bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Both Enantiomers of Diastereomeric 4‐Fluoro‐4,5‐Dihydroceramides
Authors: Oldendorf Jens , Haufe Günter 
Published: August 2006

AbstractTwo diastereomeric enantiopure 4‐fluoro‐4,5‐dihydroceramides with the natural D‐erythro configuration at the 2‐ and 3‐carbon atoms have been synthesized in an enantioselective eleven‐step sequence. The key step of the synthesis was a diastereoselective asymmetric Sharpless dihydroxylation of ethyl trans‐4‐fluorooctadec‐2‐enoate (8) with AD‐mix‐β to afford the D‐erythro arrangement. The diastereomers of the other enantiomeric series were synthesized analogously with the use of AD‐mix‐α. In all cases, the nitrogen heteroatom was introduced into the 2‐position by regio‐ and stereoselective ring opening of cyclic sulfates 13 and 14 with azide. Staudinger reduction, acylation of the intermediary formed amino group, chromatographic separation of the diastereomers and chemoselective reduction of the ester functionality with sodium borohydride in the presence of methanol afforded both title compounds in an enantiopure form. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Perceived group and personal discrimination: differential effects on personal self‐esteem
Authors: Bourguignon David , Seron Eleonore , Yzerbyt Vincent , Herman Ginette 
Published: August 2006

AbstractIn two studies, we investigate the differential influence of perceived group and personal discrimination on self‐esteem in the context of the Rejection–Identification model (Branscombe, Schmitt, & Harvey, 1999). We first polled a group of African immigrants and found that whereas personal discrimination was negatively related to personal self‐esteem, group discrimination was positively associated with it. As expected, identification served as a buffer between personal discrimination and self‐esteem. We replicated these effects in a second study using women as our respondents. These results suggest that perceiving group discrimination may be positively related to self‐esteem because people feel less alone in their plight, thereby alleviating the ill‐effects of exclusion. We discuss these results in relation to both the Rejection–Identification model and the discounting hypothesis (Crocker & Major, 1989). Copyright © 2006 John Wiley & Sons, Ltd.
Prejudice toward immigrant workers among Dutch employees: integrated threat theory revisited
Authors: Curşeu Petru Lucian , Stoop Ron , Schalk René 
Published: August 2006

AbstractIntegrated Threat Theory (ITT) (Stephan & Stephan, 1993, 1996) describes four types of threats as mediators in the relation between antecedent factors (previous intergroup conflict, intergroup contact, status inequalities, in‐group identification, knowledge about the out‐group, and intergroup contact) and prejudice. The four mediating types of threats, which influence prejudice according to ITT are: intergroup anxiety, negative stereotyping, realistic and symbolic threats. In this study, the ITT model was tested using structural equation modeling on data collected in sample of 187 Dutch employees. Two alternative explanatory models are proposed in which, first intergroup anxiety and then negative stereotyping mediate the relation between the other ITT threats and prejudice. The data show a good fit with the model in which negative stereotypes are considered as mediator variable. The implications of these findings for ITT are discussed in the context of recent theoretical developments in the study of stereotypes and prejudice. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of perceived experience on likelihood judgments for self and others: an experimental approach
Authors: Harris Peter 
Published: August 2006

AbstractThis study examines the effect of an experimental manipulation of perceived experience on self and others' likelihood ratings for a set of relatively commonplace misfortunes. Participants were randomly assigned to a condition in which they were asked whether they had ever experienced the events (designed to induce higher perceived experience) or whether they had done so frequently, typically, etc. (designed to induce lower perceived experience). The manipulation led to increases in ratings of both perceived self‐likelihood and others' likelihood, in ease of imagining the outcome and recall of a past occurrence, and to decreases in perceived control over the events in the higher perceived experience condition. The increases in ease of imagining mediated the impact of manipulated experience on comparative likelihood whereas the decreases in perceived control did not. There was little evidence that event controllability moderated the impact of experience on comparative likelihood for these events. Copyright © 2006 John Wiley & Sons, Ltd.
No guts, no glory: courage, harassment and minority influence
Authors: Baron Robert S. , Bellman S. Beth 
Published: August 2006

