série de 3 reps a 100% do PT e 2 séries de 10 reps a 50% do PT). Nenhuma diferença no PT foi observada nos dois grupos. Diminuições no CV foram obervadas durante a extensão (~25-35%, P<0.001) e flexão de joelho (~22-33%, P<0.001) após a aETCC comparada com Sham nos hemiparéticos, entretanto, somente o CV na extensão de joelhos diminuiu (~13-27%, P<0.001) nos saudáveis, o que sugere que aETCC pode melhorar o CV, mas não o PT em sujeitos hemiparéticos. No 3 estudo, 9 adultos saudáveis realizaram 2 testes incrementais máximos precedidos por aETCC ou Sham sobre o CPF com as respostas cardiorrespiratórias, percepção de esforço (PSE) e cEEG do CPF sendo monitoradas. O VO2 de pico (42.64.2 vs. 38.23.3 mL.kg.min-1; P=0,02), potência total (252.776.5 vs. 23773.3 W; P=0,05) e tempo de exaustão (531.1140 vs. 486.7115.3 seg; P=0,04) foram maiores após aETCC do que a Sham. Nenhuma diferença foi encontrada para FC e PSE em função da carga de trabalho (P>0,05). A cEEG do CPF aumentou após aETCC vs. repouso (0.700.40 vs. 0.380.05; P=0,001), mas não após Sham vs. repouso (0.360.49 vs. 0.330.50; P=0,06), sugerindo que a aETCC pode retardar a fadiga aumentando a conectividade funcional entre os hemisférios do CPF e desempenho aeróbio durante exercício exaustivo. No 4 estudo, o VO2 e EE foram avaliados em 11 adultos saudáveis antes, durante a aETCC ou Sham no CPF e 30 min após exercício aeróbio submáximo isocalórico (~200kcal). Diferenças não foram observadas no VO2 vs. repouso durante aETCC e Sham (P=0.95 e P=0.85). Porém, a associação entre exercício e aETCC aumentou em ~19% o EE após ao menos, 30 min de recuperação após exercício quando comparada a Sham (P<0,05).

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The effects of El Niño–Southern Oscillation events on catches of Bigeye Tuna (Thunnus obesus) in the eastern Indian Ocean (EIO) off Java were evaluated through the use of remotely sensed environmental data (sea-surface-height anomaly [SSHA], sea-surface temperature [SST], and chlorophyll a concentration), and Bigeye Tuna catch data. Analyses were conducted for the period of 1997–2000, which included the 1997–98 El Niño and 1999–2000 La Niña events. The empirical orthogonal function (EOF) was applied to examine oceanographic parameters quantitatively. The relationship of those parameters to variations in catch distribution of Bigeye Tuna was explored with a generalized additive model (GAM). The mean hook rate was 0.67 during El Niño and 0.44 during La Niña, and catches were high where SSHA ranged from –21 to 5 cm, SST ranged from 24°C to 27.5°C, and chlorophyll-a concentrations ranged from 0.04 to 0.16 mg m–3. The EOF analysis confirmed that the 1997–98 El Niño affected oceanographic conditions in the EIO off Java. The GAM results indicated that SST was better than the other environmental factors (SSHA and chlorophyll-a concentration) as an oceanographic predictor of Bigeye Tuna catches in the region. According to the GAM predictions, the highest probabilities (70–80%) for Bigeye Tuna catch in 1997–2000 occurred during oceanographic conditions during the 1997–98 El Niño event.

