Showing papers by "Ben-Gurion University of the Negev published in 2006"
04 Mar 2006
TL;DR: In this article, the authors show that for several particular applications substantially less noise is needed than was previously understood to be the case, and also show the separation results showing the increased value of interactive sanitization mechanisms over non-interactive.
Abstract: We continue a line of research initiated in [10,11]on privacy-preserving statistical databases. Consider a trusted server that holds a database of sensitive information. Given a query function f mapping databases to reals, the so-called true answer is the result of applying f to the database. To protect privacy, the true answer is perturbed by the addition of random noise generated according to a carefully chosen distribution, and this response, the true answer plus noise, is returned to the user.
Previous work focused on the case of noisy sums, in which f = ∑ig(xi), where xi denotes the ith row of the database and g maps database rows to [0,1]. We extend the study to general functions f, proving that privacy can be preserved by calibrating the standard deviation of the noise according to the sensitivity of the function f. Roughly speaking, this is the amount that any single argument to f can change its output. The new analysis shows that for several particular applications substantially less noise is needed than was previously understood to be the case.
The first step is a very clean characterization of privacy in terms of indistinguishability of transcripts. Additionally, we obtain separation results showing the increased value of interactive sanitization mechanisms over non-interactive.
6,211 citations
TL;DR: The present introduction to the special issue on 'Empirical studies of the user experience' attempts to give a provisional answer to the question of what is meant by 'the user experience', and provides a cursory sketch of UX and how the authors think UX research will look like in the future.
Abstract: Over the last decade, ‘user experience’ (UX) became a buzzword in the field of human – computer interaction (HCI) and interaction design. As technology matured, interactive products became not only more useful and usable, but also fashionable, fascinating things to desire. Driven by the impression that a narrow focus on interactive products as tools does not capture the variety and emerging aspects of technology use, practitioners and researchers alike, seem to readily embrace the notion of UX as a viable alternative to traditional HCI. And, indeed, the term promises change and a fresh look, without being too specific about its definite meaning. The present introduction to the special issue on ‘Empirical studies of the user experience’ attempts to give a provisional answer to the question of what is meant by ‘the user experience’. It provides a cursory sketch of UX and how we think UX research will look like in the future. It is not so much meant as a forecast of the future, but as a proposal – a stimulus for further UX research.
2,415 citations
TL;DR: A cross-cultural validation of an Internet consumer trust model is reported on, which examined both antecedents and consequences of consumer trust in a Web merchant and provides tentative support for the generalizability of the model.
Abstract: Many have speculated that trust plays a critical role in stimulating consumer purchases over the Internet. Most of the speculations have rallied around U.S. consumers purchasing from U.S.–based online merchants. The global nature of the Internet raises questions about the robustness of trust effects across cultures. Culture may also affect the antecedents of consumer trust; that is, consumers in different cultures might have differing expectations of what makes a web merchant trustworthy. Here we report on a cross-cultural validation of an Internet consumer trust model. The model examined both antecedents and consequences of consumer trust in a Web merchant. The results provide tentative support for the generalizability of the model.
1,684 citations
TL;DR: It is shown that dNK cells, but not peripheral blood–derived NK subsets, regulate trophoblast invasion both in vitro and in vivo by production of the interleukin-8 and interferon-inducible protein–10 chemokines.
Abstract: Human CD56(bright) NK cells accumulate in the maternal decidua during pregnancy and are found in direct contact with fetal trophoblasts. Several mechanisms have been proposed to explain the inability of NK cells to kill the semiallogeneic fetal cells. However, the actual functions of decidual NK (dNK) cells during pregnancy are mostly unknown. Here we show that dNK cells, but not peripheral blood-derived NK subsets, regulate trophoblast invasion both in vitro and in vivo by production of the interleukin-8 and interferon-inducible protein-10 chemokines. Furthermore, dNK cells are potent secretors of an array of angiogenic factors and induce vascular growth in the decidua. Notably, such functions are regulated by specific interactions between dNK-activating and dNK-inhibitory receptors and their ligands, uniquely expressed at the fetal-maternal interface. The overall results support a 'peaceful' model for reproductive immunology, in which elements of innate immunity have been incorporated in a constructive manner to support reproductive tissue development.
