On the influence of psychrometric ambient conditions on cooling tower drift deposition

Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health hazards. A numerical model to study the influence of psychrometric ambient conditions on cooling tower drift deposition was developed as a tool to evaluate liquid droplet dispersion and risk area. Both experimental plume performance and drift deposition were employed to validate the numerical results. This study shows the influence of variables like ambient dry bulb temperature, ambient absolute humidity and droplet exit temperature from cooling tower on the drift evaporation (and therefore deposition) and on the zone affected by the cooling tower. The strongest effect detected corresponds to the ambient dry bulb temperature. When a higher ambient temperature was present, deposition was lower (evaporation was therefore higher) and the zone affected by the cooling tower was smaller. The influence of the other two variables included in the study was weaker than the dry bulb ambient temperature. A high level of ambient absolute humidity increased drift deposition and also the size of the zone affected by the cooling tower. Finally, a high level of droplet exit temperature decreased deposition and increased the zone affected by the cooling tower.     

Time to abandon small-sample cohort research in health psychology?

Comments on the original article, "Avoidant coping as a predictor of mortality in veterans with end-stage renal disease" by E. J. Wolf and D. L. Mori (see record 2009-06704-009), in which the authors report that among 61 patients with endstage renal disease (ESRD), avoidant coping more than doubled the odds of mortality in multivariable analysis. The authors concluded that evaluating coping style in patients with ESRD would be clinically useful and that interventions targeting avoidant coping should be investigated. In this commentary, the current authors note that Wolf and Mori’s (2009) finding was based on a sample where only 23 patients died over 9 years, and results were evaluated using a Cox regression model with six covariates, a ratio of only 3.8 outcome events per variable—well below recommended thresholds (e.g., Babyak, 2004; Peduzzi et al., 1995). Beyond this, the model did not assess key variables typically included in studies of ESRD outcomes (e.g., transplant status, cardiovascular problems). Wolf and Mori chose to focus on the relationship between avoidant coping and mortality. However, bivariable correlations and confidence intervals reported or generated from data in the article showed that the association between avoidant coping and mortality (r=.28, 95% CI [.03 to .50]) was not significantly stronger than two other correlations that were in the opposite direction of what would have been expected: hypertension with mortality (r=?.39, 95% CI [?.15 to ?.59]) and medication compliance with mortality (r=.16, 95% CI [?.10 to .40]). Oddities of this sort are often encountered in very small datasets and, as a result, stronger evidence must be accrued from larger, more robust samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Avoidant coping as predictor of mortality in veterans with end-stage renal disease": Response to Jewett, Newton, Smith, & Thombs (2010).

Responds to the comments by L. R. Jewett, E. G. Newton, S. Smith, and B. D. Thombs (see record 2010-14873-001) on the current authors' original article, "Avoidant coping as predictor of mortality in veterans with end-stage renal disease" (see record 2009-06704-009). In their commentary, Jewett et al note that oddities often encountered in very small datasets—such as the one used by Wolf and Mori—and, as a result, stronger evidence must be accrued from larger, more robust samples. In this response, Jewett et al acknowledge that theirs is a preliminary study of a small and highly select sample and recognize the limited generalizability of our results. Jewett et al maintain that they do not assert that there should be radical changes in clinical or research programs based on their study results, but instead, suggest that further follow-up would be valuable and that readily available and commonly used assessment and intervention procedures may be appropriate in ameliorating avoidant coping in the endstage renal disease (ESRD) population. At the same time, given the focus on mortality, the risk of doing nothing because the evidence is preliminary far outweighs the minimal costs associated with assessing and addressing avoidant coping, particularly since psychological assessment, including of coping behavior, is part of the standard of practice in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associations between adult attachment ratings and health conditions: Evidence from the National Comorbidity Survey Replication.

Objective: Attachment insecurity has been hypothesized to be a risk factor for the development of disease and chronic illness. This study was the first to investigate associations between adult attachment ratings and a wide range of health conditions. Design: Cross-sectional data from the National Comorbidity Survey Replication (N = 5645) were used. Measures: Participants completed Hazan and Shaver's (1987) measure of adult attachment and provided reports regarding 15 health conditions. Results: Logistic regression analyses that adjusted for demographic variables indicated that avoidant attachment ratings were positively associated with conditions defined primarily by pain (e.g., frequent or severe headaches). Anxious attachment ratings were positively associated with a wider range of health conditions, including several involving the cardiovascular system (i.e., stroke, heart attack, high blood pressure). Secure attachment ratings were unrelated to the health conditions. Additional analyses investigated whether the attachment ratings accounted for unique variance in the health conditions beyond that accounted for by lifetime histories of depressive, anxiety, and alcohol- or substance-related disorders. In these analyses, anxious attachment ratings continued to have significant positive associations with chronic pain, stroke, heart attack, high blood pressure, and ulcers. Conclusion: The findings were generally supportive of the theory that insecure attachment is a risk factor for the development of disease and chronic illness, particularly conditions involving the cardiovascular system. Further research regarding the role of attachment in the development of specific health conditions is warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic networks for odors and colors in Alzheimer's disease.

