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排序方式: 共有496条查询结果,搜索用时 140 毫秒
1.
Differentiation of apple juice samples on the basis of heat treatment and variety using chemometric analysis of MIR and NIR data 总被引:4,自引:0,他引:4
Linda M. Reid Tony Woodcock Colm P. ODonnell J. Daniel Kelly Gerard Downey 《Food research international (Ottawa, Ont.)》2005,38(10):1109-1115
The potential of mid-infrared (MIR) and near-infrared (NIR) spectroscopy for their ability to differentiate between apple juice samples on the basis of apple variety and applied heat-treatment was evaluated. The heat-treatment involved exposure of juice samples (15 ml) for 30 s in a 900 W microwave oven and the apple varieties used to produce the juice samples were Bramley, Elstar, Golden Delicious and Jonagold. The chemometric procedures applied to the MIR and NIR data were partial least squares regression (PLS1 for differentiation on the basis of heat-treatment, PLS2 for varietal differentiation) and linear discriminant analysis (LDA) applied to principal component (PC) scores. PLS1 and PLS2 gave the highest level of correct classification of the apple juice samples according to heat-treatment (77.2% for both MIR and NIR data) and variety (78.3–100% for MIR data; 82.4–100% for NIR data), respectively. 相似文献
2.
Thirty-four heifers (24 Holstein, 8 Ayrshire, 2 Jersey) and 12 Holstein steer calves were grouped into 23 blocks of 2 animals each according to breed, sex, and body weight. Animals in each block were randomly assigned to control or treated groups. The treated group received an anthelmintic bolus containing morantel tartrate before they were permitted access to pasture. A 2.6 ha pasture was divided in half with a double fence; the resulting two pastures had separate feed and water troughs. Steer calves were slaughtered upon termination of the trial to ascertain gastrointestinal parasite burdens. Two worm-free tracer calves were placed on each pasture every 2 mo and slaughtered after 4 wk of grazing to determine parasite infectivity of pastures. Herbage samples were obtained monthly and analyzed for infective larvae. The trial was conducted for 141 d during the grazing season. Treatment resulted in 90% reduction in infective larvae on pasture, 74% reduction in fecal worm-eggs, 91% reduction in adult worm burdens, and a trend toward reduced worm burdens in tracer calves by 52%. An overall average daily gain of .68 and .88 kg was obtained for control and treated animals. Reproductive data for the heifers remaining in the herd from the trial showed that treatment resulted in 44 less days to first breeding. 相似文献
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4.
Despite great progress in the neurosciences, our understanding of the determinants of sexual orientation is incomplete. The authors review for the clinician/neuropsychiatrist studies pertaining to the formation of sexual orientation in the following areas: hormone effects on sexual behavior (animal and human); the complicated relationship between gender identity, gender role, and sexual orientation in humans; cross-cultural studies of homosexuality; behavioral observations in pseudohermaphrodites and offspring of mothers treated with hormones during pregnancy; brain studies of homosexual and heterosexual individuals; and genetic studies. The authors conclude that human sexual orientation is complex and diversely experienced and that a biopsychosocial model best fits the current state of knowledge in the field. 相似文献
5.
B Burckhartt XM Yang A Tsuchida KM Mullane JM Downey MV Cohen 《Canadian Metallurgical Quarterly》1995,29(5):653-657
OBJECTIVE: Ischaemic preconditioning protects myocardium from infarction if the reperfusion interval between the brief and prolonged ischaemic intervals is less than 1 h. In anaesthetised rabbits acadesine (5-amino-4-imidazolecarboxamide riboside, AICAR), an adenosine enhancer which increases tissue adenosine during ischaemia, prolongs the window of protection to 2 h. The aim of this study was to try to determine the maximum extension of this window of protection, using chronically instrumented, unsedated rabbits. METHODS: Rabbits were instrumented with a balloon occluder around a major branch of the left coronary artery for reversible coronary occlusion. Five to seven days after surgery all animals underwent a 30 min coronary occlusion. Animals were randomised to one of seven groups: (1) No additional treatment (control); (2) Ischaemic preconditioning with 5 min regional ischaemia followed by 10 min reperfusion before the 30 min coronary occlusion; (3) and (4) Ischaemic preconditioning followed by 2 or 4 h of reperfusion before the 30 min occlusion, respectively; (5) Treatment with acadesine (2.5 mg.kg-1.min-1 intravenously for 5 min and then 0.5 mg.kg-1.min-1 beginning 45 min before and continuing until 30 min after release of the 30 min occlusion) without ischaemic preconditioning; (6) and (7) Treatment with the higher dose of acadesine for 5 min beginning 35 min before the 5 min ischaemic period, and then the lower dose continuing until 30 min after release of the 30 min coronary occlusion in rabbits with 4 or 6 h reperfusion intervals, respectively. RESULTS: Rabbits with ischaemic preconditioning with 10 min reperfusion preceding the 30 min