Showing papers by "Ben-Gurion University of the Negev published in 2004"

Assessing dimensions of perceived visual aesthetics of web sites

Abstract: Despite its centrality to human thought and practice, aesthetics has for the most part played a petty role in human-computer interaction research. Increasingly, however, researchers attempt to strike a balance between the traditional concerns of human-computer interaction and considerations of aesthetics. Thus, recent research suggests that the visual aesthetics of computer interfaces is a strong determinant of users' satisfaction and pleasure. However, the lack of appropriate concepts and measures of aesthetics may severely constraint future research in this area. To address this issue, we conducted four studies in order to develop a measurement instrument of perceived web site aesthetics. Using exploratory and confirmatory factor analyses we found that users' perceptions consist of two main dimensions, which we termed "classical aesthetics" and "expressive aesthetics". The classical aesthetics dimension pertains to aesthetic notions that presided from antiquity until the 18th century. These notions emphasize orderly and clear design and are closely related to many of the design rules advocated by usability experts. The expressive aesthetics dimension is manifested by the designers' creativity and originality and by the ability to break design conventions. While both dimensions of perceived aesthetic are drawn from a pool of aesthetic judgments, they are clearly distinguishable from each other. Each of the aesthetic dimensions is measured by a five-item scale. The reliabilities, factor structure and validity tests indicate that these items reflect the two perceived aesthetics dimensions adequately.

Hazardous duty pay and the foraging cost of predation

Abstract: We review the concepts and research associated with measuring fear and its consequences for foraging. When foraging, animals should and do demand hazardous duty pay. They assess a foraging cost of predation to compensate for the risk of predation or the risk of catastrophic injury. Similarly, in weighing foraging options, animals tradeoff food and safety. The foraging cost of predation can be modelled, and it can be quantitatively and qualitatively measured using risk titrations. Giving-up densities (GUDs) in depletable food patches and the distribution of foragers across safe and risky feeding opportunities are two frequent experimental tools for titrating food and safety. A growing body of literature shows that: (i) the cost of predation can be big and comprise the forager’s largest foraging cost, (ii) seemingly small changes in habitat or microhabitat characteristics can lead to large changes in the cost of predation, and (iii) a forager’s cost of predation rises with risk of mortality, the forager’s energy state and a decrease in its marginal value of energy. In titrating for the cost of predation, researchers have investigated spatial and temporal variation in risk, scale-dependent variation in risk, and the role of predation risk in a forager’s ecology. A risk titration from a feeding animal often provides a more accurate behavioural indicator of predation risk than direct observations of predator-inflicted mortality. Titrating for fear responses in foragers has some well-established applications and holds promise for novel methodologies, concepts and applications. Future directions for expanding conceptual and empirical tools include: what are the consequences of foraging costs arising from interference behaviours and other sources of catastrophic loss? Are there alternative routes by which organisms can respond to tradeoffs of food and safety? What does an animal’s landscape of fear look like as a spatially explicit map, and how do various environmental factors affect it? Behavioural titrations will help to illuminate these issues and more.

CP-nets: a tool for representing and reasoning with conditional ceteris paribus preference statements

Abstract: Information about user preferences plays a key role in automated decision making. In many domains it is desirable to assess such preferences in a qualitative rather than quantitative way. In this paper, we propose a qualitative graphical representation of preferences that reflects conditional dependence and independence of preference statements under a ceteris paribus (all else being equal) interpretation. Such a representation is often compact and arguably quite natural in many circumstances. We provide a formal semantics for this model, and describe how the structure of the network can be exploited in several inference tasks, such as determining whether one outcome dominates (is preferred to) another, ordering a set outcomes according to the preference relation, and constructing the best outcome subject to available evidence.

