975 resultados para FLUCTUATION THEOREM
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The paper deals with a technique to synchronize two crops, fish and makhana (Euryale ferox Salisb) in a pond. In such eco-friendly integration both crops are mutually benefited. Decomposed plant parts of makhana crop form organic matter that releases nutrients in the water to enhance plankton population. Organic detritus not only acts as food for bottom dwelling fishes (mrigal and common carp) but also provides a suitable substratum for the growth of zooplankton, insect larvae, nematodes and gastropods. Fishes contribute to the control of makhana pests. Their faecal matter acts as organic manure for makhana crop. Plankton population fluctuated between 1260 u/l to 4030 u/l in the control pond and 1630 u/l to 4722 u/l in the experimental pond. During the grand growth period of makhana crop (April to July) the dissolved oxygen content fluctuated between 5.02 mg/l to 6.68 mg/l in the covered areas and 6.04 mg/l to 6.92 mg/l in uncovered areas. Makhana leaves acting as blanket barrier over the water surface brought down the D.O. content in the covered areas of the pond. Free CO sub(2) content showed wider fluctuation in the experimental pond (25.2 mg/l to 30.9 mg/l) than in the control pond (25.1 mg/l to 28.6 mg/l). This could be due to decomposition of plant parts of the presiding crop lying as debris at the pond bottom. Autochthonous supply of nutrients enhanced the content of nitrogen, phosphorous and organic carbon in the soil of experimental pond. The experimental pond covering an area of 0.40 ha yielded 852 kg fish and 200 kg pops whereas the control pond covering the same area produced 777 kg fish only. The net profit per ha came out to be Rs.1,04,700 and Rs. 66,200 in integrated and non-integrated system respectively. Owing to crop diversification, the present integrated system was found to be more viable than the non-integrated system in terms of production and net profit.
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Drained weight of canned prawn depends on moisture content of blanched meat and equilibrium moisture (EM) content of processed meat. The greater the difference between the two values the more is the fluctuation in drained weight. EM is a fixed value with particular reference to the species of prawn, which has been justified mathematically and by material balance of can contents before and after processing.
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Landing data of 21 fisheries from Karnataka (quarterly landings for the period 1956 to 1978 and annual landings for the period 1979 to 1981) were analysed to study the te111poral behaviour of the landings. The relative distribution and secular trends in each of the fisheries are reported. On an average, mackerel and oil sardine together account for about 70% of the annual landings. The fluctuation in the landings in all the fisheries was very high with the coefficient of variation attaining a minimum value of 61.53%. The inverse relationship between the landings of oil sardine and mackerel was found to be statistically significant. It is suggested that fishing effort be further increased in fisheries that have demonstrated a rising trend (about 73% of the total annual landings) as also in the case of the fisheries whose trends appear stagnant (about 21% of the annual landings). However, there seems to be some evidence of a need for regulating fishing in Hemirhamphus and Belone, Caranx and penaeid prawns. Regulations need to be made authentic with the help of sufficient information on not merely the fishery but on the whole population.
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Seasonal patterns of 21 fisheries in Karnataka (after isolation from time-series components) are presented. Depending on the pattern of seasonal fluctuation in landings, 19 fisheries have been grouped into five patterns, A, B, C, D and E. Ribbon fishes and 'other clupeids' did not exhibit any significant seasonal pattern. Pattern A with highest landings in the 4th quarter (October to December), followed by the 1, 2 and 3 quarters, is the most common in 10 species/groups (comprising 78% of the total landings). Harmonic analysis has been carried out using the seasonal indices.
