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61.
This article examines whether longitudinal reading trajectories vary by the generational status of immigrant children as they begin formal schooling through the 3rd grade. The results of the hierarchical linear model indicated that 1st and 2nd generation children (i.e., those born in a foreign country and those born in the United States to foreign-born parents, respectively) had higher achievement scores at the spring of kindergarten than did 3rd generation children. Yet, controlling for race/ethnicity and maternal education fully reduced the 1st generation advantage. In addition, 1st generation children grew in reading achievement at a faster rate than did 3rd generation children. Controlling for a host of proximal and distal factors that included demographic, race/ethnic, family, and school characteristics somewhat reduced the association between generational status and rate of growth. First and 2nd generation children continued to increase their reading scores at a faster rate than did 3rd generation children. It is likely that additional factors not measured in the Early Childhood Longitudinal Survey-Kindergarten cohort, such as selection, cultural, or motivational factors, would be useful in further explaining the immigrant advantage. (PsycINFO Database Record (c) 2008 APA, all rights reserved).  相似文献   
62.
Science and Engineering Ethics - Ethics settings allow for morally significant decisions made by humans to be programmed into autonomous machines, such as autonomous vehicles or autonomous weapons....  相似文献   
63.
During the elaboration of an instrumental reflex, it is not obligatory to use a conditioned stimulus, which signals the necessity to generate an instrumental reaction in order to receive reinforcement. However, the presence of a conditioned stimulus simplifies analysis of instrumental reaction, which in this case is the response to the conditioned stimulus. On the other hand, it is necessary to distinguish between instrumental and classical conditioning, since in both cases the response to a conditioned stimulus increases. We studied neuronal analogs of classical and instrumental conditioning in the identified neurons responsible for the defensive closure of the pneumostome in the Helix mollusk under the same conditions. During classical conditioning, a mollusk received punishment after a tactile stimulus. During instrumental conditioning, a mollusk received punishment when an identified neuron did not generate an action potential in response to a tactile stimulus. The appearance of a painful stimulus did not depend on the generation or failure of a spike in the related control neuron. Another tactile stimulus, which was never paired with an unconditioned stimulus, was used as a discriminated stimulus. We also compared the behavior of such identified neurons during pseudoconditioning. The experiments were carried out in a semi-intact preparation. We examined how responses to the tactile and painful stimuli changed during different forms of training. It was shown that the dynamics of neuronal responses to a conditioned tactile stimulus were much more complex during instrumental conditioning and consisted of several phases. Throughout a learning session, neural system consecutively acquired information as to which kind of learning was presented, whether a reaction of the neural system must be generated or inhibited and which instrumental reaction is correct. We have demonstrated that response to a painful stimulus during classical conditioning decreases after short-term initial increase. However, during instrumental learning, the neurons controlling instrumental action remained highly sensitive to the unconditioned stimulus. Meanwhile, foreign neurons decreased their responses to the unconditioned stimulus. We may tentatively conclude that classical and instrumental paradigms are fundamentally different at the cellular level.  相似文献   
64.
In Experiment 1, 15 skilled and 15 less skilled participants performed 1-handed catching in 4 conditions. For both groups, catching performance deteriorated significantly when no visual information was available for 40 ms between 20-ms visual samples (20/40) and continued to decline with subsequent increases in the duration between visual samples (i.e., 20/80 and 20/120). In Experiment 2, 50 participants performed a pretest and a posttest in a 20/80 condition, separated by 4 blocks of practice (N=80). Participants who practiced with intermittent vision (20/40, 20/80, and 20/120) exhibited a significant improvement between pretest and posttest. Although general practice with intermittent vision enabled some adaptation, posttest performance did not equal performance in the 1st block of continuous vision.  相似文献   
65.
To assess the construct validity of the endogenous subtype of depression, 2 studies examined the relation of mood regulation skill to the symptoms of endogenous depression versus hopelessness depression in adolescent samples. It was hypothesized that the relationship between mood regulation skill and endogenous depression would be weaker than the relationship between mood regulation skill and hopelessness depression, because endogenous depression may be less influenced by personality variables, such as mood regulation skill. In spite of the high degree of correlation between the symptoms of hopelessness depression and endogenous depression, the relationship between mood regulation skill and hopelessness depression was stronger than the relationship between mood regulation skill and endogenous depression, as predicted. This is consistent with proposed definition of endogenous depression.  相似文献   
66.
The role of coding time in estimating and interpreting growth curve models   总被引:2,自引:0,他引:2  
The coding of time in growth curve models has important implications for the interpretation of the resulting model that are sometimes not transparent. The authors develop a general framework that includes predictors of growth curve components to illustrate how parameter estimates and their standard errors are exactly determined as a function of receding time in growth curve models. Linear and quadratic growth model examples are provided, and the interpretation of estimates given a particular coding of time is illustrated. How and why the precision and statistical power of predictors of lower order growth curve components changes over time is illustrated and discussed. Recommendations include coding time to produce readily interpretable estimates and graphing lower order effects across time with appropriate confidence intervals to help illustrate and understand the growth process.  相似文献   
67.
