bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size‐dependence of anisotropic exchange interaction in InAs/GaAs quantum dots
Authors: Seguin R. , Rodt S. , Schliwa A. , Pötschke K. , Pohl U. W. , Bimberg D. 
Published: October 2006

AbstractA comprehensive study of the exchange interaction between charge carriers in self‐organized InAs/GaAs quantum dots is presented. Single quantum‐dot cathodoluminescence spectra of quantum dots of different sizes are analyzed. Special attention is paid to the energetic structure of the charged excited exciton (hot trion). A varying degree of intermixing within the hot trion states leads to varying degrees of polarization of the corresponding emission lines. The emission characteristics change from circularly polarized for small quantum dots to elliptically polarized for large quantum dots. The findings are explained by a change of magnitude of the anisotropic exchange interaction and compared to the related effect of fine‐structure splitting in the neutral exciton and biexciton emission. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entangled photon pairs from radiative cascades in semiconductor quantum dots
Authors: Akopian N. , Lindner N. H. , Poem E. , Berlatzky Y. , Avron J. , Gershoni D. , Gerardot B. D. , Petroff P. M. 
Published: October 2006

AbstractEntangled photon pairs are emitted from a biexciton decay cascade of single quantum dots when spectral filtering is applied. We show this by experimentally measuring the density matrix of the polarization state of the photon pair emitted from a continuously pumped quantum dot. The matrix clearly satisfies the Peres criterion for entanglement. By applying in addition a temporal window, the quantum dot becomes an entangled light source. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Richard E. Smalley (6 June 1943–28 October 2005)
Authors: Weisman Bruce 
Published: October 2006

AbstractThe international scientific community suffered a great loss with the death of Richard Errett (Rick) Smalley at age 62 following a 6‐year battle against cancer. Throughout his career, Rick had a profound influence through his pioneering research in chemistry and nanoscience, his mentorship of young scientists, and his advocacy for the role of science in solving major societal problems.As a postdoctoral fellow working with Donald Levy and Lennard Wharton at the University of Chicago, Rick spearheaded the invention of supersonic jet spectroscopy. This powerful method cools gas phase molecules nearly to absolute zero, enormously simplifying many complex and otherwise uninterpretable spectra. Thirty years later, supersonic jet spectroscopy remains a vital tool in chemical physics.Rick Smalley came to Rice University in Houston, Texas in 1976 to accept his first and only faculty appointment. He and his students quickly built an advanced apparatus for supersonic jet spectroscopy and made important contributions to molecular physics. Rick then invented a device to laser‐vaporize high melting materials into small molecular clusters. By spectroscopically probing these novel species, he pioneered another new field: the study of small metal and semiconductor clusters. Rick, Harry Kroto and Robert Curl were investigating carbon clusters in 1985 when they made their famous discovery of the fullerenes, for which they shared the 1996 Nobel Prize in Chemistry. To date, tens of thousands of scientific papers have been published on fullerenes.In the early 1990's, Rick Smalley turned his attention to the new field of carbon nanotubes. His group made many landmark discoveries and invented nanotube growth methods that supplied samples for researchers around the world. Most recently, Rick expanded his horizons to seek solutions to the immense problem of global energy needs. He helped shape national and international research priorities, including the U.S. National Nanotechnology Initiative. Rick was a visionary and passionate believer in the power of science and technology to solve great problems. He advised students: “Be a scientist and save the world.”Rick Smalley had great personal charm and charisma. He loved to teach and inspire his students, some of whom described him as “Moses‐like”. He was fearless not only in abandoning the comforts of a successful research program to leap into promising but uncertain new fields, but also in battling his fatal disease while working intensely until the very end of his life. He was devoted to and is survived by his wife Deborah and two sons, Chad and Preston.Rick Smalley's untimely death is a loss not only to his family, friends, students, colleagues, and collaborators, but to the worldwide communities that he led and served. He will be deeply missed and long remembered. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A diagnostic environment for automaton networks
Authors: Cerutti S. , Lamperti G. , Scaroni M. , Zanella M. , Zanni D. 
Published: October 2006