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This study was carried out to seasonal determination of some morphological characteristics, Seasonal fecundity, Seasonal fluctuations of vertebrate-type steroids and seasonal analysis of gonadal histology in both female and male sexes of freshwater crayfish (Astacus leptodactylus Eschscholtz 1823) in the area of Aras dam Lake. Crayfish were collected respectively in June, August, November (2011) and January (2012). The average length and weight of male crayfish was higher than that of females. %GSI of females fluctuated within an extended range (between 0.6 and 13.5% from June to January). Both of synchronous and asynchronous ovaries were seen in August sampled ovaries; however asynchronous form was higher than another. The annual reproductive cycle of male A. leptodactylus was surveyed by study on the seasonal changes of the external appearance of the testes and vasa deferentia, fluctuations in the gonadosomatic index (GSI%) and the histological analysis of the male reproductive system. Based on the histological differentiation of testis, spermatogenisis devided to 5 separated stages. The findings suggested asynchronous testis in the species A.leptodactylus. The presence of primary spermatophore layer may help keeping spermatozoa alive while the secondary spermatophore layer may produces spermatophore or synthesize of acellular material which forms spermatophre. Pleopodal fecundity was 37.3%lower than ovarian fecundity observed. The significantly higher number of eggs attached to 3rd and 4th pairs of pleopods. The egg number and gonadosomatic index increased with female size while egg weight and egg diameter didn’t increase with female size. Hemolymph levels of 17β-estradiol and progesterone followed a similar fluctuation pattern with % GSI in females, while testosterone didn’t follow the mentioned pattern. The testis of November sampled crayfish presented significantly higher gonadosomatic (%GSI) index (P < 0.05).The most observed gonadosomaticindices were 13.5%(forfemales) and 1.21% (for males, in autumn. Althogh the lowest GSI was (0.50%) formales in spring and (0.26%0 for spent females in January. Testosterone which followed a similar pattern with %GSI in males increased remarkably in November. 17β-estradiol increased strictly in January. The strictly enhancement of the three estroid hormones in January in both male and female sexes could bedue totheir stimulating role in in spermatophre and egg lying in the mating season (In January). Most of the ovaries followed the asynchoronous growth pattern. Also the testes presented asynchoronous growth pattern in autumn.
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Phytoplankton productivity is the common and important factor being considered in determining the overall status of a given body of water. This is because they are found at the base of an energy or food chain, being the basic source of primary food in a given aquatic system. Hence, information on their contribution is essential in indicating how much biomass energy will be available to all other living resources in the system. Though the primary productivity of shallow lakes is characterized by mixed populations of phytoplankton and submersed aquatic vegetation in the open water. Lake Choghakhor, is a shallow lake, located in Chaharmahal-Bakhtiyari Province. This lake is the most important ecosystem in the region especially for waterfowl populations, has a recreational value and supports tourism and fisheries. During last decade Choghakhor has been influenced by some man-made impacts such as water level fluctuation, agricultural discharge and fish (Cyprinids) introduction causing a serious problem in its trophic states. So water quality for physical, chemical and biological was monitored in five sampling stations, from April 2003 to March 2004. As biological parameters we studied phytoplankton, epiphytic algae, and zooplankton and macrobenthose community structure. Chlorophyll a content for phytoplankton and epiphytes was measured to estimate production of these groups (biomass over time). Also we determined biomasses of submersed macrophytes and macrobenthose and primary production of phytoplankton (dark and light bottles technique) to estimate fish production. The results of this study showed Lake Choghakhor did not undergo stable thermal and oxygen stratification, and the lake water was mixed throughout the study (the lake mixing regime is polymictic). Now submerged plants especially Myriophyllum spicatum has covered almost the entire lake and dense macrophyte beds (Polygonom amphibium), located on the east southern end of the lake appear to act as a sink for these nutrients. Lake Choghakhor appeared to be in a macrophyte dominated clear water state with low TP (annual mean: 24± 15μg.l-1) and chlorophyll a (annual mean: 3±1.28μg.l-1) concentrations and very high Secchi depth. The grazing pressure of dominant pelagic filtering zooplankton Daphnia longespina did not seem to be significant in determining the low phytoplankton crop expressed as chlorophyll a. We expect that sequestering of nutrients by submerged plants and associated epiphytes are the dominant stabilizing mechanisms suppressing the phytoplankton crop of Lake Choghakhor.