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Between June 1995 and May 1996 seven rookeries in the Gulf of California were visited four times in order to collect scat samples for studying spatial and seasonal variability California sea lion prey. The rookeries studied were San Pedro Mártir, San Esteban, El Rasito, Los Machos, Los Cantiles, Isla Granito, and Isla Lobos. The 1273 scat samples collected yielded 4995 otoliths (95.3%) and 247 (4.7%) cephalopod beaks. Fish were found in 97.4% of scat samples collected, cephalopods in 11.2%, and crustaceans in 12.7%. We identified 92 prey taxa to the species level, 11 to genus level, and 10 to family level, of which the most important were Pacific cutlassfish (Trichiurus lepturus), Pacific sardine (Sardinops caeruleus), plainfin midshipman (Porichthys spp.), myctophid no. 1, northern anchovy (Engraulis mordax), Pacific mackerel (Scomber japonicus), anchoveta (Cetengraulis mysticetus), and jack mackerel (Trachurus symmetricus). Significant differences were found among rookeries in the occurrence of all main prey (P≤0.04), except for myctophid no. 1 (P>0.05). Temporally, significant differences were found in the occurrence of Pacific cutlassfish, Pacific sardine, plainfin midshipman, northern anchovy, and Pacific mackerel (P<0.05), but not in jack mackerel (χ 2=2.94, df=3, P=0.40), myctophid no. 1 (χ 2=1.67, df= 3, P=0.64), or lanternfishes (χ 2=2.08, df=3, P=0.56). Differences were observed in the diet and in trophic diversity among seasons and rookeries. More evident was the variation in diet in relation to availability of Pacific sardine.

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Young-of-year (YOY) blue-fish (Pomatomus saltatrix) along the U.S. east coast are often assumed to use estuaries almost exclusively during the summer. Here we present data from 1995 to 1998 indicating that YOY (30–260 mm FL) also use ocean habitats along the coast of New Jersey. An analysis of historical and recent data on northern and southern ocean beaches (0.1–2 m) and the inner continental shelf (5–27 m) during extensive sampling in New Jersey waters from 1995 to 1998 indicated that multiple cohorts occurred (June–August) in every year. When comparable collections of YOY were made in the ocean and in an adjacent estuary, the abundance was 1–2 orders of magnitude greater on ocean beaches during the summer. The YOY were even more abundant in ocean habitats in the fall (September–October), presumably as a result of YOY leaving estuaries to join the coastal migration south. During 1999 and 2000, YOY bluefish were tagged with internal sequential coded wire microtags in order to refine our under-standing of habitat use and movement. Few (0.04%) of the fish tagged on ocean beaches were recaptured; however, 2.2% of the fish tagged in the estuary were recaptured from 2 to 27 days after tagging. Recaptured fish grew quickly (average 1.37 mm FL/d). On ocean beaches YOY fed on a variety of invertebrates and fishes but their diet changed with size. By approximately 80–100 mm FL, they were piscivorous and fed primarily on engraulids, a pattern similar to that reported in estuaries. Based on distribution, abundance, and feeding, both spring- and summer-spawned cohorts of YOY bluefish commonly use ocean habitats. Therefore, attempts to determine factors affecting recruitment success based solely on estuarine sampling may be inadequate and further examination, especially of the contribution of the summer-spawned cohort in ocean habitats, appears warranted.

