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71.
ER Smith GM Pesti RI Bakalli GO Ware JF Menten 《Canadian Metallurgical Quarterly》1998,77(11):1678-1687
An experiment was conducted to quantify genetic differences in response to dietary protein level of male vs female broilers. Broilers (1 d old) from a "high-yield" strain cross (Ross x Ross 208) and a "fast-growing" strain cross (Peterson x Arbor Acres) were placed on fresh pine shavings in floor pens. From Day 0 to 18, all birds were fed a 23% CP starter diet. During Days 18 to 53 male birds were fed either a 16, 18, 20, 22, 24, or 26% CP diet (3,200 kcal ME/kg) and female birds were fed the 16, 20, or 24% CP diet. Significant differences (P < 0.05) were noted in the performance of the different strains. Ross x Ross 208 male birds had a higher body weight (3.37 vs 3.16 kg), higher feed intake (7.08 vs 6.78 kg), higher breast yield (31.76 vs 29.25%), higher carcass yield (73.90 vs 71.85%), and a lower adjusted feed conversion ratio (FCR; 2.10 vs 2.16 g:g) than Peterson x Arbor Acres males at 53 d of age. As compared to Peterson x Arbor Acres females, Ross x Ross 208 female broilers also had a higher body weight (2.68 vs 2.55 kg), higher breast meat yield (33.61 vs 30.80%), higher carcass yield (75.31 vs 73.91%), and lower adjusted FCR (1.97 vs 2.04 g:g). Qualitative differences in the response of these strains were confirmed and better qualitative data is presented that can be used to predict the important output parameters from the import inputs in broiler production. 相似文献
72.
We have previously derived a theoretical measure of neural complexity (CN) in an attempt to characterize functional connectivity in the brain. CN measures the amount and heterogeneity of statistical correlations within a neural system in terms of the mutual information between subsets of its units. CN was initially used to characterize the functional connectivity of a neural system isolated from the environment. In the present paper, we introduce a related statistical measure, matching complexity (CM), which reflects the change in CN that occurs after a neural system receives signals from the environment. CM measures how well the ensemble of intrinsic correlations within a neural system fits the statistical structure of the sensory input. We show that CM is low when the intrinsic connectivity of a simulated cortical area is randomly organized. Conversely, CM is high when the intrinsic connectivity is modified so as to differentially amplify those intrinsic correlations that happen to be enhanced by sensory input. When the input is represented by an individual stimulus, a positive value of CM indicates that the limited mutual information between sensory sheets sampling the stimulus and the rest of the brain triggers a large increase in the mutual information between many functionally specialized subsets within the brain. In this way, a complex brain can deal with context and go "beyond the information given." 相似文献
73.
Emma Murphy Ravi Kuber Graham McAllister Philip Strain Wai Yu 《Universal Access in the Information Society》2008,7(1-2):79-91
In this paper, an empirical based study is described which has been conducted to gain a deeper understanding of the challenges faced by the visually impaired community when accessing the Web. The study, involving 30 blind and partially sighted computer users, has identified navigation strategies, perceptions of page layout and graphics using assistive devices such as screen readers. Analysis of the data has revealed that current assistive technologies impose navigational constraints and provide limited information on web page layout. Conveying additional spatial information could enhance the exploration process for visually impaired Internet users. It could also assist the process of collaboration between blind and sighted users when performing web-based tasks. The findings from the survey have informed the development of a non-visual interface, which uses the benefits of multimodal technologies to present spatial and navigational cues to the user. 相似文献
74.
GM Roshchina EB Lishnevskaia IA Sizova VA Orlova IM Tereshin 《Canadian Metallurgical Quarterly》1980,25(11):850-854
The technique of accumulating preparation of the mucosa and "turned out sac" was used to show that levorin, a polyenic antibiotic in a concentration of 10(-6) M, lowered the transport rate and accumulation of glucose by the epithelial cells of the rat thin intestine under conditions of oxygenation. Suppression of the glucose transport in the first stages resulted in partial inhibition of the transmembrane transfer. It is suggested that levorin suppression of the glucose transport through the erythrocyte apical membrane in the thin intestine is associated with a decrease in the electrochemical gradient of Na+. 相似文献
75.
The kinetics of the male gametogenesis during the pregonadal period, prespermatogenesis, and "early" spermatogenesis has been described in detail. Concerning spermatogenesis in the adult individual reference is made to the articles of Courot, Hochereau-de Reviers and Ortavant (1970) and of Clermont (1972). The comparison of female and male gametogenesis (Fig. 1) shows that the "gonia stage" (asterisks) of the female germ cells is limited to one proliferation wave only, whereas the "gonia stage" of the male germ cells consists of a first proliferation wave, comparable to that of oogonia, a preparative phase to initiate spermatogenesis, and a second proliferation wave with renewal and differentiation of the spermatogonia. Germ cells in the "gonia stage" are highly sensitive towards ionising radiation and cytostatic drugs. 相似文献
76.