coronary occlusion (group 2) had only 5.6(SEM 1.1)% infarction of the ischaemic zone. Ischaemic preconditioning followed by 2 h reperfusion (group 3) offered continued protection [18.2(2.2)% infarction] as compared to control animals [37.7(2.6)% infarction]. However, protection waned if ischaemic preconditioning was followed by 4 h reperfusion (group 4) [36.7(3.0)% infarction]. Additionally, treatment with acadesine alone did not modify infarct size (group 7) [39.5(4.0)%], but acadesine largely restored the protection of ischaemic preconditioning despite a 4 h reperfusion interval (group 5) [20.4(3.0)% infarction, P < 0.01 v control]. However, when reperfusion was extended to 6 h (group 6) acadesine could no longer restore protection [36.2(0.9)% infarction]. CONCLUSIONS: The protection afforded by a 5 min ischaemic preconditioning period lasts from 2 to 4 h in the awake, unsedated rabbit, and acadesine can extend the duration of this window of protection to at least 4 h but not to 6 h. 相似文献
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7.
Alexander N. Chen James P. Downey Ronald E. McGaughey Kan Jin 《International journal of human-computer interaction》2016,32(2):132-142
Technology, particularly information technology (IT), is changing rapidly and offers many advantages for users. IT has the potential to improve one’s quality of life, but only if used. Research has shown that, in most developed and developing nations, senior use of IT lags behind that of other segments of society. This “gray divide” is a concern for government, business, and others. Concern about senior adoption and use of IT has been the motivation for numerous studies and is the motivation for this study of Chinese seniors. This exploratory study examines urban Chinese seniors’ IT use, computers and mobile phones in particular, but also their attitudes and behaviors as they relate to the use of those devices. More specifically it examines several potential factors that motivate or hinder senior’s use of information technology, including self-efficacy, satisfaction, comfort with technology, and both positive and negative attitudes. This study provides some insight into the quantity and diversity of Chinese senior technology use in urban China. Particularly noteworthy, the study found that technology ownership was quite high, and in general the Chinese seniors studied had positive attitudes and beliefs concerning information technology. This is generally good news for the Chinese government, which must efficiently provide services for the growing population of Chinese seniors, as well as for businesses that wish to capitalize on one of the largest senior populations in the world. 相似文献
8.
Despite extensive research and practitioner literature on inter-organizational information systems (IOIS), our understanding of non-adoption still has some under-explored issues. This paper offers an explanation of non-adoption that focuses on the potential structural changes that IOIS adoption entails; in particular, we contend that the contradictions between the initial social structure and the structure enacted in the use of an IOIS can be a cause of non-adoption. This paper analyses adoption from a logic of opposition where non-adoption occurs because forces of transformation are offset by forces of persistence. Relying on the concepts of social structure, duality of structure, and structural contradiction from Structuration theory, we develop a framework that categorizes the underlying social structure where an IOIS is to be adopted, and formulate some theoretical propositions. From a practitioner perspective, this paper contends that the fact that IOIS management uncovers the contradictions in the social structure that result from IOIS adoption can help avoid dead ends. Accordingly, this framework, which can be used as a coarse-grained picture for anticipating adoption problems, can inform managers when devising an IOIS implementation strategy. 相似文献
9.
This paper is devoted to estimation and numerical approximation of basins of attraction for a class of uncertain systems. We consider systems described by a differential equation depending of a disturbance known by its bounds. By using viability theory tools, we derive basins of attraction lower and upper estimates. We present numerical simulation results of the viability kernel algorithm to basin of attraction approximation problems. 相似文献
10.
The thermoelectricpower, referenced to bulk copper, of thin films of copper about 150 Å thick was measured by preparing a thin film bridge between two copper wires which served as leads. This arrangement produces two junctions between the thin film copper and the bulk copper. The two junctions were maintained at a temperature difference which was measured using a calibrated copper-constantan thermocouple. It was found that the thin film-to-bulk thermoelectric power varies with time and can be fitted to an equation of the form where λ depends on temperature. The constant λ in the equation has values very close to those found from thin film resistance aging measurements, suggesting that the same mechanism is responsible for both aging phenomena. The heated junctions is negative, in agreement with a simple electron diffusion model of thermoelectric power. 相似文献