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随着现代工业的发展,重金属污染日趋严重。重金属污染引发的环境和健康问题在许多国家都有报道,我国的重金属污染状况也不容乐观。土壤和水体中的重金属污染可以通过食物链进入人体,对人类健康造成很大的危害,如诱发癌症 和畸胎等。 植物修复是一种利用植物对重金属或有机污染物的超富集能力清除或减低污染的环境生物技术。植物修复的生物学机制的研究为这项技术走向实用化奠定了基础。植物修复近期的进展可能来自于可更有效地富集重金属的植物品种的选择、土壤条件的改善等;但长远看来,植物修复技术的巨大进步将取决于新的可更好地抵抗重金属或降解有机毒物的基因的鉴定和克隆,并通过转基因技术创造一批新的植物品种,如可迅速大量富集重金属的高生物量的用作环境净化的植物,以及可排拒重金属吸收的粮食、蔬菜和水果等作物。 本研究针对砷污染的植物修复机制,以超富集砷的凤尾蕨属植物——蜈蚣草为试材取得了如下进展: 1. 以从砷污染地区采集的蜈蚣草(Pteris vittataL.)为植物材料,利用抑制消减杂交(SSH)分离了经砷诱导处理与其对照间表达有差异的cDNA片段,以期得到与砷富集密切相关的基因。其中筛选到的一个cDNA片段与ABC transporter (ATP-binding cassette transporter)有较高的同源性。通过RACE方法对该基因进行了克隆,并进行了初步的结构和功能分析。结果表明所获得的PvABCTl (Accession No. AY496966)为一全长cDNA,长度为2165 bp,其中开读框架为1791 bp,编码597个氨基酸。该基因所编码的蛋白中含有2个ABC transporter特性结构域,1个ATP-binding cassette和2个ATP/GTP结合位点(P-loop),没有明显的跨膜区。 2. 对蜈蚣草在砷胁迫下PvABCT1基因的表达模式进行了研究。转录水平分析表明PvABCT1的表达受砷的诱导。进一步通过PvABCTl-GFP融合基因在洋葱细胞中的表达进行亚细胞定位,结果显示该基因可能定位于细胞质中。 3. 为了研究所克隆的PvABCT1基因的功能,本研究构建了PvABCT1的酵母表达载体,把该基因转入因ACR3基因缺失而对砷敏感的酵母突变株。酵母功能互补实验表明PvABCT1不仅不能与ACR3基因功能互补,反而使酵母对砷的敏感性增加,同时酵母细胞中的砷含量较未转化的酵母细胞增加。即在转入PvABCT1后,酵母细胞吸收了更多的砷。这暗示该基因与蜈蚣草中砷的高吸收有关。 针对食品重金属污染问题,本研究探讨了减低蔬菜对重金属吸收的方法及其 作用机理,取得了如下进展: 1.研究了钙离子和镧离子对镉离子胁迫下生菜种子萌发和植株生长的影响,结果表明在种子萌发时外施4 mM CaCI2或0.04 mg/L La(N03)3均可提高生菜对重金属镉的抗性。 2.通过检测0.5 mM CdCl2胁迫下生菜植株中的镉含量以及外施钙离子或镧离子后相应的镉含量,发现4 mM CaCl2可以增加镉胁迫下生菜植株中镉的积累;而0.04 mg/L La(N03)3可以降低镉胁迫下生菜植株中镉的积累。 3.对生菜中植物络合素合酶基因进行了克隆,通过RT-PCR分析以及植物络合素( phytochelatins,PCs)的检测,探讨了外施钙离子或镧离子对镉胁迫下生菜植株中植物络合素合酶基因在转录水平的表达量、植物络合素含量以及镉的积累三者之间的关系。结果表明:4 mM CaCl2可以提高镉胁迫下生菜植株中植物络合素合酶基因在转录水平的表达以及植物络合素的含量,增加镉的积累;而0.04 mg/L La(N03)3虽然同样可以提高植物络合素合酶基因在转录水平的表达以及植物络合素的含量,却能降低镉胁迫下生菜植株中镉的积累。这暗示外施钙离子可以促进用于重金属污染环境修复的植物对重金属的吸收,而外施镧离子可以用于降低叶菜类蔬菜中重金属镉的积累。

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Visakhapatnam is on the eastern sea board of India (17 degree 40' N and 83 degree 15' E) having a continental shelf of 45 km width which is provided with a polychaete rich, silty clay sea floor to a distance of 15 km and beyond, from the shore. Repeated trawling by a large number of trawlers over an area of 900 sq.km (30 x 30) resulted in the hardening of the substratum to the extent of making it uninhabitable to the polychaetes and polychaete feeding fish. The shoaling and strictly demersal marine catfish, Arius tenuispinis, which is a prolific polychaete feeder on the fishing grounds off Visakhapatnam, has been on the decline since 1979. The catch rate of fish dropped from 9.7 kg/boat per day in 1979 to 2.6 kg by 1985-86. In the bottomset gillnets, the catch per net dwindled from 4.4 kg in 1973 to 0.04 kg by 1985-86. The species has virtually disappeared from the fishing grounds off Visakhapatnam and further north, as a results of the cumulative effect of overfishing with trawlnets and bottomset gillnets. It is further aggravated by the hardening of the sea floor on these grounds due to repeated trawling over a narrow zone.