Resource pulses, species interactions and diversity maintenance in arid and semi-arid environments

Abstract: Arid environments are characterized by limited and variable rainfall that supplies resources in pulses. Resource pulsing is a special form of environmental variation, and the general theory of coexistence in variable environments suggests specific mechanisms by which rainfall variability might contribute to the maintenance of high species diversity in arid ecosystems. In this review, we discuss physiological, morphological, and life-history traits that facilitate plant survival and growth in strongly water-limited variable environments, outlining how species differences in these traits may promote diversity. Our analysis emphasizes that the variability of pulsed environments does not reduce the importance of species interactions in structuring communities, but instead provides axes of ecological differentiation between species that facilitate their coexistence. Pulses of rainfall also influence higher trophic levels and entire food webs. Better understanding of how rainfall affects the diversity, species composition, and dynamics of arid environments can contribute to solving environmental problems stemming from land use and global climate change.

Postural stability in the elderly: a comparison between fallers and non-fallers

Abstract: Background: the identification of specific risk factors for falls in community-dwelling elderly persons is required to identify older people at risk of falling. Objective: the aim of the study was to determine the ability of various biomechanical measures of postural stability to identify fallers in the elderly population. Method: 19 subjects (78.4 ± 1.3 years old) who reported having fallen unexpectedly at least twice in the last 6 months, and 124 non-fallers (77.8 ± 0.53 years old) participated in the study. Balance measurements were made in the upright position in six different conditions using a force platform, and the Limits of Stability Test was carried out. Static two-point discrimination (TPD) testing to the underside of the first toe was made to evaluate the innervation density of the slowly adapting receptors. Finally, maximal isometric lower limb strength was measured in major muscle groups. Repeated measures analysis of variance tests were performed to assess the mean differences between the two groups (fallers and non-fallers). The level of significance was set to 0.05. Results and discussion: results suggest that control of balance in narrow base stance may be an important tool in identifying elderly fallers. The findings show an increase in mediolateral sway in narrow base stance in older people who experienced recurrent falls. Also, TPD appears to be impaired in elderly fallers (14.93 ± 1.1 mm versus 12.98 ± 0.3 mm). Conclusions: simple and safe laboratory quantitative tests were able to differentiate between elderly fallers and elderly individuals who did not fall, suggesting a possible clinical application as a preliminary screening tool for predicting future risk of falling.

Urban optical wireless communication networks: the main challenges and possible solutions

Abstract: Urban optical wireless communication (UOWC) is rapidly gaining popularity as an effective means of transferring data at high rates over short distances The UOWC terminal includes an optical transmitter and a receiver positioned, for example, on high-rise buildings separated by several hundred meters Light beams propagating through the atmosphere carry the information from the transmitter to the receiver UOWC boasts many advantages over its rivals Notably, UOWC facilitates rapidly deployable, lightweight, high-capacity communication without licensing fees and tariffs However, UOWC still faces many challenges, including how to improve communication performance in adverse weather conditions or during building sway We present and evaluate some of the exciting new research approaches that have been suggested to deal with these issues, including optimization of telescope gain, new technologies for pointing systems, and solutions at the network level

The emotional costs of parents' conditional regard: a self-determination theory analysis.

Abstract: Parents' use of conditional regard as a socializing practice was hypothesized to predict their children's introjected internalization (indexed by a sense of internal compulsion), resentment toward parents, and ill-being. In Study 1, involving three generations, mothers' reports of their parents' having used conditional regard to promote academic achievement predicted (a) the mothers' poor well-being and controlling parenting attitudes, and (b) their collge-aged daughters' viewing them as having used conditional regard, thus showing both negative affective consequences from and intergenerational transmission of conditional regard. Study 2 expanded on the first by using four domains, including both genders, and examining mediating processes. College students' perceptions of their mothers' and fathers' having used conditional regard in four domains (emotion control, prosocial, academic, sport) were found

Salinity up‐regulates the antioxidative system in root mitochondria and peroxisomes of the wild salt‐tolerant tomato species Lycopersicon pennellii