AbstractAutomated diagnosis of communicating‐automaton networks (CANs) is a complex task, which is typically faced by model‐based reasoning, where the behavior of the network is reconstructed based on its observation. This task may take advantage of knowledge‐compilation techniques, where a large amount of reasoning is anticipated off‐line (when the diagnostic process is not active), by simulating the behavior of the network and by constructing suitable data structures embedding diagnostic information. This (general‐purpose) compiled knowledge is exploited on‐line (when the diagnostic process becomes active), so as to generate the solution to the problem. Additional reusable (special‐purpose) compiled knowledge is generated on‐line when solving new problems. A software environment for the diagnosis of CANs has been developed in the C programming language with the support of the PostgreSQL relational database management system, under the Linux operating system. It supports the modeling and preprocessing of CANs as well as the solution of diagnostic problems, including on‐line knowledge compilation. The environment has been tested through a variety of experiments. Results are encouraging and provide a valuable feedback for further work. Copyright © 2006 John Wiley & Sons, Ltd.
Sequential changes in uterine artery blood flow pattern between the first and second trimesters of gestation in relation to pregnancy outcome
Authors: Gómez O. , Figueras F. , Martínez J. M. , del Río M. , Palacio M. , Eixarch E. , Puerto B. , Coll O. , Cararach V. , Vanrell J. A. 
Published: October 2006

AbstractObjectiveTo describe sequential changes in uterine artery waveform between the first and second trimesters of gestation and to analyze their association with the subsequent risk of hypertensive disorders and fetal growth restriction (IUGR).MethodsSequential uterine artery Doppler recordings were obtained in a final cohort of 870 singleton pregnancies over two gestational age intervals: 11–14 weeks and 19–22 weeks. The left and right uterine arteries were examined by color and pulsed Doppler and the mean pulsatility index (PI) as well as the presence of a bilateral protodiastolic notch were recorded during both intervals. Pregnancies were followed for occurrence of hypertensive disorders and IUGR.ResultsMean uterine artery PI showed a significant linear decrease within each of the two intervals considered, while the prevalence of a bilateral notch showed decreasing values only throughout 11–14 weeks of gestation. Sixty‐four (7.3%) pregnancies developed a hypertensive disorder and/or IUGR, including three (0.34%) cases of gestational hypertension, 24 cases of pre‐eclampsia (2.75%) and 37 (4.25%) of IUGR. Compared with pregnancies with a normal outcome, complicated pregnancies showed a significantly higher prevalence of a bilateral notch and a higher mean PI in each of the two intervals studied. Compared with normal pregnancies, complicated pregnancies had a significantly higher persistence of a bilateral notch (30% vs. 8%), a higher proportion of women with an abnormal first‐trimester uterine artery PI shifting to normal in the second trimester (14% vs. 4%) and a higher incidence of a normal first‐trimester mean PI that shifted to abnormal in the second trimester (13% vs. 4%). Persistence of an abnormal mean PI from the first to the second trimester identified the group with the greatest risk for adverse perinatal outcome (OR, 10.7; 95% CI, 3.7–30.9). In addition, women in whom the uterine artery mean PI shifted from abnormal to normal between the two trimesters and women in whom the reverse shift occurred showed a similar intermediate risk (OR, 5; 95% CI, 2.1–10.6), comparable to that in women with persistence of a bilateral notch (OR, 5.6; 95% CI, 2.9–10.7).ConclusionsThe sequence of changes in uterine flow between the first and second trimesters correlates with the subsequent development of hypertensive disorders and IUGR. Women with a persistent abnormal mean PI represent the group with the greatest risk for adverse perinatal outcome. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Litigation in otolaryngology – trends and recommendations
Authors: Savage J R , Weiner G M 
Published: October 2006

