Effective proximity retrieval by ordering permutations

We introduce a new probabilistic proximity search algorithm for range and K-nearest neighbor (K-NN) searching in both coordinate and metric spaces. Although there exist solutions for these problems, they boil down to a linear scan when the space is intrinsically high-dimensional, as is the case in many pattern recognition tasks. This, for example, renders the K-NN approach to classification rather slow in large databases. Our novel idea is to predict closeness between elements according to how they order their distances towards a distinguished set of anchor objects. Each element in the space sorts the anchor objects from closest to farthest to it, and the similarity between orders turns out to be an excellent predictor of the closeness between the corresponding elements. We present extensive experiments comparing our method against state-of-the-art exact and approximate techniques, both in synthetic and real, metric and non-metric databases, measuring both CPU time and distance computations. The experiments demonstrate that our technique almost always improves upon the performance of alternative techniques, in some cases by a wide margin.     

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.     

Potential Food Applications of Biobased Materials. An EU‐Concerted Action Project

The objective of the study was to ascertain the state of the art with regard to the applicability of biobased packaging materials to foods and to identify potential food applications for biobased materials. The study revealed relatively few examples of biobased materials used as primary, secondary or tertiary packaging materials for foods. This is due to the fact that published investigations on the use of biobased materials are still scarce, and results obtained remain unpublished because of commercial pressures. The scientific literature contains numerous reports on applications of edible films and coatings to food but novel commercial applications of these are scarce. Based on information currently available on the properties of biobased packaging materials the study identified products in the fresh meat, dairy, ready meal, beverage, fruit and vegetable, snack, frozen food and dry food categories where conventional packaging may be replaced by biobased packaging.     

Physical and Mechanical Properties of Biobased Materials Starch,Polylactate and Polyhydroxybutyrate

Commercial and semi‐commercial biobased materials (Polylactate, PLA, polyhydroxy‐butyrate, PHB, wheat starch and corn starch) were investigated. Physical and mechanical characterisation (tensile strength, elongation, tear strength, compression, gas permeability (CO₂ and O₂) and water vapour permeability (WVP)) was examined. Tests on both films and cups show potential use of these materials for primary food packaging, especially PLA and PHB. An interesting O₂:CO₂ permeability ratio (1:7 to 1:12) was seen, which make these materials suitable for packaging of food with high respiration. The mechanical properties were comparable to conventional materials such as polyethylene (PE) and polystyrene (PS). The WVP measured on films ranged from 12.6 to 18.6 [g H₂O/(m² ? 24h)], and on cups the range was 2.2 to 10.5 [g H₂O ? 700 μm/(m² ? 24h)]. The WVP for the starch‐based materials seems to be the most crucial parameter, and needs improvement if these materials are to be used as food packaging.     

Intrinsic Angiogenic Potential and Migration Capacity of Human Mesenchymal Stromal Cells Derived from Menstrual Blood and Bone Marrow

Several therapies are being developed to increase blood circulation in ischemic tissues. Despite bone marrow-derived mesenchymal stromal cells (bmMSC) are still the most studied, an interesting and less invasive MSC source is the menstrual blood, which has shown great angiogenic capabilities. Therefore, the aim of this study was to evaluate the angiogenic properties of menstrual blood-derived mesenchymal stromal cells (mbMSC) in vitro and in vivo and compared to bmMSC. MSC’s intrinsic angiogenic capacity was assessed by sprouting and migration assays. mbMSC presented higher invasion and longer sprouts in 3D culture. Additionally, both MSC-spheroids showed cells expressing CD31. mbMSC and bmMSC were able to migrate after scratch wound in vitro, nonetheless, only mbMSC demonstrated ability to engraft in the chick embryo, migrating to perivascular, perineural, and chondrogenic regions. In order to study the paracrine effects, mbMSC and bmMSC conditioned mediums were capable of stimulating HUVEC’s tube-like formation and migration. Both cells expressed VEGF-A and FGF2. Meanwhile, PDGF-B was expressed exclusively in mbMSC. Our results indicated that mbMSC and bmMSC presented a promising angiogenic potential. However, mbMSC seems to have additional advantages since it can be obtained by non-invasive procedure and expresses PDGF-B, an important molecule for vascular formation and remodeling.     

