bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size‐selective excitation of biexcitons in CuCl quantum dots under two‐photon resonant excitation
Authors: Miyajima K. , Ashida M. , Itoh T. 
Published: May 2007

AbstractPhotoluminescence (PL) spectra of excitons and biexcitons confined in CuCl quantum dots have been measured under two‐photon resonant excitation of the biexcitons in order to examine size‐selective excitation of the biexcitons. Although the PL energy of the biexciton does not exhibit an obvious dependence on the excitation photon energy, the PL energy of the exciton clearly reveals the size of the quantum dots in which the biexcitons are generated under the two‐photon resonant excitation. As a result, the possibility of the size‐selective excitation of the biexcitons was confirmed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations of EPR parameters for Cr3+ and Mn4+ ions in anatase (TiO2) crystals
Authors: Wu Xiao‐Xuan , Feng Wen‐Ling , Zheng Wen‐Chen 
Published: May 2007

AbstractThe electron paramagnetic resonance (EPR) parameters (g factors g‖ and g⊥ and zero‐field splitting D) of 3d3 ions Cr3+ and Mn4+ at the tetragonal substitutional site of anatase (TiO2) crystals are calculated from the complete high‐order perturbation formulas based on the cluster approach. These formulas involve not only the widely used crystal field (CF) mechanism, but also the charge transfer (CT) mechanism (which is neglected in the CF theory). The calculated results are in agreement with the observed values. It is found that the relative importance of the CT mechanism for EPR parameters increases with increasing valence state of the 3d3 ion. So, in the case of 3d3 ions having high valence state (e.g. Mn4+ ion), a reasonable explanation of EPR parameters should take both CF and CT mechanisms into account. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A brief survey of self‐organization in wireless sensor networks
Authors: Mills Kevin L. 
Published: May 2007

AbstractMany natural and man‐made systems exhibit self‐organization, where interactions among components lead to system‐wide patterns of behavior. This paper first introduces current, scientific understanding of self‐organizing systems and then identifies the main models investigated by computer scientists seeking to apply self‐organization to design large, distributed systems. Subsequently, the paper surveys research that uses models of self‐organization in wireless sensor networks to provide a variety of functions: sharing processing and communication capacity; forming and maintaining structures; conserving power; synchronizing time; configuring software components; adapting behavior associated with routing, with disseminating and querying for information, and with allocating tasks; and providing resilience by repairing faults and resisting attacks. The paper closes with a summary of open issues that must be addressed before self‐organization can be applied routinely during design and deployment of senor networks and other distributed, computer systems. Copyright © 2007 John Wiley & Sons, Ltd.
A practical approach of ID‐based cryptosystem in ad hoc networks
Authors: Kim Heeyoul , Song Jumin , Yoon Hyunsoo 
Published: May 2007

AbstractAs research in ad hoc networking has advanced, the importance of security increases more and more. But it suffers from the restriction that ad hoc networks do not have the established infrastructure. In this paper we propose a security‐enhanced model with ID‐based cryptosystem which removes the necessity for any infrastructure and provides sound authentication. Also we provide a more secure and concrete routing protocol with aggregate signature. For confidentiality, we also provide a key exchange protocol. And our model not only distributes the role of key generation center in ID‐based cryptosystem to the nodes with threshold cryptography, but also increases availability by providing a secret re‐sharing protocol. Therefore, our model is very appropriate for ad hoc networks. Copyright © 2007 John Wiley & Sons, Ltd.
Increasing mobile clients' cache reusability in a wireless client‐server environment
Authors: Yi Song‐Yi , Jung Sungwon 
Published: May 2007

AbstractIn a wireless client‐server environment, data broadcasting is an efficient data dissemination method and some of the broadcast data are often cached at each mobile client's cache. Data broadcasting and caching save communication bandwidth, resource usage, and data access time. A server also broadcasts invalidation reports (IRs) to maintain the consistency between server data and clients' cached data. Most existing cache invalidation policies simply purge the entire cache after a client has been disconnected long enough to miss a certain number (window size) of IRs. We present a cache invalidation scheme to increase the reusability of the data in mobile clients' caches after long disconnection. Instead of clearing the entire cache regardless of its consistency after long disconnection, a client estimates the relative cost of purging all data and the cost of a selective purge. If a selective purge is cheaper, the client sends server an uplink message to ask the validity of data whose update rate is low to salvage as many valid data as possible. Simulation results show that our scheme effectively increases cache reusability since our cost functions respect update rates at a server, broadcast intervals, the communication bandwidth, and data sizes as well as disconnection
time. Copyright © 2007 John Wiley & Sons, Ltd.
Der Durchfluß von Wasser durch konzentrische und exzentrische zylindrische Drosselspalte mit und ohne Ringnuten
Authors: Schneckenberg Erich 
Published: May 2007

