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1.
On 30 June 1981 the wind fields around an Oklahoma severe thunderstorm were observed in detail using an airborne Doppler lidar operated by NASA. Despite uncertainties caused by inertial navigation errors and problems in sampling some of the aircraft attitude and motion parameters, reasonably clear pictures of the distributions of relative reflectivity, horizontal wind velocity, and velocity spectral width near the cloud base have been obtained. Aspects of the design and functioning of the NASA lidar relevant to the collection and analysis of the data are described.  相似文献   
2.
Protein phosphorylation is a well-known mechanism by which extracellular molecules or factors transduce their signals into intracellular effects. In the context of myelin assembly, phosphorylation of major myelin proteins affects the electrostatic repulsion between adjacent proteins within myelin structure and therefore constitutes one of the mechanisms by which myelin stability is regulated. We report here that arachidonic acid (AA) decreases the phosphorylation of myelin basic protein (MBP) both in the absence and in the presence of phorbol esters in cultured rat oligodendrocytes (OLGs). The effect of AA on MBP phosphorylation is not mediated by cyclooxygenase products, though the possibility that leukotrienes or other epoxides may have a role cannot be excluded. AA did not act by inactivation of protein kinase C. Based on our findings from gadolinium and low K+ experiments, we conclude that inhibition of MBP phosphorylation is not dependent on AA-induced increases in OLG Ca(i), but rather on its depolarizing action. We have thus demonstrated that a brief exposure to AA, which either acts as a diffusible paracrine signal to OLGs or as a signal transducer, can trigger changes in protein phosphorylation in OLGs/myelin via ionic signaling events at the plasma membrane.  相似文献   
3.
A 3-year-old, right-handed girl developed a conduction-type aphasia following a second generalized seizure in the setting of a developing abscess involving left subcortical and cortical angular gyrus and arcuate fasciculus, and the posterior corpus callosum. The language disorder was fluent, characterized by age appropriate mean length of utterance and syntax, but with markedly reduced spontaneity of output, rapid rate of speech and mild dysarthria. Comprehension was relatively, but not completely spared. Naming, repetition, and reading (letters) were initially markedly impaired. Improvements in naming and repetition were associated with both literal and semantic paraphasias. Writing skills in the form of drawing were spared, but a mild apraxia to verbal command and imitation was initially present. Despite her young age, this child's fluent conduction aphasia and lesion localization were adult-like. Multimodal memory difficulties appeared to underlie what is best described as conduction aphasia.  相似文献   
4.
Tested the effects of commitment (CM) to nonsmoking on resistance to arguments favoring cigarette smoking. In Exp I, 37 7th graders were assigned to a public CM condition, in which they were audiotaped as they explained why they would not become smokers, or to information control or no-treatment conditions. In Exp II, 51 7th graders participated in conditions of (1) high CM, in which they were given high choice to write and publicly audiotape a speech about why smoking is bad; (2) low CM, in which they were given low choice to write an anonymous essay about why smoking is bad; or to (3) a no-treatment condition. Ss then listened to arguments favoring smoking. CM failed to enhance resistance to persuasion in either experiment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
The native Australian marsupial Phascolarctos cinereus, otherwise known as the koala, is prone to infection by the obligate intracellular parasite Chlamydia psittaci, which causes ocular 'pink eye' and urogenital 'dirty tail' diseases. Several chlamydial DNA probes to both chromosomal and plasmid sequences were used to type by Southern blot analysis 51 samples taken from wild and captive koalas from habitats on the eastern seaboard of Australia as far apart as Queensland and Victoria. Two types of C. psittaci were observed and called types I and II. Type II was found more frequently than type I and occurred in both ocular and urogenital samples, while type I showed a strong but not absolute preference for ocular sites. Cross-hybridization analyses indicated that type I and type II had about 10% DNA sequence identity to each other. DNA analyses showed that type II was very closely related to some ovine and bovine chlamydiae but type I could not be related to any other C. psittaci strain available. Light and electron microscopic analyses of infected BGM monolayers revealed that the two strains were similar in morphological characteristics. The type I strain was considerably more infectious than the type II strain in BGM cells and in the yolk sacs of embryonated eggs. A PCR based assay detected both type I and type II koala chlamydiae in samples that had been negative by Southern blot and tissue culture and provided the first evidence that both types can occur simultaneously at the one site of infection.  相似文献   
6.
Objective: Accurate measurement of beliefs about risk probability is essential to determine what role these beliefs have in health behavior. This study investigated the ability of several types of risk perception measures and of other constructs from health behavior theories to predict influenza vaccination. Design: Prospective study in which students, faculty, and staff at 3 universities (N = 428) were interviewed in the fall, before influenza vaccine was available, and again early in the next calendar year. Main Outcome Measure: Self-reported influenza vaccination. Results: Two interview questions that asked about feeling at risk and feeling vulnerable predicted subsequent behavior better (r = .44, p = .001) than 2 questions that asked for agreement or disagreement with statements about risk probability (r = .25, p = .001) or 4 questions that asked respondents to estimate the magnitude of the risk probability (r = .30, p = .001). Of the 4 perceived risk magnitude scales, a 7-point verbal scale was the best predictor of behavior. Anticipated regret was the strongest predictor of vaccination (r = .45, p = .001) of all constructs studied, including risk perceptions, worry, and perceived vaccine effectiveness. Conclusion: Risk perceptions predicted subsequent vaccination. However, perceived risk phrased in terms of feelings rather than as a purely cognitive probability judgment predicted better. Because neither feeling at risk nor anticipated regret is represented in the most commonly used theories of health behavior, the data suggest that these theories are missing important constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
8.
Breast cancer concerns were measured among 353 women, ages 40–75, from North Dakota. One year later, participants were recontacted and asked about their screening behavior during the previous year. Greater concern about breast cancer, even the highest level of concern, was related to a higher likelihood that women performed breast self-examination, had a mammography screening, and had a clinical breast examination. These data do not support the idea that worry inhibits action; instead, they suggest that nonpathological worry motivates self-protective behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
This meta-analytic review addresses the issue of how a woman's risk of breast cancer relates to the likelihood that she will obtain mammography screenings. Studies that compared women with or without a family history of breast cancer (n?=?19) showed that women with a family history were more likely to have been screened. Studies that measured perceived risk (n?=?19) showed that feeling vulnerable to breast cancer was positively related to having obtained a screening. Studies that compared women who did or did not have a history of breast problems (n?=?10) showed that those with a positive history were more likely to have been screened. Finally, studies that measured worry (n?=?6) showed that greater worry was related to higher screening levels. Taken together, these data suggest that increasing perceptions of personal vulnerability may increase screening behavior for breast cancer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
Compared the effects of distracting oneself from, vs attending to, the sensations produced by cold-pressor stimulation. Exp I (35 undergraduates) revealed that distraction was a better coping strategy than attention to sensations when Ss were asked to report pain threshold and tolerance. Exps II and III (75 Ss) examined the hypothesis that distraction is effective because persons hold a commonsense belief in the benefits of distraction as a coping device. Neither experiment supported the commonsense hypothesis as an explanation for Exp I's results. In Exp IV, 39 male Ss were assigned to either distraction, attention, or no-instruction conditions and asked to report their distress during a 4-min cold-pressor trial. Distraction reduced distress early in the trial, but attention to sensations was a superior strategy for the last 2 min. It is proposed that distraction and attention to sensations may be differentially effective depending on the duration of the painful stimulus. Possible mediating processes underlying the 2 strategies are discussed. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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