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In this study the process of female gray mullet brooders was carried out by using histological study and masurment of sex steroids. Results of histological studies showed that oocyte of gray mullet brooders in Gomishan Rearing Center conditions of develop to the end of yolk globule stage. The results were observed with oocyte in chromatin nucleolar stage (first stage) with means of diameter of 20 p m, in August, perinucleolar stage (second stage) in September with mean diameter of 87 p m, yolk vesicle stage (third stage) in October with mean diameter 200 p m and yolk granules stage (forth stage) from October to November with average diameter of 180 — 650 p m. For the reason of stopping oocyte develop at the end of fourth stage, hormonal induction to final oocyte maturation and ovulation was used. For this purpose, carp pituitary , HCG and LRH-A2 with different combinations were used in two stages, second injection was used 24 hours after first injection. 15 females brooders were divided in 5 groups, different hormonal combinations were injected to four groups and to fifth group as control, only saline, was injected. The process of female brooder rippening in hormonal induction was studied via masurment of sex steroids including 17 a - hydroxy progestrone, estradio1-17)6 and testosterone. Blood samples were collected from caudal vein during first injection, 24, 30 and 48 hours after the first injection. At the same time, for distinguishing histological changes the sample has been attained from the gonads Sex stroid fluctuation patterns in different brooder groups that injected hormon were similar, however hormonal composition had similar effects. All brooder that their oocyte in the beginning of hormonal injection were At the end of fourth stage with oocyte diameter average of 600 p m received to final maturation and ovulation. The brooder that its oocytes were At the begining or mid-fourth stage did not show ovulation but hormonal induction caused oocyte develop at the beginning of fifth stage. Study of 17-hydroxy progestrone fluctuation showed that the maximum level of this steroid (0.347 ng/ml) measured 30 hours after the first injection and was significantly higher (p< 0.05) than those of control group. So, 17-hydroxy progestrone is probably precursor of maturation inducing steroid (MIS). However the maximum level of that observed was coincident with germinal vesicle breakdown, oil droplets coalescence and dissolution of yolk granuls The maximum levels of esteradiol— 17/0 and testosterone (3.778 and 16.801ng/ml,respectively) in spawned brooders,were observed 24 hours after the first injection. levels of those steroids were significantly higher (p<0.05) than control group. Maximum level of sex steroids in the brooders that did not spawn to the end of treatment was observed with more delay than those in spawned brooders. Therefor maximum level of 17a-hydroxy progestrone (0.264 ng/ml) in those brooders observed in fourth sampling time and the maximum levels of estradio1-17a and testosterone (2.944 and 18.993 ng/ml, respectivly)observed in third sampling time that was significantly higher (p<0.05) than those of control group. For the study of stress effect on brooders during the hormonal induction, level of cortisol was measured in every sampling time. level of cortisol had high fluctuation that showed handling level and stress effect on brooders. However maximum level of cortisol in majority of brooders was dominant in third sampling time that was coincident with final maturation.