AbstractAufgabe: Es sollte untersucht werden, wie der Wasserverlust aus engen zylindermantelförmigen Drosselspalten durch exzentrische Verlagerung von Kern und Mantel und ferner durch Ringnuten in den Spaltflächen beeinflußt wird.
What do Patients Prefer: Informed Consent Models for Genetic Carrier Testing
Authors: Ormond K. E. , Iris M. , Banuvar S. , Minogue J. , Annas G. J. , Elias S. 
Published: May 2007

AbstractThe recent increased number of conditions for which patients can undergo genetic carrier testing raises the question of how best to obtain pre‐test informed consent. Clinical approaches vary from a minimalist model to a model where patients are given detailed information about all conditions to be screened for. Few data exist as to patient preferences, or how information impacts decision‐making. Eight high‐literacy focus groups were conducted to assess the knowledge and preferences of pregnant patients and their male partners. Most groups indicated that some balance between details and brevity was optimal, recognizing that anxiety can occur when patients are provided with too much information and that the wide range of tests offered during pregnancy often led to confusion. Critical areas for the informed consent process included (1) details about the conditions and risk of being a carrier, (2) logistics of testing, (3) next steps if the test is positive, and (4) prognosis, options and resources if the child were to be affected with a disorder. It will be useful to develop model consent programs and prospectively assess their impact on informed consent and patient satisfaction, both when positive and negative results are received.
Formation of Granular Crystals in Margarine with Excess Amount of Palm Oil
Authors: Tanaka L. , Miura S. , Yoshioka T. 
Published: May 2007

AbstractCrystallization behavior of palm oil and tripalmitin (PPP) in a model margarine system was investigated. The model margarine was held in a programmable oven, heated to 5 °C for 12 h and then 20 °C for a further 12 h. After 3 weeks, the model margarine was evaluated by polarization microscopy. Granular crystals were observed in the margarine containing an excess amount of palm oil and PPP. The concentration of higher‐melting fatty acids was higher in the crystals relative to the surroundings. Likewise, the presence of lower‐melting fatty acids was lower in the crystals. The polymorphic structure of the margarine with excess palm oil and PPP was determined to be all β′ by X‐RD spectra. The result suggested that the agglomeration of higher‐melting point triglycerides (TAGs), such as PPP in this study, led to the formation of granular crystals in the margarine without β polymorphic emergence.
Prognostic indices with brief and standard CBT for panic disorder: I. Predictors of outcome
Authors: DOW MICHAEL G. T. , KENARDY JUSTIN A. , JOHNSTON DEREK W. , NEWMAN MICHELLE G. , TAYLOR C. BARR , THOMSON AILEEN 
Published: May 2007

ABSTRACTBackgroundAlthough the effectiveness of cognitive behavioural therapy (CBT) in the management of panic disorder (PD) is now well established, there have been few studies of predictors of outcome with this patient group using clinical effectiveness trial data, a hypothesis-testing model, and a dependent measure of clinically significant change.MethodThe data for this study came from a randomized controlled trial of three forms of CBT delivery for PD with and without agoraphobia (two 6-week CBT programmes, one of which was computer assisted, and one therapist-directed 12-week CBT programme), comprising a total of 186 patients across two sites. Based on previous related research, five hypothesized predictors of post-treatment and follow-up outcome were identified and examined, using a series of bivariate and multivariate analyses.ResultsThe results in general supported the hypotheses. Strength of blood/injury fears, age of initial onset of panic symptoms, co-morbid social anxieties and degree of agoraphobic avoidance were predictive of both measures of post-treatment outcome. Degree of residual social difficulties and the continued use of anxiolytics at post-treatment were also shown to predict poor outcome at the 6-month follow-up. However, strength of continuing dysfunctional agoraphobic cognitions by the end of active treatment did not predict outcome at follow-up for the sample as a whole.ConclusionsThe identification of consistent predictors of outcome with CBT has many clinical and research benefits. As CBT, however, is being delivered increasingly in a variety of brief formats, further research is required to identify moderators of response to these ‘non-standard’ treatment formats.
Effects of a functional COMT polymorphism on brain anatomy and cognitive function in adults with velo-cardio-facial syndrome
Authors: van Amelsvoort T. , Zinkstok J. , Figee M. , Daly E. , Morris R. , Owen M. J. , Murphy K. C. , De Haan L. , Linszen D. H. , Glaser B. , Murphy D. G. M. 
Published: May 2007