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The marine environment near Karachi, particularly the Baba channel, Chari Kundi channel and Manora channel have been found contaminated with industrial effluents discharged by Malir and Lyari rivers, since they carry a high concentration of toxic heavy metals viz. Pb, Zn, Cu and Mn emanating from the industrial area and are received and discharged by the Lyari river. Out of 60 seawater samples collected from the above mentioned areas, Pb was present in 55 samples and Zn in 58 samples. The concentration of Pb was between 0.04 and 59.2ppm and the concentration of Zn was between 0.05 and 1.9ppm. Similarly all the 60 sludge samples collected from Lyari outfall and its adjoining area have been found to contain Pb and Zn in alarmingly high concentratios, which for Pb was between 15.4 and 3209.9ppm while for Zn was between 87 and 111.3ppm. Cu and Mn were also found in all the above samples.

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空中花粉是植被类型、气候状况与大气环境质量的指示物之一。空中花粉雨的取样实验对化石花粉谱的解释和古植被的恢复具有指导意义,因此空中花粉分析成为第四纪孢粉学和古生态学研究的有效辅助手段。本研究在新疆天山中段北坡进行了短期的空中花粉监测(2001年7月~2006年7月),目的是获得局域性和区域性植被所散发的花粉类型及其数量信息,并探讨花粉数量的植被与气候指示意义、花粉传播以及受环境条件影响的程度,同时分析和检测花粉浓度受气候条件的影响情况。空中花粉的收集使用Cour-type捕捉器,分别在3个不同海拔梯度进行5年连续的空中花粉收集(夏秋季节每周一个样品,冬春季节每两周一个样品)。取样地点分别是新疆天山中段北部的天池气象观测站(43°53'58.38"N, 88°07'15.75"E , 海拔1942.5m)、中科院阜康荒漠生态系统定位站(44°17'27.41"N, 87°55'52.65"E, 海拔477m)和准噶尔盆地古尔班通古特沙漠南缘的北沙窝试验站(44°22'40.74"N, 87°55'9.74"E, 海拔443m),取样点的植被带跨度天山北坡的森林草原到低海拔的典型荒漠。 光学显微镜鉴定的空中花粉主要有43种类型(24科30属),而蕨类、苔藓与真菌孢子数量较少。孢粉类型多样性指数为2.45(Shannon Index)。显然,从样品中所鉴定的空中花粉种类与所观察的植物种类有很大的差距。花粉类型与数量在三个不同海拔梯度的取样点上也有明显差异。天池取样点的花粉类型较丰富,与天山北坡垂直带植被分布以及丰富的植被成分相对应,花粉的优势种类为雪岭云杉(Picea schrenkiana)、蒿属(Artemisia)、藜科(Chenopodiaceae)、柽柳科(Tamaricaceae)和麻黄属(Ephedra),高代表性的外源荒漠花粉类型“削弱了”本地花粉类型的代表性;阜康与北沙窝取样点的花粉类型主要来自荒漠成分的藜科、蒿属、麻黄属、蒺藜科(Zygophyllaceae, 白刺属Nitraria为主)、柽柳科(柽柳属为主)、蓼科(Polygonaceae, 沙拐枣属Calligonum为主)等耐旱植物。花粉数量与植被数量并非简单的线性关系。空中和表土花粉的数量分析表明,藜科、蒿属、麻黄属花粉具有超代表性;雪岭云杉花粉的代表性适中;禾本科(Gramineae)、榆属(Ulmus)、白刺属、柽柳科、沙拐枣属花粉代表性较差。 5年平均花粉浓度大小依次是阜康(81.668 grains/100m3)>天池(51.726 grains/100m3)>北沙窝(45.7685 grains/100m3)。蒿属花粉的峰值出现在秋季,并且出现双峰现象(可能与不同蒿类花期分布不均有关),而其它木本和草本类植物花粉浓度的峰值为单峰,具有明显的季节性,春夏之交开花的桦木属、榆属等类型较为明显。藜科花粉的峰值出现在夏季,麻黄和柽柳的峰值出现在盛夏,桦木属、柳属Salix、雪岭云杉等花粉浓度峰值出现在初夏,与其花期物候相对应。木本植物花粉以雪岭云杉为主,其次为桦木属(Betula)、榆属、柳属、胡颓子科(Elaeagnaceae)花粉,柳属花粉百分比在三个取样点分配比较均匀,桦木属花粉在空间分布上差异明显,与植物分布数量相关。