Assessment of pelagic primary and secondary production in Sefidrud River estuary

Sefid-Rood River Estuary (SRE) is the most important riverine ecosystem in the south Caspian Sea along the Iranian coast lines. The aim of this study was to examine spatial and temporal variability in Phytoplankton and Zooplankton abundance and diversity in SRE. Variability of Chlorophyll a and inorganic nutrient concentration were determined during a year (November 2004– October 2005) in five sampling stations. Primary and secondry production were determined during a year. Total chlorophyll a concentration during the investigation ranged between zero to 22.8 μgl-1 and the highest levels were consistently recorded during summer and the lowest during winter with a annual mean concentration 4.48 μgl-1. Nutrient concentration was seasonally related to river flow with annual mean concentration: NO2 0.05±0.2 mgl-1, NO3 1.13±0.57 mgl-1, NH4 0.51±0.66 mgl-1, total phosphate 0.13±0.1mgl-1 and SiO2 5.68±1.91 mgl-1. Bacillariophytes, Cyanophytes, Chlorophytes, Pyrophytes and Euglenophytes were the dominant phytoplankton groups in this shallow and turbid estuary. The diversity and abundance of phytoplankton had a seasonal pattern while Diatomas and Chrysophytes were dominant throughout the year but Cyanophytes observed only during the summer. Zooplankton community structure was dominated by copepods which 68% of the total zooplankton. In the winter and summer seasons two increased in the number of zooplankton community and usually toward the sea had occurred. Zooplankton also showed a significant spatial and temporal variation. The high turbidity and temperature prime characteristics of SRE seem to be determining factors acting directly on phytoplankton and zooplankton temporal variability and nutrient fluctuations. Everywhere in this estuary nutrients appeared to be in excess of algal requirement and did not influence a phytoplankton and zooplankton composition. Also there was a positive correlation between chlorophyll a and temperature and a negative one with DIN and TP. Primary production determined in this estuary by dark and light butter method and G.P.P. 38.27±34.12 mgcm-2h-1 and N,PP 201.6±289.9 mgcm-2d-1. secondry production determined 15/128 mgc/m3/year. Everywhere in this estuary nutrients appeared to be in excess to algal requirement and did not influence in Chl. a and primary production. The most important factor influence on Chl. a was water temperature.

The study of different protein in diet and water salinity on growth and survival rate in Pacific white shrimp (Litopenaeus vannamei)

In this research reared white western shrimp (Litopenaeus vannamei ,Boone, 1931) with five diet with five different protein level contain 20%, 25%, 30%, 35% and 40% and three salinity level contain 15-17 ppt, 27-30 ppt,and 40-45 ppt researched protein percent effect and water salinity on growth, survival, feed conversion ratio, hemolymph osmolatity, hemolymph protein and corpse protein contain. In this research was 15 sorrow with 3 repeat and used from 45 tanks with 300 liters capacity. Shrimps first weight average was about 2 grams and after 60 days culture cropped down results: Shrimps biomass growth in 15-17 ppt salinity was higher than anther salinities who had meaning different with growth in 40-45 ppt salinity ( p< 0.05). But hadn’t meaning different with growth 27-30 ppt salinity. survival rate in 15-17 ppt salinity was 97.03 who was lower than another salinities. survival percent in 24-30 ppt salinity and 40-45 ppt salinity was 99.33% Highest biomass growth in different diets was in diet number 5 with 40 percent protein that it had meaning different with another diets (p<0.05) . although with informed to product expense in different diets. One kilogram shrimp product expense in different diets hadn’t meaning different (P<0.05) Survival rate in different diets hadn’t meaning different lowest feed conversion ratio was 1.67 in 15-14 salinity that hadn’t meaning different with another salinities also corpse protein quantity in different salinities and different diets hadn’t meaning different. Hemolymph Osmolality in 15-17 ppt salinity was 573.88 mOsm/kg had meaning different with hemolymph osmolality in 27-30 ppt salinity that was 650. 380 mOsm/kg and in 40-45 ppt salinity was 630.38 mOsm/kg. Hemolymph protein in 15-17 ppt salinity was 124.72 mg/ml had meaning different with hemlymph protein in 27-30 ppt salinity that was 136.52 mg/ml but hadn’t meaning different with hemolymph protein in 40-45 ppt salinity that was 128.84 mg/ml. Hemolymph protein in different diets hadn’t meaning different (p<0.05). Keywords: shrimp, Litopenaeus vannamei, protein , salinity, growth, survival rate, FCR, hemolymph osmolality, hemolymph protein.

