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1.
Hybrid carp and grass carp from the zygote to the prolarval stage and adults were compared to establish distinguishing characteristics. Zygote diameter, yolk sac and embryo length were not different between the fishes. Body pigmentation patterns showed distinct separation among the prolarvae of the hybrids and grass carp. Total and preanal myomeres were higher in grass carp larvae than in the hybrids. The grass carp and hybrid larvae also differed in 38% of the proportional morphometric characters.
Average meristic counts of adults were significantly higher in hybrids compared with grass carp. Adults of the two fishes showed significant differences in 63% of the proportional morphometric measurements. Gill raker counts showed no overlap and lateral line scales were smaller and more numerous in the hybrid adults.  相似文献   
2.
Innervation of the gut is segmentally lost in Hirschsprung disease (HSCR), a consequence of cell-autonomous and non-autonomous defects in enteric neuronal cell differentiation, proliferation, migration, or survival. Rare, high-penetrance coding variants and common, low-penetrance non-coding variants in 13 genes are known to underlie HSCR risk, with the most frequent variants in the ret proto-oncogene (RET). We used a genome-wide association (220 trios) and replication (429 trios) study to reveal a second non-coding variant distal to RET and a non-coding allele on chromosome 7 within the class 3 Semaphorin gene cluster. Analysis in Ret wild-type and Ret-null mice demonstrates specific expression of Sema3a, Sema3c, and Sema3d in the enteric nervous system (ENS). In zebrafish embryos, sema3 knockdowns show reduction of migratory ENS precursors with complete ablation under conjoint ret loss of function. Seven candidate receptors of Sema3 proteins are also expressed within the mouse ENS and their expression is also lost in the ENS of Ret-null embryos. Sequencing of SEMA3A, SEMA3C, and SEMA3D in 254 HSCR-affected subjects followed by in silico protein structure modeling and functional analyses identified five disease-associated alleles with loss-of-function defects in semaphorin dimerization and binding to their cognate neuropilin and plexin receptors. Thus, semaphorin 3C/3D signaling is an evolutionarily conserved regulator of ENS development whose dys-regulation is a cause of enteric aganglionosis.  相似文献   
3.
Crimean-Congo hemorrhagic fever (CCHF) virus is one among the major zoonosis viral diseases that use the Hyalomma ticks as their transmission vector to cause viral infection to the human and mammalian community. The fatality of infectious is high across the world especially in Africa, Asia, Middle East, and Europe. This study regarding codon usage bias of S, M, and L segments of the CCHF virus pertaining to the host Homo sapiens, reveals in-depth information about the evolutionary characteristics of CCHFV. Relative Synonymous Codon Usage (RSCU), Effective number of codons (ENC) were calculated, to determine the codon usage pattern in each segment. Correlation analysis between Codon adaptation index (CAI), GRAVY (Hydrophobicity), AROMO (Aromaticity), and nucleotide composition revealed bias in the codon usage pattern. There was no strong codon bias found among any segments of the CCHF virus, indicating both the factors i.e., natural selection and mutational pressure shapes the codon usage bias.  相似文献   
4.
Hybrid carp were raised in 1651 indoor tanks. Two tanks were used in this study each stocked with five fish (average total length and weight = 235.7 mm; 116.1 g); one tank was provided with zooplankton and the other with zooplankton and Chara sp. The hybrids fed actively on zooplankton at an average daily rate of 39% and Chara at 2.6% by body weight. Growth was estimated as 0.36% (0.43 g) per day. The hybrids on the two food types showed no significant differences either in plankton consumption or growth rate.  相似文献   
5.

Background  

The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics.  相似文献   
6.
The objective of the present study was to design and evaluate unilaminate transdermal adhesive matrix systems capable of diffusing bupropion base at a constant rate over an extended period of time as an alternative route of administration. Unilaminate transdermal adhesive matrices have been fabricated with different concentrations of Eudragit E as the adhesive and rate-controlling polymer. The in vitro release and epidermal flux through human cadaver skin were studied. The release of drug from the matrices obeyed zero order release kinetics (r 2=0.9810 to 0.9960). The delivery rate of bupropion ranged from 10.5 mg to 31.4 mg per day from a 3.14 cm2 area of matrix. The relation between concentration of bupropion base in matrix and epidermal flux, concentration of drug in matrix, and epidermal adsorption of bupropion during diffusion follow hyperbolic fashion. Triethylcitrate (TEC) and dibutylphthalate (DBP) have no influence on the diffusion of bupropion through human cadaver skin when used as plasticizers. Incorporation of succinic acid in the adhesive matrix retarded diffusion due to the formation of rigid cross linking of the polymer, while propylene glycol and myristic acid, alone or in combination, significantly enhanced the flux of bupropion through human cadaver skin.  相似文献   
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Grass carp were raised in 227 1 indoor tanks at 12.8, 18.3, 23.9 and 29.4° C temperatures, each experimental condition received five fish. Five grass carp were also raised in a 1135 1 tank maintained at 29.4° C representing low stocking density (29.4° C-L). Food consumption, food conversion, and growth of carp were not different among the 18.3, 23.9, and 29.4° C experimental conditions with identical stocking density. The least growth and food consumption were noted for the fish at the 12.8° C temperature. The fish at the low stocking density had the best growth and maximum food consumption.  相似文献   
10.
In wetlands the effects of fire on vegetation dynamics are somewhat uncertain. A change detection analysis in the herbaceous wetlands of KwaMbonambi, South Africa, which were subject to frequent fires, revealed that in 1937 the study area comprised grassland (69%), herbaceous wetland (25%), indigenous swamp forest (4%) and tree plantations (1%). However, by 1970, tree plantations occupied 78% of the landscape and grasslands and herbaceous wetlands had declined to 9% and 6%, respectively, whereas indigenous swamp forest had increased to 6%. By 2009 tree plantations had been removed from the wetland areas. Despite this opportunity for herbaceous wetlands to recover their historical extent, they decreased to only 2%, mostly changing to indigenous swamp forest or to an herbaceous/fern (Stenochlaena tenuifolia)/woodland mosaic. Fire records showed suppression of fire to be an important contributing factor, particularly in wetlands that had been disturbed by tree plantations, although subsequently removed. A pilot burning experiment revealed that S. tenuifolia did not inhibit fire. It is therefore practicable to increase fire frequency to prevent the mosaic developing into forest. A conceptual model of the influence of fire regime on wetland vegetation type is presented and priorities for further research on wetlands and fire are recommended.  相似文献   
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