胡颓子科的花粉出现时间短,数量也较少。榆属花粉出现的季节性明显,代表性也较差。因此解释地层中出现类似的低代表性和高代表性的花粉类型时,需要注意其百分比数量的适当校正。木本植物花粉百分比随海拔高度变化成正比关系,对植被的指示性较好。雪岭云杉的年平均花粉浓度在天池取样点明显高于其它两个取样点,5年的平均花粉浓度和百分比与海拔高度呈正比。天池取样点的百分比最高为28.85%,平均为21.15%,而北沙窝与阜康两地5年平均百分比含量分别为0.69%和1.57%,这种时空变化规律与植被数量的关系密切。藜科花粉百分比在阜康和北沙窝取样点占绝对优势,5年的平均花粉浓度与海拔高度呈反比。蒿属花粉年平均浓度与海拔高度关系微弱(R2=0.04,p =0.46),而花粉百分比与海拔高度有显著的线性正比关系(R2=0.72,p<0.0001)。但在低海拔的两个取样点之间差异不明显。 年平均花粉百分比和花粉浓度随海拔梯度而变化,主要花粉类型的变化规律存在差异。暗针叶林雪岭云杉花粉的年平均百分比在低海拔的阜康和北沙窝地区低于3%,在盛花期的6月初,低海拔的取样点也未见超过5%,雪岭云杉花粉的传播在研究区范围内数量分布变化较大,再次表明该类型的花粉在原地沉积效率很高。空中花粉数量能够较好地指示主要的植被带,盛花期内50%以上的雪岭云杉花粉含量则指示了雪岭云杉森林植被带,而高含量的蒿属植物花粉指示了天山山前冲积平原上的蒿类荒漠,相反,高含量的藜科花粉代表了低海拔地区的荒漠。雪岭云杉花粉百分比与浓度均与海拔高度呈显著的线性正比关系,表明雪岭云杉花粉传播的局限性。主要的非木本植物藜科花粉的浓度与海拔高度成反比,蒿属则相反,表明藜科与蒿属花粉在研究区具有很好的植被与气候指示意义。 花粉绝对数量、百分比、浓度具有明显的年际变化,其原因与气候状况的变化有关,年平均花粉浓度、主要类型的花粉浓度与气候参数(降水量、平均温度、最高和最低温度、相对湿度等)的相关分析表明,降水量和湿度与花粉浓度呈负相关程度较高,与其它气候参数则呈显著的正相关。干旱指数、花粉比值、花粉百分比(AP,NAP)与七月份平均气温,年平均降水量的相关系数(Pearson correlation),Ar/Ch与七月平均温度在0.01水平上呈显著的正相关(R2=0.894), 与年平均降水量在0.01水平上呈显著的负相关(R2=0.874)。AP花粉百分比与七月份平均温度呈显著的负相关(R2=0.71, p<0.0001),与年降水量呈正相关(R2=0.43, p=0.01),而NAP花粉正相反。利用短期监测的空中花粉雨数据计算得到的花粉比值以及干旱指数在研究区具有明确的指示意义,尤其是干旱指数、Ar/Ch、Ar/Ep,这些都可为表土花粉、植被与气候关系模型的建立提供重要的参考信息。 气候参数在很大程度上影响大气花粉的浓度,而风速和风向对空中花粉的传播、散布影响较大,花粉的来源与传播受风向和风速的控制。不同取样点的空中花粉数量差异受地形条件影响很明显,这种差异也可利用地形空气动力学特征的差异来解释,天池监测站因“逆坡”(upslope)的气流促进了低海拔的花粉流向高海拔传播。 研究区的空中花粉数量信息是研究表土花粉、植被和气候关系以及第四纪古生态学的重要基础。本研究提高了对研究区空中孢粉的类型及其传播规律的认识和理解,增加了解空中花粉受环境影响的主要因素及其影响程度,对地层孢粉类型鉴定和花粉数据的解释提出指导性建议,对本地区的古植被与古环境研究增加现代孢粉学的参考依据和信息,并可为建立区域性的现代孢粉-植被-气候关系模型提供可靠依据。 同时,本报告也讨论了存在问题和不足,并提出了今后工作的可能完善方案。

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Value of length growth parameters L∞, K and t(sub)0 from age-length relation obtained from length-frequency analysis for the soldier catfish stock were estimated to be 47.6 cm, 0.51 per year and 0.03 year respectively. The age at recruitment (t [sub]r) was 0.58 year and the age at first capture (t[sub]c) 0.83 year. The total mortality (Z) was 0.88 including the present natural mortality (M) of 0.84 and fishing mortality (F) of 0.04. The total stock of this fish along the Northwest coast of India was assessed to be 32,413 tons and the MSY 5,426 tons which is much higher than the current catch of 863.8 tons. The potential yield (P[sub]y) of 38.7 g per recruit could be obtained at the optimum of exploitation (t[sub]y) of 2.84 years.