Sleeping sites, sleeping trees, and sleep-related behaviors of black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, central Yunnan, China

Data on sleep-related behaviors were collected for a group of central Yunnan black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China from March 2005 to April 2006. Members of the group usually formed four sleeping units (adult male and juvenile, adult female with one semi-dependent black infant, adult female with one dependent yellow infant, and subadult male) spread over different sleeping trees. Individuals or units preferred specific areas to sleep; all sleeping sites were situated in primary forest, mostly (77%) between 2,200 and 2,400 m in elevation. They tended to sleep in the tallest and thickest trees with large crowns on steep slopes and near important food patches. Factors influencing sleeping site selection were (1) tree characteristics, (2) accessibility, and (3) easy escape. Few sleeping trees were used repeatedly by the same or other members of the group. The gibbons entered the sleeping trees on average 128 min before sunset and left the sleeping trees on average 33 min after sunrise. The lag between the first and last individual entering the trees was on average 17.8 min. We suggest that sleep-related behaviors are primarily adaptations to minimize the risk of being detected by predators. Sleeping trees may be chosen to make approach and attack difficult for the predator, and to provide an easy escape route in the dark. In response to cold temperatures in a higher habitat, gibbons usually sit and huddle together during the night, and in the cold season they tend to sleep on ferns and/or orchids.

小鲤地理分化的研究

小鲤Ｃｙｐｒｉｎｕｓ（Ｍｅｓｏｃｙｐｒｉｎｕｓ）ｍｉｃｒｉｓｔｉｕｓ分布于云南省的滇池、抚仙湖和星云湖。对历年馆藏和作者近年定期野外收集的２００尾标本和生态资料进行综合分析的结果表明：小鲤已分化为两个地理亚种，即滇池特有的小鲤指名亚种Ｃ．（Ｍ．）ｍｉｃｒｉｓｔｉｕｓｍｉｃｒｉｓｔｉｕｓＲｇｅｇａｎ和分布于抚仙湖、星云湖的抚仙小鲤Ｃ．（Ｍ．）ｍｉｃｒｉｓｔｉｕｓｆｕｘｉａｎｅｎｓｉｓＹａｎｇｅｔａｌ．，亚种间形态的分化主要表现在头长、尾柄长、眼间距与有关部分的比值、侧线鳞和背鳍前鳞的数目等方面；亚种间主要形态特征的分化是在长期的演化过程中适应不同的湖泊环境而产生的；小鲤亚种间繁殖生物学特性的分化主要表现在产卵行为、卵径、繁殖力以及达初次性成熟的年龄等方面；此外，亚种间在其空间分布、食性、年龄和生长等生态学特性上均表现出不同程度的分化。

Prefrontal white matter abnormalities in young adult with major depressive disorder: A diffusion tensor imaging study

Prefrontal impairments have been hypothesized to be most strongly associated with the cognitive and emotional dysfunction in depression. Recently, white matter microstructural abnormalities in prefrontal lobe have been reported in elderly patients with ma

关注会计信息的管理价值—管理会计的过去、现在和未来

市场环境的改变,推动了管理会计的发展.而对管理会计而言,所有的创新都来自管理会计体制的创新.归根结底,没有信息系统的创新就没有管理会计的发展.