AbstractTo test a courage hypothesis of minority influence, participants read a jury transcript in which a four person majority argued for conviction, while a two person minority argued for acquittal. Across two studies a harassed minority was more persuasive than an un‐harassed minority on both obvious and subtle measures of social influence. In certain cases, these effects occurred only when weak minority arguments were used. In‐group/out‐group status of the minority, manipulated in Study 2, had negligible effects on persuasion. In Study 2, comparisons to a control condition in which all participants argued for acquittal, did not verify the contention that minority influence provokes more careful processing than majority influence despite the fact that harassed minorities were more persuasive on several measures than this type of majority‐control. Copyright © 2006 John Wiley & Sons, Ltd.
Polysemy of traits and judgment of familiar people
Authors: Mollaret Patrick , Mignon Astrid 
Published: August 2006

AbstractThis paper develops a polysemic view of traits labels and outlines the fact that the same label may activate two modes of person perception (1) the agent mode is elicited by behavioural descriptions and emphasizes the role of the actor, and (2) the experiencer mode is elicited by state descriptions and implies an external view of people. The experiment was designed to investigate consequences of mode induction on perception of familiar people. Participants had first to rate traits as behavioural descriptions (agent condition) or as state descriptions (experiencer condition). Then, they had to think about four familiar persons, located at the four poles of the circumplex taxonomy (‘a person they like’, ‘a person they don't like’, ‘a person who has qualities to get on in life’, ‘a person who lacks qualities to get on in life’) and to rate them on a variety of traits scales. Control participants were directly enrolled in the description phase. Results show that, compared to agent induction and control conditions, state induction weakened (1) the evaluative consistency of trait ratings within a dimension (2) the perceived differentiation between people. Consequences of the polysemic conception of traits are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Acrylonitrile‐induced oxidative DNA damage in rat astrocytes
Authors: Pu Xinzhu , Kamendulis Lisa M. , Klaunig James E. 
Published: August 2006

AbstractChronic administration of acrylonitrile results in a dose‐related increase in astrocytomas in rat brain, but the mechanism of acrylonitrile carcinogenicity is not fully understood. The potential of acrylonitrile or its metabolites to induce direct DNA damage as a mechanism for acrylonitrile carcinogenicity has been questioned, and recent studies indicate that the mechanism involves the induction of oxidative stress in rat brain. The present study examined the ability of acrylonitrile to induce DNA damage in the DI TNC1 rat astrocyte cell line using the alkaline Comet assay. Oxidized DNA damage also was evaluated using formamidopyrimidine DNA glycosylase treatment in the modified Comet assay. No increase in direct DNA damage was seen in astrocytes exposed to sublethal concentrations of acrylonitrile (0–1.0 mM) for 24 hr. However, acrylonitrile treatment resulted in a concentration‐related increase in oxidative DNA damage after 24 hr. Antioxidant supplementation in the culture media (α‐tocopherol, (−)−epigallocathechin‐3 gallate, or trolox) reduced acrylonitrile‐induced oxidative DNA damage. Depletion of glutathione using 0.1 mM DL‐buthionine‐[S,R]‐sulfoximine increased acrylonitrile‐induced oxidative DNA damage (22–46%), while cotreatment of acrylonitrile with 2.5 mM L‐2‐oxothiazolidine‐4‐carboxylic acid, a precursor for glutathione biosynthesis, significantly reduced acrylonitrile‐induced oxidative DNA damage (7–47%). Cotreatment of acrylonitrile with 0.5 mM 1‐aminobenzotriazole, a suicidal inhibitor of cytochrome P450, prevented the oxidative DNA damage produced by acrylonitrile. Cyanide (0.1–0.5 mM) increased oxidative DNA damage (44–160%) in astrocytes. These studies demonstrate that while acrylonitrile does not directly damage astrocyte DNA, it does increase oxidative DNA damage. The oxidative DNA damage following acrylonitrile exposure appears to arise mainly through the P450 metabolic pathway; moreover, glutathione depletion may contribute to the induction of oxidative DNA damage by acrylonitrile. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Modeling doline populations with logistic growth functions
Authors: Kemmerly Phillip R. 
Published: August 2006