1,489 citations
TL;DR: The evidence indicating that the pathological processes implicated in the preterm parturition syndrome include: intrauterine infection/inflammation; uterine ischaemia; (3) uterine overdistension; (4) abnormal allograft reaction; (5) allergy; (6) cervical insufficiency; and (7) hormonal disorders (progesterone related and corticotrophin‐releasing factor related).
1,193 citations
TL;DR: This work identifies T lymphocytes and microglia as being important to the maintenance of hippocampal neurogenesis and spatial learning abilities in adulthood and suggests that a common immune-associated mechanism underlies different aspects of hippocampusal plasticity and cell renewal in the adult brain.
Abstract: Neurogenesis is known to take place in the adult brain. This work identifies T lymphocytes and microglia as being important to the maintenance of hippocampal neurogenesis and spatial learning abilities in adulthood. Hippocampal neurogenesis induced by an enriched environment was associated with the recruitment of T cells and the activation of microglia. In immune-deficient mice, hippocampal neurogenesis was markedly impaired and could not be enhanced by environmental enrichment, but was restored and boosted by T cells recognizing a specific CNS antigen. CNS-specific T cells were also found to be required for spatial learning and memory and for the expression of brain-derived neurotrophic factor in the dentate gyrus, implying that a common immune-associated mechanism underlies different aspects of hippocampal plasticity and cell renewal in the adult brain.
1,074 citations
TL;DR: This paper shows that the configuration with spatially orthogonal signal transmission is equivalent to additional virtual sensors which extend the array aperture with virtual spatial tapering and provides higher performance in target detection, angular estimation accuracy, and angular resolution.
Abstract: In this paper, we propose a new space-time coding configuration for target detection and localization by radar or sonar systems. In common active array systems, the transmitted signal is usually coherent between the different elements of the array. This configuration does not allow array processing in the transmit mode. However, space-time coding of the transmitted signals allows to digitally steer the beam pattern in the transmit in addition to the received signal. The ability to steer the transmitted beam pattern, helps to avoid beam shape loss. We show that the configuration with spatially orthogonal signal transmission is equivalent to additional virtual sensors which extend the array aperture with virtual spatial tapering. These virtual sensors can be used to form narrower beams with lower sidelobes and, therefore, provide higher performance in target detection, angular estimation accuracy, and angular resolution. The generalized likelihood ratio test for target detection and the maximum likelihood and Cramer-Rao bound for target direction estimation are derived for an arbitrary signal coherence matrix. It is shown that the optimal performance is achieved for orthogonal transmitted signals. Target detection and localization performances are evaluated and studied theoretically and via simulations
990 citations
TL;DR: NADPH oxidases catalyze the production of superoxides, a type of reactive oxygen species (ROS), and their role in promoting pathogen killing has long motivated research in this area.
Abstract: NADPH oxidases (NOX) catalyze the production of superoxides, a type of reactive oxygen species (ROS). The dramatic induction of ROS production by human NOX2 in activated blood phagocytic cells and its role in promoting pathogen killing has long motivated research in this area ([Babior et al., 2002][
725 citations
TL;DR: In this paper, the authors explore the nature of the marketing of higher education and universities in an international context and make recommendations for further research in this field, and find that potential benefits of applying marketing theories and concepts that have been effective in the business world are gradually being recognized by researchers in the higher education field.
Abstract: Purpose – The purpose of this systematic review was to explore the nature of the marketing of higher education (HE) and universities in an international context. The objectives of the review were to: systematically collect, document, scrutinise and critically analyse the current research literature on supply‐side higher education marketing; establish the scope of higher education marketing; identify gaps in the research literature; and make recommendations for further research in this field.Design/methodology/approach – The approach for this study entailed extensive searches of relevant business management and education databases. The intention was to ensure that, as far as possible, all literature in the field was identified – while keeping the focus on literature of greatest pertinence to the research questions.Findings – The paper finds that potential benefits of applying marketing theories and concepts that have been effective in the business world are gradually being recognised by researchers in the ...