Background: Seeking to identify where litigious claims against otolaryngologists are targeted (i.e. areas of highest risk) within the NHS and private sector would have positive implications in risk management and limiting the amount of litigation against otolaryngologists.Method: The National Health Service Litigation Authority (NHSLA) and Medical Defence Union (MDU) were contacted and anonymous data obtained on claims within ENT.Results: 887 claims were notified – 457 NHSLA and 430 MDU. The commonest claim in both groups was failure or delay in diagnosis (12 per cent NHSLA, 23 per cent MDU). The other commonest claims were all related to complications (nerve damage 10 per cent, deafness 8 per cent and dental damage 5 per cent). Dissatisfaction with results was 8 per cent total and, within the private sector, was almost exclusively in rhinology.Conclusions: This study once again emphasizes the need for thorough clinical assessment, record keeping and good communication with patients. Recognising these areas of highest risk may limit future claims.
Positive inotropic effects of carbon monoxide‐releasing molecules (CO‐RMs) in the isolated perfused rat heart
Authors: Musameh M D , Fuller B J , Mann B E , Green C J , Motterlini R 
Published: October 2006

Background and purpose:Carbon monoxide (CO) generated by the enzyme haeme oxygenase‐1 (HO‐1) during the breakdown of haeme is known to mediate a number of biological effects. Here, we investigated whether CO liberated from two water soluble carbon monoxide‐releasing molecules (CO‐RMs) exerts inotropic effects on the myocardium.Experimental approach:Rat isolated hearts perfused either at constant flow or constant pressure were used to test the effect of CO‐RMs.Key results:CORM‐3, a fast CO releaser, produced a direct positive inotropic effect when cumulative doses (3, 10 and 30 μg min−1) or a single dose (5 μM) were infused at either constant coronary pressure (CCP) or constant coronary flow (CCF). The inotropic effect mediated by CORM‐3 was abolished by blockade of soluble guanylate cyclase or Na+/H+ exchanger, but not by inhibitors of L‐type Ca2+ channels and protein kinase C. CORM‐3 also caused a slight reduction in heart rate but did not alter coronary flow. In contrast, the slow CO releaser CORM‐A1 produced significant coronary vasodilatation when given at the highest concentration (30 μg min−1) but exerted no effect on myocardial contractility or heart rate.Conclusion and implications:A rapid CO release from CORM‐3 exerts a direct positive inotropic effect on rat isolated perfused hearts, whereas CO slowly released by CORM‐A1 had no effect on myocardial contractility but caused significant coronary vasodilatation. Both cGMP and Na+/H+ exchange appear to be involved in this effect but further work is needed to determine the relative contribution of each pathway in CO‐mediated inotropic effect.British Journal of Pharmacology (2006) 149, 1104–1112. doi:10.1038/sj.bjp.0706939
Factors that contribute to high turnover among residential child care staff
Authors: Colton Matthew , Roberts Susan 
Published: October 2006

ABSTRACTIn this paper we draw on our own empirical research and that of others to consider the factors that contribute to high staff turnover in residential child care. First, we focus on the problem of retaining staff in children’s services. Second, we turn our attention to the factors that contribute to staff turnover in residential care: namely, perceptions of the service; of children and young people; and of human resource issues. Third, we attempt to draw out the implications of high turnover for policy and practice. The negative image of residential care has persisted in the wake of a plethora of abuse scandals. The increasing emotional and behavioural problems presented by the children cared for, and the violence and verbal abuse directed at staff are key retention issues. Moreover, poor conditions of employment contribute to staff perceptions of the work as a short‐term career choice only. The potential means of resolving these problems are explored, and the future research agenda highlighted.
Relationships between microcystins and environmental parameters in 30 subtropical shallow lakes along the Yangtze River, China
Authors: WU S. K. , XIE P. , LIANG G. D. , WANG S. B. , LIANG X. M. 
Published: October 2006