BackgroundVelo-cardio-facial syndrome (VCFS) is associated with deletions at chromosome 22q11, abnormalities in brain anatomy and function, and schizophrenia-like psychosis. Thus it is assumed that one or more genes within the deleted region are crucial to brain development. However, relatively little is known about how genetic variation at 22q11 affects brain structure and function. One gene on 22q11 is catechol-O-methyltransferase (COMT): an enzyme that degrades dopamine and contains a functional polymorphism (Val158Met) affecting enzyme activity. Here, we investigated the effect of COMT Val158Met polymorphism on brain anatomy and cognition in adults with VCFS.MethodThe COMT Val158Met polymorphism was genotyped for 26 adults with VCFS on whom DNA was available. We explored its effects on regional brain volumes using hand tracing approaches; on regional grey- and white-matter density using computerized voxel-based analyses; and measures of attention, IQ, memory, executive and visuospatial function using a comprehensive neuropsychological test battery.ResultsAfter corrections for multiple comparisons Val-hemizygous subjects, compared with Met-hemizygotes, had a significantly larger volume of frontal lobes. Also, Val-hemizygotes had significantly increased grey matter density in cerebellum, brainstem, and parahippocampal gyrus, and decreased white matter density in the cerebellum. No significant effects of COMT genotype on neurocognitive performance were found.ConclusionsCOMT genotype effects on brain anatomy in VCFS are not limited to frontal regions but also involve other structures previously implicated in VCFS. This suggests variation in COMT activity is implicated in brain development in VCFS.
Patterns of remission, continuation and incidence of broadly defined eating disorders during early pregnancy in the Norwegian Mother and Child Cohort Study (MoBa)
Authors: BULIK CYNTHIA M. , VON HOLLE ANN , HAMER ROBERT , KNOPH BERG CECILIE , TORGERSEN LEILA , MAGNUS PER , STOLTENBERG CAMILLA , SIEGA-RIZ ANNA MARIA , SULLIVAN PATRICK , REICHBORN-KJENNERUD TED 
Published: May 2007

ABSTRACTBackgroundWe explored the course of broadly defined eating disorders during pregnancy in the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health.MethodA total of 41 157 pregnant women, enrolled at approximately 18 weeks' gestation, had valid data from the Norwegian Medical Birth Registry. We collected questionnaire-based diagnostic information on broadly defined anorexia nervosa (AN), and bulimia nervosa (BN), and eating disorders not otherwise specified (EDNOS). EDNOS subtypes included binge eating disorder (BED) and recurrent self-induced purging in the absence of binge eating (EDNOS-P). We explored rates of remission, continuation and incidence of BN, BED and EDNOS-P during pregnancy.ResultsPrepregnancy prevalence estimates were 0·1% for AN, 0·7% for BN, 3·5% for BED and 0·1% for EDNOS-P. During early pregnancy, estimates were 0·2% (BN), 4·8% (BED) and 0·1% (EDNOS-P). Proportions of individuals remitting during pregnancy were 78% (EDNOS-P), 40% (BN purging), 39% (BED), 34% (BN any type) and 29% (BN non-purging type). Additional individuals with BN achieved partial remission. Incident BN and EDNOS-P during pregnancy were rare. For BED, the incidence rate was 1·1 per 1000 person-weeks, equating to 711 new cases of BED during pregnancy. Incident BED was associated with indices of lower socio-economic status.ConclusionsPregnancy appears to be a catalyst for remission of some eating disorders but also a vulnerability window for the new onset of broadly defined BED, especially in economically disadvantaged individuals. Vigilance by health-care professionals for continuation and emergence of eating disorders in pregnancy is warranted.
Effects of multi‐year droughts on fish assemblages of seasonally drying Mediterranean streams
Authors: MAGALHÃES M. FILOMENA , BEJA PEDRO , SCHLOSSER ISAAC J. , COLLARES‐PEREIRA MARIA J. 
Published: May 2007