722 citations
TL;DR: The study of borders has undergone a renaissance during the past decade, reflected in an impressive list of conferences, workshops and scholarly publications as mentioned in this paper. But this meeting of disciplines has not yet succeeded in creating a common language or glossary of terms which is relevant to all scholars of borders.
Abstract: The study of borders has undergone a renaissance during the past decade. This is reflected in an impressive list of conferences, workshops and scholarly publications. This renaissance has been partly due to the emergence of a counternarrative to the borderless and deterritorialized world discourse which has accompanied much of globalization theory. The study of borders has moved beyond the limited confines of the political geography discourse, crossing its own disciplinary boundaries, to include sociologists, political scientists, historians, international lawyers and scholars of international relations. But this meeting of disciplines has not yet been successful in creating a common language or glossary of terms which is relevant to all scholars of borders. Central to the contemporary study of borders are notions such as 'borders are institutions', the process of 'bordering' as a dynamic in its own right, and the border terminologies which focus on the binary distinctions between the 'us' and 'them', the 'included' and the 'excluded'. Borders should be studied not only from a top-down perspective, but also from the bottom up, with a focus on the individual border narratives and experiences, reflecting the ways in which borders impact upon the daily life practices of people living in and around the borderland and transboundary transition zones. In positing an agenda for the next generation of border-related research, borders should be seen for their potential to constitute bridges and points of contact, as much as they have traditionally constituted barriers to movement and communication.
715 citations
08 Jan 2006
TL;DR: It is shown that for many expressive specifications of hardware designs the problem of synthesizing digital designs from their ltl specification can be solved in time N3, where N is the size of the state space of the design.
Abstract: We consider the problem of synthesizing digital designs from their ltl specification. In spite of the theoretical double exponential lower bound for the general case, we show that for many expressive specifications of hardware designs the problem can be solved in time N3, where N is the size of the state space of the design. We describe the context of the problem, as part of the Prosyd European Project which aims to provide a property-based development flow for hardware designs. Within this project, synthesis plays an important role, first in order to check whether a given specification is realizable, and then for synthesizing part of the developed system.
TL;DR: A critical function for Ncr1 is demonstrated in the in vivo eradication of influenza virus, and accumulation of natural killer cells at the site of influenza infection is noted by tracking the green fluorescent protein.
Abstract: The elimination of viruses and tumors by natural killer cells is mediated by specific natural killer cell receptors. To study the in vivo function of a principal activating natural killer cell receptor, NCR1 (NKp46 in humans), we replaced the gene encoding this receptor (Ncr1) with a green fluorescent protein reporter cassette. There was enhanced spread of certain tumors in 129/Sv but not C57BL/6 Ncr1(gfp/gfp) mice, and influenza virus infection was lethal in both 129/Sv and C57BL/6 Ncr1(gfp/gfp) mice. We noted accumulation of natural killer cells at the site of influenza infection by tracking the green fluorescent protein. Our results demonstrate a critical function for Ncr1 in the in vivo eradication of influenza virus.
TL;DR: It is proposed that membrane-associated IL-1α expressed on malignant cells stimulates anti-tumor immunity and activates inflammation that promotes invasiveness and also induces tumor-mediated suppression, pointing to its feasibility in cancer therapy.
