Competitive routing in multiuser communication networks

The authors consider a communication network shared by several selfish users. Each user seeks to optimize its own performance by controlling the routing of its given flow demand, giving rise to a noncooperative game. They investigate the Nash equilibrium of such systems. For a two-node multiple links system, uniqueness of the Nash equilibrium is proven under reasonable convexity conditions. It is shown that this Nash equilibrium point possesses interesting monotonicity properties. For general networks, these convexity conditions are not sufficient for guaranteeing uniqueness, and a counterexample is presented. Nonetheless, uniqueness of the Nash equilibrium for general topologies is established under various assumptions     

Generation of hardened steel surfaces with adjustable roughness by means of a pulsed electron beam

In this work we are utilizing a Pulsed Cold Cathode Electron Beam (PCCEB) for steel surface treatment that presents distinct properties as compared to other beam sources for rapid heating of metal surfaces. The possibility of producing different surface transformations like, melting and solid-solid transformations by adjusting the gun control parameters is demonstrated. It is shown that for the same base material, different pulse conditions give rise to distinct structures, a roughened or smooth martensitic surface or a smooth pearlite layer several microns thick. For the liquid-solid transformation, it is shown for the first time that with an adequate impurity content the instability onset threshold (giving rise to a rough topography) is different from the melting threshold. Hence, by controlling the discharge parameters, it is possible to obtain different topographies with similar crystallographic structure and hardness, allowing an adjustment of the final roughness to the particular application requirements.     

Comparison of Cuban and Anglo-American cultural values in a clinical population.

Attempted to replicate an earlier study investigating cultural differences between Cuban immigrants and Anglo-Americans. Whereas the earlier study used a nonclinical adolescent population, the current study used 52 adults in outpatient treatment. Ss were given a biographical questionnaire and the Value Orientation scales. Results indicate that the groups differed in relational, temporal, and person–nature orientations, confirming previous findings and clinical observations. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can research on morality be "scientific"?

Proposes a particular ground for moral formulation that is consistent with the consensually based scientific ethic. Researchers' acts of formulating investigatory designs constitute moral values, but these assumptions of value often go unnoticed because they violate the positivist mandate that science should be value neutral. Only a special kind of consensus is "scientific" (as opposed to ideological) because the scientific ethic accepts knowledge as truthful only when it is openly achieved after evenhanded consideration and tested in debate. Since truth in science is a moral issue, close examination should be made of science's moral grounds. The kinds of analyses typically performed by philosophers are an essential part of this empirical search. The author concludes that moral research cannot be "scientific" if this means being value neutral, but it can be scientific in the sense of impartially submitting all formulations to the full reality of people's moral consensuses and interactions in everyday life. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical and functional characterization of PHASCL membranes

Dense semicrystalline membranes of polyhydroxyalkanoates with medium change length (PHA_SCL), polyhydroxybutyrate (PHB) and poly β (hydroxybutyrate-co-hydroxyvalerate) [P(βHB-co-XβHV)] were characterized using wide-angle X-ray (WAXS) and scanning electron microscopy. PHB membranes showed a more rugged surface than those of copolymers (0-22%HV). Properties such as swelling capacity, vapor permeability and selectivity were investigated. Swelling percentage in water-ethanol mixtures was 34% for PHB as compared to 14% for copolymers membranes. The ethanol/water selectivity (α_s) of PHB was 5.8 which shows that it is more selective than copolymers.The water vapor and ethanol vapor permeability were determined by a gravimetric technique at different temperatures by static and dynamic methods. PHB permeability was 69.5 Barrer at 30 °C and a discreet increment was observed at temperatures (30-50 °C). The difference in permeability between PHB and [P(βHB-co-X%βHV)] could be interpreted in terms of the crystallization rate, crystallite size and distribution which impact to transport properties of amorphous phase.     

Processes of moral development: Cognitive or social disequilibrium?

