983 resultados para Released.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The success of breeding of common carp (Cyprinus carpio) using hormonal inducement and environmental stimuli was evaluated considering different sex ratios, and natural and artificial substrates. A total of 18 females (weighing 250 to 2200g) divided into 6 treatments were investigated. A successful spawning was observed in all the treatment groups, only. 66.66% female responded successfully to LHRH-A combined with dompheridone and 83.33% female in natural stimuli. Females induced with LHRH-A and dompheridone found prompt ovulation than that of natural stimulation. A significant variation (F=7.45, P<0.05) was found among the different treatment groups. The number of eggs released appear to depend on body weight (t=15.72, P<0.05), sex ratio (t=7.96, P<0.05) and percentage of ovulated females (t=5.34, P<0.05). Although environmentally stimulated females released more eggs than injected female (t=5.18, P<0.05) but their survival rate was similar (t=1.77, P<0.05). Comparison between the two approaches under the conditions of AIT hatchery shown that both are suitable for spawning induction in common carp. However, environmental stimulation is advantageous because of the less labor and lower cost required for ovulation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A TiNi/diamond-like-carbon (DLC) microcage for biological application has been designed, fabricated and characterized. A compressively stressed DLC film with TiNi pattern on top lifts the fingers upwards once they are released from the substrate, and the microcage can be closed through shape memory effect of top TiNi film with temperature below 80°C. Further heating above 100°C, the gradual opening of the microcage can be obtained due to thermal bimorph effect. The biocompatibility of both the TiNi and DLC films has been proved using a cell-culture method.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The impact of waste discharge on fishery resources is a matter of great concern. The accepted norm in all environmental impact assessment studies is to avoid areas of high fishery potential while locating a marine outfall. Contemplating on this aspect a case study was conducted in the Amba River estuary before and after the establishment of a petrochemical complex at Nagothane. The treated wastewater from this complex is released through a subsurface outfall after adopting effective control measures for marine disposal of waste. Experimental trawling was done at five locations covering a distance of 30 km during 1990 to 1991. The catch rate within the estuary varied from 0.6 to 255 kg/h (av 24 kg/h). The trend indicated considerable decrease in fishery potential from the mouth of the estuary (av 64 kg/h) to the upstream location (av 11 kg/h). A total of 49 species of fishes, 16 species of prawns, 7 species of crabs and 1 species of lobster were identified from the collections. Number of species gradually increased from the interior segment at Dharamtar (8) to the outer area near Revas (18). A comparison of the quantitative and qualitative nature of the post outfall and pre outfall data revealed only marginal difference. The study indicates that if necessary precautions are taken to render the waste harmless the marine ecology will hardly be affected.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The crystal quality of 0.3-μm-thick as-grown epitaxial silicon-on-sapphire (SOS) was improved using solid-phase epitaxy (SPE) by implantation with silicon to 1015 ions/cm2 at 175 keV and rapid annealing using electron-beam heating, n-channel and p-channel transistormobilities increased by 31 and 19 percent, respectively, and a reduction in ring-oscillator stage delay confirmed that crystal defects near the upper silicon surface had been removed. Leakage in n-channel transistors was not significantly affected by the regrowth process but for p-channel transistors back-channel leakage was considerably greater than for the control devices. This is attributed to aluminum released by damage to the sapphire during silicon implantation. © 1985 IEEE