GM Shambes 《Canadian Metallurgical Quarterly》1976,55(5):221-252
The purpose of this study was to investigate "static" balance characteristics in four and eight year old children performing six developmental tasks leading to upright stance. The data were evaluated with electromyographic, center of gravity and photographic procedures. The results of the study indicated that the older age group of children demonstrated higher degrees of motor control in all the balance tasks involving upper and/or lower extremity support of the trunk. The eight year old children showed less postural sway, more definitive muscular localizations and smaller degrees of motor activity occurring during the execution of the developmental tasks. 相似文献
77.
The mirrors of laser interferometric gravitational wave detectors hang from multi-stage suspensions. These support the optics against gravity while isolating them from external vibration. Thermal noise must be kept small so mechanical loss must be minimized and the resulting structure has high-Q resonances rigid-body modes, typically in the frequency range between about 0.3 Hz and 20 Hz. Operation of the interferometer requires these resonances to be damped. Active damping provides the design flexibility required to achieve rapid settling with low noise. In practice there is a compromise between sensor performance, and hence cost and complexity, and sophistication of the control algorithm. We introduce a novel approach which combines the new technique of modal damping with methods developed from those applied in GEO 600. This approach is predicted to meet the goals for damping and for noise performance set by the Advanced LIGO project. 相似文献
78.
It is demonstrated for the first time that an epoxy thermoset resin can be cured at temperatures well below its Tg∞. This study compared the use of a uniform variable frequency microwave (VFM) field to standard oven curing at temperatures above and below Tg∞. Using Tg, tan δ, modulus, and FTIR measurements, it is shown that the reaction of BFDGE with MDA to attain a product with Tg∞ of 133 °C is achieved by VFM at temperatures from 100 to 140 °C; in contrast, the thermal cure normally requires 170 °C to attain the same Tg∞ and the same extent of cure. By following the pregel cure reaction with 13C‐NMR spectroscopy, it was determined that the lower cure temperatures of VFM cure predominately lead to chain extension and smaller amounts of crosslinking compared to the thermal cure. To explain these results, it is suggested that, after gelation, with VFM cure there is higher mobility from dipole rotations that continues the cure to completion without vitrification. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44222. 相似文献
79.
Alessia Costa Barbara Rani Thomaz F. S. Bastiaanssen Francesco Bonfiglio Eoin Gunnigle Gustavo Provensi Moira Rossitto Marcus Boehme Conall Strain Clara S. Martínez Patrizio Blandina John F. Cryan Sophie Lay Renato Corradetti Maria Beatrice Passani 《International journal of molecular sciences》2022,23(2)
Exposure to repeated social stress may cause maladaptive emotional reactions that can be reduced by healthy nutritional supplementation. Histaminergic neurotransmission has a central role in orchestrating specific behavioural responses depending on the homeostatic state of a subject, but it remains to be established if it participates in the protective effects against the insults of chronic stress afforded by a healthy diet. By using C57BL/6J male mice that do not synthesize histamine (Hdc−/−) and their wild type (Hdc+/+) congeners we evaluated if the histaminergic system participates in the protective action of a diet enriched with polyunsaturated fatty acids and vitamin A on the deleterious effect of chronic stress. Behavioural tests across domains relevant to cognition and anxiety were performed. Hippocampal synaptic plasticity, cytokine expression, hippocampal fatty acids, oxylipins and microbiota composition were also assessed. Chronic stress induced social avoidance, poor recognition memory, affected hippocampal long-term potentiation, changed the microbiota profile, brain cytokines, fatty acid and oxylipins composition of both Hdc−/− and Hdc+/+ mice. Dietary enrichment counteracted stress-induced deficits only in Hdc+/+ mice as histamine deficiency prevented almost all the diet-related beneficial effects. Interpretation: Our results reveal a previously unexplored and novel role for brain histamine as a mediator of many favorable effects of the enriched diet. These data present long-reaching perspectives in the field of nutritional neuropsychopharmacology. 相似文献
80.
R Lewis S Kapur C Jones J DaSilva GM Brown AA Wilson S Houle RB Zipursky 《Canadian Metallurgical Quarterly》1999,156(1):72-78
BACKGROUND: In the FRISC trial, dalteparin 120 IU/kg body weight twice daily for unstable coronary artery disease was safe and reduced the risk of new coronary events. This risk reduction was maintained during the following extended treatment with a fixed dose of 7500 IU dalteparin once daily. METHODS AND RESULTS: Minor bleeding was more frequent in women compared with men: relative risk (CI) 2.88 (1.78 to 4.67) during the weight-adjusted and 2.36 (1.37 to 2.63) during the fixed dose treatment. The anti-Xa activity determined in samples (n = 175) obtained during the acute phase treatment was higher in women compared with men (P <.001) and in nonsmokers compared with smokers (<.001) in multiple regression analysis. Also, during the fixed-dose treatment (n = 131) an independent relation between anti-Xa activity and sex (P <.001), but not smoking habits, persisted. CONCLUSION: To improve future low-molecular-weight heparin dose regimens for the treatment of acute coronary syndromes, it might be important to consider the influence of sex and smoking habits. 相似文献