Abstract: The effect of salinity on the antioxidative system of root mitochondria and peroxisomes of a cultivated tomato Lycopersicon esculentum (Lem) and its wild salt-tolerant related species L. pennellii (Lpa) was studied. Salt stress induced oxidative stress in Lem mitochondria, as indicated by the increased levels of lipid peroxidation and H(2)O(2). These changes were associated with decreased activities of superoxide dismutase (SOD) and guaiacol peroxidases (POD) and contents of ascorbate (ASC) and glutathione (GSH). By contrast, in mitochondria of salt-treated Lpa plants both H(2)O(2) and lipid peroxidation levels decreased while the levels of ASC and GSH and activities of SOD, several isoforms of ascorbate peroxidase (APX), and POD increased. Similarly to mitochondria, peroxisomes isolated from roots of salt-treated Lpa plants exhibited also decreased levels of lipid peroxidation and H(2)O(2) and increased SOD, ascorbate peroxidase (APX), and catalase (CAT) activities. In spite of the fact that salt stress decreased activities of antioxidant enzymes in Lem peroxisome, oxidative stress was not evident in these organelles.

T cell deficiency leads to cognitive dysfunction: Implications for therapeutic vaccination for schizophrenia and other psychiatric conditions

Abstract: The effects of the adaptive immune system on the cognitive performance and abnormal behaviors seen in mental disorders such as schizophrenia have never been documented. Here, we show that mice deprived of mature T cells manifested cognitive deficits and behavioral abnormalities, which were remediable by T cell restoration. T cell-based vaccination, using glatiramer acetate (copolymer-1, a weak agonist of numerous self-reactive T cells), can overcome the behavioral and cognitive abnormalities that accompany neurotransmitter imbalance induced by (+)dizocilpine maleate (MK-801) or amphetamine. The results, by suggesting that peripheral T cell deficit can lead to cognitive and behavioral impairment, highlight the importance of properly functioning adaptive immunity in the maintenance of mental activity and in coping with conditions leading to cognitive deficits. These findings point to critical factors likely to contribute to age- and AIDS-related dementias and might herald the development of a therapeutic vaccination for fighting off cognitive dysfunction and psychiatric conditions.

Prior Statin Therapy Is Associated With a Decreased Rate of Severe Sepsis

Abstract: Background— Statins have anti-inflammatory properties that are independent of their lipid-lowering abilities. We hypothesized that statin therapy before the onset of an acute bacterial infection may have a protective effect against severe sepsis. The aim of this study was to determine whether patients treated with statins develop severe sepsis less frequently. Methods and Results— In this prospective observational cohort study, consecutive patients admitted with presumed or documented acute bacterial infection were enrolled. The primary outcomes were the rate of severe sepsis and intensive care unit (ICU) admission. Of the 361 patients enrolled, 82 (22.7%) were treated with statins before their admission. Both groups had a similar severity of illness on admission. Severe sepsis developed in 19% of patients in the no-statin group and in only 2.4% of the statin group (P<0.001). Statin treatment was associated with a relative risk of developing severe sepsis of 0.13 (95% CI, 0.03 to 0.52) and an absolute ris...

Nomenclature of amphiboles: additions and revisions to the International Mineralogical Association’s amphibole nomenclature

Abstract: The introduction of a fifth amphibole group, the Na-Ca-Mg-Fe-Mn-Li group, defined by 0.50 < B(Mg,Fe2+,Mn2+,Li) < 1.50 and 0.50 ≤ B(Ca,Na) ≤ 1.50 a.f.p.u. (atoms per formula unit), with members whittakerite and ottoliniite, has been required by recent discoveries of B(LiNa) amphiboles. This, and other new discoveries, such as sodicpedrizite (which, here, is changed slightly, but significantly, from the original idealized formula), necessitate amendments to the IMA 1997 definitions of the Mg-Fe-Mn-Li, calcic, sodic-calcic and sodic groups. The discovery of obertiite and the finding of an incompatibility in the IMA 1997 subdivision of the sodic group, requires further amendments within the sodic group. All these changes, which have IMA approval, are summarized.