Summary1. This study analysed changes occurring in Mediterranean stream fish assemblages over a sequence of dry years followed by a generally wet period (1991–98). Variations in assemblage attributes were quantified at the basin and stream reach scales, and related to variables reflecting the occurrence of unusually dry or wet conditions.2. Assemblage variability increased along with the resolution of analysis, with little changes in species richness, composition and rank abundances, but significant variation in individual species abundances. Fluctuations in relative abundances were significantly affected by variables reflecting the severity of summer droughts and the occurrence of rainy springs. These patterns were evident at the basin scale, while variability at individual stream reaches tended to be higher and less related to rainfall patterns.3. At least three response guilds to rainfall variation could be identified: two of the four abundant and widespread species (chub and loach) declined following dry years, whereas the two other core species (nase and eel) declined after rainy spring; one scarce native species (stickleback) increased in dry years.4. Except at the two most upstream reaches, the assemblages tended to recover quickly to previous configuration after the changes occurring during the sequence of dry years.5. Temporal variability of local assemblages was concordant among reaches but did not follow any consistent spatial pattern. Instead, spatial patterns in assemblage attributes changed over time in response to environmental variability, with a tendency for a disruption of upstream–downstream gradients following dry years.6. Results supported the view that present‐day droughts cause relatively small and transient changes to Mediterranean stream fish assemblages. However, longer and more severe droughts expected under altered future climates, may result in declines or local extinctions of the most sensitive species and their potential replacement by more resistant species. Changing drought regimes thus need to be duly considered in the development of conservation strategies for Mediterranean stream fish.
The impact of an introduced predator on a threatened galaxiid fish is reduced by the availability of complex habitats
Authors: STUART‐SMITH RICK D. , STUART‐SMITH JEMINA F. , WHITE ROBERT W.G. , BARMUTA LEON A. 
Published: May 2007

Summary1. The availability of complex habitats such as macrophytes may be vital in determining the outcomes of interactions between introduced predators and native prey. Introduced brown trout (Salmo trutta) have impacted numerous small native freshwater fishes in the southern hemisphere, but the potential role of complex habitats in determining the direct outcomes of brown trout – native fish interactions has not been experimentally evaluated.2. An in‐lake enclosure experiment was used to evaluate the importance of structurally complex habitats in affecting the direct impacts of brown trout on a threatened galaxiid fish. Five Galaxias auratus and a single brown trout were added to enclosures containing one of three different habitat types (artificial macrophytes, rocks and bare silt substrate). The experiment also had control enclosures without brown trout. Habitat‐dependence of predation risk was assessed by analysis of G. auratus losses to predation, and stomach contents of remaining fish were analysed to determine if brown trout directly affect the feeding of G. auratus and whether this is also habitat‐dependent.3. Predation risk of G. auratus differed significantly between habitat types, with the highest mortality in enclosures with only bare silt substrate and the lowest in enclosures containing artificial macrophytes. This result highlights the importance of availability of complex habitats for trout – native fish interactions and suggests that increasing habitat degradation and loss in fresh waters may exacerbate the direct impacts of introduced predators.4. Stomach contents analyses were restricted to fish in enclosures with artificial macrophytes and rocks, as most fish were consumed in enclosures with brown trout and only bare silt substrate. These analyses suggest that brown trout do not directly affect the feeding of G. auratus in complex habitats, but it is still unknown whether its feeding is reduced if complex habitats are unavailable.
Stable nitrogen isotope ratios of macrophytes and associated periphyton along a nitrate gradient in two subtropical, spring‐fed streams
Authors: BRABANDERE LORETO DE , FRAZER THOMAS K. , MONTOYA JOSEPH P. 
Published: May 2007

