A preliminary study on the protein requirement of Chanos chanos (Forskal) fry in a controlled environment

Growth rate of fish appeared to be related to the levels of the protein in the diet up to 40%. Fish fed diets containing 50 and 60% grew slower than those fed 40%, and the optimum level appears to be 40% when fed to fry at a rate of 10% of body weight. Best feed conversion of 1.96 was also obtained from the 40% protein diet. Mean survival rates were low in all treatments, but highest for the 40% protein diet. The competition of 5 isocaloric experimental diets containing various levels of protein are tabulated, as are weight gains, diet conversions and survival rates for milkfish fry fed various dietary levels of protein. Growth curves for milkfish fry are shown, and the relationship between weight gains of milkfish fry and the dietary levels of protein are illustrated.

Studies on the fungal diseases in crustaceans. I. Lagenidum scyllae sp. nov. isolated from cultivated ova and larvae of the mangrove crab (Scylla serrata)

Lagenidium scyllae , a marine mastigomycete from the ova and larvae of the mangrove crab, is described and illustrated as new. The fungus grew at a temperature range of 16-42 C, with an optimum at 22.5-31.8 C. It grew well in peptone-yeast-glucose (PYG) broth containing 2-3% NaCl. In PYG-sea water medium, it grew at a pH range of 5-11.

Anti Human Immunodeficiency Virus Type 1 (HIV-1) Agents 4. Discovery of 5,5 '-(p-Phenylenebisazo)-8-hydroxyquinoline Sulfonates as New HIV-1 Inhibitors in Vitro

To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.

Study of distribution, growth and reproduction polychaetes Nereidae in intertidal zone of Bandar Abbas and effect dominant species on white Indian shrimp brood stocks (Fenneropenaeus indicus)

Distribution of polychaetes worms Nereidae in intertidal zone of Bandar Abbass indicated that distribution rate of worms from the west to east for the reason status of seabed type, habitat and feeding substrate used to worms increased. Also investigation description that last-mentioned worms are belong to Nereididae family, Perinereis genus and species of Perinereis nuntia. By viewpoint seabed soil types experiments implement indicated Nereididae worms have higher survival with sandy clay loam soil texture. Statistical analysis showed positive relation coefficient correlation of Pearson between substrate type to frequency of worms and too substrate type with soil organic matter value (P<0.05). By viewpoint feeding also experiments with different feed treatment indicated that Nereid worms is Omnivore but in natural condition more utilized algae substrate special Entermorpha and survival rate had the worms last-mentioned in dietary treatments on this algae 93/3% different significant with other treatments (P<0.05). In this project pond-reared white Indian shrimp (Fenneropenaeus indicus) were used in four maturation and spawning trials lasting 60 days. one group of shrimps was fed a formulated pelleted special of broodstock diet only, a second group was fed squid meat diet; a third group of shrimps with mollusca (Solen vagina) meat diet and fourth group was fed polychaete worms Nereidae family, collected in intertidal zone of Bandar Abbass. Four types of dietary treatments (M1, M4) were given to separate batches that were run in three duplicate. Results of experiments demonstrate that more grew rate and maturation and spawning rate and we found that shrimps fed with polychaete worms have the best condition and then shrimps fed with solen. This is demonstrate furthermore environmental circumstance, endocrine hormone, types of feed important of maturation and spawning of shrimps and in polychaete worms used HUFA help to maturation ovarian in shrimp.

Some characteristics of the fish fauna of a dam in the Lake Victoria region of Tanzania including the effects of multispecific stocking with tilapia species

Malya dam had been stocked with several species of Tilapia. However all but the species endemic to the region, T esculentus, made only marginal contributions to the fishery. T. zilli particularly had failed to establish itself, probably because its niche had been previously filled by T. rendalii. Planktivorou Tilapia species predominate in Malya dam but in smaller dams in the region herbivoorous tilapia are relatively more abundant. Six non-cichlid species and one of Haplochromis were found in the dam. Tilapia esculenta the most economically important species, was estimated to grow within 9-10 cm first year and 16-18 cm second year. The largest, specimen caught was 30.5 cm and the smallest mature individual 19 cm. The fish of the dam grew more slowly and matured at a smaller size than those of the same species in Lake Victoria The biological pattern of T. esculenta in Malya dam was similar to that of this species in Lake Victoria.