Abstract: Interleukin-1 (IL-1) includes a family of closely related genes; the two major agonistic proteins, IL-1α and IL-1β, are pleiotropic and affect mainly inflammation, immunity and hemopoiesis. The IL-1Ra antagonist is a physiological inhibitor of pre-formed IL-1. Recombinant IL-1α and IL-1β bind to the same receptors and induce the same biological functions. As such, the IL-1 molecules have been considered identical in normal homeostasis and in disease. However, the IL-1 molecules differ in their compartmentalization within the producing cell or the microenvironment. Thus, IL-1β is solely active in its secreted form, whereas IL-1α is mainly active in cell-associated forms (intracellular precursor and membrane-bound IL-1α) and only rarely as a secreted cytokine, as it is secreted only in a limited manner. IL-1 is abundant at tumor sites, where it may affect the process of carcinogenesis, tumor growth and invasiveness and also the patterns of tumor–host interactions. Here, we review the effects of microenvironment- and tumor cell-derived IL-1 on malignant processes in experimental tumor models and in cancer patients. We propose that membrane-associated IL-1α expressed on malignant cells stimulates anti-tumor immunity, while secretable IL-1β, derived from the microenvironment or the malignant cells, activates inflammation that promotes invasiveness and also induces tumor-mediated suppression. Inhibition of the function of IL-1 by the IL-1Ra, reduces tumor invasiveness and alleviates tumor-mediated suppression, pointing to its feasibility in cancer therapy. Differential manipulation of IL-1α and IL-1β in malignant cells or in the tumor’s microenvironment can open new avenues for using IL-1 in cancer therapy.
TL;DR: In this article, three main strategies for dispersing carbon nanotubes (NTs) into a polymer matrix to get conductive nanocomposites are described, and illustrated with some appealing examples.
Abstract: The three main strategies for dispersing carbon nanotubes (NTs) into a polymer matrix to get conductive nanocomposites are described, and illustrated with some appealing examples. The direct mixing of the NTs and the polymer is the ‘simplest' concept to achieve this goal. Other approaches concern the modification of either the polymer matrix or the NT walls in order to improve the wetting of the filler with the matrix material, and thus promote the incorporation of the NTs into the polymer matrix. Most promising results seem to be obtained upon the addition of a third component. The basic concept is the generation of a stable colloidal system containing both a suspension of NTs stabilized by surfactant molecules in water, and polymer latex. After removal of the water, the resulting powder can be processed into the desired shape. This versatile and environmentally benign concept offers low percolation thresholds and relatively high conductivity levels.
TL;DR: The value of high-density SNP genotyping for homozygosity mapping and the use of expression correlation data for evaluation of candidate genes are shown and the proteasome degradation pathway is identified as a pathway involved in BBS.
Abstract: The identification of mutations in genes that cause human diseases has largely been accomplished through the use of positional cloning, which relies on linkage mapping. In studies of rare diseases, the resolution of linkage mapping is limited by the number of available meioses and informative marker density. One recent advance is the development of high-density SNP microarrays for genotyping. The SNP arrays overcome low marker informativity by using a large number of markers to achieve greater coverage at finer resolution. We used SNP microarray genotyping for homozygosity mapping in a small consanguineous Israeli Bedouin family with autosomal recessive Bardet–Biedl syndrome (BBS; obesity, pigmentary retinopathy, polydactyly, hypogonadism, renal and cardiac abnormalities, and cognitive impairment) in which previous linkage studies using short tandem repeat polymorphisms failed to identify a disease locus. SNP genotyping revealed a homozygous candidate region. Mutation analysis in the region of homozygosity identified a conserved homozygous missense mutation in the TRIM32 gene, a gene coding for an E3 ubiquitin ligase. Functional analysis of this gene in zebrafish and expression correlation analyses among other BBS genes in an expression quantitative trait loci data set demonstrate that TRIM32 is a BBS gene. This study shows the value of high-density SNP genotyping for homozygosity mapping and the use of expression correlation data for evaluation of candidate genes and identifies the proteasome degradation pathway as a pathway involved in BBS.
TL;DR: DGDG accumulated under P-deprivation in M. subterraneus, did not resemble PC and the positional distribution of its fatty acids was not altered, preserving the C20/C16 structure of its molecular species and it is suggested that under phosphate starvation DGTS is a likely source of C20 acyl groups that can be exported to the sn-1 position of DGDG and can partially compensate for the decrease in PE.
13 Mar 2006
TL;DR: This paper provides an overview of the approaches and techniques developed during the last decade to overcome limitations in 3-D imaging techniques and expects that II-based 3- D imaging systems will reach practical applicability in various fields.
