Hostilidad,patrón de conducta tipo A y reactividad cardíaca

Resumen

La presente investigación tuvo como objetivo estudiar el efecto de la hostilidad autoinformada en la reactividad cardíaca de sujetos Tipo A/B. Los sujetos fueron 40 estudiantes varones repartidos en cuatro grupos: (1) Tipo A con alta Hostilidad, (2) Tipo A con baja Hostilidad, (3) Tipo B con alta Hostilidad y (4) Tipo B con baja Hostilidad. Todos ellos pasaron por tres pruebas de reactividad psicofisiológica: El Test de la Respuesta Cardíaca de Defensa ante estimulación auditiva intensa, una Tarea de Aritmética Mental y una Tarea de Juego de Vídeo Competitivo. La variable dependiente registrada fue la tasa cardíaca. Los resultados indican que en las tres pruebas no se observan diferencias en la reactividad de la tasa cardíaca entre sujetos Tipo A y B con alta Hostilidad autoinformada. Sin embargo, sí se observan diferencias entre sujetos Tipo A y B con baja Hostilidad autoinformada, siendo los sujetos Tipo A los que muestran mayores incrementos en tasa cardíaca durante la Respuesta Cardíaca de Defensa y el Juego de Vídeo Competitivo. En la Tarea de Aritmética Mental se observa esta tendencia, aunque no llegan a ser diferencias significativa s. Estos resultados sugieren que la supresión o negación de la hostilidad en sujetos Tipo A está asociada con un incremento en la reactividad cardiovascular.     

环境雌激素双酚A对成年小鼠学习记忆和突触结构的影响*

双酚A (bisphenol, BPA)是一种广泛存在的环境内分泌干扰物,它可与雌激素受体结合干扰内源性雌激素对中枢神经系统的调控作用。本研究通过将10周龄小鼠灌胃染毒BPA (0.4、4、40 mg/kg/day)3个月,研究长期BPA暴露对成年小鼠记忆行为和突触可塑性的影响。开场行为测试结果表明, BPA (0.4、4、40 mg/kg/day)增加雄性的站立次数和理毛频率, BPA (4 mg/kg/day)却显著减少雌鼠的站立次数。水迷宫和被动回避行为模型检测显示, BPA主要损伤雄鼠的空间学习记忆和被动回避记忆。通过制备海马CA1区超薄切片后,电镜观测发现, BPA (0.4、40 mg/kg/day)暴露降低雄鼠海马CA1区突触数密度,缩短雄鼠突触前活性带长度,减小雄鼠突触后致密体(PSD)厚度,增加雄鼠突触间隙宽度。进一步用Western blot方法检测突触前、后的标志性蛋白Synapsin I和PSD95以及兴奋性氨基酸NMDA受体NR1亚基和AMPA受体GluR1亚基蛋白的表达,发现BPA暴露致雄鼠Synapsin I、PSD95、NR1蛋白表达水平下调。而BPA对雌鼠的记忆行为、突触形态、突触蛋白和受体蛋白均没有明显作用。以上结果提示长期B PA暴露性别特异性地影响成年小鼠的活动性和探究行为,损伤雄鼠的学习记忆,这些作用可能通过下调突触蛋白和NMDA受体的表达而负性影响突触结构可塑性,最终影响雄鼠的学习记忆功能。     

Gender differences in type a behavior and hostility within an organizational setting

Abstract

Recent investigations suggest that the hostility component of the Type A behavior patter (TABP) is a greater detriment to health than the overall pattern. Some researchers suggest that certain Type A characteristics (e.g., job-involvement) are actually adaptive. This study compared the relative relationship of the TABP and hostility to career-related achievement and psychosocial adjustment among 223 service-delivery employees. Male and female participants completed the Jenkins Activity Survey and the MMPI Hostility Scale as part of a cardiovascular disease risk factor screening. The TABP was positively associated with managerial status for both men and women. However, the TABP was positively related to psychosocial adjustment variables among men only. Hostility was significantly related to undesirable outcomes including lower job status, life dissatisfaction, and unfavorable perceptions of the workplace for both men and women. Discussion addresses organizational factors which might perpetuate hostility and the TABP, as well as gender differences in the experience of these constructs.     

Response of the pituitary-adrenal axis in terms of type a behaviour,hostility and vital exhaustion in healthy middle-aged men

Abstract

Pituitary-adrenal axis was studied in terms of Type A behaviour, hostility and vital exhaustion among 69 healthy middle-aged men. The results showed that psychological factors could explain a significant proportion of the biologically manipulated responses of HPA axis, but they worked in different ways. Type A behaviour was related to a high level of mean basal ACTH and a low level of cortisol response to ACTH stimulation after dexamethasone suppression; hostility was related to a high level of mean basal cortisol and a high cortisol in cortisol/ACTH ratio, while vital exhaustion was characterized by a low level of mean basal ACTH and a decreased ACTH in relation to cortisol. The adrenocortical patterns, i.e. a high ACTH-low cortisol; a high cortisol; and a low ACTH-low mean basal cortisol, as related to Type A behaviour, hostility and exhaustion, respectively, are in line with the traditional physiological stress model and suggest that different adrenocortical responses might be able to identify different mental stress processes. Sense of control has been suggested to be a key concept for psychological understanding of this finding.     