Colonization, biofilm formation and biodegradation of polyethylene by a strain of Rhodococcus ruber

Abstract: A two-step enrichment procedure led to the isolation of a strain of Rhodococcus ruber (C208) that utilized polyethylene films as sole carbon source. In liquid culture, C208 formed a biofilm on the polyethylene surface and degraded up to 8% (gravimetrically) of the polyolefin within 30 days of incubation. The bacterial adhesion to hydrocarbon assay and the salt aggregation test both showed that the cell-surface hydrophobicity of C208 was higher than that of three other isolates which were obtained from the same consortium but were less efficient than C208 in the degradation of polyethylene. Mineral oil, but not nonionic surfactants, enhanced the colonization of polyethylene and increased biodegradation by about 50%. Fluorescein diacetate (FDA) hydrolysis and protein content analysis were used to test the viability and biomass density of the C208 biofilm on the polyethylene, respectively. Both FDA activity and protein content of the biofilm in a medium containing mineral oil peaked 48-72 h after inoculation and then decreased sharply. This finding apparently reflected rapid utilization of the mineral oil adhering to the polyethylene. The remaining biofilm population continued to proliferate moderately and presumably played a major role in biodegradation of the polyethylene. Fourier transform infrared spectra of UV-photooxidized polyethylene incubated with C208 indicated that biodegradation was initiated by utilization of the carbonyl residues formed in the photooxidized polyethylene.

In self-defence: hexokinase promotes voltage-dependent anion channel closure and prevents mitochondria-mediated apoptotic cell death.

Abstract: In tumour cells, elevated levels of mitochondria-bound isoforms of hexokinase (HK-I and HK-II) result in the evasion of apoptosis, thereby allowing the cells to continue proliferating. The molecular mechanisms by which bound HK promotes cell survival are not yet fully understood. Our studies relying on the purified mitochondrial outer membrane protein VDAC (voltage-dependent anion channel), isolated mitochondria or cells in culture suggested that the anti-apoptotic activity of HK-I occurs via modulation of the mitochondrial phase of apoptosis. In the present paper, a direct interaction of HK-I with bilayer-reconstituted purified VDAC, inducing channel closure, is demonstrated for the first time. Moreover, HK-I prevented the Ca(2+)-dependent opening of the mitochondrial PTP (permeability transition pore) and release of the pro-apoptotic protein cytochrome c. The effects of HK-I on VDAC activity and PTP opening were prevented by the HK reaction product glucose 6-phosphate, a metabolic intermediate in most biosynthetic pathways. Furthermore, glucose 6-phosphate re-opened both the VDAC and the PTP closed by HK-I. The HK-I-mediated effects on VDAC and PTP were not observed using either yeast HK or HK-I lacking the N-terminal hydrophobic peptide responsible for binding to mitochondria, or in the presence of an antibody specific for the N-terminus of HK-I. Finally, HK-I overexpression in leukaemia-derived U-937 or vascular smooth muscle cells protected against staurosporine-induced apoptosis, with a decrease of up to 70% in cell death. These results offer insight into the mechanisms by which bound HK promotes tumour cell survival, and suggests that its overexpression not only ensures supplies of energy and phosphometabolites, but also reflects an anti-apoptotic defence mechanism.

The precursor form of IL-1alpha is an intracrine proinflammatory activator of transcription.

Abstract: Although most cytokines are studied for biological effects after engagement of their specific cell surface membrane receptors, increasing evidence suggests that some function in the nucleus. In the present study, the precursor form of IL-1α was overexpressed in various cells and assessed for activity in the presence of saturating concentrations of IL-1 receptor antagonist to prevent receptor signaling. Initially diffusely present in the cytoplasm of resting cells, IL-1α translocated to the to nucleus after activation by endotoxin, a Toll-like receptor ligand. The IL-1α precursor, but not the C-terminal mature form, activated the transcriptional machinery in the GAL4 system by 90-fold; a 50-fold increase was observed using only the IL-1α propiece, suggesting that transcriptional activation was localized to the N terminus where the nuclear localization sequence resides. Under conditions of IL-1 receptor blockade, intracellular overexpression of the precursor and propiece forms of IL-1α were sufficient to activate NF-κB and AP-1. Stable transfectants overproducing precursor IL-1α released the cytokines IL-8 and IL-6 but also exhibited a significantly lower threshold of activation to subpicomolar concentrations of tumor necrosis factor α or IFN-γ. Thus, intracellular functions of IL-1α might play an unforeseen role in the genesis of inflammation. During disease-driven events, the cytosolic precursor moves to the nucleus, where it augments transcription of proinflammatory genes. Because this mechanism of action is not affected by extracellular inhibitors, reducing intracellular functions of IL-1α might prove beneficial in some inflammatory conditions.