Summary1. An increase in human population and associated changes in land use have caused an increase in groundwater nitrate concentrations throughout central Florida. Within the region, this nitrate‐laden groundwater returns to the surface via numerous large springs that serve as the origin of flow for many coastal streams and rivers. These rivers can exhibit strong nitrate gradients because of the high nutrient uptake potential of the rivers.2. We hypothesised that downstream declines in nitrate concentrations would be manifested spatially as increases in the δ15N of the residual pool of nitrate, macrophytes and periphyton as a consequence of isotopic fractionation associated with preferential use of 14NO3−. This hypothesis was tested in two spring‐fed river systems, the Chassahowitzka and Homosassa rivers, along Florida's central Gulf of Mexico coast.3. In general, δ15N values of nitrate, macrophytes and periphyton increased with decreasing fraction of nitrate remaining in each of the two study systems. The fractionation associated with nitrate uptake by macrophytes and associated periphyton was determined from the relationship between δ15N of both constituents of the macrophyte community and the fraction of nitrate removed from the system. Values for fractionation by macrophytes and periphyton ranged from 1.9‰ to 3.6‰ and from 0.7‰ to 2.5‰, respectively.
Infection with Salmonella typhimurium has no effect on the composition and cleavage specificity of the 20S proteasome in human lymphoid cells
Authors: Marcilla Miguel , De Castro José Antonio López , Castaño José G. , Alvarez Iñaki 
Published: May 2007

SummaryHuman leucocyte antigen (HLA)‐B27 is strongly associated with spondyloarthropathies, including reactive arthritis. Several Gram‐negative bacteria, such as Salmonella typhimurium, can trigger this disease. It has been suggested that peptides derived from bacterial proteins and presented by HLA‐B27 to cytotoxic T lymphocytes might show molecular mimicry with autologous peptides, leading to T‐cell cross‐reaction and autoimmunity. Antigen presentation in Salmonella‐infected cells could be modulated by changes in the composition of the proteasome, which is the major proteolytic system that generates major histocompatibility complex class I ligands. In this study we analysed whether the composition or activity of the 20S proteasome was altered upon infection of lymphoid cells by S. typhimurium. Two‐dimensional gel electrophoresis failed to show any differences between the composition of 20S proteasomes from cells infected with S. typhimurium for 24 hr, relative to non‐infected cells. In addition, digestions of oxidized insulin B‐chain with purified 20S proteasomes from non‐infected and infected cells generated the same products, indicating that the proteasomal cleavage specificity was not altered upon infection. These data indicate that infection of lymphoid cells by S. typhimurium fails to induce formation of immunoproteasomes or otherwise alter the proteolytic specificity of the 20S proteasome.
Interferon‐γ‐dependent inhibition of late allergic airway responses and eosinophilia by CD8+γδ T cells
Authors: Isogai Susumu , Athiviraham Aravind , Fraser Russell S. , Taha Rame , Hamid Qutayba , Martin James G. 
Published: May 2007

SummaryWe have previously shown that CD8+γδ T cells decrease late allergic airway responses, airway eosinophilia, T helper 2 cytokine expression and increase interferon‐γ (IFN‐γ) expression. We hypothesized that the effects of CD8+γδ T cells were IFN‐γ mediated. Brown Norway rats were sensitized to ovalbumin on day 1. Cervical lymph node CD8+γδ T cells from sensitized animals were treated with antisense oligodeoxynucleotide (5 µmol/l) to inhibit IFN‐γ synthesis or control oligodeoxynucleotide and 3·5 × 104 CD8+γδ T cells were injected intraperitoneally into sensitized recipients on day 13. Rats were challenged with aerosolized ovalbumin on day 15 and lung resistance was monitored over an 8 hr period, after which bronchoalveolar lavage was performed. Control oligodeoxynucleotide treated γδ T cells decreased late airway responses and eosinophilia in bronchoalveolar lavage. There was a complete recovery of late airway responses and a partial recovery of airway eosinophilia in recipients of antisense oligodeoxynucleotide treated cells. Macrophage ingestion of eosinophils was frequent in rats administered γδT cells but reduced in recipients of antisense oligodeoxynucleotide treated cells. These results indicate that CD8+γδ T cells inhibit late airway responses and airway eosinophilia through the secretion of IFN‐γ. Defective or altered γδ T‐cell function may account for some forms of allergic asthma.