Responses of plant-parasitic nematodeMeloidogyne incognita to carbon dioxide determined by video camera-computer tracking

A computer tracking system was used to quantify the responses of infective second-stage juveniles of the plant-parasitic nematodeMeloidogyne incognita to carbon dioxide. A sudden increase in concentration caused an increase in the rate of locomotion and a decrease in the frequency of changes of direction. The threshold was about 0.01 % vol CO₂/vol gas when the baseline concentration was very low and 0.05% CO₂ when the baseline concentration was 1% CO₂. The latter value represents a relative change of 5%. Concentrations above 10% CO₂ caused a general decrease in movement. In a second type of experiment, a constant concentration gradient of CO₂ was established, and the net movement of the nematodes along the gradient was determined. At low concentrations, the threshold was about 0.02% CO₂/cm. At higher concentrations, the threshold gradient was below 0.01% CO₂/cm or a relative gradient of less than 1% change/cm. At all concentrations to which nematodes responded they were attracted. The degree of orientation was estimated to be approximately 10% under most conditions. The rate of migration under the most favorable conditions was about 0.7 cm/hr. Three possible functions of the response are discussed: attraction to roots, movement toward optimal depth in soil, and as a collimating stimulus.     

Social support, life stress, and subsequent medical care utilization.

246 men and 191 women (aged 40–72 yrs) were monitored for medical care utilization in a health maintenance organization (HMO) over a 5-yr period. Rates of utilization were related to initially obtained indicators of life stress and social support and to interactions between life stress, social support, and age. Predictors of male and female HMO use are discussed. Multiple regression permitted a distinction between immediate and delayed effects of stresses on HMO visits. Implications regarding the buffering hypothesis for the mitigating effects of social support on the likelihood of health breakdown are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal instability with radiation by the method of energy

Energy-stability theory is applied to the case of radiation heat transfer in an optically thin, quiescent fluid layer heated from below and bounded by rigid, black, perfectly conducting planes. The radiation term in the energy equation destroys the quadratic character of the energy identity. It is shown, however, that the right-hand side of the energy identity can be bounded by a suitable quadratic term for all physically allowable disturbances. The result is a conditional stability limit dependent upon disturbance amplitude. Results are computed for a variety of cases; these are compared to existing linear and energy stability results.     

Sexual relationships, sexual behavior, and HIV infection: HIV-seropositive gay and bisexual men seeking prevention services.

The authors evaluated sexual practices, sexually tempting situations, and risk avoidance coping strategies among HIV-seropositive men who have sex with men and who were seeking HIV prevention services. HIV-seropositive men who practiced unprotected anal intercourse in the previous 4 weeks reported stronger temptations to engage in high-risk sex than men who were sexually safe. Being in a positive mood and being with desirable partners were particularly tempting risk situations for seropositive men, who also possessed less coping capacity to deal with risky situations than safer men. Prevention interventions must address the needs of men infected with HIV and must remove barriers to enrolling in prevention programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrapsychic conflict versus developmental deficit: A causal modeling approach to examining psychoanalytic theories of narcissism.

Over the past 15 years, disorders of the self have occupied the attention of the psychoanalytic community. In particular, Otto Kernberg and Heinz Kohut have written extensively about narcissism, but from distinctly different theoretical vantage points. Each theorist has attracted adherents, but the debate between the conflict and deficit models of narcissism has been largely polemical, serving to further polarize the psychoanalytic community. Using the techniques of causal modeling, the article introduces this powerful data analytic strategy to psychoanalytic researchers and tests a model of narcissism which permits a direct, empirical comparison of some of the ideas of Kernberg and Kohut. In a number of strategic comparisons involving the theoretical underpinnings of narcissism--the structural stability of the self, damaged self-esteem, and grandiosity--these data appear to be more consistent with the deficit model, although various aspects of the conflict model also find support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scenarios and Covert Channels: Another Game...

Covert channels are information leaks in systems that use resources to transfer secretly a message. They are a threat for security, performance, but also for a system's profitability. This paper proposes a new approach to detect covert channels from scenario models of protocols. The problem of finding covert channels in scenarios is first modeled as a game, in which a pair of malicious users S,R is trying to transfer information while the rest of the protocol tries to prevent it. The messages transferred are encoded by behavioral choices at some precise moments, and decoded by a transducer whose input vocabulary is an observation of the system. We then characterize the presence of a covert channel as the existence of a winning strategy for S,R and of a decoder.     

Supercritical Debinding of Injection Molded Ceramics

Extraction of organic additives from extrusion-molded cylinders of alumina by a supercritical fluid is investigated. Hildebrand parameters alone are not adequate to predict conditions for optimal polymer extraction with supercritical CO₂. The results obtained with two models developed for the kinetics of binder extraction suggest that polymer extraction from green samples is controlled by diffusion without development of a reaction front. The solubility and diffusivity of polymers both affect the extraction rate, with opposite pressure and temperature dependencies.     

Review of Devenir consultant: instrument autogéré de formation (Module d'apprentissage I et Dossier d'intervention II).

Reviews the book, Devenir consultant: instrument autogéré de formation (Module d'apprentissage I et Dossier d'intervention II by Robert Robert Lescarbeau, Maurice Rayette, and Yves St-Arnaud (1985). This book is a pedagogic tool intended to facilitate the consultation training. It is composed of two handbooks. The first, Modules of Training, constitute the basic text. The second, File of Intervention, are a collection of relevant instruments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)