991 resultados para 140


Relevância:

10.00% 10.00%

Publicador:

Resumo:

EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two driving parameters to bound terrestrial carbon sequestration associated with an increase in carbon dioxide concentration.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Four feeds having different protein levels were separately tested on Tor khudree fry having an average length of 23.5 mm and weight 55 mg. The best average growth of 15.66 mg and 0.456 mm/day was obtained with Feed IV which comprised rice bran, ground nut oil cake, Acetes, wheat flour and mineral mix at the ratio of 1:1:1:0.7143:0.01428. These constitute 35.29% of proteins. The Feed II which comprised R.B + G.O.C. + prawn shell + wheat flour and mineral mix at a ratio of 1:1:1:0.7143:0.01428 contained 32.61% crude proteins. It provided a growth rate of 14.83 mg and 0.440 mm per day. The conversion rates were 38.258 and 37.776 for feeds IV and II respectively. Since Feed II is cheaper than Feed IV and provides almost equal growth rate, it can be used in the nurseries for intensive rearing of T. khudree fry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

水青冈林是欧洲、北美东部和日本温带地区最主要的地带性植被之一。在我国,水青冈林仅分布在亚热带山地。因此,无论其物种组成,还是其群落特征都具有明显的区域特点。然而,有关我国水青冈林群落特征的研究还相对较少。大巴山是我国水青冈林分布最集中的地区之一,保存有较大面积的原始水青冈林。本文通过样方调查和植物群落数量特征统计分析的方法,研究了当地巴山水青冈群落和米心水青冈群落的物种多样性特征和群落结构与动态。主要结果如下: 巴山水青冈群落7个样地中,共记录到维管束植物77科、142属、217种。乔木层以壳斗科、杜鹃花科等科为主;灌木层以蔷薇科、忍冬科以及乔木树种的幼树为主;草本层以苔草属植物及普通鹿蹄草占优势。群落区系地理成分划分为16个类型及亚型。不同多样性指数的大小在不同层次有所不同。阳坡、半阳坡的物种多样性高于阴坡;不同层次的物种多样性与海拔、土壤特征的回归关系不同。群落建群种和乔木层主要树种的重要值与物种多样性主要表现为负相关关系。灌木层物种多样性主要受到环境因素的影响,而乔木层和草本层物种多样性更明显地受到环境因子和群落自身特征的双重影响。 巴山水青冈群落的乔木层成层明显。根据树冠高度分布可以将其划分为两个亚层,第一亚层高度约为19-27m,第二亚层高度约为5-9m。高位芽植物在群落生活型谱中所占比例最高,其次是地下芽植物、地面芽植物、一年生植物和地上芽植物。巴山水青冈的株数-高度、株数-胸径分布曲线均呈现两头高、中间低的格局,中间高度和中间径级的植株数量很少。 米心水青冈群落4个样地中,共记录到维管束植物74科、140属、197种。乔木层以壳斗科、蔷薇科等科为主;灌木层以蔷薇科、忍冬科等占优势;草本层主要由莎草科、菊科和百合科等科组成。群落的区系地理成分一共划分为18个类型及亚型。除物种丰度外,物种多样性各个指数的顺序均为草本层>乔木层>灌木层。乔木、灌木、竹子的多度和盖度(乔木的盖度以胸高面积代替)均与物种多样性密切相关。 根据树冠高度可将米心水青冈群落的乔木层划分为两个亚层,第一亚层高度约为16-22m,第二亚层高度约为5-9m。近半数乔木物种在群落中呈簇生状。生活型谱中,高位芽植物占优势,其次是地下芽植物、地面芽植物、一年生植物,没有地上芽植物。米心水青冈的实生幼苗十分匮乏,幼树以萌生树为主。其株数-高度、株数-胸径分布曲线呈递减趋势,幼龄个体数>中龄个体数>老龄个体数。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The gonads of Otolithes cuvieri and Johnius elongatus are described in seven maturity stages. O. Cuvieri spawns once a year from April to September as evidence by ova diameter frequency distribution and GSI values. 50% maturity is attained at 210mm TL in males and 200mm TL in females. Fecundity ranged from 2387 to 104379 with a mean value of 33502. Log-Log relationship between fecundity and total lenght, body weight and ovary weight were determined. An overall sex ratio of 1.54:1.00 was unequal in favour of males. Johnius elongatus spawns twice a year from January-February to Aprile-May and from August to October as evidence by ova diameter frequency distribution and GSI values. 50% maturity is attained at 140-143mm TL in both sexes. Fecundity ranged from 4238 to 167669 with a mean value of 42818. Log-Log relationship between fecundity and total lenght, body weign and ovary weight were determined. An overall sex ratio of 1.00:1.20 was unequal in favour of females.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Discolouration of sands and other marine substrata caused by benthic diatoms have been reported by Aleem (1950) Eaton and Moss (1975), Sullivan (1980), Maple (1983), Navarro (1983) and Wah and Wee (1988). However, this is for the first time such a phenomenon is being reported from a mangrove habitat of Karachi. It was caused by a pennate diatom Navicula cancellata Donkin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In appreciation of the pressing need for coordinated research in various aspects of fishery technology and for the overall development of fisheries industries in India, the Ministry of Food and Agriculture had decided to set up the Central Institute of Fisheries Technology. The Institute was established in 1957 at Cochin (Ernakulam). The research work at the Institute including its sub-stations and units is carried out in two wings: Craft and Gear Wing and Processing Wing. The third unit, the Extension Information and Statistics Wing, renders a service by functioning as a liaison between the research laboratories and the industry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El 10 de septiembre de 2014 se cumplieron cien años del nacimiento de Raúl A. Ringuelet, una de las figuras consulares de las Ciencias Naturales de la Argentina. A modo de homenaje y dentro de las modestas posibilidades de ProBiota, queremos recordar este