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271.
On a medium containing either acetate as the sole source of carbon or arginine as the sole source of nitrogen and the two amino acid analogs,p-fluorophenylalanine (FPA) and ethionine, eight FPA-resistant mutants were selected. Dominance tests in heterozygous diploids showed that 3 out of 8 are recessive, 1 semidominant, and 4 dominant to their wild-type alleles. Mutants were characterized by the nature of amino acid transport detected on the basis of amino acid utilization patterns. Six new loci identified after genetic analysis were located on two linkage groups: three each on linkage groups I and II. Recombinants between pairs of locifpaD andfpaQ, andfpaK andfpaP, were found to be sensitive to FPA. The patterns of segregation of resistant markers and amino acid utilization were considered to characterize the specificity of transport mutants. 相似文献
272.
Japanese macaque societies are characterized by frequent intragroup conflict both in free-ranging and zoo-housed conditions. In zoos, understanding the factors that contribute to wounding is of interest because this knowledge can aid in proactive husbandry and management planning that can minimize the negative impacts wounding can have on individual welfare. This study sought to determine whether the variables sex, season and age predicted wounding rates. Data were collected for 24 months on 119 Japanese macaques living in 10 zoos, and we analyzed the contribution of variables using generalized linear mixed models. A total of 1,007 wounds were reported, and the best model included the interaction between sex and season. Follow-up analyses revealed that females incurred more wounds than males, and this sex difference was more pronounced during the breeding compared to the nonbreeding season. On average, individuals received 4.67 (±SEM: 0.55) wounds per year and 77.31% of the population incurred at least one wound in the study period. The majority of wounds were superficial and did not require veterinary intervention. Wound locations were not randomly distributed across body regions and were most often reported on the face. Finally, macaques living in larger social groups experienced more wounds, on average. This study represents the first quantification of wounding in this species and may provide insight to help inform husbandry and management strategies in zoos. 相似文献
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Patrick W. Tank 《Developmental biology》1977,57(1):15-32
The timing of morphogenetic events in the regenerating forelimb of the axolotl was investigated by rotation of limb coverings at well-defined stages in the regenerative process. Both the skin covering the stump and the epidermis covering the regenerate were manipulated independently and together as a unit. The results show that the transmission of morphogenetic information covers a broad range of regenerative stages. This morphogenetic information seems first to become irreversibly fixed in the regenerate by the stage of late bud. The regenerate is sensitive to stump influences at early stages of regeneration, but it becomes insensitive to stump influences by the stage of palette. Evidence is presented which implies that epidermis that covers the regenerate is capable of influencing morphogenesis. 相似文献
276.
Summary Using cell recycle, the concentration of M. trichosporium OB3b was increased to more than 12g/L in continuous culture and biomass productivity was enhanced up to 0.708g/L/h. The optimal temperature and pH for soluble MMO activity were 35°C and 6.2–6.4. The Optimal concentrations of methanol and sodium formate, as cofactor regenerators, were 0.5mM and 10 mM, respectively, at which the soluble MMO activity was about 8 times enhanced. 相似文献
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Trentman Matt T. Tank Jennifer L. Davis Robert T. Hanrahan Brittany R. Mahl Ursula H. Roley Sarah S. 《Ecosystems》2022,25(2):441-456
Ecosystems - Stream metabolism, in the form of gross primary production (GPP) and ecosystem respiration (ER), is an important metric of stream ecosystem function, given GPP and ER are integrative... 相似文献
280.
Bhupendra Mathpal Prakash Chandra Srivastava Deepti Shankhdhar Shailesh Chandra Shankhdhar 《Physiology and Molecular Biology of Plants》2015,21(4):567-572
Zinc (Zn) is an important micronutrient for the physiology of plants. It is poorly available to the plants in soil solution. A pot experiment was conducted to evaluate effectiveness of various Zn application methods on key enzyme activities and protein content of two contrasting rice genotypes viz., PD16 (Zn efficient) and NDR359 (Zn inefficient). The treatments were, control (0 mg Zn kg−1 soil), soil application (5 mg Zn kg−1 soil), foliar application (0.5 % ZnSO4 + 0.25 % lime at 30, 60 and 90 days after transplanting), soil (5 mg Zn kg−1 soil) + foliar application of 0.5 % ZnSO4 + 0.25 % lime at 30, 60 and 90 days after transplanting. Among all the methods tested soil+foliar application of Zn fertilizers was found most effective in increasing superoxide dismutase (SOD) and carbonic anhydrase (CA) activities as well as chlorophyll and protein content in both the rice varieties. NDR359, showed higher enzyme activities and more chlorophyll content in leaves than PD16, when Zn was applied either through foliar spray alone or in soil along with foliar application. Regarding the protein content in grains, PD16 showed higher protein content than NDR359, thus showed better translocation of Zn from leaves to grains. 相似文献