How to Extend the Use of Grid‐Based Interaction Energy Maps from Chemistry to Biotopics

Many computational tools routinely used in chemistry could successfully be applied to the biosciences since protein–protein and protein–ligand interactions are governed by the laws of chemistry. This paper shows that it is possible to extend the use of existing computational tools from their traditional application field (e.g. chemistry) to culturally‐related research areas by the implementation of simple but well‐designed utilities. In particular, a computational strategy obtained by combining GRID (the program originally designed by Peter Goodford, and now distributed by Molecular Discovery Ltd.) and BIOCUBE4mf (an application freely available at www.casmedchem.unito.it ) was used to a) characterize the surface properties of the cavity of the Bacillus anthracis protective antigen heptameric prepore; b) suggest how to design mutagenesis experiments; c) quantitatively show the selectivity of the KvAP channel for K⁺ over Na⁺ ions and d) rationalize the pharmacokinetic behavior of 1,4‐DHP third‐generation drugs.     

A globally stabilizing hybrid variable structure control strategy

A hybrid variable structure control strategy for a class of second order systems is presented in this paper. It relies on a system state decomposition into regions, and on a suitable event-driven switching among the corresponding control laws. By enforcing conventional and unconventional sliding-mode behaviors, as well as avoiding the generation of limit cycles, the proposed strategy proves to globally asymptotically stabilize the origin of the system state space.     

Mapping the charged residues in the second immunoglobulin-like domain of the vascular endothelial growth factor/placenta growth factor receptor Flt-1 required for binding and structural stability

Flt-1 is one of two receptor tyrosine kinases through which the angiogenic factor vascular endothelial growth factor (VEGF) functions. Placenta growth factor (PlGF) is an additional ligand for Flt-1. The second immunoglobulin-like domain in the extracellular domain of Flt-1 has previously been identified as the region containing the critical ligand-binding determinants. We analyzed the contribution of charged residues within the first three domains of Flt-1 to ligand binding by alanine-scanning mutagenesis. Domain 2 residues Arg159, Glu208 and His223-Arg224 (together) affect both VEGF and PlGF binding, while Glu137, Lys171, His223, and Arg224 affect PlGF but not VEGF. Several charged residues, especially Asp187, are important in maintaining the structural integrity of domain 2. In addition, some residues in domain 3 contribute to binding (Asp231) or provide for additional discrimination between ligands (Arg280-Asp283).     

The science network in Italian population research: An analysis according to the social network perspective

The scientific community organises its relationships into network patterns, where the nodes are individuals (scientists) and the links are acquaintance and common work, usually presented at workshops and conferences and/or published in books and scientific journals. A references review on Population Studies by Italian scientists is delivered every two years by the Demography Section of the Italian Statistical Society; the review is exhaustive for academic demographers. In this paper, the properties of the demographers' network in 1998-1999 are evaluated, with the aim of identifying factors which may influence collaborative relations among actors. The probability of cooperation between couples (dyads) of demographers is modelled, conditionally on observed characteristics of the dyad (sex, academic position, university affiliation). Main results suggest that “closeness”, defined in a wider sense and not simply as geographical proximity, plays a major role in determining actors' relationships.     

Host reactive donor T cells are associated with lung injury after experimental allogeneic bone marrow transplantation

Noninfectious lung injury is common after allogeneic bone marrow transplantation (BMT), but its association with acute graft-versus-host disease (GVHD) is unclear. Using a murine BMT system where donor and host differ by multiple minor histocompatibility (H) antigens, we investigated the nature of lung injury and its relationship both to systemic GVHD and host-reactive donor T cells. Lethally irradiated CBA hosts received syngeneic BMT or allogeneic (B10.BR) T-cell-depleted (TCD) bone marrow (BM) with and without the addition of T cells. Six weeks after BMT, significant pulmonary histopathology was observed in animals receiving allogeneic BMT compared with syngeneic controls. Lung damage was greater in mice that received allogeneic T cells and developed GVHD, but it was also detectable after TCD BMT when signs of clinical and histologic acute GVHD were absent. In each setting, lung injury was associated with significant alterations in pulmonary function. Mature, donor (Vbeta6(+) and Vbeta3(+)) T cells were significantly increased in the broncho-alveolar lavage (BAL) fluid of all allogeneic BMT recipients compared with syngeneic controls, and these cells proliferated and produced interferon-gamma (IFN-gamma) to host antigens in vitro. These in vitro responses correlated with increased IFN-gamma and tumor necrosis factor-alpha (TNF-alpha) in the BAL fluid. We conclude that alloreactive donor lymphocytes are associated with lung injury in this allogeneic BMT model. The expansion of these cells in the BAL fluid and their ability to respond to host antigens even when systemic tolerance has been established (ie, the absence of clinical GVHD) suggest that the lung may serve as a sanctuary site for these host reactive donor T cells. These findings may have important implications with regard to the evaluation and treatment of pulmonary dysfunction after allogeneic BMT even when clinical GVHD is absent.     

Self-Presentation Processes in Job Analysis: A Field Experiment Investigating Inflation in Abilities, Tasks, and Competencies.

Although job analysis is a widely used organizational data collection technique, little research has investigated the extent to which job analysis information is affected by self-presentation processes. This study represents the first direct test of the propositions offered by F. P. Morgeson and M. A. Campion (1997) concerning self-presentation in job analysis measurement. Using an experimental design, the authors examined job incumbent response differences across ability, task, and competency statements. Results indicated that ability statements were more subject to inflation than were task statements across all rating scales. Greater endorsement of nonessential ability statements was responsible for the differences. This produced higher endorsement of ability items but lower mean ratings. Finally, frequency and importance ratings of global competency statements were generally higher than decomposed ability and task scales, but required-at-entry judgments demonstrated the opposite relationship. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ideal contrast visual cryptography schemes with reversing

A visual cryptography scheme (VCS) for a set of n participants is a method to encode a secret image, consisting of black and white pixels, into n transparencies, one for each participant. Certain qualified subsets of participants can “visually” recover the secret image by stacking their transparencies, whereas, other, forbidden, subsets of participants, cannot gain any information about the secret image.Recently, Viet and Kurosawa proposed a VCS with reversing, which is a VCS where the participants are also allowed to reverse their transparencies, i.e., to change black pixels to white pixels and vice-versa. They showed how to construct VCSs with reversing where the reconstruction of black (white, respectively) pixels is perfect, whereas, the reconstruction of white (black, respectively) pixels is almost perfect. In both their schemes there is a loss of resolution, since the number of pixels in the reconstructed image is greater than that in the original secret image.In this paper we show how to construct VCSs with reversing where reconstruction of both black and white pixels is perfect. In our schemes each participant is required to store a certain number of transparencies, each having the same number of pixels as the original secret image. Moreover, our schemes guarantee no loss of resolution, since the reconstructed image is exactly the same as the original secret image. Finally, compared to the schemes of Viet and Kurosawa, our schemes require each participant to store a smaller amount of information.