We undertook a secondary data analysis to study issues relevant to co-occurring mental health and substance disorder in a combined sample of offenders (N = 3,197). Using the Personality Assessment Inventory, we compared the frequency of depressive, traumatic stress, and personality disorder symptom elevations across offenders with and without substance problems, identified the extent to which co-occurring problems were accompanied by risk factors for suicide and aggression, and tested for gender differences. Offenders with substance problems were more likely than others to have increased mental health problems and risk factors for suicide or aggression. Women with substance problems, compared with men, had higher depression, traumatic stress, and borderline features, in addition to lower antisocial features. The frequency with which suicide and aggression risk factors were associated with mental health problems was generally similar across men and women. Measurement issues relevant to co-occurring disorder and risk assessment are discussed.  相似文献   
68.
The article presents results of an ongoing study of centers of intellectual innovations in post-Soviet Russia. Using the European University at St. Petersburg as the main object of their analysis, the authors demonstrate how new models of academic careers, which became available in the 1980s and 1990s, were eventually institutionalized as new models of knowledge production and educational practices. Supported by American foundations, this private university had to invent a new institutional structure and to position itself within the field of higher education, still mostly dominated by the state.  相似文献   
69.
Acoustic analysis provides objective quantitative measures of speech that enable a comprehensive and accurate understanding of motor disorders and complement the traditional measures. This paper aims to distinguish between normal and pathological speech, more specifically between apraxia of speech and spastic dysarthria in native Spanish speaking patients using acoustic parameters. Participants (4 aphasic with apraxia of speech, 4 with spastic dysarthria, and 15 without speech disorders) performed three different tasks: repeating the syllable sequence [pa-ta-ka], repeating the isolated syllable [pa] and repeating the vowel sequence [i-u]. The results showed that the normative values of motor control, in general, coincide with those obtained in previous research on native English speakers. They also show that damage to motor control processes results in a decrease in the rate of alternating and sequential movements and an increase in the inter-syllabic time for both types of movements. A subset of the acoustic parameters analyzed, those that measure motor planning processes, enable differentiation between normal population and apraxic and dysarthric patients, and between the latter. The differences between the pathological groups support the distinction between motor planning and motor programming as described by van der Merwe's model of sensorimotor processing (1997).  相似文献   
70.
Canavan disease: a white matter disorder   总被引:1,自引:0,他引:1  
Breakdown of oligodendrocyte-neuron interactions in white matter (WM), such as the loss of myelin, results in axonal dysfunction and hence a disruption of information processing between brain regions. The major feature of leukodystrophies is the lack of proper myelin formation during early development or the onset of myelin loss late in life. These early childhood WM diseases are described as hypomyelination or dysmyelination arising from a primary block in normal myelin synthesis because of a genetic mutation expressed in oligodendrocytes, or failure in myelination secondary to neuronal or astroglial dysfunctions (van der Knaap 2001 Dev. Med. Child Neurol. 43:705-712). Here, we describe the pathophysiological parameters of Canavan disease (CD), caused by genetic mutations of the aspartoacylase (ASPA) gene, a metabolic enzyme restricted in the central nervous system (CNS) to oligodendrocytes. CD presents pathophysiological dysfunctions similar to diseases caused by myelin gene mutations, such as Pelizaeus-Merzbacher disease (PMD) and several animal models, such as myelin deficient rat (md), jimpy (jp), shiverer (sh), and quaking (qk viable) mutant mice. These single gene mutations have pleiotropic effects, whereby the alteration of one myelin gene expression disrupts functional expression of other oligodendrocyte genes with an outcome of hypomyelination/dysmyelination. Among all of the known leukodystrophies, CD is the first disorder, which was approved and tested for the adeno-associated virus vector (AAV)-ASPA gene therapy (Leone et al. 2000 Ann. Neurol. 48:27-38; Janson et al. 2001 Trends Neurosci. 24:706-712) without much success following the first two attempts. ASPA gene delivery attempts in animal models have shown a lowering of N-acetyl L-aspartate and a change in motor functions, while sponginess of the WM, a characteristic of CD remained unchanged (Matalon et al. 2003 Mol. Ther. 7 (5, Part 1):580-587; McPhee et al. 2005 Brain Res. Mol. Brain Res. 135:112-121) even with better viral serotype and delivery of the gene during early phase of development (Klugmann et al. 2005 Mol. Ther. 11:745-753). While different approaches are being sought for the success of gene therapy, there are pivotal developmental questions to address regarding the specific regions of the CNS and cell lineages that become the target for the onset and progression of CD symptoms from early to late stages of development.  相似文献   
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