Neurobehavioral Changes in Adolescence

Adolescents across a variety of species exhibit age-specific behavioral characteristics that may have evolved to help them attain the necessary skills for independence. These adolescent-related characteristics, such as an increase in risk taking, may be promoted less by the hormonal changes of puberty than by developmental events occurring in brain. Among the prominent brain transformations of adolescence are alterations in the prefrontal cortex, limbic brain areas, and their dopamine input, systems that are sensitive to stressors and form part of the neural circuitry modulating the motivational value of drugs and other reinforcing stimuli. Such developmental transformations of the adolescent brain may predispose adolescents to behave in particular ways and make them particularly likely to initiate use of alcohol and other drugs.     

A Regional Study of Risk Factors for Drug Abuse and Delinquency: Sex and Racial Differences

Many juveniles are at high risk for delinquency and drug abuse by virtue of the characteristics of their neighborhoods, which are often economically impoverished, socially unstable, physically neglected, and rife with crime, drug use, and drug selling. However, a significant proportion of these youth do not engage in deviant behavior, while others participate to varying degrees. This study examined what factors discriminate between high-risk youth who do and who do not exhibit deviant behavior. Self-reported measures of several attitudes and behaviors known to correlate with drug abuse and delinquency were assessed in relation to reports of property offenses, person offenses, drug use, and drug selling. Additional analyses were conducted to distinguish between sex and racial groups to further qualify the relationships between deviant behaviors and attitudes. The most notable finding was that types of deviance that primarily involve material and monetary gain may be largely influenced by relationships with significant others, while deviance with potentially harmful consequences to both self and others are influenced largely by personal attitudes. Examination of individual variables showed that negative peer influences and positive attitudes toward fighting significantly increased the likelihood of reporting involvement in three of the four deviance measures, and that positive relationship with the father and prosocial values were inversely related to two of the behavioral deviance measures. There were very few differences in significant predictors of deviance for males versus females. Several self-reported attitudes and behaviors distinguished African Americans from Hispanics and Whites, even though Whites were reportedly responsible for a higher incidence of deviant behaviors.     

Truth as a way of developing and preserving the space for thinking in the minds of the patient and the analyst

Clinical material from the analysis of a young patient diagnosed with borderline personality disorder and heavily dependent on drugs was examined to identify changes in setting that may be necessary to enable the psychoanalytical treatment of this type of patient. The article describes a lack of truth in the patient's life and the absence of a good enough space for thinking in her mind. In order to enhance the development of the capacity for symbolization in the patient's mind, the analyst had to become an object the patient needed. In order to do this the analyst had to manage setting alteration. Theoretical frameworks proposed by Ferenczi, Winnicott and Bion were used to guide the psychoanalyst's approach to this patient. The survival of the capacity for thinking psychoanalytically inside the analyst's mind when the setting has been significantly distorted by the disruptive behavior of the patient is guaranteed by the trueness of their link. It is suggested that maybe this is decisive for a successful psychoanalytical treatment of this type of patient.     

Utility of gambling under p(olynomial)-additive joint receipt and segregation or duplex decomposition

This article continues our exploration of the utility of gambling, but here under the assumption of a non-additive but p(olynomial)-additive representation of joint receipt. That assumption causes the utility of gambling term to have a multiplicative impact, rather than just an additive one, on what amounts to ordinary weighted utility. Assuming the two rational recursions known as branching and upper gamble decomposition, we investigate separately the rational property of segregation and the non-rational one of duplex decomposition. Under segregation, we show that each pair of disjoint events either exhibits weight complementarity or both support no utility of gambling, a property called UofG-singular. We develop representations for both cases. The former representation is a simple weighted utility with each term multiplied by a function of the event underlying that branch. The latter representation is an ordinary rank-dependent utility with Choquet weights but with no utility of gambling. Under duplex decomposition, we show that weights have the intuitively unacceptable property that there is essentially no dependence upon the events, making duplex decomposition, in this context, of little behavioral interest.     

EFFECTS OF DRUGS AND DRUG COMBINATIONS IN PIGEONS TRAINED TO DISCRIMINAT AMONG PENTOBARBITAL,DIZOCILPINE, A COMBINATION OF THESE DRUGS,AND SALIN