Observations on the biology of Nothobranchius guentheri (Pfeffer) (Cyprinodontidae), an annual fish from the coastal region of East Africa

Nothobranchius guntheri is found in seasonal pools and streams in the coastal region of Tanzania. A population recurring annually in a pond near Kilosa has been studied. Growth in length was rapid and maximum mean lengths were attained within 11-12 and 7-8 weeks of hatching by males and females respectively. Males grew larger and exhibited wider variation in length than females. N. guentheri shows clear sexual dichromatism. No significant inequality in the sex ratio was found. Females with ripe eggs were found 7-8 weeks after hatching. Spawning continued throughout adult life and fecundity increased markedly with increasing length. In laboratory aquaria, aggressiveness between adult males was noted and females were actively driven on to the substratum preparatory to spawning. The diet of the fish pond consisted chiefly of aquatic and terrestrial insects, of which midge larvae and pupae were the most common. N. guentheri is exploited by man in the aquarist trade and for the biological control of mosquitoes. An extended redescription of the species is appended which includes N. melanospilus (Pfeffer) as a synonym.

Growth rates of juvenile Nile perch, Lates niloticus L. in lakes Victoria, Kyoga and Nabugabo

The growth rates of Nile perch, Lates niloticus L. of 20 cm to 40 cm total length were estimated in lakes Victoria and Kyoga in 1991 and 1992 and Nabugabo in 1992 and 1993 by tagging. Fish grew faster in Lake Kyoga (mean growth rate 28.7 ± 1.3 cm S.E. per year, N = 49) than in Lake Victoria (18.9 ± 1.4 cm per year, N = 20) and Lake Nabugabo (19.0 ± 0.7 cm per year, N = 43). There were significant differences in growth rates between the lakes (F2 109 = 24.037, P < 0.001). Growth rates in Lake Kyoga were significantly higher than those of lak'es Victoria and Nabugabo (p < 0.001) but those of lakes Victoria and Nabugabo were not significantly different from each other (p = > 0.05). The faster growth rates in Lake Kyoga were attributed to improvement in food supply due to increases in stocks of haplochromine prey. Growth rates in Lake Kyoga were significantly higher, but those of lakes Victoria and Nabugabo were within the ranges of those reported in several native habitats of Nile perch.

宁夏二代防护林网结构抗虫性评价与判别

应用数量化理论 、聚类分析和逐步判别分析法将二代林网林分受光肩星天牛、木蠹蛾和枝梢害虫危害各分为 4类 (即林分抗虫性分类 ) ,并建立了相应类别的判别函数 ,经检验所分类别和所建判别函数均达到显著水平。综合分析得出 :类别的前 2类为相应害虫的抗性林分 ;抗虫林分是指在三类害虫危害分类时均被分在前两类中的林分 ,也是二代林网进一步发展所应采取的林分配制形式 ;林分结构合理化是害虫不成灾最有效的手段之一 ;新建林网有效控制了光肩星天牛的发生 ;各类防护林以城市林网的综合抗虫性最强 ;二代林网中对各害虫都具有较高抗性林分的比例为 2 0 % ;光肩星天牛、木蠹蛾、枝梢害虫的倾性林分在林网中所占比例分别为 1 5 %、1 2 %、8%。

Ageing, Adaption and Accessibility: Time for the Inclusive Revolution!