Association between common Toll-like receptor 4 mutations and severe respiratory syncytial virus disease.

Abstract: Background The clinical spectrum of respiratory syncytial virus (RSV) bronchiolitis in previously healthy infants is extremely variable. Thus, it is likely that factors such as genetic heterogeneity contribute to disease severity. Toll-like receptor 4 (TLR4) and CD14 are part of a receptor complex involved in the innate immune response to RSV. Methods The association of the TLR4 mutations (Asp299Gly and Thr399Ile) and the CD14/-159 polymorphism were analyzed in 99 infants hospitalized with severe RSV bronchiolitis (group I). Eighty-two ambulatory infants with mild RSV bronchiolitis (group II) and 90 healthy adults (group III) composed the 2 control groups. The TLR4 mutations and the CD14/-159 polymorphism were genotyped by use of reverse-transcriptase polymerase chain reaction and restriction fragment-length polymorphism analysis, respectively. Results Each of the TLR4 mutations, either alone or in cosegregation, were associated with severe RSV bronchiolitis: the Asp299Gly and Thr399Ile mutations were significantly overrepresented in group I, compared with groups II and III. No association between the CD14/-159 polymorphism and RSV bronchiolitis was found. Conclusions These findings suggest that TLR4 mutations, but not the CD14/-159 polymorphism, are associated with an increased risk of severe RSV bronchiolitis in previously healthy infants.

Ecosystem Engineers: From Pattern Formation to Habitat Creation

Abstract: Habitat and species richness in drylands are affected by the dynamics of a few key species, termed “ecosystem engineers.” These species modulate the landscape and redistribute the water resources so as to allow the introduction of other species. A mathematical model is developed for a pair of ecosystem engineers commonly found in drylands: plants forming vegetation patterns and cyanobacteria forming soil crusts. The model highlights conditions for habitat creation and for high habitat richness, and suggests a novel mechanism for species loss events as a result of environmental changes.

The Scale of Finiteness and the Calculus of Control

Abstract: Prevalent treatments of Obligatory Control (OC) derive the distribution of PRO from either government or case theory. However, ample crosslinguistic evidence demonstrates that PRO is case-marked just like any other DP. The phenomenon of finite control in the Balkan languages and in Hebrew, where subjunctive complements exhibit OC, demonstrates that the licensing of PRO must be sensitive to the distribution of the features [Tense] and [Agr] both on I0 and C0 OC is conceived as an instance of Agree; a local calculus, interacting with feature checking and deletion, determines that PRO is in general the "elsewhere'' case of referential subjects. However, the two types of subjects may alternate in certain environments, an inexplicable fact for most existing accounts. The system proposed naturally extends to other types of complements, like inflected infinitives and obviative subjunctives. The resulting typology offers a systematic picture of the intricate ways in which finiteness and control interact in different languages.

Modeling mass transfer in hepatocyte spheroids via cell viability, spheroid size, and hepatocellular functions.

