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1.
The pyrolytic behavior of inulin, a (2-->1)-linked fructofuranan, is described. Parallel investigations of the pyrolysis of glucose and of fructose were conducted to supplement the inulin results and to aid comparison with previous results from glucans. Effects of neutral and basic additives are emphasized. As with glucans, the addition of such additives (especially basic) increases the yields of the one-, two-, and three-carbon products (as well as of hexosaccharinolactones), while generally decreasing the yields of anhydro sugar and furan derivatives. The former products include glycolaldehyde, acetol, dihydroxy-acetone, acetic acid, formic acid, and lactic acid. Mechanistic speculations are made regarding the origins of these compounds, as well as of furan derivatives and saccharinic acid lactones. Parallels with alkaline degradation are considered.  相似文献   
2.
R. Cools  Ann Haegemans 《Computing》1988,40(2):139-146
The knots and weights of a cubature formula are determined by a system of nonlinear equations. The number of equations and unknowns can be reduced by imposing some structure on the formula. We are concerned with the construction of cubature formulae which are invariant under rotations. Using invariant theory, we obtain a smaller system of algebraically independent equations. This is used to construct cubature formulae for the square. One of the results is a 24-point formula of degree 11.  相似文献   
3.
Cubature formulae of degree 11 with minimal numbers of knots for the integral $$\int\limits_{ - 1}^1 { \int\limits_{ - 1}^1 {(1 - x^2 )^\alpha } } (1 - y^2 )^\alpha f(x,y) dxdy \alpha > - 1$$ which are invariant under rotation over an angle π/2 are determined by a system of 18 nonlinear equations in 18 unknowns. We start with a known solution for this system for α=0. By varying α smoothly, the knots and weights of the cubature formula vary smoothly except in the singular solutions such as turning points and bifurcation points where new solutions branches arise. We use for this purpose the program AUTO. We obtain surprisingly many branches of cubature formulae.  相似文献   
4.
A failure to adapt to novel or changing environmental demands is a core feature of a wide variety of neuropsychiatric disorders as well as the normal states of stress and fatigue. We review the neurochemistry of cognitive control, which has been associated primarily with the prefrontal cortex. Many drugs affect the functioning of the prefrontal cortex, but the direction and extent of drug effects vary across individuals and tasks. Apparently paradoxical effects are often observed, where the same medication causes both cognitive enhancement as well as cognitive side effects. We review neurobiological research that is beginning to elucidate the nature of these contrasting effects and the factors underlying the large variability across individuals and behaviours. The work has considerable implications for the understanding of and treatment development for abnormalities such as Parkinson's disease, attention deficit hyperactivity disorder and drug addiction.  相似文献   
5.
Individual human travel patterns captured by mobile phone data have been quantitatively characterized by mathematical models, but the underlying activities which initiate the movement are still in a less-explored stage. As a result of the nature of how activity and related travel decisions are made in daily life, human activity-travel behavior exhibits a high degree of spatial and temporal regularities as well as sequential ordering. In this study, we investigate to what extent the behavioral routines could reveal the activities being performed at mobile phone call locations that are captured when users initiate or receive a voice call or message.Our exploration consists of four steps. First, we define a set of comprehensive temporal variables characterizing each call location. Feature selection techniques are then applied to choose the most effective variables in the second step. Next, a set of state-of-the-art machine learning algorithms including Support Vector Machines, Logistic Regression, Decision Trees and Random Forests are employed to build classification models. Alongside, an ensemble of the results of the above models is also tested. Finally, the inference performance is further enhanced by a post-processing algorithm.Using data collected from natural mobile phone communication patterns of 80 users over a period of more than one year, we evaluated our approach via a set of extensive experiments. Based on the ensemble of the models, we achieved prediction accuracy of 69.7%. Furthermore, using the post processing algorithm, the performance obtained a 7.6% improvement. The experiment results demonstrate the potential to annotate mobile phone locations based on the integration of data mining techniques with the characteristics of underlying activity-travel behavior, contributing towards the semantic comprehension and further application of the massive data.  相似文献   
6.
We tested the effects of film-induced negative affect (i.e., exposure to a frightening film) in 60 women classified as either restrained or unrestrained eaters on the basis of their responses to the Revised Restraint Scale (C. P. Herman and J. Polivy, 1980). Exposure to the frightening film, in contrast to a neutral film, was associated with increases in anxiety, sadness, and anger. High restraint subjects exposed to the frightening film ate more than did equally restrained subjects exposed to a neutral film or low restraint subjects exposed to either film. Thus, negative affect triggered overeating among restrained eaters. Although unrestrained eaters exposed to the frightening film ate less than those who viewed the neutral film, this difference was not statistically significant. These results suggest that negative affect may prompt overeating in persons who attempt to restrict their caloric intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
A diathesis-stress model had been proposed (D. E. Schotte and G. H. Clum; see PA, Vols 69:1287 and 74:15906), in which deficits in interpersonal problem-solving skills are said to predispose individuals under chronic stress to depression, hopelessness, and suicide ideation. The present study examined the stability of interpersonal problem-solving skills in a short-term, longitudinal study of hospitalized suicide ideators (N?=?36). The Ss displayed marked changes in depressive symptoms, state anxiety, hopelessness, and suicide intent over time, and these improvements were associated with improvements in interpersonal problem-solving skills. It is concluded that interpersonal problem-solving deficits may be a concomitant, rather than a cause, of depression, hopelessness, and suicide intent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
9.
The IL-15 receptor alpha subunit (IL-15Ralpha) mediates high-affinity binding of IL-15, a pleiotropic cytokine implicated in the development of innate immune cells. We have generated IL-15Ralpha null (IL-15Ralpha-/-) mice to understand the role of IL-15Ralpha in immune development and function. IL-15Ralpha-/- mice are markedly lymphopenic despite grossly normal T and B lymphocyte development. This lymphopenia is due to decreased proliferation and decreased homing of IL-15Ralpha-/- lymphocytes to peripheral lymph nodes. These mice are also deficient in natural killer cells, natural killer T cells, CD8+ T lymphocytes, and TCRgammadelta intraepithelial lymphocytes. In addition, memory phenotype CD8+ T cells are selectively reduced in number. Thus, IL-15Ralpha has pleiotropic roles in immune development and function, including the positive maintenance of lymphocyte homeostasis.  相似文献   
10.
Tested the effects of 3 mood inductions (neutral, positive, and negative) on food intake in 91 women of varying degrees of dietary restraint. Mood induction was accomplished by exposure to 1 of 3 film segments: a travelogue (neutral affect), a comedy film (positive affect), and a horror film (negative affect). In Ss exposed to the neutral film, food intake decreased with increasing levels of dietary restraint. Among Ss who viewed either the comedy film or the horror film, however, food intake increased with increasing restraint. Although the horror film appeared to be more disinhibiting than the comedy film, this effect may have resulted from a difference in the intensity of the emotions induced rather than from their valence. These results suggest that emotional arousal, regardless of valence, may trigger overeating among restrained eaters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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