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Experiment was conducted to study the effect of dietary protein level on growth and nutrient utilization by angel fish (Pterophyllum scalare) juveniles. Fifty-four juveniles (average wt. 2-2.5 g) were equally divided in three treatments with each of three replicates. Three formulated diets with graded protein levels, T1 (35% CP), T2 (40% CP) and T3 (45% CP) were fed to juveniles for 45 days. A trend of higher weight gain %, SGR, FER and PER was found with the increased CP level in the feed. Feed intake was similar in all the groups. T3 group fed with 45% CP registered highest weight gain % (43.26 ± 2.07), SGR (0.78 ± 0.04), FER (0.29 ± 0.01), which were significantly higher (P<0.05) than the T1 and T2 groups. Protein digestibility of T2 and T3 groups was significantly higher than the T1 group. Survival was similar in all the experimental groups. Diet with 45% CP with protein energy ratio of 112.62 mg protein/K cal. is ideal for juvenile angel fish for indoor rearing.

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A 90-day experiment was conducted to determine the effect of restricted ration and full feeding on the recovery growth and carcass compositions of fingerlings (average weight - 20.74 ± 0.13 g) of rohu, Labeo rohita (H.). Rohu fingerlings procured from a local fish breeder were fed with commercial pelleted feed (27% crude protein) during the two-week acclimatization in the laboratory condition. Experimental pelleted diet (30% crude protein) was prepared and the control group (T sub(CFR)) was fed at 3% of body weight for the 90-day trial period. The experimental group T sub(1FR) was fed for three days at 1% of body weight and the next three days at 3% of body weight, T sub(2FR) was fed for seven days at 1% of body weight and the next seven days at 3% of body weight, T sub(3FR) was fed for 15 days at l% of body weight and the 15 days at 3% of body weight and T sub(4FR) was fed for 25 days at 1% of body weight and the next 25 days at 3% of body weight, alternating between 1 and 3% for the specified period during the 90-day trial period. Daily rations were divided into two equal meals per day at 09.00 and 16.00 hours. Average percent survival rate of rohu during the 90-day trial period was more than 90. Percent live weight gain (98.90 ± 0.34, 113.0 ± 5.93, 125.71 ± 11.01 and 141.90 ± 2.89), specific growth rate (1.53 ± 0.01 1.68 ± 0.06, 1.80 ± 0.10 and 1.96 ± 0.02%/d) and absolute growth rate (1.33 ± 0.13, 1.38 ± 0.07, 1.39 ± 0.04 and 1.44 ± 0.07g/d) of the experimental groups (T sub(1FR), T sub(2FR), T sub(3FR) and T sub(4FR) respectively) increased with the advancement of the experiment in comparison to those in control, T sub(CFR) (90.92 ± 5.81%, 1.44 ± 0.07%/d and 1.34 ± 0.20g/d, respectively) and were proportionately correlated with the degree of deprivation probably through the mechanism of increased feed intake (hyperphagia), feed efficiency ratio or gross growth efficiency, protein efficiency ratio and the superior feed conversion ratio reflecting in better performance index. The body length and muscle composition of fish indicated that recovery growth happened due to protein growth but certainly not due to fat deposition in the gut. Feeding at 1 and 3% of body weight alternating over a period of 25 days might economize the culture operation of rohu.

