Interactive Dynamics of Cell Volume and Cell Death in Human Erythrocytes Exposed to α-Hemolysin from Escherichia coli

α-hemolysin (HlyA) of E. coli binds irreversibly to human erythrocytes and induces cell swelling, ultimately leading to hemolysis. We characterized the mechanism involved in water transport induced by HlyA and analyzed how swelling and hemolysis might be coupled. Osmotic water permeability (P_f) was assessed by stopped-flow light scattering. Preincubation with HlyA strongly reduced P_f in control- and aquaporin 1-null red blood cells, although the relative P_f decrease was similar in both cell types. The dynamics of cell volume and hemolysis on RBCs was assessed by electrical impedance, light dispersion and hemoglobin release. Results show that HlyA induced erythrocyte swelling, which is enhanced by purinergic signaling, and is coupled to osmotic hemolysis. We propose a mathematical model of HlyA activity where the kinetics of cell volume and hemolysis in human erythrocytes depend on the flux of osmolytes across the membrane, and on the maximum volume that these cells can tolerate. Our results provide new insights for understanding signaling and cytotoxicity mediated by HlyA in erythrocytes.     

Effect of Size, Shape and Hardness of Particles in Suspension on Oral Palatability

The size, shape. and hardness of particles in suspension can influence the oral sensory perception and palatability. This information can be used in the design of a suspension dosage form or to define optimal parameters for a reconstitutible oral delivery system. The report summarizes the effect of garnet, polyethylene and mica suspension on texture, taste and consistency. Significant differences in sensory perception exist between different samples based on the size, shape or hardness of the particles.     

A replication and extension of "Physical attractiveness and mental illness."

A. Farina et al (see record 1978-23202-001) investigated the relation between mental illness and physical attractiveness and found that female psychiatric inpatients were less attractive than normal controls. The current study extended this investigation in 2 ways. First, 28 psychiatric inpatients were compared to 3 separate control groups of 53 low, middle, and high socioeconomic status Ss. Mental patients were judged significantly less attractive than either middle- or high-income controls but were not significantly different from low-income controls. Second, to examine physical attractiveness prior to hospitalization, attractiveness ratings of the patients' high school yearbook pictures were compared with ratings of the adjacent same-sex photographs. Patients' photographs were judged significantly less attractive than their peers' even in high school. Findings suggest that being physically unattractive may predispose an individual to a number of negative social outcomes, one of which is mental illness. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regenerative effects by temperature variations in dye-sensitized solar cells

The effect of repeated temperature variations on the performance of both fresh and aged dye-sensitized solar cells with liquid and semi-solid electrolytes has been studied. The cell performance was characterized with IV-curves obtained at different cell operating temperatures and electrochemical impedance spectroscopy measurements before and after the temperature treatments. Consecutive temperature rampings of the aged cells did regenerate the cell function, so that the total efficiency drop over the observation period was on average 18%/unit less for the temperature-treated cells than for reference cells aged at constant temperature.     

Is production outside management?

It is contended that the root cause for disagreement between lean construction proponents and management scholars is related to the new direction of management research which was proposed in 1959 in two influential books, by R.A. Gordon and J.E. Howell and by F.C. Pierson. It was argued that management was to be approached through three root stems: behavioural science, economics and quantitative modelling. The mainstream academic work on management has followed the guidelines presented in these books. Unfortunately, this kind of management science has also attracted vocal and wide criticism regarding its practical relevance. The 1959 work rejected the production-centric scientific management tradition – a tradition on which lean construction has been based. Thus, the underlying disagreement is about the role of production in management: is production a starting point for management or outside management? This root disagreement is demonstrated through two research topics at the heart of the development of management science after 1959: organizational theory, as developed by J.R. Galbraith, and transaction cost economics, initiated by O. Williamson. Based on evidence from the analyses made, it is suggested that the failure to include production in theory has been one major cause for the problematic situation of management science in the last 50 years.

Il est soutenu que la cause première du désaccord entre les partisans de la construction rationalisée et les chercheurs en gestion est liée à la nouvelle orientation de la recherche en gestion qui a été proposée en 1959 dans deux livres influents de R.A. Gordon et J.E. Howell et de F.C. Pierson. Il était avancé que la gestion devait être abordée selon trois branches principales: les sciences du comportement, les sciences économiques, et la modélisation quantitative. Le courant dominant des travaux universitaires en gestion a suivi les directives exposées dans ces livres. Malheureusement, ce type de sciences de gestion s'est également attiré de vigoureuses et larges critiques à l'égard de sa pertinence pratique. L'ouvrage de 1959 rejetait la tradition d'une gestion scientifique centrée sur la production – une tradition sur laquelle s'est fondée la construction rationalisée. Ainsi, le désaccord sous-jacent porte-t-il sur le rôle de la production dans la gestion: la production est-elle un point de départ pour la gestion ou se situe-t-elle en dehors de la gestion? Ce désaccord de fond est démontré à travers deux thèmes de recherche se situant au coeur du développement des sciences de gestion après 1959: la théorie organisationnelle, telle qu'elle a été élaborée par J.R. Galbraith, et l'économie des coûts de transaction, dont O. Williamson est l'initiateur. Sur la base des éléments probants apportés par les analyses faites, il est suggéré que le fait de ne pas avoir inclus la production dans la théorie a été l'une des causes principales de la situation problématique des sciences de gestion ces cinquante dernières années.

Mots clés: gestion de la construction?construction rationalisée?théorie du design organisationnel?économie des coûts de transaction?déchets     

Mechanical and physical properties of thermally modified Scots pine wood in high pressure reactor under saturated steam at 120, 150 and 180 °C

Scots pine sapwood and heartwood were thermally modified under saturated steam at 120, 150 and 180 °C in a high pressure reactor. Mechanical properties such as dynamic and static modulus of elasticity (MOE), static modulus of rupture (MOR), Brinell hardness and impact toughness were evaluated. The static MOE for sapwood did not decrease substantially (approximately 1 %), not even with a high mass loss of more than 12 %, when the wood was modified at 180 °C. Static MOE of the wood increased approximately 14 %, when modified at 150 °C. Surprisingly, MOR increased by 15 %, when modified at 150 °C with mass loss of 2.3 %. Whereas impact strength and hardness decreased somewhat, when modified at 180 °C. Moreover, high anti-swelling efficiency values were obtained (60 % for sapwood and 52 % for heartwood) when modified at 180 °C.