Abstract: Three dimensional (3-D) imaging and display have been subjects of much research due to their diverse benefits and applications. However, due to the necessity to capture, record, process, and display an enormous amount of optical data for producing high-quality 3-D images, the developed 3-D imaging techniques were forced to compromise their performances (e.g., gave up the continuous parallax, restricting to a fixed viewing point) or to use special devices and technology (such as coherent illuminations, special spectacles) which is inconvenient for most practical implementation. Today's rapid progress of digital capture and display technology opened the possibility to proceed toward noncompromising, easy-to-use 3-D imaging techniques. This technology progress prompted the revival of the integral imaging (II)technique based on a technique proposed almost one century ago. II is a type of multiview 3-D imaging system that uses an array of diffractive or refractive elements to capture the 3-D optical data. It has attracted great attention recently, since it produces autostereoscopic images without special illumination requirements. However, with a conventional II system it is not possible to produce 3-D images that have both high resolution, large depth-of-field, and large viewing angle. This paper provides an overview of the approaches and techniques developed during the last decade to overcome these limitations. By combining these techniques with upcoming technology it is to be expected that II-based 3-D imaging systems will reach practical applicability in various fields.
TL;DR: The suggested methods for evaluation and treatment of RIF are discussed: repeated hysteroscopy, myomectomy, endometrial stimulation, immunotherapy, preimplantation genetic screening (PGS), assisted hatching, zygote intra-Fallopian transfer (ZIFT), co-culture, blastocyst transfer, cytoplasmic transfer, tailoring stimulation protocols and salpingectomy for hydrosalpinges.
Abstract: Pregnancy rate following one cycle of IVF and ET can be as high as 60%. But even in the very successful units, some couples fail repeatedly. The causes for repeated implantation failure (RIF) may be because of reduced endometrial receptivity, embryonic defects or multifactorial causes. Various uterine pathologies, such as thin endometrium, altered expression of adhesive molecules and immunological factors, may decrease endometrial receptivity, whereas genetic abnormalities of the male or female, sperm defects, embryonic aneuploidy or zona hardening are among the embryonic reasons for failure of implantation. Endometriosis and hydrosalpinges may adversely influence both. In this mini review, we discuss the suggested methods for evaluation and treatment of RIF: repeated hysteroscopy, myomectomy, endometrial stimulation, immunotherapy, preimplantation genetic screening (PGS), assisted hatching, zygote intra-Fallopian transfer (ZIFT), co-culture, blastocyst transfer, cytoplasmic transfer, tailoring stimulation protocols and salpingectomy for hydrosalpinges.
TL;DR: The resurgence of border studies has been characterized by a crossing of disciplinary borders, bringing together geographers, political scientists, sociologists, anthropologists, historians, literary scholars, legal experts, along with border practitioners engaged in the practical aspects of boundary demarcation, delimitation and management as mentioned in this paper.
Abstract: The renaissance of border studies during the past decade has been characterized by a crossing of disciplinary borders, bringing together geographers, political scientists, sociologists, anthropologists, historians, literary scholars, legal experts, along with border practitioners engaged in the practical aspects of boundary demarcation, delimitation and management. This growth in border studies runs contrary to much of the globalization discourse which was prevalent during the late 1980s and early 1990s, positing a new ‘borderless’ world, in which the barrier impact of borders became insignificant. The article points to the common use of terminology which can create a shared border discourse among a diverse group of scholars, such as boundary demarcation, the nature of frontiers, borderlands and transition zones, and the ways in which borders are crossed. The article also discusses the reclosing of borders which is taking place as a result of 9/11 as part of the stated war against global terror.
TL;DR: Parameter variability and robustness of the different CWSI estimates are discussed, and future research should aim at developing thermal imaging into an irrigation scheduling tool applicable to different crops.