AbstractInitiation and evolution of a large karst depression population consisting of parent and daughter dolines were spatially and temporally modeled using logistic growth functions. Logistic growth models are well suited for analyzing doline population initiation and evolution because they reflect the density‐dependent growth mechanisms present in the evolution of karst depressions. Seven assumptions based upon previous studies were refined into mathematical statements and tested using more than 2000 dolines from a subpopulation of both parent and daughter karst depressions on the Western Highland Rim and Pennyroyal Plain of Tennessee and Kentucky. Logistic growth models quantify the initiation and evolution of doline populations and interface well with recent models describing the evolution of three‐dimensional conduit systems. Logistic growth models should apply to modeling other doline populations in karst terranes with hydraulically efficient, three‐dimensional conduit systems. Copyright © 2006 John Wiley & Sons, Ltd.
Organization of hippocampal cell assemblies based on theta phase precession
Authors: Maurer Andrew P. , Cowen Stephen L. , Burke Sara N. , Barnes Carol A. , McNaughton Bruce L. 
Published: August 2006

AbstractThe factors that control the spatial tuning of hippocampal neurons are incompletely understood, and there is no generally agreed upon definition of what constitutes a “place field”. One factor that must be considered is the phenomenon of “phase precession”. As a rat passes through the place field of a particular hippocampal neuron, its spikes shift to earlier phases of the theta rhythm. Except for the special cases discussed herein, the phase shift never exceeds 360°. Moreover, under conditions in which place field sizes change dynamically, precession rate is tightly coupled with the place field size, suggesting that a single cycle of theta phase precession could be used to define unitary place field boundaries. Theta phase precession implies that the “cell assembly” of active hippocampal neurons changes systematically over the course of a single theta cycle. A given cell can exhibit more than one place field in a given environment, each field showing the same pattern of 360° of phase precession. The existence of multiple fields implies that one cell can participate in multiple cell assemblies within the same environment. We show here that place fields, defined as a single cycle of phase precession, can overlap spatially, with the result that the cell fires with spikes clustered at two different phases over the theta cycles in which the fields overlap. Thus, the same neuron can participate in different cell assemblies within a single theta cycle. © 2006 Wiley‐Liss, Inc.
Behavioral correlates of the distributed coding of spatial context
Authors: Anderson Michael I. , Killing Sarah , Morris Caitlin , O'Donoghue Alan , Onyiagha Dikennam , Stevenson Rosemary , Verriotis Madeleine , Jeffery Kathryn J. 
Published: August 2006

AbstractHippocampal place cells respond heterogeneously to elemental changes of a compound spatial context, suggesting that they form a distributed code of context, whereby context information is shared across a population of neurons. The question arises as to what this distributed code might be useful for. The present study explored two possibilities: one, that it allows contexts with common elements to be disambiguated, and the other, that it allows a given context to be associated with more than one outcome. We used two naturalistic measures of context processing in rats, rearing and thigmotaxis (boundary‐hugging), to explore how rats responded to contextual novelty and to relate this to the behavior of place cells. In experiment 1, rats showed dishabituation of rearing to a novel reconfiguration of familiar context elements, suggesting that they perceived the reconfiguration as novel, a behavior that parallels that of place cells in a similar situation. In experiment 2, rats were trained in a place preference task on an open‐field arena. A change in the arena context triggered renewed thigmotaxis, and yet navigation continued unimpaired, indicating simultaneous representation of both the altered contextual and constant spatial cues. Place cells similarly exhibited a dual population of responses, consistent with the hypothesis that their activity underlies spatial behavior. Together, these experiments suggest that heterogeneous context encoding (or “partial remapping”) by place cells may function to allow the flexible assignment of associations to contexts, a faculty that could be useful in episodic memory encoding. © 2006 Wiley‐Liss, Inc.
Assessing progressivity of out‐of‐pocket payment: with illustration to Malaysia
Authors: Yu Chai Ping , Whynes David K. , Sach Tracey H. 
Published: August 2006