Drugs with multiple actions can have complex discriminative‐stimulus properties. An approach to studying such drugs is to train subjects to discriminate among drug combinations and individual drugs in the combination so that all of the complex discriminative stimuli are present during training. In the current experiments, a four‐choice procedure was used to train pigeons to discriminate among dizocilpine (noncompetitive NMDA receptor blocker), pentobarbital (GABA_A receptor agonist), a fixed‐dose combination of these two drugs, and saline. Following extended training, low doses of pentobarbital or dizocilpine administered alone produced saline‐appropriate responding. Higher doses of pentobarbital produced responding on the pentobarbital‐appropriate key and higher doses of dizocilpine produced responding on the dizocilpine key. Administering the lowest doses of pentobarbital and dizocilpine together resulted in responding on the saline‐appropriate key. Increasing the dose of pentobarbital in the presence of low doses of dizocilpine produced responding primarily on the pentobarbital‐appropriate key; increasing the dose of dizocilpine in the presence of the lowest dose of pentobarbital produced responding primarily on the dizocilpine‐appropriate key. Combining the higher doses of pentobarbital and dizocilpine resulted in responding primarily on the drug‐combination key. Low doses of phencyclidine or ethanol produced responding on the saline‐appropriate key, but intermediate doses resulted in individual subjects responding predominately on either the pentobarbital key, the dizocilpine key, or the drug‐combination key depending on the subject. After the highest dose of phencyclidine or ethanol, most subjects responded predominantly on the drug‐combination key. Low doses of other drugs tested produced responding on the saline‐appropriate key. With the highest diazepam doses responding was largely confined to the pentobarbital‐appropriate key. The highest doses of dextromethorphan or dextrorphan resulted in responding on the dizocilpine key more frequently than on other keys. Across a range of doses, morphine produced responding predominantly on the saline key. The results using the four‐key procedure emphasized the role of both GABA_A and NMDA receptors in the complex discriminative stimulus properties of phencyclidine and of ethanol.     

Researching a Local Heroin Market as a Complex Adaptive System

This project applies agent-based modeling (ABM) techniques to better understand the operation, organization, and structure of a local heroin market. The simulation detailed was developed using data from an 18-month ethnographic case study. The original research, collected in Denver, CO during the 1990s, represents the historic account of users and dealers who operated in the Larimer area heroin market. Working together, the authors studied the behaviors of customers, private dealers, street-sellers, brokers, and the police, reflecting the core elements pertaining to how the market operated. After evaluating the logical consistency between the data and agent behaviors, simulations scaled-up interactions to observe their aggregated outcomes. While the concept and findings from this study remain experimental, these methods represent a novel way in which to understand illicit drug markets and the dynamic adaptations and outcomes they generate. Extensions of this research perspective, as well as its strengths and limitations, are discussed.     

β受体阻滞剂是冠心病中的重要一线治疗药物

冠心病的治疗包括三个层面：血管重建治疗解决局部狭窄;改善生活方式是基础;全面合理的药物治疗是核心。而β受体阻滞剂又是重要的一线治疗药物,不仅能降低动脉粥样硬化及急性冠脉综合征的发生发展,还能有效预防、缓解心绞痛发生,改善梗死后左室重构和心功能;降低心肌再梗死率,降低心性猝死和病死率。临床上应用β受体阻滞剂的时机和剂量非常重要。     

基于啮齿类动物的决策行为研究及其脑机制

介绍了近年来以啮齿类动物为对象,关于决策的行为表现及其内在脑机制的研究进展。首先介绍了决策的概念,以及啮齿类动物的决策模型。在这些模型的基础上,总结了不同决策模型的共同的心理过程：计算、动机和记忆,并且介绍了业已发现的参与这些心理机制的脑机制。最后,还从决策的角度探讨了其与药物成瘾之间的关系,包括成瘾药物对决策行为的影响以及决策个体差异与药物成瘾易感性之间的关系     

Combining Patient Utility with Health Status Assessment to Improve Medical Decision Making

Physicians often use health status assessment tools to evaluate a patient's condition, then apply established guidelines to determine the most medically effective treatment. Yet additional criteria, such as the appropriateness of the treatment given the particular patient's preferences and attitude toward risk, are also highly relevant to quality care. While such preferences could be addressed via patient utility functions, their use in actual practice is somewhat limited because elicitation is often considered too burdensome for patients, unreliable, or redundant given other measures. For a small group of real patients who have suffered a stroke, we measure both traditional health status and patient utility for the current state to determine whether limited, focused utility assessment is a practical means of obtaining additional and relevant patient information. We find that utility assessment is perceived as reasonable and useful by patients, even when quite ill, and that utilities and health status are not redundant. In fact, investigating apparent inconsistencies between patient utility and observed health status can alert the physician to patient concerns and criteria not captured by more traditional measures. We propose an approach to medical decision making that uses both measures to improve patient–physician communication.     

Transforming continuous utility into additive utility using kolmogorov's theorem

For a multidimensional criteria space to have an additive utility function, the strong condition of independence among the co-ordinates (also known as separability) must be satisfied. However, if we are allowed to transform the criteria space into another, then a theorem due to Kolmogorov implies that we can, even in the absence of independence, transform the space into one that has a continuous additive utility function. Since this transformation is complex, it has only theoretical significance. However, certain related results from neurocomputing theory are quite practical and signify that there exists some scope for neurocomputing in multi-criteria decision analysis.