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To investigate the effect of protein restriction with subsequent re-alimentation on nutrient utilization, hematological and biochemical changes of Indian major carp, Rohu (Labeo rohita H.), 150 acclimatized Rohu fingerlings (average 20.74 ± 0.13 g) divided into five experimental groups (30 fingerlings in each groups with three replications with 10 fingerlings in each) for experimental trial of 90 days using completely randomized design. Control group (T sub(CPR)) was fed with feed having 30% crude protein at 3% of body weight for 90 days trial period. Other experimental groups T sub(1PR) was alternatively 3 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(2PR) was alternatively 7 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(3PR) was alternatively 15 days fed with feed having 20% CP and 30% CP at 3% of body weight and T sub(4PR) was alternatively 25 days fed with feed having 20% CP and 30% CP at 3% of body weight during 90 days trial period with daily ration in two equal halves at morning and afternoon. It was noticed that retention of different nutrients was almost similar among all treatment groups indicated improvement of digestibility of nutrients might not be the mechanisms for recovery growth in carps. Increased percent feed intake of body weight (hyperphagia) (4.14 ± 0.30 or 4.94 ± 0.46 and 3.33 ± 0.29), improved specific growth rate (1.86 ± 0.09 or 2.26 ± 0.05 and 1.43 ± 0.01), absolute growth rate (1.57 ± 0.08 or 1.84 ± 0.18 and 1.36 ± 0.12), protein efficiency ratio (1.19 ± 0.11 or1.16 ± 0.12 and 1.05 ± 0.09) were the important mechanism showing better performance index (21.60 ± 1.09 or 23.80 ± 0.21 and 19.45 ± 0.37) through which the experimental groups which were protein restricted and re-alimented at 3 or 7 days alternatively during 90 days trial period could able to compensate the growth retardation and to catch up the final body weight of control (128.68 ± 11.53 g/f) but other experimental groups failed to compensate during 90 days trial period. Result of the present study indicated that deprived fish i.e., fish received alternate 3 or 7 days protein restriction and re-alimentation showed recovery growth had still lower values of Hb (10.21 ± 0.02, and 9.88 ± 0.04 g/dl), hematocrit value (30.62 ± 0.05 and 26.64 ± 0.11%), total erythrocytic count (3.40 ± 0.01 and 3.29 ± 0.01 X10super(6) mm³), plasma glucose (126.93 ± 0.20 and 126.67 ± 0.05 mg/dl), total plasma lipid (1.04 ± 0.01 and 1.02 ± 0.01 g/dl) and liver glycogen (290.10 ± 0.80 and 288.99 ± 0.95 mg/kg) in comparison to control (10.56 ± 0.08 g/dl, 31.68 ± 0.24%, 3.52 ± 0.03 X10super(6) mm³, 128.23 ± 0.25 mg/dl, 1.07 ± 0.01g/dl and 292.00 ± 0.23 mg/kg) at the end of 90 days trial but total plasma protein in deprived group was compensated with advancement of trial period. All hematological and biochemical parameters studied were proportionately lowered in the experimental group got higher degree of deprivation. These findings suggested that with the increase of trial length complete compensation of hematological and biochemical profiles of rohu might be achieved. The results indicated that the implementation of alternative 7 days low and high protein diet feeding during aquaculture of carps could make economize the operation through minimizing the feed input cost.

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Three short-chain neurotoxins named NT-I, NT-II, and NT-III were purified from the venom of Naja kaouthia, a snake distributed throughout the south of Yunnan province, China, by a series of chromatographic steps, including an FPLC Resource S column. Their molecular weights, determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS, were 6952.19 Da, 6854.92 Da, and 6828.80 Da, respectively. NT-I consisted of 62 amino acid residues, and the other two consisted of 61 amino acid residues, including 8 cysteines. After hydrolysis by endoproteinase Glu-C, their primary sequences were determined. A test of their activities demonstrated that they effectively inhibited muscle contractions induced by electric stimulation. Furthermore, the extent of inhibition caused by NT-II and NT-III was less than that of NT-I. The IC(50)s were 0.04 mug/ml, 0.20 mug/ml, and 0.23 mug/ml for NT-I, NT-II, and NT-III, respectively. Compared with NT-II and NT-III, the higher activity of NT-I may be a result of the amino acid residue substitution Ile36 to Arg36.