Summary1. A survey of 30 subtropical shallow lakes in the middle and lower reaches of the Yangtze River area in China was conducted during July–September in 2003–2004 to study how environmental and biological variables were associated with the concentration of the cyanobacterial toxin microcystin (MC).2. Mean MC concentration in seasonally river‐connected lakes (SL) was nearly 33 times that in permanently river‐connected lakes (RL), and more than six times that in city lakes (NC) and non‐urban lakes (NE) which were not connected to the Yangtze River. The highest MC (8.574 μg L−1) was detected in Dianshan Lake.3. MC‐RR and MC‐LR were the primary toxin variants in our data. MC‐RR, MC‐YR and MC‐LR were significantly correlated with Chl a, biomass of cyanobacteria, Microcystis and Anabaena, indicating that microcystins were mainly produced by Microcystis and Anabaena sp. in these lakes.4. Nonlinear interval maxima regression indicated that the relationships of Secchi depth, total nitrogen (TN) : total phosphorus (TP) and NH with MC were characterised by negative exponential curves. The relationships between MC and TN, TP, NO + NO were fitted well with a unimodal curve.5. Multivariate analyses by principal component and classifying analysis indicated that MC was mainly affected by Microcystis among the biological factors, and was closely related with temperature among physicochemical factors.
Interleukin‐4 inhibits cyclo‐oxygenase‐2 expression and prostaglandin E2 production by human mature dendritic cells
Authors: Teloni Raffaela , Giannoni Federico , Rossi Paolo , Nisini Roberto , Gagliardi Maria Cristina 
Published: October 2006

SummaryInterleukin‐4 (IL‐4) is considered the key cytokine for inducing T helper type 2 (Th2) cell differentiation, while interferon‐γ and IL‐12 are pivotal cytokines for Th1 immune responses. Paradoxically, IL‐4 has also been demonstrated to enhance IL‐12 production by dendritic cells, suggesting an IL‐4‐dependent regulatory feedback of the Th1/Th2 system. In addition, prostaglandin E2 (PGE2), a lipid mediator of inflammation, has been implicated in the enhancement of Th2‐type responses acting directly on T and B lymphocytes. PGE2 synthesis is dependent on the serial engagement of various enzymes, among which the inducible cyclo‐oxygenase‐2 (COX‐2) exerts a critical role in monocytes and dendritic cells. In this study we demonstrate that IL‐4 inhibits COX‐2 gene expression and consequently prevents secretion of PGE2 by mature human dendritic cells. We also show that PGE2 does not regulate IL‐12 and IL‐10 production by dendritic cells in an autocrine fashion. Hence, we suggest that IL‐4 may exploit an IL‐12‐independent regulatory feedback of the Th1/Th2 system through PGE2 inhibition.
The influence of pH and digestion with commercial enzymes on calcium adsorption in casabe
Authors: Navas Petra Beatriz , Carrasquero‐Durán Armando 
Published: October 2006

SummaryThe Ca2+ binding capacity of a sample of casabe made from cassava (Manihot esculenta) was evaluated by using adsorption isotherms after a digestion process with commercial enzymes. It was found that enzymatic treatment increased the ability of vegetable material to retain calcium and to release endogenous mineral ions as a consequence of possible modifications to the carbohydrate matrix. Untreated casabe did not release mineral ions. pH also influenced the retention of Ca2+: at pH 4.5 release was the main process but adsorption increases with alkalinity up to pH 8.5. The Ca concentrations at which neither adsorption nor release occurred [Ca2+]e were as follows: 5.2 mm (pH 4.5), 3.5 mm (pH 7.1), and 0.63 mm (pH 8.5). The pH effect was explained by an increase in the density of negatively charged functional groups produced by ionization reactions at pH below the point of zero net charge (pHo) which was evaluated by using the Gouy–Chapman double layer model. Values of pHo were 6.4 for raw material and 4.1 after digestion with enzymes. In both cases, the density of positively charged sites below pHo was much higher that the density of negatively charged sites above pHo.
Diagnostic errors and reflective practice in medicine
Authors: Mamede Sílvia , Schmidt Henk G. , Rikers Remy 
Published: October 2006