Information and Communication Technology (ICT) is becoming increasingly central to many people’s lives, making it possible to be connected in any place at any time, be unceasingly and instantly informed, and benefit from greater economic and educational opportunities. With all the benefits afforded by these new-found capabilities, however, come potential drawbacks. A plethora of new PCs, laptops, tablets, smartphones, Bluetooth, the internet, Wi-Fi (the list goes on) expect us to know or be able to guess, what, where and when to connect, click, double-click, tap, flick, scroll, in order to realise these benefits, and to have the physical and cognitive capability to do all these things. One of the groups most affected by this increase in high-demand technology is older people. They do not understand and use technology in the same way that younger generations do, because they grew up in the simpler electro-mechanical era and embedded that particular model of the world in their minds. Any consequential difficulty in familiarising themselves with modern ICT and effectively applying it to their needs can also be exacerbated by age-related changes in vision, motor control and cognitive functioning. Such challenges lead to digital exclusion. Much has been written about this topic over the years, usually by academics from the area of inclusive product design. The issue is complex and it is fair to say that no one researcher has the whole picture. It is difficult to understand and adequately address the issue of digital exclusion among the older generation without looking across disciplines and at industry’s and government’s understanding, motivation and efforts toward resolving this important problem. To do otherwise is to risk misunderstanding the true impact that ICT has and could have on people’s lives across all generations. In this European year of Active Ageing and Solidarity between Generations and as the British government is moving forward with its Digital by Default initiative as part of a wider objective to make ICT accessible to as many people as possible by 2015, the Engineering Design Centre (EDC) at the University of Cambridge collaborated with BT to produce a book of thought pieces to address, and where appropriate redress, these important and long-standing issues. “Ageing, Adaption and Accessibility: Time for the Inclusive Revolution!” brings together opinions and insights from twenty one prominent thought leaders from government, industry and academia regarding the problems, opportunities and strategies for combating digital exclusion among senior citizens. The contributing experts were selected as individuals, rather than representatives of organisations, to provide the broadest possible range of perspectives. They are renowned in their respective fields and their opinions are formed not only from their own work, but also from the contributions of others in their area. Their views were elicited through conversations conducted by the editors of this book who then drafted the thought pieces to be edited and approved by the experts. We hope that this unique collection of thought pieces will give you a broader perspective on ageing, people’s adaption to the ever changing world of technology and insights into better ways of designing digital devices and services for the older population.

洞庭湖浮游生物群落DNA指纹拓扑结构与物种组成对应关系

对东洞庭湖7个采样站点的浮游生物群落进行了DNA多态性的RAPD指纹分析和物种组成的分类鉴定,并通过聚类分析探讨了DNA指纹拓扑结构与物种组成对应关系。结果如下:(1)筛选出的11条随机引物共获得148条长度在180~2000bp的谱带,多态率为98.6%,各引物扩增谱带数在11~16不等;各站点平均有57.6条谱带,其中站最多(70条),站最少(45条),而站的特有带最多(7条),站最少(2条);(2)共观察到54种/类浮游生物,其中站出现的最多(27),其它各站点在7~13不等,分布概率在85%以上的

When fear is near: threat imminence elicits prefrontal-periaqueductal gray shifts in humans.

Humans, like other animals, alter their behavior depending on whether a threat is close or distant. We investigated spatial imminence of threat by developing an active avoidance paradigm in which volunteers were pursued through a maze by a virtual predator endowed with an ability to chase, capture, and inflict pain. Using functional magnetic resonance imaging, we found that as the virtual predator grew closer, brain activity shifted from the ventromedial prefrontal cortex to the periaqueductal gray. This shift showed maximal expression when a high degree of pain was anticipated. Moreover, imminence-driven periaqueductal gray activity correlated with increased subjective degree of dread and decreased confidence of escape. Our findings cast light on the neural dynamics of threat anticipation and have implications for the neurobiology of human anxiety-related disorders.

Taper-free and vertically oriented Ge nanowires on Ge/Si substrates grown by a two-temperature process

Taper-free and vertically oriented Ge nanowires were grown on Si (111) substrates by chemical vapor deposition with Au nanoparticle catalysts. To achieve vertical nanowire growth on the highly lattice mismatched Si substrate, a thin Ge buffer layer was first deposited, and to achieve taper-free nanowire growth, a two-temperature process was employed. The two-temperature process consisted of a brief initial base growth step at high temperature followed by prolonged growth at lower temperature. Taper-free and defect-free Ge nanowires grew successfully even at 270 °C, which is 90 °C lower than the bulk eutectic temperature. The yield of vertical and taper-free nanowires is over 90%, comparable to that of vertical but tapered nanowires grown by the conventional one-temperature process. This method is of practical importance and can be reliably used to develop novel nanowire-based devices on relatively cheap Si substrates. Additionally, we observed that the activation energy of Ge nanowire growth by the two-temperature process is dependent on Au nanoparticle size. The low activation energy (∼5 kcal/mol) for 30 and 50 nm diameter Au nanoparticles suggests that the decomposition of gaseous species on the catalytic Au surface is a rate-limiting step. A higher activation energy (∼14 kcal/mol) was determined for 100 nm diameter Au nanoparticles which suggests that larger Au nanoparticles are partially solidified and that growth kinetics become the rate-limiting step. © 2011 American Chemical Society.