Abstract: Achieving high quality wine grapes depends on the ability to maintain mild to moderate levels of water stress in the crop during the growing season. This study investigates the use of thermal imaging for monitoring water stress. Experiments were conducted on a wine-grape (Vitis vinifera cv. Merlot) vineyard in northern Israel. Irrigation treatments included mild, moderate, and severe stress. Thermal and visible (RGB) images of the crop were taken on four days at midday with a FLIR thermal imaging system and a digital camera, respectively, both mounted on a truck-crane 15 m above the canopy. Aluminium crosses were used to match visible and thermal images in post-processing and an artificial wet surface was used to estimate the reference wet temperature (T(wet)). Monitored crop parameters included stem water potential (Psi(stem)), leaf conductance (g(L)), and leaf area index (LAI). Meteorological parameters were measured at 2 m height. CWSI was highly correlated with g(L) and moderately correlated with Psi(stem). The CWSI-g(L) relationship was very stable throughout the season, but for that of CWSI-Psi(stem) both intercept and slope varied considerably. The latter presumably reflects the non-direct nature of the physiological relationship between CWSI and Psi(stem). The highest R(2) for the CWSI to g(L) relationship, 0.91 (n=12), was obtained when CWSI was computed using temperatures from the centre of the canopy, T(wet) from the artificial wet surface, and reference dry temperature from air temperature plus 5 degrees C. Using T(wet) calculated from the inverted Penman-Monteith equation and estimated from an artificially wetted part of the canopy also yielded crop water-stress estimates highly correlated with g(L) (R(2)=0.89 and 0.82, respectively), while a crop water-stress index using 'theoretical' reference temperatures computed from climate data showed significant deviations in the late season. Parameter variability and robustness of the different CWSI estimates are discussed. Future research should aim at developing thermal imaging into an irrigation scheduling tool applicable to different crops.
TL;DR: There is evidence for sex- and gender-related differences in FGID, particularly irritable bowel syndrome (IBS), and there appears to be a greater clinical response to serotonergic agents developed for IBS in women compared to men.
TL;DR: In the absence of fog, dew formation and direct water vapor adsorption are two mechanisms by which water can be added to the soil in arid zones as mentioned in this paper, however, since plants cover only a small fraction of the desert surface, such assessments apply only to a small proportion of the area.
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TL;DR: This paper argued that tourists too can become the "mad" behind bars, closely watched by the locals, and that tourists' behaviour is reflected in the tourists' behavior, but it also influences the local gaze, a situation which in turn affects the behaviour of both the host and guest populations.
01 Nov 2006-International Journal of Human-computer Studies \/ International Journal of Man-machine Studies
TL;DR: The results provide direct evidence in support of the premise that aesthetic impressions of web pages are formed quickly and suggest that visual aesthetics plays an important role in users' evaluations of the IT artifact and in their attitudes toward interactive systems.
Abstract: Two experiments were designed to replicate and extend [Lindgaard et al.'s, 2006. Attention web designers: you have 50 ms to make a good first impression! Behaviour and Information Technology 25(2), 115-126] findings that users can form immediate aesthetic impression of web pages, and that these impressions are highly stable. Using explicit (subjective evaluations) and implicit (response latency) measures, the experiments demonstrated that, averaged over users, immediate aesthetic impressions of web pages are remarkably consistent. In Experiment 1, 40 participants evaluated 50 web pages in two phases. The average attractiveness ratings of web pages after a very short exposure of 500 ms were highly correlated with average attractiveness ratings after an exposure of 10 s. Extreme attractiveness evaluations (both positive and negative) were faster than moderate evaluations, landing convergent evidence to the hypothesis of immediate impression. The findings also suggest considerable individual differences in evaluations and in the consistency of those evaluations. In Experiment 2, 24 of the 50 web pages from Experiment 1 were evaluated again for their attractiveness after 500ms exposure. Subsequently, users evaluated the design of the web pages on the dimensions of classical and expressive aesthetics. The results showed high correlation between attractiveness ratings from Experiments 1 and 2. In addition, it appears that low attractiveness is associated mainly with very low ratings of expressive aesthetics. Overall, the results provide direct evidence in support of the premise that aesthetic impressions of web pages are formed quickly. Indirectly, these results also suggest that visual aesthetics plays an important role in users' evaluations of the IT artifact and in their attitudes toward interactive systems.
TL;DR: Omega-3 fatty acids may have therapeutic benefits in childhood depression and analysis of variance showed highly significant effects of omega-3 on symptoms using the CDRS, CDI, and CGI.