ERG1, encoding squalene epoxidase,is located on the right arm of chromosome VII of Saccharomyces cerevisiae

The ERG1 gene of Saccharomyces cerevisiae encodes squalene epoxidase, a key enzyme in the ergosterol pathway. ERG1 is an essential gene. Disruption of the gene with URA3 results in a lethal phenotype when cells are grown under aerobic conditions, even in the presence of ergosterol. However, cells are viable in the presence of ergosterol under anaerobic growth conditions during which ergosterol is taken up by cells. Physical and genetic mapping data reveal that ERG1 is located on the right arm of chromosome VII proximal to QCR9 at a distance of 14·6 cM from ADE3.     

Health psychology and scientific consensus: The case of depression and cardiovascular disease.

Science proceeds, directly or indirectly, by consensus. Obtaining scientific consensus proactively when investigating the impact of depression on cardiovascular disease has been daunting, as the professions interested in this area include health psychology, psychiatry, cardiology, epidemiology, and others. Whereas consensus is at times difficult when sought within one specialty, it is almost inconceivable when attempted across disciplines. Therefore, we applaud a new trend, as the National Heart, Lung, and Blood Institute recently called for a working group to provide recommendations on the assessment and treatment of depression in patients with cardiovascular disease. The publication of this working group's report signals two important landmark accomplishments. First, it offers concrete recommendations for researchers interested in contributing to this field. Second, and perhaps more important, the publication of this report signifies a process through which interdisciplinary research areas can be proactive in fostering scientific consensus. Health psychology, an area and a field of research that is naturally interdisciplinary, may be one of the key benefactors of joining and creating stronger consensus processes for this type of science. Whether health psychologists will play a role in creating opportunities to promote consensus in areas of scientific interest remains to be seen. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Top-down-driven grouping overrules the central attentional bias.

A central bias in spatial selection has been proposed to explain the decreasing search efficiency with increasing target eccentricity that results when distractors can occur closer to fixation than the target (J. M. Wolfe, P. O'Neill, & S. C. Bennett, 1998). The authors found evidence for such a bias using an odd-man-out variant of conjunction search. However, the bias was absent for the same displays when the identity of the odd-man-out target was known in advance. The authors propose that (a) top-down knowledge of a target feature supports grouping on this feature and (b) grouping links a peripheral target to central distractors expressing the same feature, increasing the attentional weighting afforded to the target and, consequently, facilitating its detection. The effects are independent of bottom-up priming effects occurring across trials. Thus, feature-based grouping can be driven top-down and can overrule the central bias in spatial selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanical behavior of alumina and alumina-feldspar based ceramics in an acetic acid (4%) environment

This study investigates the mechanical properties of alumina-feldspar based ceramics when exposed to an aggressive environment (acetic acid 4%). Alumina ceramics containing different concentrations of feldspar (0%, 1%, 5%, 10%, or 40%) were sintered at either 1300, 1600, or 1700 °C. Flaws (of width 0%, 30%, or 50%) were introduced into the specimens using a saw. Half of these ceramic bodies were exposed to acetic acid. Their flexural strength, K_IC, and porosity were measured and the fractured samples were evaluated using scanning electronic- and optical microscopy. It was found that in the ceramic bodies sintered at 1600 °C, feldspar content up to 10% improved flexural strength and K_IC, and reduced porosities. Generally, it was found that acetic acid had a weakening effect on the flexural strength of samples sintered at 1700 °C but a beneficial effect on K_IC of ceramics sintered at 1600 °C. It was concluded that alumina-based ceramics with feldspar content up to 10% and sintered at higher temperatures would perform better in an aggressive environment similar to oral cavity.     

Delta for Middle Dutch Author and Copyist Distinction in Walewein

The Middle Dutch Arthurian romance Roman van Walewein (‘Romanceof Gawain’) is attributed in the text itself to two authors,Penninc and Vostaert. Very little quantitative research intothis dual authorship has been done. This article describes ourprogress in applying different non-traditional authorship attributionmethods to the text of Walewein. After providing an introductionto the romance and an overview of earlier research, we evaluateprevious statements on authorship and stylistics by applyingboth Yule's measure of lexical richness and Burrows's Delta.To find out whether these new methods would confirm or evenenhance our present knowledge about the differences betweenthe two authors, we applied an adapted version of John Burrows'sDelta procedure. The adapted version seems to be able to distinguishthe double authorship of the romance. It also helps us to confirmsome and to reject other earlier statements about the positionin the text where the second author started his work.