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文探讨了五十年来北京地区广泛推广的17个冬小麦(Triticun aestivum L)品种在品种改良的过程中农艺性状和某些光合特性的变化趋势。从中选出形态、产量和推出年代差异最大的3个冬小麦品种:京冬8号、农大139和燕大1817,种植在相同的环境条件下,进一步研究与冬小麦产量提高有关的生理生态特性,以及它们的气体交换特性对于外界环境变化的响应。本试验于1999-2001年在北京农林科学院试验农场(39o09’N, 116o04’E)进行。结果如下: 1. 在冬小麦品种改良的过程中,小麦品种的经济产量、收获指数、千粒重提高,而生物产量、株高、单株穗数、单株籽粒产量和穗长降低。籽粒产量与株高、穗数极显著负相关,与穗粒重、收获指数、千粒重极显著正相关。株高与穗长、单株籽粒产量、穗数显著正相关,而与收获指数和千粒重极显著负相关。收获指数与穗数极显著负相关,而与千粒重极显著正相关。说明株高降低、收获指数提高和千粒重的提高对于冬小麦品种改良过程中产量的提高起重要作用。 2. 随品种推出年代的延迟,各品种苗期-拔节期的净光合速率(PN)、 气孔导度(gs)、蒸腾速率( E)、量子产率(Fv/Fm)均呈增加的趋势,水分利用率(WUE)呈降低的趋势。在孕穗期-蜡熟期,旗叶的PN也随品种推出年代而呈增大的趋势,而在成熟期呈减小的趋势。gs在孕穗期-灌浆期增大,在蜡熟期和成熟期减小;各个时期的E均呈递增趋势;而WUE呈降低趋势。旗叶的Fv/Fm在孕穗期和开花期呈递增的趋势,而在成熟期下降。在苗期至孕穗期,PN、 E均与产量显著正相关;在拔节始期和孕穗期gs与产量显著正相关(R=0.616, 0.499, P<0.05),在苗期-拔节期、开花期和成熟期,WUE与历史产量和试验产量显著负相关(P<0.05, 或P<0.001),在苗期和拔节期Fv/Fm与产量正相关(P<0.05)。在冬小麦品种的改良过程中,其光合作用的改良不仅表现在净光合速率上,而且还表现在荧光动力学参数Fv/Fm上, 即PSII的原初光能转化效率有所提高。 3. 孕穗期至灌浆期,高产品种京冬8号旗叶的PN、gs、E、叶绿素含量和水分含量均最高,而水分利用率(WUE)较低,且具有较高的光呼吸和较低的暗呼吸,其旗叶的叶比重也较高。京冬8号(上世纪90年代推出)叶片气体交换的日变化表现为:在拔节期,全天的净光合速率均最高,而后随生育进程差异变小,通常上午较高,而在中午和下午较低。其旗叶Fv/Fm的变化趋势与净光合速率相似。燕大1817(上世纪40年代推出)的光合作用的午休现象较不明显,且在下午恢复较快,说明它可能具有一定的抗光抑制能力。孕穗至灌浆期是冬小麦籽粒形成和充实的关键时期,此时,叶片光合产物充足与否直接影响千粒重。进一步研究它们“源库”关系的结果表明,京冬8号“源库”关系协调,能够充分发挥“源“和“库”的潜力,且具有最高的收获指数、穗粒重和千粒重,而其它两个品种燕大1817和农大139都存在提高其品种产量潜力的限制因素。因此我们认为,高产品种的高产不仅因为其叶片具有较高的光合速率和较低的暗呼吸消耗,而且有较大的“库”容量和收获指数。 4. 当CO2浓度从360增加到720 µmol.mol-1时,单位叶面积的净光合速率和叶片的水分利用率 随CO2浓度升高而升高。但不同品种差异很大,京冬8号PN 和WUE最高,增加最多,分别提高了173 %和81 %;其次为农大139(上世纪70年代推出),燕大1817增加最少,分别提高了76 %和65 %。E随CO2 浓度的增加而提高;农大139和燕大1817的gs随CO2浓度的增大而减小,而京冬8号则增大。京冬8号和农大139旗叶胞间CO2浓度(Ci) 随CO2 浓度的增加而增大,而燕大1817 的Ci先增大,而后又急剧降低,且京冬8号的Ci最低,燕大1817 最高。在高CO2浓度下,京冬8号的光合速率显著高于其它两个品种,而Ci却低于其它两个品种,说明京冬8号的光合潜力高于其它两个品种。灌浆期高产品种京冬8号旗叶在田间不同自然光强下,净光合速率都是最高的(差异最大时,比燕大1817提高24.8 %)。因此,冬小麦光合作用的潜力,也在一定程度上得到改良。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The paper deals with the experimental studies on breeding of Indian Major Carps - Catla catla (Valenciennes), Labeo rohita (Hamilton), Cirrhinus mrigala (Hamilton), & Labeo calbasu (Hamilton) with the help of 'Ovatide' which is being used as an alternative inducing agent for commercial seed production. This study has been conducted for six consecutive months (April - September, 2000) in a stone-pitched breeding channels of a farm located at Midnapore District, West Bengal. The doses of 'Ovatide' (0.5 ml/kg of fish weight) remained same for each female species during the entire study period and males were released without any dose. The physicochemical parameters of water during different months were estimated. The latency period and fertilization percentage varied in different months and species. The results confirmed that 'Ovatide' can be used successfully in a much more cost-effective way for induced breeding of carps, even in rural fish farms with morrum-pitched breeding channels.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The last major pearl fishery in the Gulf of Mannar was held in February-March, 1958, when about 4.5 million oysters were collected from the south-west Cheval Paar by dredging. (Sivalingam 1961). Subsequently, two smaller fisheries, one in 1960 and another in 1961 took place. In these two fisheries one million oysters and four hundred thousand oysters respectively were collected from the Cheval paar by dredging. (De Fonselm 1953). Inspections of the Banks were carried out in 1962, 1963, 1964 and 1965. (Balasuriya 1964 and Silva 1965 and 66). Since then inspections were not possible due to one of two reasons or both the non-availability of operational dredges and a suitable vessel for this type of work.The "Pesalai" a 235-ton stern trawler was made available by the Ceylon Fisheries Corporation management for the 1970 inspection. Two new 6-foot dredges turned out by the Government Factory were also available for this work. However, the survey was limited to 3 days-the period for which the vessel had been released. It was further limited to those areas of the banks over 6 fathoms in depth because of the risk in operating a large vessel in shallower depths.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

