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701.
Different data sources were used to examine hypothesized relations among neighborhood-, family-, and individual-level variables, and perceptions of neighborhood collective efficacy. Data were from 1,105 individuals (56% female, 42% African American, and 58% White) nested within 55 neighborhoods and 392 families, analyzed within a multilevel design using a 3-level model. At the neighborhood level, the study examined relations between Census, police, and neighborhood representative indicators. At the family level, the model examined the influence of marital status and family income. At the individual level, gender and age were examined. Results indicated that age at the individual level, marital status at the family level, and poverty and perceived gang activity at the neighborhood level predicted levels of neighborhood collective efficacy. The study illustrated significant variation across neighborhoods and families, and demonstrates the utility of combining different sources of neighborhood data to examine relations of interest within a multilevel framework.  相似文献   
702.
Pavlovian conditioning in Hermissenda consists of pairing light, the conditioned stimulus (CS) with activation of statocyst hair cells, the unconditioned stimulus (US). Conditioning produces CS-elicited foot shortening and inhibition of light-elicited locomotion, the two conditioned responses (CRs). Conditioning correlates have been identified in the primary sensory neurons (photoreceptors) of the CS pathway, interneurons that receive monosynaptic input from identified photoreceptors, and putative pedal motor neurons. While cellular mechanisms of acquisition produced by the synaptic interaction between the CS and US pathways are well-documented, little is known about the mechanisms responsible for the generation or expression of the CR. Here we show that in conditioned animals light reduced tonic firing of ciliary activating pedal neurons (VP1) below their pre-CS baseline levels. In contrast, pseudorandom controls expressed a significant increase in CS-elicited tonic firing of VP1 as compared to pre-CS baseline activity. Identified interneurons in the visual pathway that have established polysynaptic connections with VP1 were examined in conditioned animals and pseudorandom controls. Depolarization of identified type Ie interneurons with extrinsic current elicited a significant increase in IPSPs recorded in VP1 pedal neurons of conditioned animals as compared with pseudorandom controls. Conditioning also enhanced intrinsic excitability of type Ie interneurons of conditioned animals as compared to pseudorandom controls. Light evoked a modest increase in IPSP frequency in VP1 of conditioned preparations and a significant decrease in IPSP frequency in VP1 of pseudorandom controls. Our results show that a combination of synaptic facilitation and intrinsic enhanced excitability in identified components of the CS pathway may explain light-elicited inhibition of locomotion in conditioned animals.  相似文献   
703.
This article is based on the author's address at the National Multicultural Conference and Summit III in Los Angeles, California, in January 2003. The author focuses on culture as a resource--a resource for theories that can inform one's understanding of human behavior; a resource for healing, self-help, and positive emotions; a resource for clinical practice; and a resource for mental health and wellness. The author uses a healing story from native culture to describe the essence of his relational worldview and to reframe the professional thinking about culture as one of the greatest assets for healing and mental wellness rather than as a problem to solve.  相似文献   
704.
This paper reports on the meeting of the Sounding Board of the EU Reprogenetics Project that was held in Budapest, Hungary, 6-9 November 2005. The Reprogenetics Project runs from 2004 until 2007 and has a brief to study the ethical aspects of human reproductive cloning and germline gene therapy. Discussions during The Budapest Meeting are reported in depth in this paper as well as the initiatives to involve the participating groups and others in ongoing collaborations with the goal of forming an integrated network of European resources in the fields of ethics of science.  相似文献   
705.
We investigated how viewing task-irrelevant emotional pictures affects the performance of a subsequent nonemotional visual detection task. Subjects performed target-detection trials following the offset of individual unpleasant, pleasant, and neutral pictures. Sustained interference occurred when subjects viewed unpleasant pictures (mutilated bodies) in a sequential, "blocked" fashion. Such slowing down of reaction time appeared to build up with time, consistent with the instatement of a defensive emotional state. With a randomized picture presentation, only a transient interference effect was observed, consistent with increased attentional demands during the processing of unpleasant pictures. During blocked presentation of affiliative pleasant pictures, reaction times were faster, suggesting the activation of appetitive motivational systems. Ultimately, both attentional and motivational systems are intricately tied in the brain and, together, determine behavior.  相似文献   
706.
The ability of the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A; J. N. Butcher et al., 1992) validity scales to detect random, partially random, and nonrandom MMPI-A protocols was investigated. Investigations included the Variable Response Inconsistency scale (VRIN), F, several potentially useful new F and VRIN subscales, and formulas F-sub-2 - F-sub-1 and F + F-sub-2 + |F - F-sub-2|. Protocols completed by 150 adolescents at a juvenile court setting, screened for randomness with a matched-pair Millon Adolescent Clinical Inventory (MACI) or Jesness Inventory, were compared with 100 computer-generated, all-random protocols, and with 5 levels of partially random protocols. VRIN was the most effective scale in detecting all-random protocols; however, the optimum cutoff of >or= 75 failed to identify 1/3 of them. Using the new scales, a decision algorithm was described that correctly classified 94%-95% of protocols as interpretable, partially interpretable, or uninterpretable.  相似文献   
707.
The polyamines, spermine, spermidine, and putrescine, are a group of aliphatic amines that may act as physiological modulators of N-methyl-D-aspartate (NMDA) receptors. Although the modulatory role of polyamines in NMDA receptor function has long been known, the effects of polyamines on learning and memory only recently began to be unraveled. In the present study, we investigated the effect of bilateral infusions of spermidine (0.02-2 nmol), a polyamine agonist, into the CA1 region of the rat dorsal hippocampus on inhibitory avoidance learning 30 min pre-training, immediately post-training, 6 h post-training, or 10 min pre-test. Bilateral microinjections of 0.2 nmol spermidine prolonged step-down latencies compared to the respective control group when administered 30 min pre-training or immediately post-training. These results provide evidence that the modulatory effects of spermidine on the acquisition and/or early consolidation of memory of inhibitory avoidance tasks in the hippocampus occur within a limited time window.  相似文献   
708.
In this experiment, we investigated the impact of vibrotactile prepulse frequency and intensity on the acoustically elicited startle response in humans. Mechanoreceptive channels differing in their sensitivity to transient stimulation have been identified in the skin. The Pacinian channel is optimally sensitive to vibrations at approximately 300 Hz and is specialized for the detection of stimulus transients, whereas the non-Pacinian I and III channels are optimally sensitive to vibrations at approximately 30 Hz. Vibrotactile prepulses with frequencies of 30 and 300 Hz and intensities of 95 and 130 mV were presented for 50 msec to the dominant hand of college students (N = 31), followed on some trials by a 95-dB broadband acoustic startle stimulus. The 300-Hz prepulses resulted in significantly more pronounced inhibition of startle magnitude, amplitude, and probability, whereas only the 30-Hz prepulses significantly facilitated blink latency. These results support the idea that the inhibition of acoustic startle is determined more by transient than by sustained aspects of vibrotactile prepulse stimuli. This study also demonstrates that different aspects of the startle response differentially reflect stimulus characteristics of the prepulse.  相似文献   
709.
268 students (M age = 20.0 yr., SD = 4.4; 68% women), randomly chosen from psychology classes, completed Rotter's I-E scale and Pettijohn's 1992 locus of control scale for class demonstration. The two sets of scores were similar but examination of reliability and validity indicated the latter was best used as a demonstration.  相似文献   
710.
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