RESPONSES OF Elodea nuttallii AND Ceratophyllum demersum TO HIGH TEMPERATURE

There were large losses of exotic species Elodea nuttallii during summer in eutrophic lakes of the middle and lower reaches of the Yanatze River, China. To investigate the main causes, the heat tolerance of E. nuttallii was studied and compared with that of native species Ceratopkyllum demersum by using an aquaria system in the laboratory. Under 4500 lx light intensity and 12-h L/12-h D cycle, E. nuttallii cultured in 1/5 Hoaglands solution at 39 degrees C showed a positive growth rate during the first 15 days, and the growth rate was higher than that at 35 degrees C. But after 15 days, the growth rates became negative for those cultured both at 39 and 35 degrees C. However, the growth rate was positive for more than 20 days for those cultured at 25 degrees C. Under the same conditions, the growth rate, productivity and chlorophyll content of E. nuttallii were significantly higher than that of C. demersum. Heat tolerance of E. nuttallii was also stronger than that of C. demersum. The optimal temperature for the growth of the two plants depended on the experimental period: both plants grew at an optimal rate at higher temperature if the experimental period was short; nevertheless the plants achieved optimal growth at a lower temperature if the experiment was conducted for a longer period. At the same light intensity, the heat tolerance of C. demersum in tap water with sediment was markedly stronger than that of E. nuttallii at 39 degrees C. Average growth rate of C. demersum was 4.5 times higher than that of E. nuttallii within 25 days. The positive growth period lasted for less than 25 days for E. nuttallii and for more than 25 days for C. demersum. When they were cultured in 1/5 Hoaglands solution and in tap water with sediment, the growth rate of C. demersum increased from 0.4 to 79.4 mg/d.g fresh weight (FW) within 20 days. E. nuttallii increased from 8.3 to 24.4 mg/d-g FW within 20 days. Both grew better in tap water with sediment than in 1/5 Hoaglands solution. The results demonstrated that the nutritional status of the water other than the high temperature affected the heat tolerance of E. nuttallii during summer. E. nuttallii has great ecological safe risk in China.

Growth and food availability of silver and bighead carps: evidence from stable isotope and gut content analysis

A 2-year investigation of growth and food availability of silver carp and bighead was carried out using stable isotope and gut content analysis in a large pen in Meiliang Bay of Lake Taihu, China. Both silver carp and bighead exhibited significantly higher delta 13C in 2005 than in 2004, which can probably be attributed to two factors: (i) the difference between isotopic compositions at the base of the pelagic food web and (ii) the difference between the compositions of prey items and stable isotopes. The significantly positive correlations between body length, body weight and stable isotope ratios indicated that isotopic changes in silver carp and bighead resulted from the accumulation of biomass concomitant with rapid growth. Because of the drastic decrease in zooplankton in the diet in 2005, silver carp and bighead grew faster in 2004 than in 2005. Bighead carp showed a lower trophic level than silver carp in 2005 as indicated by stable nitrogen isotope ratios, which was possibly explained by the interspecific difference between the prey species and the food quality of silver carp and bighead.

ApcD is necessary for efficient energy transfer from phycobilisomes to photosystem I and helps to prevent photoinhibition in the cyanobacterium Synechococcus sp PCC 7002

Phyrobilisomes (PBS) are the major light-harvesting, protein-pigment complexes in cyanobacteria and red algae. PBS absorb and transfer light energy to photosystem (PS) II as well as PS I, and the distribution of light energy from PBS to the two photosystems is regulated by light conditions through a mechanism known as state transitions. In this study the quantum efficiency of excitation energy transfer from PBS to PS I in the cyanobacterium Synechococcus sp. PCC 7002 was determined, and the results showed that energy transfer from PBS to PS I is extremely efficient. The results further demonstrated that energy transfer from PBS to PS I occurred directly and that efficient energy transfer was dependent upon the allophycocyanin-B alpha subunit, ApcD. In the absence of ApcD, cells were unable to perform state transitions and were trapped in state 1. Action spectra showed that light energy transfer from PBS to PS I was severely impaired in the absence of ApcD. An apcD mutant grew more slowly than the wild type in light preferentially absorbed by phyrobiliproteins and was more sensitive to high light intensity. On the other hand, a mutant lacking ApcF, which is required for efficient energy transfer from PBS to PS II, showed greater resistance to high light treatment. Therefore, state transitions in cyanobacteria have two roles: (1) they regulate light energy distribution between the two photosystems; and (2) they help to protect cells from the effects of light energy excess at high light intensities. (C) 2009 Elsevier B.V. All rights reserved.