DLC films with different thicknesses (from 100 nm to 1.9 μm) were deposited using sputtering of graphite target in pure argon atmosphere without substrate heating. Film microstructures (sp2/sp3 ratio) and mechanical properties (modulus, hardness, stress) were characterized as a function of film thickness. A thin layer of aluminum about 60 nm was deposited on the DLC film surface. Laser micromachining of Al/DLC layer was performed to form microcantilever structures, which were released using a reactive ion etching system with SF6 plasma. Due to the intrinsic stress in DLC films and bimorph Al/DLC structure, the microcantilevers bent up with different curvatures. For DLC film of 100 nm thick, the cantilever even formed microtubes. The relationship between the bimorph beam bending and DLC film properties (such as stress, modulus, etc.) were discussed in details. © 2005 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ticks are blood-feeding arthropods that may secrete immunosuppressant molecules, which inhibit host inflammatory and immune responses and provide survival advantages to pathogens at tick bleeding sites in hosts. In the current work, two families of immunoregulatory peptides, hyalomin-A and -B, were first identified from salivary glands of hard tick Hyalomma asiaticum asiaticum. Three copies of hyalomin-A are encoded by an identical gene and released from the same protein precursor. Both hyalomin-A and -B can exert significant anti-inflammatory functions, either by directly inhibiting host secretion of inflammatory factors such as tumor necrosis factor-alpha, monocyte chemotectic protein-1, and interferon-gamma or by indirectly increasing the secretion of immunosuppressant cytokine of interleukin-10. Hyalomin-A and -B were both found to potently scavenge free radical in vitro in a rapid manner and inhibited adjuvant-induced inflammation in mouse models in vivo. The JNK/SAPK subgroup of the MAPK signaling pathway was involved in such immunoregulatory functions of hyalomin-A and -B. These results showed that immunoregulatory peptides of tick salivary glands suppress host inflammatory response by modulating cytokine secretion and detoxifying reactive oxygen species.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Buniyar hydroelectric project and the lower Jhelum Barrier at Gantamulla constructed across river Jhelum are in operation from several years. The two power stations have changed the hydrological features of the area where dam is situated. Therefore, the impact of hydroelectric projects on fishery resources of river Jhelum is a matter of great concern. The treated water from the power house is released through turbines, having cooling effect on them. The change in the hydrological parameters such as increase in temperature, depletion of oxygen etc. might have brought fishes under stress which is the main cause in decreased population of finfishes from site to site. The golden mahseer, Tor putitora which was once an abundant species in river Jhelum has disappeared due to human intervention. The prevailing water quality around hydroelectric projects is unsuitable for finfishes of river Jhelum.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Role of eye-stalk of Macrobrachium gangeticum Bate, 1868 in its reproductive behaviour has been examined by conducting deletion and addition experiments. Eye-stalk ablation induced gonadal maturity in both sexes, leading to change in colour and size of ovaries and increase in GSI and oocyte diameter in females and increased length of testes and diameters of seminiferous tubules in males. Injection of eye-stalk extracts tended to at least partly restrict the effects in both sexes. The experiments thus suggested that the eye-stalk of M. gangeticum released some gonad inhibiting factors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