Abstract: Hepatocyte aggregation into spheroids attributes to their increased activity, but in the absence of a vascular network the cells in large spheroids experience mass transfer limitations. Thus, there is a need to define the spheroid size which enables maximal cell viability and productivity. We developed a combined theoretical and experimental approach to define this optimal spheroid size. Hepatocyte spheroids were formed in alginate scaffolds having a pore diameter of 100 microm, in rotating T-flasks or spinners, to yield a maximal size of 100, 200, and 600 microm, respectively. Cell viability was found to decrease with increasing spheroid size. A mathematical model was constructed to describe the relationship between spheroid size and cell viability via the oxygen mass balance equation. This enabled the prediction of oxygen distribution profiles and distribution of viable cells in spheroids with varying size. The model describes that no oxygen limitation will take place in spheroids up to 100 microm in diameter. Spheroid size affected the specific rate of albumin secretion as well; it reached a maximal level, i.e., 60 microg/million cells/day in 100-microm diameter spheroids. This behavior was depicted in an equation relating the specific albumin secretion rate to spheroid size. The calculated results fitted with the experimental data, predicting the need for a critical number of viable hepatocytes to gain a maximal albumin secretion. Taken together, the results on mass transport in spheroids and its effects on cell viability and productivity provide a useful tool for the design of 3D scaffolds with pore diameters of 100 microm.

Swelling and morphology of the skin layer of polyamide composite membranes: an atomic force microscopy study.

Abstract: The paper introduces a new methodology for studying polyamide composite membranes for reverse osmosis (RO) and nanofiltration (NF) in liquid environments. The methodology is based on atomic force microscopy of the active layer, which had been separated from the support and placed on a solid substrate. The approach was employed to determine the thickness, interfacial morphology, and dimensional changes in solution (swelling) of polyamide films. The face (active) and back (facing the support) surfaces of the RO films appeared morphologically similar, in agreement with the recently proposed model of skin formation. Measured thickness and swelling data in conjunction with the intrinsic permeability of the membranes suggest that the selective barrier in RO membrane constitutes only a fraction of the polyamide skin, whereas NF membranes behave as nearly uniform films. For NF membranes, there was reasonable correlation between the changes in the swelling and in the permeability of the membrane and the salinity and pH of the feed.

The Relationship between Risk-Taking, Sensation-Seeking, and the Tourist Behavior of Young Adults: A Cross-Cultural Study

Abstract: This study analyzed the effects of the combined psychological characteristics of risk-taking and sensation seeking on the travel behavior and preferred tourist activities of young adults on leisure trips. The results of this cross-cultural study, which was conducted among 1,429 students at 11 universities located in 11 different countries, found that respondents with high combined risk-taking and sensation seeking (RSS) scores differed significantly in their travel behavior, mode of destination choice, preferred tourist activities and demographics, from those who had low RSS scores. The study also discovered a significant difference between nationalities on RSS scores.

Links between Tourists, Heritage, and Reasons for Visiting Heritage Sites

Abstract: This article clarifies heritage tourism by identifying and segmenting reasons for visiting heritage sites. In doing so, it shows that the links between a site’s attributes and the tourists themselves are essential to understanding tourists’ motivations to visit heritage places. The sample was composed of English-speaking international tourists leaving Israel through Ben-Gurion airport. The research was implemented by the use of structured questionnaires using face-to-face interviews. Responses were grouped using an interpretability approach to exploratory factor analysis. Reasons for visiting heritage sites were classified into three groups: “heritage experience,” “learning experience,” and “recreational experience.” Reasons for visiting heritage sites were linked to the tourists’ perception of the site in relation to their own heritage and their willingness to be exposed to an emotional experience. The results lead to a better understanding of reasons for visiting heritage places and provide further insi...

Nasopharyngeal carriage of Streptococcus pneumoniae by adults and children in community and family settings.

Abstract: The rate of Streptococcus pneumoniae carriage among adults was compared with that among children (age =6 years) in the same population. Nasopharyngeal culture results for 1300 adults and 404 children were analyzed. S. pneumoniae was carried by only 4% of the adults compared with 53% of children in the same community. Young age day care center attendance having young siblings and no antibiotic use during the month before screening were associated with the high carriage rate among children whereas the only risk factor associated with carriage among adults was the presence of a respiratory infection on the screening day. S. pneumoniae serotype distribution and antibiotic resistance patterns differed between adults and children. Isolates of the same serotype—even of the same clone—differed in their antibiotic susceptibility patterns between children and adults. In a subanalysis of 151 pairs of children and their parents and of 32 pairs of siblings intrafamilial transmission of S. pneumoniae could not be demonstrated. (authors)

The associative memory deficit of older adults: further support using face-name associations.