Studied the processes of development in 2 moral systems—L. Kohlberg's (1981) and an interactional formulation by N. Haan (1983)—by comparing the effects of 2 curricular experiences. The 2 curricular experiences involved (1) a discussion of hypothetical dilemmas, which was designed to promote cognitive disequilibrium and the playing of moral games, (2) which in turn was designed to promote social disequilibrium. Ss were 119 university students who were members of 15 naturally existing friendship groups of 8 members each. 10 friendship groups played moral games during 5 3-hr sessions; 5 groups discussed hypothetical dilemmas for the same length of time. Individual interviews, held before, immediately after, and 3 mo after these group sessions, provided the bases for constructing developmental indices. Eight moral scores for each moral system—3 interview and 5 session-based—were thereby secured. Other data collected before the session began included measures of characteristic ego functioning and friends' sociometric evaluations, and during the sessions, measures of students' situational ego functioning and the behavior of friendship groups. Development in both moral systems was generally and strongly predicted by positive interactions between individual S's characteristic ego coping and their friendship group's social disequilibrium. Cognitive disequilibrium only occasionally and weakly facilitated moral development in both systems. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Replies to Leary, Houts and Krasner, Waterman, and Einhorn.

The author replies to 4 previous articles in the present journal (see cases PA, Vol 71:16610, 16604, 16639, and 16594) that criticized her (see record 1983-22367-001) argument that research about morality can be scientific. It is suggested that the assumption that diversity reigns and that there is no moral umbrella for humanity has the effect of relieving social scientists of all responsibility for investigating morality. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of risk factors and pharmacological treatment on mortality in patients with essential hypertension

BACKGROUND: The V JNC consensus stated that although new antihypertensive agents, such as angiotensin converting enzyme inhibitors and calcium channel blockers, are considered safer drugs, there is no firm evidence from large controlled trials that these drugs are associated with a lower cardiovascular mortality. AIM: To study the association between cardiovascular risk factors, blood pressure levels, pharmacological treatment and mortality in a group of hypertensive patients followed at an hypertension outpatient clinic. PATIENTS AND METHODS: Patients with essential hypertension were treated with different antihypertensive medications, according to physicians criteria, and controlled until death or loss from follow up. Causes of death were obtained from hospital records and death certificates. Survival was analyzed using life tables, comparisons between groups of patients were done using chi square or a Cox's proportional hazards model. RESULTS: Three hundred thirty-nine hypertensive patients aged 33 to 80 years old were followed for a mean period of 9.8 +/- 4.9 years. Eighty-six were treated with beta blockers, 64 with diuretics, 133 with calcium antagonists and 56 with ACE inhibitors. Blood pressure dropped similarly with all medications. During follow up, 79 patients died. Life table analysis showed that patients with a history of angina, diabetes or myocardial infarction had higher mortality rates. Similarly, patients treated with beta blockers and diuretics had higher mortality than patients treated with calcium antagonists or angiotensin converting enzyme inhibitors. The proportional hazards model showed that the effect of treatment modality persisted after correction for the other risk factors for mortality. CONCLUSIONS: In this series of hypertensive patients, those treated with beta blockers or diuretics had higher mortality rates than those receiving calcium channel antagonists or angiotensin converting enzyme inhibitors.     

Attachment theory and group processes: The association between attachment style and group-related representations, goals, memories, and functioning.

Four studies examined attachment-style differences in group-related cognitions and behaviors. In Studies 1-2, participants completed scales on group-related cognitions and emotions. In Studies 3-4, participants were divided into small groups, and their performance in group tasks as well as the cohesion of their group were assessed. Both attachment anxiety and avoidance in close relationships were associated with negative group-related cognitions and emotions. Anxiety was also related to the pursuit of closeness goals and impaired instrumental performance in group tasks. Avoidance was related to the pursuit of distance goals and deficits in socioemotional and instrumental performance. Group cohesion significantly moderated the effects of attachment anxiety. The discussion emphasizes the relevance of attachment theory within group contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)