Neuropsychological Functioning in Children with Medium Chain Acyl Coenzyme A Dehydrogenase Deficiency (MCADD): The Impact of Early Diagnosis and Screening on Outcome

Children with medium chain acyl coenzyme A dehydrogenase deficiency (MCADD) have been reported to be at high risk for neurocognitive deficits. However this has not been systematically studied and little is known about the exact nature of neuropsychological sequelae or of the impact of early diagnosis and screening on outcome. We examined cognitive and adaptive outcome in children with MCADD (N?=?38, age range: 2 years, 2 months – 10 years, 3 months) diagnosed either through a newborn screening program (tandem mass spectrometry/MSMS) or upon clinical presentation. There was no evidence of overall intellectual impairment in either groups but there was some suggestion of poorer verbal and specific executive functioning (i.e., planning) abilities in the unscreened cohorts. Adaptive functioning was relatively intact with the exception of reduced Daily Living Skills in both our screened and unscreened groups. Early diagnosis and greater number of hospitalizations were related to higher verbal, communication, and socialization skills. Overall, our results highlight the importance of early diagnosis and management for children with MCADD.     

Whiteheadian Societies and Peirce's Law of Mind: Actuality and Potentiality in the Cosmic Process

Abstract

A more suitable philosophical position to counter the claims of scientific materialism re the nature of physical reality can possibly be found in combining the metaphysics of A.N. Whitehead and C.S. Peirce. Peirce postulated a habit-forming tendency or inbuilt potentiality of the cosmic process as a whole to move over time toward ever greater organization and more complex structure. But he is vague on how “the law of the mind” applies to nature below the level of human self-awareness. Whitehead's notion of actual entities (momentary self-constituting subjects of experience) as the “final real things of which the world is made up” logically allows for some primitive form of subjectivity with the requisite potentiality for habit-formation at all levels of existence and activity within nature. In addition, Whitehead's notion of structured societies made up of subsocieties with a “regnant” subsociety seems philosophically to justify the new emphasis on bottom-up rather than top-down causation in the emergence of more complex levels of existence and activity within the life-sciences.     

On the a priori and a posteriori assessment of probabilities

We argue that in spite of their apparent dissimilarity, the methodologies employed in the a priori and a posteriori assessment of probabilities can both be justified by appeal to a single principle of inductive reasoning, viz., the principle of symmetry. The difference between these two methodologies consists in the way in which information about the single-trial probabilities in a repeatable chance process is extracted from the constraints imposed by this principle. In the case of a posteriori reasoning, these constraints inform the analysis by fixing an a posteriori determinant of the probabilities, whereas, in the case of a priori reasoning, they imply certain claims which then serve as the basis for subsequent probabilistic deductions. In a given context of inquiry, the particular form which a priori or a posteriori reason may take depends, in large part, on the strength of the underlying symmetry assumed: the stronger the symmetry, the more information can be acquired a priori and the less information about the long-run behavior of the process is needed for an a posteriori assessment of the probabilities. In the context of this framework, frequency-based reasoning emerges as a limiting case of a posteriori reasoning, and reasoning about simple games of chance, as a limiting case of a priori reasoning. Between these two extremes, both a priori and a posteriori reasoning can take a variety of intermediate forms.     

Fear response to dissociation challenge

Abstract

Participants (N = 101) scoring high or low on a new scale for assessing fear of dissociative sensations (Dissociation Sensitivity Index) underwent an audio/visual sensory challenge using a device called the D.A.V.I.D. Participants' report of subjective fear and level of dissociation were measured before and after completing the audio/visual sensory challenge. Consistent with prediction, participants scoring high on the DSI responded to the challenge with significantly greater increases in subjective fear and dissociative symptoms relative to those scoring low on the DSI. Contrary to prediction, the DSI performed poorer than the Anxiety Sensitivity Index in predicting participants' response to the audio/visual sensory challenge. Theoretical and clinical implications of the findings are discussed.     

Arguing at Cross-Purposes: Discharging the Dialectical Obligations of the Coalescent Model of Argumentation

The paper addresses the manner in which the theory of Coalescent Argumentation [CA] has been received by the Argumentation Theory community. I begin (section 2) by providing a theoretical overview of the Coalescent model of argumentation as developed by Michael A. Gilbert (1997). I next engage the several objections that have been raised against CA (section 3). I contend that objectors to the Coalescent model are not properly sensitive to the theoretical consequences of the genuinely situated nature of argument. I conclude (section 4) by suggesting that the resolution to the dispute between Gilbert and his objectors hinges on the outcome of several foundational theoretical questions identified over the course of the paper.