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Ecological study on Kolahy and 'flab estuaries were carried out during 1996-1997. Water and sediment sampling was done seasonally. In order to study the physical and chemical characteristic of the water, various animal fauna from different material niches including planktons and fish from water, benthousi from the sediment , and surface living animal such as Arthropod (Crabs) and Waterbirds were identified. I he result shoved, that water salinity of both estuaries was the same as the general salinity existing its the Persian Gulf water, and its variation is same IN those waters Minimum water salinity in both estuaries are seen during Bahairdan or early winter mooth(Jaa.), which is about 31ppt and Maximum is during .rirldlun.) or summer mouth at about 19 ppt. Dissolved otygen and pH are slime as the general Persian Gulf waters., Dissolve Oxygen being directly associated to temperature and its fluctuation is between 7- Sing/I and pH between 7.5-LS. The animals of both estuaries are almost similar having a sal factory species diversity . The birds of the region are often seasonal migrants , the maximum population of which occurs in winter season and the minimum during summer month. Nam coverage is richer in Tiab than Kolahy estuary, where in Kolahy a signal Mangrove tree is in exigence. 'Ile total coverage of Mangrove forest in Tiab is estimated about -29 hec.Both estuaries are included with in the international Ramsar Convention sites in 1971. Due to national importance of these estuaries inproviding refugee for various birds species and also hinting grounds and access traffic for local fishing vehicles, Actiog as an important access for various inhabitancy living with these area of the Persian Gulf. Due to importance or prawn aquacultur for the economical well being of local inhabitance, these areas provide a suitable grandees for prawn production. I-test statistics show, there are no significant difference among various invertebrate and vertebrate animals. In over all out look 21) phytoplankton genera, 21) zeoplankton genera 17 miafauna and 32 roaerofauna genera , 11 different species Carcineacearions and 119 species of walerbirds were identified with in the Tiab and Kolahy estuariesregioos. The X statistic show that the animal density is directly associated to season. Where density of miofauna and maerofauna in both estuaries are in maiticrourn during summer and the minimums existing during the winter season. In addition the bentic invertebrate population density in closlly association to birds population density since , the later, feeds on the former animals. Where the increasing in bird population density during the winter season, the bentic invertebrate animal population density decreases. The over all trend of animal population density in winter tend to increased towards the summer seasons, which this is due to climatic conditions of the region. The bird population on the contrary to other animals of both estuaries tend to increase from summer towards the winter seasons and which this bird population density is in maximum in winter with in the region.
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Acoustic radiation from a spherical source undergoing angularly periodic axisymmetric harmonic surface vibrations while eccentrically suspended within a thermoviscous fluid sphere, which is immersed in a viscous thermally conducting unbounded fluid medium, is analyzed in an exact fashion. The formulation uses the appropriate wave-harmonic field expansions along with the translational addition theorem for spherical wave functions and the relevant boundary conditions to develop a closed-form solution in form of infinite series. The analytical results are illustrated with a numerical example in which the vibrating source is eccentrically positioned within a chemical fluid sphere submerged in water. The modal acoustic radiation impedance load on the source and the radiated far-field pressure are evaluated and discussed for representative values of the parameters characterizing the system. The proposed model can lead to a better understanding of dynamic response of an underwater acoustic lens. It is equally applicable in miniature transducer analysis and design with applications in medical ultrasonics.
Resumo:
This paper follows the work of A.V. Shanin on diffraction by an ideal quarter-plane. Shanin's theory, based on embedding formulae, the acoustic uniqueness theorem and spherical edge Green's functions, leads to three modified Smyshlyaev formulae, which partially solve the far-field problem of scattering of an incident plane wave by a quarter-plane in the Dirichlet case. In this paper, we present similar formulae in the Neumann case, and describe a numerical method allowing a fast computation of the diffraction coefficient using Shanin's third modified Smyshlyaev formula. The method requires knowledge of the eigenvalues of the Laplace-Beltrami operator on the unit sphere with a cut, and we also describe a way of computing these eigenvalues. Numerical results are given for different directions of incident plane wave in the Dirichlet and the Neumann cases, emphasising the superiority of the third modified Smyshlyaev formula over the other two. © 2011 Elsevier B.V.
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In order to understand the behavior of RNAs with large bulges In solution, molecular dynamics was performed on the RNA molecule in water with A6 bulge. The result of simulation showed that nonstacked conformation Is the main conformation in large bulges, and the backbone of large bulge is of great conformational flexibility, but bulges-induced bends are relatively rigid. The fluctuation in bulge has little influence on the bend angle of RNAs.
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Based on the statistical analysis of 119 human and 92 E. coli proteins it was found that for both human and E. coli, the mRNA sequences consisting of tri-codon and tetra-codon with high translation speed preferably code for alpha helices more than for coils. For beta strand, the preference/ avoidance oscillates with the translation speed. Moreover, the non-homogeneous usages of tri-codon and tetra-codon with different translation speeds in a given secondary structure have also been found. These results cannot be simply explained by the effect of stochastic fluctuation.