Objective: Impairment in odor-naming ability and in verbal and visual semantic networks raised the hypothesis of a breakdown in the semantic network for odors in Alzheimer's disease (AD). The current study addressed this hypothesis. Method: Twenty-four individuals, half patients with probable AD and half control participants, performed triadic-similarity judgments for odors and colors, separately, which, utilizing the multidimensional scaling (MDS) technique of individual difference scaling analysis (INDSCAL), generated two-dimensional configurations of similarity. The abilities to match odors and colors with written name labels were assessed to investigate disease-related differences in ability to identify and conceptualize the stimuli. In addition, responses on attribute-sorting tasks, requiring the odor and color perceptions to be categorized as one polarity of a certain dimension, were obtained to allow for objective interpretation of the MDS spatial maps. Results: Whereas comparison subjects generated spatial maps based predominantly on relatively abstract characteristics, patients with AD classified odors on perceptual characteristics. The maps for patients with AD also showed disorganized groupings and loose associations between odors. Their normal configurations for colors imply that the patients were able to comprehend the task per se. The data for label matching and for attribute sorting provide further evidence for a disturbance in semantic odor memory in AD. The patients performed poorer than controls on both these odor tasks, implying that the ability to identify and/or conceptualize odors is impaired in AD. Conclusion: The results provide clear evidence for deterioration of the structure of semantic knowledge for odors in AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of healthy aging and early stage dementia of the Alzheimer's type on components of response time distributions in three attention tasks.

Objective: The characteristics of response time (RT) distributions beyond measures of central tendency were explored in 3 attention tasks across groups of young adults, healthy older adults, and individuals with very mild dementia of the Alzheimer's type (DAT). Method: Participants were administered computerized Stroop, Simon, and switching tasks, along with psychometric tasks that tap various cognitive abilities and a standard personality inventory (NEO-FFI). Ex-Gaussian (and Vincentile) analyses were used to capture the characteristics of the RT distributions for each participant across the 3 tasks, which afforded 3 components: μ and σ (mean and standard deviation of the modal portion of the distribution) and τ (the positive tail of the distribution). Results: The results indicated that across all 3 attention tasks, healthy aging produced large changes in the central tendency μ parameter of the distribution along with some change in σ and τ (mean ηp2 = .17, .08, and .04, respectively). In contrast, early stage DAT primarily produced an increase in the τ component (mean ηp2 = .06). τ was also correlated with the psychometric measures of episodic/semantic memory, working memory, and processing speed, and with the personality traits of neuroticism and conscientiousness. Structural equation modeling indicated a unique relation between a latent τ construct (–.90), as opposed to σ (–.09) and μ constructs (.24), with working memory measures. Conclusions: The results suggest a critical role of attentional control systems in discriminating healthy aging from early stage DAT and the utility of RT distribution analyses to better specify the nature of such change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

风湿性心脏病易感基因多态性研究进展

风湿性心脏病(Rheumatic heart disease,RHD)是一种A组溶血性链球菌感染引起的风湿热的后遗症,属于自身免疫性疾病,主要表现为瓣膜口狭窄或关闭不全。大约30%~45%的风湿热(Rheumatic fever,RF)患者会发展为风湿性心脏病,这就提示风湿性心脏病可能存在着个体易感性的差异。对RHD易感性的研究,有助于进一步探讨其发病的分子机制,为RHD的防治提供新的思路。随着人类基因组计划的迅速发展及新的分析技术问世,RHD遗传易感性研究有了很大的发展。目前已知多种遗传基因与人类RHD易感性有关联,例如白细胞抗原 (HLA)、肿瘤坏死因子 (TNF)等,某些易感基因与炎症反应及免疫系统相关,本文主要就近年来RHD遗传易感性的研究进展作一综述。     

左旋多巴药物基因组学的研究进展

左旋多巴被认为是治疗帕金森病的金标准,本文综述了多个相关基因的遗传多态性对左旋多巴药代动力学、药效学及不良反应的影响,以期为指导左旋多巴的临床个体化用药提供基础。     

多发性骨髓瘤骨病发病机制的研究及治疗进展

多发性骨髓瘤(Multiple myeloma,MM)是恶性克隆性浆细胞疾病,骨髓瘤骨病(Myeloma bone disease,MBD)是其重要的临床表现之一。其发病机理与骨吸收增加及骨生成减少有关,对骨髓瘤骨病病理机制的研究促进了新的靶向性药物研发。现就目前已知参与MBD发病机制及治疗新进展作一综述。     

一种抑制IVUS 图像序列中运动伪像的方法

针对连续回撤超声导管采集的冠状动脉血管内超声（intravascular ultrasound,IVUS）图像序列中存在由周期性心脏运动所致运动伪像的问题,提出一种抑制 方法,以改善IVUS 纵向视图的视觉效果。首先,在综合分析运动伪像产生机制和表现形式 的基础上,对相邻帧之间血管壁的刚性运动进行定量估计;然后,采用谱分析方法完成刚性 运动参数中运动分量和几何分量的分离;最后,通过对各帧图像中血管壁的运动分量进行补 偿,完成对运动伪像的抑制。该方法既不需要专门的ECG 门控图像采集装置,也无需记录 ECG 信号,同时不需要抛弃有用帧,在抑制运动伪像的同时保证图像数据集合的完整性。 对模拟图像和临床图像的实验验证了方法的可行性。