acontecimiento reuniendo sus principales contribuciones biogeográficas, de las que ya realizaron un excelente análisis Lopretto y Menni durante el 2003. No obstante, entiendo que es oportuno recordar que en 1944, a la edad de 30 años, pública Sinopsis sistemática y zoogeográfica de los Hirudíneos de la Argentina, Brasil, Chile, Paraguay y Uruguay. Además, en su trayectoria docente en la Facultad de Ciencias Naturales y Museo de la UNLP, crea la Cátedra de Zoogeografía (1958), la de Ecología y Zoogeografía (1960) y posteriormente la de Biogeografía (1981). Como alumno de esta última materia, no puedo dejar de mencionar que las autoridades de ese momento le hacían dictar sus clases en un subsuelo de un edificio céntrico, con luz artificial, humedad y otros elementos que conspiraban contra su salud ya deteriorada. A más de treinta años del fallecimiento, mucho se ha dicho y escrito sobre Raúl A. Ringuelet, tanto por parte de colegas, discípulos, alumnos (ver López y Ponte Gómez, 2009) como de aquellos que no lo conocieron personalmente. Un ejemplo de esto último y que vale destacar, ha sido la exposición en el auditorio del Museo de La Plata de Fabián Grosman en mayo de 2012 (ver http://raulringuelet.blogspot.com.ar/), quién junto con Miguel Mancini acuñaron el término “Neo ringueletismo” (ver Mancini y Grosman, 2008: 140). Como reflexión final y parafraseando a Raúl Larra al recordar a Roberto Arlt, podemos afirmar Treinta y cuatro años después sigue (R.A.R.) estando entre nosotros. ¿Por qué está con nosotros?. Su intemporalidad reside en la intemporalidad de su obra.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A modified method for the preparation of laminated Bombay duck is presented. Investigation was carried out to find out an effective chemical to control the discoloration of dried laminated Bombay duck. Among various chemicals tried, NDGA and BHT were found to have considerably retarded the discoloration and extended the storage life of the product. Attempt was also made to suggest the optimum humidity level for the proper storage of the commercially dried fish. It was found that a level of about 65% R. H. provided maximum storage life to commercial product.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An experiment was conducted for rearing of Meni, Nandus nandus in laboratory condition for seven months with the objective to select appropriate feed for the species and to develop a rearing technique of the species up to the stage of sexual maturation. Different trials were conducted using artificial feed (35.5% protein), dead fresh kachki (Carica soborna), dead fresh prawn (Macrobrachium lamarrei) and live prawn (Macrobrachium lamarrei). The provision of bottom sediment did not significantly influence the growth of fish. Between dead fresh kachki and dead fresh prawn, the fish preferred dead fresh prawn. The fish was found to be reluctant to take dead fresh kachki and prawn as food unless they became very hungry. The fish was found actively feeding on live prawn. The FCR of the prawn as food for N. nandus was found to be 2.5. From the study, it was observed that in laboratory rearing N. nandus preferred live prawn as food than artificial feed, dead fresh kachki and dead fresh prawn. The fish fed on live prawn became sexually matured (eggs or white milt extruded by gentle pressure on the abdomen of the fish) in the laboratory at the end of the experiment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The key factor in success of a Macrobrachium hatchery is to yield maximum number of larvae with minimum number of brooders. Suitable environmental conditions were provided and the breeding performance of females of M. rosenbergii was observed. A total number of 140 females brought from wild were used for this purpose. Each female was tagged and given a code number which made it possible to record the gestation period, interbreed period, number of breeding and larval yield of individual female during each breeding. Females were found to breed six times during the ten months duration. Of the total females studied, 99.12 % bred once, while only 2.16 % females bred six times in a total span of ten months. The average number of larvae decreased successively from first to fourth breeding. The average interbrood period was minimum between the first and second breeding and maximum between the fourth and fifth breeding. The highest average larval yield of 25,428 was recorded in the first breeding, the lowest of 4,596 in the fourth breeding. The possible reasons for variations in interbrood period and larval yield are discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Prawn pickle was produced using smaller variety of prawn. Vinegar and salt was used to preserve the prawn muscle against spoilage. Different spices were used to get desired attractive flavour. Benzoic acid to the extent of 200 ppm was used as preservative. Several trials were carried out using different amounts of spices and different methods of preparation. After each trial the sample was subjected to sensory evaluation by judges consisting of five members who had previous experience of acting as panel members. Several trials were carried out to arrive at a final recipe as judged best by the taste panel. Utilizing this final recipe, a product was prepared and subjected to biochemical, bacteriological and organoleptic evaluation and found to be quite acceptable after seven months of storage in glass jar at ambient temperature. The product was subjected to large scale consumer acceptance trial involving 140 consumers, 42% of them ranked it excellent, 41% rated very good, 12% rated good while 5% of the consumers rated it as average.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the present study, fish cutlets were prepared from bleached and unbleached mackerel mincemeat. Fish cutlets prepared from bleached meat had scored higher values for taste, flavour and overall acceptability as compared to those from unbleached mincemeat. Fish cutlets prepared with corn flour at the rate of 15% of fish mincemeat had scored higher values for all attributes as compared to other levels. Between the bleached and unbleached mincemeat, the scores for cutlet prepared with bleached mincemeat had higher score than that for the latter. There were no cracks in cutlets prepared with 15% and above corn flour levels as compared to those with lower levels. Fish cutlets prepared from bleached and unbleached mincemeat with spice mixture at 20 and 30% of the fish mince, respectively, had higher scores for taste, flavour, texture and overall acceptability as compared to those with other levels. Organoleptic quality of cutlet prepared from bleached and unbleached mackerel mince did not show changes in the appearance, colour and texture during storage. Changes were more prominent in flavour, taste and overall acceptability. Fish cutlets prepared from bleached mincemeat were acceptable for two months and those from unbleached mincemeat were acceptable up to one month from the point of view of organoleptic and biochemical qualities.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Very few records of freshwater molluscs of Ceylon are available in several publications and although they are of importance as food for fishes and vectors of parasites we know little of their role in these capacities in Ceylon. The present paper is to be considered more as a pointer to the group than as a study of the freshwater molluscs of Ceylon. The author collected freshwater molluscs during surveys made for the study of systematics and distribution of various freshwater invertebrates. Material of freshwater molluscs purchased by the Museum in Leiden and labelled Ceylon was also seen by the author. The nomenclature used in this paper has been simplified by the omission of sub-generic and sub-specific names. The sub-generic divisions are dealt with critically for the Gastropoda by Wenz (1938-1944) and Zilch (1959-1960).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In July-August 1979 a first survey of Sofala Bank was carried out with shallow water prawn resources as the main objective. Some preliminary conclusions on the circulation in the Sofala Bank and the influence of the Zambezi River in this area were drawn. Analysis of catch rates and distribution of the different prawn species resulted in the division of Sofala Bank in 6 areas. Particular importance is given to the species Penaeus indicus and Metapenaeus monoceros which constitute 70-90% of catches in depths less than 25 m. The greatest concentrations of P. indicus are found very close to the shore, principally in an area north of Quelimane and another south of Angoche. At the time of the survey 40% of females of this species were in late maturing stages. The species M. monoceros is most abundant in depths greater than 15 m, with concentrations south of Zambezi River and in small areas near Pebane and Angoche.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A marine fish resources first assessment of Mozambique was made in 1979 (Sætre and Paula e Silva, 1979). Up to now, information on resources has increased significantly as result of the work done by the IIP’s technicians. A brief review of data is given.