AbstractThroughout the world, policy makers are considering or implementing financing strategies that are likely to have a substantial impact on the equity of health financing. The assessment of the equity implication is clearly important, given the potential impact that alternative finance sources have on households. Households incur out‐of‐pocket payment directly from their budget, apart from their public or private insurance. Out‐of‐pocket payment is the primary concern, given their undesirable impact on households. Progressivity measures departures from proportionality in the relationship between out‐of‐pocket payment and ability to pay. It is the most frequently used yardstick to assess the equity of out‐of‐pocket payments in empirical studies. This paper provides an evaluation of such progressivity measures, undertaken using four approaches (proportion approach, tabulation approach, concentration curve and Kakwani's index), in order to reveal their usefulness and underlying notion. It is illustrated empirically with data on out‐of‐pocket payment for health care in Malaysia for 1998/1999, based on the nationally representative Household Expenditure Survey. Results indicate that out‐of‐pocket payments are mildly progressive, whilst the four approaches have their benefits and limitations in assessing equity implications. This analysis is of interest from a policy perspective, given Malaysia's heavy reliance on out‐of‐pocket payments to finance health care. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐term patient monitoring for clozapine‐induced agranulocytosis and neutropenia in Korea: when is it safe to discontinue CPMS?
Authors: Kang Byung‐Jo , Cho Man‐Je , Oh Jung‐Tae , Lee Yanghyun , Chae Beang‐Jin , Ko Jaewook 
Published: August 2006

AbstractObjectivesThis study documents the incidences of agranulocytosis and neutropenia, and the patterns of incidence of the side effects of long‐term clozapine treatment in order to determine an appropriate time to stop the Clozaril Patient Monitoring System (CPMS).MethodsHematological, demographic, and other data from the CPMS for 6782 patients who took clozapine for the past 11 years in the Republic of Korea has been analyzed.ResultsTwenty‐nine (53.7%) of fifty‐four agranulocytosis cases occurred within the first 18 weeks. The cumulative incidence of agranulocytosis was 1.64% between 6 and 11 years and the crude incidence was 0.8%. Neutropenia occurred in 697 patients, and 365 (52.4%) of these cases occurred within the first 18 weeks. The cumulative incidence of neutropenia was 19.8% between 8 and 11 years, and the crude incidence was 10.3%. There were no cases of agranulocytosis or neutropenia after the 9th year of clozapine treatment.ConclusionsThe incidence of agranulocytosis in the Republic of Korea was similar to those in the rest of the world. While agranulocytosis began several years after clozapine treatment, long‐term monitoring of white blood cells is necessary. We suggest that the CPMS should be stopped or less frequently after the 9th year of treatment. Copyright © 2006 John Wiley & Sons, Ltd.
The expression of metastasis suppressor MIM/MTSS1 is regulated by DNA methylation
Authors: Utikal Jochen , Gratchev Alexei , Muller‐Molinet Isabelle , Oerther Sandra , Kzhyshkowska Julia , Arens Norbert , Grobholz Rainer , Kannookadan Sheila , Goerdt Sergij 
Published: August 2006