Characterization of genetic biodiversity of Nile perch, Lates niloticus, Tilapiines, Haplochromine flock and Ningu (Labeo victorianus) in the Victoria Lake Basin: an overview

Genetic biodiversity is the vaflatlOn among individuals within and between units of interbreeding individuals (populations) of a species. It includes inheritable and transmittable differences that occur between individuals andlor popuhitions of a given species through reproductive interaction. There exists enormous variability among individuals andlor populations of a species for most living organisms, and most of this variation is inheritable. differences among individuals arise through mutation and via recombination of genes during meiosis. These ifferences are then transmitted to successive generations through sexual reproduction and maintained in the populations through processes such as natural selection and genetic drift. Unfortunately much of this variation is normally threatened and often in danger of extinction because most focus in conservation of natural resources is put at saving species or habitats than varieties or strains of a species

Interactions between building integrated photovoltaics and microclimate in urban environments

BIPV (building integrated photovoltaics) has progressed in the past years and become an element to be considered in city planning. BIPV has significant influence on microclimate in urban environments and the performance of BIPV is also affected by urban climate. The thermal model and electrical performance model of ventilated BIPV are combined to predict PV temperature and PV power output in Tianjin, China. Then, by using dynamic building energy model, the building cooling load for installing BIPV is calculated. A multi-layer model AUSSSM of urban canopy layer is used to assess the effect of BIPV on the Urban Heat Island (UHI). The simulation results show that in comparison with the conventional roof, the total building cooling load with ventilation PV roof may be decreased by 10%. The UHI effect after using BIPV relies on the surface absorptivity of original building. In this case, the daily total PV electricity output in urban areas may be reduced by 13% compared with the suburban areas due to UHI and solar radiation attenuation because of urban air pollution. The calculation results reveal that it is necessary to pay attention to and further analyze interactions between BIPV and microdimate in urban environments to decrease urban pollution, improve BIPV performance and reduce cooling load. Copyright © 2006 by ASME.

La peche dans le fleuve Niger

The fish production of the River Niger can best be estimated from a country by country evaluation of the tonnage exported and that consumed locally. All exported and some locally consumed fish are preserved by smoking or sun drying, a process which entails a loss of weight. Coefficients to correct for this of between 2.6 to 4 have been calculated depending on the type of product. A further loss occurs due to handling and to insect attack, which may account for up to 40% of the production. Taking the above factors into account the productions estimated for the various countries of the Niger River basin are as follows: Guinea (3,600 t), Mali (90,000 t), Upper Volta and Ivory Coast (negligible), Niger (5,200 t), Dahomey (1,200 t), Nigeria (25,000 t), Cameroon (3,000 t). A total production of 128,000 t is, therefore, obtained for the basin as a whole, excluding the Kainji Reservoir. At this level of production, there have been no intimations of overfishing from any part of the basin, and there is unanimity that fishing could be intensified. On the basis of the estimates of existing production and local estimates of potential production it is possible that up to 200,000 t of fish could be produced annually from the basin as a whole.

Yield isopleths of Tilapia esculenta Graham 1928 in Lake Victoria and Tilapia nilotica (Linnaeus) 1757 in Lake Albert

The yield equation given by BEVERTON and HOLT (1957) has several parameters which are difficult to estimate for tropical freshwater fish species. Nevertheless, some simplifying assumptions can be made and the most relevant parameters used to enable the construction of yield isopleths. Tilapia esculenfa has the following parameters: maximum length (L ∞=33.8 c.m. growth rate (K) = 0.32, natural mortality rate (M)=0.17 and the length at maturity (1 m)=22 cm. The optimum yield is obtained by catching the fish at a length of first capture of 26 em and a fishing mortality rate of 0.5. Tilapia nilotica with L ∞=49 cm, 1 m=36 cm, K=0.50 and M= 0.30 gives optimum yield when caught at a length of first capture of 35-36 cm with a fishing mortality rate of 0.5-0.6. The stuned Tilapia nilotica of Lake Albert has L ∞=17 cm, K=2.77,1 m=12 cm and M=3.37. With such a very high natural mortality, maximum yields would be obtained hy using a length of first capture less than 9 cm and a fishing mortality rate exceeding 1.8.