From the venom of Trimeresurus jerdonii, a distinct thrombin-like enzyme, called jerdonobin. was purified by DEAF A-25 ion-exchange chromatography, Sephadex G-75 gel filtration, and fast protein liquid chromatography (FPLC). SDS-PAGE analysis of this enzyme shows that it consists of a single polypeptide chain with a molecular weight of 38,000. The NH2-terminal amino acid sequence of jerdonobin has great homology with venom thrombin-like enzymes documented. Jerdonobin is able to hydrolyze several chromogenic substrates. The enzyme directly clots fibrinogen with an activity of 217 NIH units/mg, The fibrinopeptides released, identified by HPLC consisted of fibrinopeptide A and a small amount of fibrinopepide B. The activities of the enzyme were inhibited by phenylmethylsulfonyl fluoride (PMSF) and p-nitrophenyl-p-guanidinobenzoate (NPGB). However, metal chelator (EDTA) had no effect on it. indicating it is venom serine protease. (C) 2000 Elsevier Science Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Jerdonobin and jerdofibrase are two serine proteases purified from the venom of Trimeresurus jerdonii. The Michaelis constant K-m and the catalytic rate constant K-cat of jerdonobin or jerdofibrase on three chromogenic substrates, H-D-Pro-Phe-Arg-pNA (S2302), H-D-Phe-pipecolyl-Arg-pNA (S2238), and H-D-Val-Leu-Lys-pNA (S2251) were obtained from lineweaver-Burk plots. Jerdofibrase could hydrolyze all three substrates, but jerdonobin had no detectable activity on S2251, suggesting a relatively broader substrate specificity for jerdofibrase than jerdonobin. By SDS-PAGE, jerdofibrase preferentially degraded Bbeta-chain of fibrinogen. It also degraded Aalpha-chain of fibrinogen with relatively slow activity, but did not act on the gamma-chain. In contrast, jerdonobin did not degrade fibrinogen within 12 h. Fibrinopeptides liberation test, identified by HPLC, showed jerdonobin released fibrinopeptide A and a small amount of fibrinopeptide B. Unlike jerdonobin, jerdofibrase mainly released fibrinopeptide B. These results indicate that the two enzymes differ in their ability to hydrolyze chromogenic substrates and in their actions on fibrinogen. (C) 2002 Elsevier Science Inc. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Certain allometric relations of the spiny lobster Panulirus polyphagus are derived. While the relation between tail length and tail weight is made for both the sexes together, separate relations are derived for the sexes in the case of tail length versus total length. For conservation and economic purposes, it appears that the undersized ones are to be released alive.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pheromones are chemical cues released and sensed by individuals of the same species, which are of major importance in regulating reproductive and social behaviors of mammals. Generally, they are detected by the vomeronasal system (VNS). Here, we first investigated and compared an essential genetic component of vomeronasal chemoreception, that is, TRPC2 gene, of four marine mammals varying the degree of aquatic specialization and related terrestrial species in order to provide insights into the evolution of pheromonal olfaction in the mammalian transition from land to water. Our results based on sequence characterizations and evolutionary analyses, for the first time, show the evidence for the ancestral impairment of vomeronasal pheromone signal transduction pathway in fully aquatic cetaceans, supporting a reduced or absent dependence on olfaction as a result of the complete adaptation to the marine habitat, whereas the amphibious California sea lion was found to have a putatively functional TRPC2 gene, which is still under strong selective pressures, reflecting the reliance of terrestrial environment on chemical recognition among the semiadapted marine mammals. Interestingly, our study found that, unlike that of the California sea lion, TRPC2 genes of the harbor seal and the river otter, both of which are also semiaquatic, are pseudogenes. Our data suggest that other unknown selective pressures or sensory modalities might have promoted the independent absence of a functional VNS in these two species. In this respect, the evolution of pheromonal olfaction in marine mammals appears to be more complex and confusing than has been previously thought. Our study makes a useful contribution to the current understanding of the evolution of pheromone perception of mammals in response to selective pressures from an aquatic environment.