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Anew integrated sequence-structure database, called IADE (Integrated ASTRAL-DSSP-EMBL), incorporating matching mRNA sequence, amino acid sequence, and protein secondary structural data, is constructed. It includes 648 protein domains. Based on the IADE database, we studied the relation between RNA stem-loop frequencies and protein secondary structure. It was found that the alpha-helices and beta-strands on proteins tend to be preferably "coded" by mRNA stem region, while the coils on proteins tend to be preferably "coded" by mRNA loop region. These tendencies are more obvious if we observe the structural words (SWs). An SW is defined by a four-amino-acid-fragment that shows the pronounced secondary structural (alpha-helix or beta-strand) propensity. It is demonstrated that the deduced correlation between protein and mRNA structure can hardly be explained as the stochastic fluctuation effect. (C) 2003 Wiley Periodicals, Inc.
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We consider the general problem of constructing nonparametric Bayesian models on infinite-dimensional random objects, such as functions, infinite graphs or infinite permutations. The problem has generated much interest in machine learning, where it is treated heuristically, but has not been studied in full generality in non-parametric Bayesian statistics, which tends to focus on models over probability distributions. Our approach applies a standard tool of stochastic process theory, the construction of stochastic processes from their finite-dimensional marginal distributions. The main contribution of the paper is a generalization of the classic Kolmogorov extension theorem to conditional probabilities. This extension allows a rigorous construction of nonparametric Bayesian models from systems of finite-dimensional, parametric Bayes equations. Using this approach, we show (i) how existence of a conjugate posterior for the nonparametric model can be guaranteed by choosing conjugate finite-dimensional models in the construction, (ii) how the mapping to the posterior parameters of the nonparametric model can be explicitly determined, and (iii) that the construction of conjugate models in essence requires the finite-dimensional models to be in the exponential family. As an application of our constructive framework, we derive a model on infinite permutations, the nonparametric Bayesian analogue of a model recently proposed for the analysis of rank data.
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This study detailed the structure of turbulence in the air-side and water-side boundary layers in wind-induced surface waves. Inside the air boundary layer, the kurtosis is always greater than 3 (the value for normal distribution) for both horizontal and vertical velocity fluctuations. The skewness for the horizontal velocity is negative, but the skewness for the vertical velocity is always positive. On the water side, the kurtosis is always greater than 3, and the skewness is slightly negative for the horizontal velocity and slightly positive for the vertical velocity. The statistics of the angle between the instantaneous vertical fluctuation and the instantaneous horizontal velocity in the air is similar to those obtained over solid walls. Measurements in water show a large variance, and the peak is biased towards negative angles. In the quadrant analysis, the contribution of quadrants Q2 and Q4 is dominant on both the air side and the water side. The non-dimensional relative contributions and the concentration match fairly well near the interface. Sweeps in the air side (belonging to quadrant Q4) act directly on the interface and exert pressure fluctuations, which, in addition to the tangential stress and form drag, lead to the growth of the waves. The water drops detached from the crest and accelerated by the wind can play a major role in transferring momentum and in enhancing the turbulence level in the water side.On the air side, the Reynolds stress tensor's principal axes are not collinear with the strain rate tensor, and show an angle α σ≈=-20°to-25°. On the water side, the angle is α σ≈=-40°to-45°. The ratio between the maximum and the minimum principal stresses is σ a/σ b=3to4 on the air side, and σ a/σ b=1.5to3 on the water side. In this respect, the air-side flow behaves like a classical boundary layer on a solid wall, while the water-side flow resembles a wake. The frequency of bursting on the water side increases significantly along the flow, which can be attributed to micro-breaking effects - expected to be more frequent at larger fetches. © 2012 Elsevier B.V.