Abstract: Major depressive disorder is a common and recurrent disorder in children. It is frequently accompanied by poor psychosocial outcome, comorbid conditions, and high risk of suicide and substance abuse, indicating the need for treatment. The prevalence of major depressive disorder is estimated to be approximately 2%–4% in children (1). Several randomized, controlled studies have shown a 50% to 60% response to both selective serotonin reuptake inhibitors and placebo (2, 3). However, these studies included a majority of adolescent children, and the efficacy of biological treatment of prepubertal childhood depression is almost unknown. We found omega-3 fatty acids to be effective in adult depression as an add-on therapy (4). We therefore performed a controlled study of omega-3 fatty acid in childhood depression, restricting our study to children between the ages of 6 and 12.
TL;DR: Physical and physiological phenomena such as browning of foods, discoloration of plants during processing, alteration of solubility and digestibility, formation of humic substances, germicidal activity, cytotoxicity and more occur when quinones from disintegrating cells meet amino acids.
Abstract: Quinones and amino acids are usually compartmentally separated in living systems, however there are several junctions in which they meet, react and influence. It occurs mainly in wounded, cut or crushed plant material during harvest, ensiling or disintegrating cells. Diffusing polyphenols are oxidized by polyphenol oxidases (PPOs) to quinonic compounds, which associate reversibly or irreversibly with amino acids and proteins. The reaction takes place with the free nucleophilic functional groups such as sulfhydryl, amine, amide, indole and imidazole substituents. It results in imine formation, in 1,4-Michael addition via nitrogen or sulphur and in Strecker degradation forming aldehydes. The formation and activity of quinone–amino acids conjugates influences the colour, taste, and aroma of foods. Physical and physiological phenomena such as browning of foods, discoloration of plants during processing, alteration of solubility and digestibility, formation of humic substances, germicidal activity, cytotoxicity and more occur when quinones from disintegrating cells meet amino acids. The mechanisms of toxicity and the pathways by which PCBs may be activated and act as a cancer initiator include oxidation to the corresponding quinones and reaction with amino acids or peptides. Sclerotization of insect cuticle is a biochemical process involving also the reaction between quinones and amino acid derivatives.
TL;DR: The aims of this paper are to define Gaussian mixture models (GMMs) of colored texture on several feature spaces and to compare the performance of these models in various classification tasks, both with each other and with other models popular in the literature.
TL;DR: The empirically investigated the effect of user-based design and Web site usability on user satisfaction across four types of commercial Web sites, finding that trading sites are the lowest rated and online shopping and customer self-service sites should serve as models for Web site developers.
TL;DR: Insight is provided into the central role of VDAC in cell life and death and its function in the regulation of mitochondria-mediated apoptosis and, thereby, its potential as a rational target for new therapeutics.
Abstract: Research over the last decade has extended the prevailing view of mitochondria to include functions well beyond the critical bioenergetics role in supplying ATP. It is now recognized that mitochondria play a crucial role in cell signaling events, inter-organelle communication, aging, many diseases, cell proliferation and cell death. Apoptotic signal transmission to the mitochondria results in the efflux of a number of potential apoptotic regulators to the cytosol that trigger caspase activation and lead to cell destruction. Accumulating evidence indicates that the voltagedependent anion channel (VDAC) is involved in this release of proteins via the outer mitochondrial membrane. VDAC in the outer mitochondrial membrane is in a crucial position in the cell, forming the main interface between the mitochondrial and the cellular metabolisms. VDAC has been recognized as a key protein in mitochondria-mediated apoptosis since it is the proposed target for the pro- and anti-apoptotic Bcl2-family of proteins and due to its function in the release of apoptotic proteins located in the inter-membranal space. The diameter of the VDAC pore is only about 2.6-3 nm, which is insufficient for passage of a folded protein like cytochrome c. New work suggests pore formation by homooligomers of VDAC or hetero-oligomers composed of VDAC and pro-apoptotic proteins such as Bax or Bak. This review provides insights into the central role of VDAC in cell life and death and emphasizes its function in the regulation of mitochondria- mediated apoptosis and, thereby, its potential as a rational target for new therapeutics.