Abstract: Previous studies have established an associative deficit hypothesis (Naveh-Benjamin, 2000), which attributes part of older adults' deficient episodic memory performance to their difficulty in creating cohesive episodes. In this article, the authors further evaluate this hypothesis, using ecologically relevant materials. Young and old participants studied name-face pairs and were then tested on their recognition memory for the names, faces, and the name-face pairs. The results extend the conditions under which older adults exhibit an associative deficit. They also show that reduced attentional resources are not the sole mediator of this deficit.

Carotenoids activate the antioxidant response element (ARE) transcription system

Abstract: 4035 Epidemiological studies have found an inverse association between the consumption of tomato products and the risk of certain types of cancers. Induction of phase II detoxification enzymes seems to be an important mechanism by which phytonutrients prevent cancer. Expression of phase II enzymes, such as NAD(P)H:quinone oxidoreductase (NQO1) and γ-glutamylcysteine synthetase (GCS), is regulated by the antioxidant response element (ARE), which is found in the promoters of genes encoding these proteins. The nuclear transcription factor Nrf2 binds to the ARE and positively regulates the expression of phase II enzymes. We tested whether carotenoids exert their cancer-preventive effect by stimulation of ARE and induction of NQO1 and GCS. In transiently transfected MCF-7 mammary cancer cells and HepG2 hepatoma cells, lycopene transactivated the expression of a reporter gene (luciferase) fused with ARE sequences. The transactivation was dose-dependent and unexpectedly specific for lycopene, since astaxanthin, β-carotene and phytoene had no effect. This specificity suggests that activation of ARE-mediated transcription by carotenoids is not related solely to their antioxidant properties. Measurement of carotenoid-induced changes in the intracellular levels of reactive oxygen species using a fluorescent probe (dichlorofluorescein diacetate) further supported this conclusion. In accordance with the transactivation data, lycopene treatment caused an increase in NQO1 and GCS protein levels in both MCF-7 and HepG2 cells. A lower potency was found for β-carotene, whereas astaxanthin and phytoene had no effect whatsoever. The induction of GCS protein was accompanied by an increase in the cellular levels of glutathione, a potent substrate for carcinogen detoxification. Nrf2 was found predominantly in the cytoplasm in non-treated (control) cells, but appeared predominantly in the nucleus after treatment with both tert-butylhydroquinone (the known ARE activator) and lycopene. Other carotenoids also induced Nrf2 translocation but with a lower potency. Our results suggest that activation of the ARE-driven induction of phase II enzymes by lycopene represents a novel molecular mechanism for the cancer-preventive action of a diet rich in tomato products.

Repetitive transcranial magnetic stimulation of the right dorsolateral prefrontal cortex in posttraumatic stress disorder: a double-blind, placebo-controlled study.

Abstract: OBJECTIVE: The efficacy of repetitive transcranial magnetic stimulation (rTMS) of the right prefrontal cortex was studied in patients with posttraumatic stress disorder (PTSD) under double-blind, placebo-controlled conditions. METHOD: Twenty-four patients with PTSD were randomly assigned to receive rTMS at low frequency (1 Hz) or high frequency (10 Hz) or sham rTMS in a double-blind design. Treatment was administered in 10 daily sessions over 2 weeks. Severity of PTSD, depression, and anxiety were blindly assessed before, during, and after completion of the treatment protocol. RESULTS: The 10 daily treatments of 10-Hz rTMS at 80% motor threshold over the right dorsolateral prefrontal cortex had therapeutic effects on PTSD patients. PTSD core symptoms (reexperiencing, avoidance) markedly improved with this treatment. Moreover, high-frequency rTMS over the right dorsolateral prefrontal cortex alleviated anxiety symptoms in PTSD patients. CONCLUSIONS: This double-blind, controlled trial suggests that in PTSD...