AbstractMIM/MTSS1 was initially described as a gene missing in invasive bladder cancer cell lines. Functional analysis revealed that MIM is an actin binding protein involved in the regulation of actin cytoskeleton dynamics. MIM was shown to be sonic hedgehog (Shh) signaling dependent and synergizes with the effects of Gli transcription factors. Overexpression of MIM in cell lines leads to the inhibition of cell proliferation. In this study, we showed that the inhibition of cell growth by MIM is anchorage independent. We identified and cloned the promoter region of MIM and located the main promoter activity to 276 bp of 5′ flanking sequence sited within a CpG island. Analysis of DNA methylation using bisulphite sequencing revealed that MIM promoter is methylated in its 5′ region in cells and tissue samples with reduced endogenous MIM expression. Using luciferase reporter assay, we demonstrated that nonmethylated MIM promoter has a similar activity in cell lines with different endogenous MIM expression. Inhibition of DNA methylation by 5‐Aza‐2′‐deoxycytidine led to upregulation of MIM expression in a low expressing cell line. In conclusion, we clearly demonstrate here that the expression of metastasis suppressor MIM is regulated by DNA methylation of a CpG island within its promoter region. © 2006 Wiley‐Liss, Inc.
Microvascular endothelial cells increase proliferation and inhibit apoptosis of native human acute myelogenous leukemia blasts
Authors: Hatfield Kimberley , Ryningen Anita , Corbascio Matthias , Bruserud Øystein 
Published: August 2006

AbstractInteractions between acute myelogenous leukemia (AML) blasts and neighbouring endothelial cells in the bone marrow seem important both for disease development and susceptibility to chemotherapy. We investigated the effects of soluble mediators released by microvascular endothelial cells on native human AML cells. AML cells derived from 33 patients were cocultured with microvascular endothelial cells, separated by a semipermeable membrane. We investigated the effect of coculture on AML cell proliferation, viability/apoptosis and cytokine release. Coculture increased AML cell proliferation, and this growth enhancement included the clonogenic leukemia cell subset. Increased release of several soluble mediators was also detected (interleukin 3, interleukin 6, granulocyte‐macrophage and granulocyte colony‐stimulating factors) in cocultures. Our cytokine neutralization experiments suggest that an intercellular crosstalk involving several soluble mediators contribute to the increased leukemia cell proliferation. The presence of endothelial cells had an additional antiapoptotic effect on the AML cells. The endothelial cells did not have any growth‐enhancing effect on native human acute lymphoblastic leukemia cells. Our in vitro results suggest that the release of soluble mediators by microvascular endothelial cells supports leukemic hematopoiesis through paracrine mechanisms by direct enhancement of AML blast proliferation and by inhibition of leukemic cell apoptosis. © 2006 Wiley‐Liss, Inc.
Dose‐dependent effect of low‐intensity pulsed ultrasound on callus formation during rapid distraction osteogenesis
Authors: Chan Chun Wai , Qin Ling , Lee Kwong Man , Cheung Wing Hoi , Cheng Jack Chun Yiu , Leung Kwok Sui 
Published: August 2006

AbstractDistraction osteogenesis of bone or callotasis causes poor bone formation when the distraction rate is beyond the optimal rate. Low‐intensity pulsed ultrasound was reported to enhance fracture healing, treatment of nonunion, and accelerate bone maturation and remodeling during consolidation stage of distraction osteogenesis. In this study, we evaluated the efficacy of different durations of LIPUS treatments during rapid bone lengthening. After 7‐day latent period, osteotomized New Zealand white rabbit tibiae were lengthened at the rate of 2 mm per day for 1 week. Two different LIPUS treatment durations of 20 min and 40 min were selected for treatment groups. Rabbits without treatment served as the control group. Plain X‐ray, peripheral quantitative computed tomography (pQCT) and histology were performed to assess bone acquisition in the distraction callus. The results showed that LIPUS increased bone mineral content and volume of the mineralized tissue of distraction callus in a dose‐dependent manner. The different regions of distraction callus exhibited various spatial response to LIPUS treatment. Moreover, LIPUS enhanced dose‐dependant endochondral formation. Compared with 20‐min treatment, the 40‐min LIPUS treatment was a more favorable treatment duration for bone regeneration in the distraction callus. In conclusion, LIPUS was able to enhance bone regeneration under rapid distraction, and its effect was dose‐dependent. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2072–2079, 2006