AbstractBackground  Adverse effects of medical errors have received increasing attention. Diagnostic errors account for a substantial fraction of all medical errors, and strategies for their prevention have been explored. A crucial requirement for that is better understanding of origins of medical errors. Research on medical expertise may contribute to that as far as it explains reasoning processes involved in clinical judgements. The literature has indicated the capability of critically reflecting upon one’s own practice as a key requirement for developing and maintaining medical expertise throughout life.Objectives  This article explores potential relationships between reflective practice and diagnostic errors.Methods  A survey of the medical expertise literature was canducted. Origins of medical errors frequently reported in the literature were explored. The potential relationship between diagnostic errors and the several dimensions of reflective practice in medicine, brought to light by recent research, were theoretically explored.Results and Dissussion  Uncertainty and fallibility inherent to clinical judgements are discussed. Stages in the diagnostic reasoning process where errors could occur and their potential sources are highlighted, including the role of medical heuristics and biases. The authors discuss the nature of reflective practice in medicine, and explore whether and how the several behaviours and reasoning processes that constitute reflective practice could minimize diagnostic errors. Future directions for further research are discussed. They involve empirical research on the role of reflective practice in improving clinical reasoning and the development of educational strategies to enhancing reflective practice.
Sensing DNA methylation in the protozoan parasite Entamoeba histolytica
Authors: Lavi Tal , Isakov Elada , Harony Hala , Fisher Ohad , Siman‐Tov Rama , Ankri Serge 
Published: October 2006

SummaryIn the protozoan parasite Entamoeba histolytica, 5‐methylcytosine (m5C) was found predominantly in repetitive elements. Its formation is catalysed by Ehmeth, a DNA methyltransferase that belongs to the Dnmt2 subfamily. Here we describe a 32 kDa nuclear protein that binds in vitro with higher affinity to the methylated form of a DNA encoding a reverse transcriptase of an autonomous non‐long‐terminal repeat retrotransposon (RT LINE) compared with the non‐methylated RT LINE. This protein, named E. histolytica‐methylated LINE binding protein (EhMLBP), was purified from E. histolytica nuclear lysate, identified by mass spectrometry, and its corresponding gene was cloned. EhMLBP corresponds to a gene of unknown function that shares strong homology with putative proteins present in Entamoeba dispar and Entamoeba invadens. In contrast, the homology dropped dramatically when non‐Entamoebidae sequences were considered and only a weak sequence identity was found with Trypanosoma and several prokaryotic histone H1. Recombinant EhMLBP showed the same binding preference for methylated RT LINE as the endogenous EhMLBP. Deletion mapping analysis localized the DNA binding region at the C‐terminal part of the protein. This region is sufficient to assure the binding to methylated RT LINE with high affinity. Western blot and immunofluorescence microscopy, using an antibody raised against EhMLBP, showed that it has a nuclear localization. Chromatin immunoprecipitation (ChIP) confirmed that EhMLBP interacts with RT LINE in vivo. Finally, we showed that EhMLBP can also bind rDNA episome, a DNA that is methylated in the parasite. This suggests that EhMLBP may serve as a sensor of methylated repetitive DNA. This is the first report of a DNA‐methylated binding activity in protozoa.
Certain clinically‐utilized antibiotics enhance the behavioural effects of cocaine
Authors: Overton Paul G. , Marrow Lynne P. , Brain Paul F. , Clark David 
Published: October 2006

AbstractCytochrome P‐450s (CYPs) belonging to subfamilies 2B and 3A are the major CYPs involved in the N ‐demethylation of cocaine in the rat. However, the effects of inhibitors of these enzymes on the behavioural actions of cocaine are unknown. Hence, the effects of the CYP 3A inhibitors troleandomycin and erythromycin, and the CYP 2B (and 3A) inhibitor chloramphenicol, were examined on the locomotor activating effects of cocaine (20 mg/kg i.p.). Troleandomycin, chloramphenicol and erythromycin all potentiated the locomotor activating effects of cocaine, although the effect was only statistically significant for the first two drugs. Since variation exists in the human population with respect to the catalytic activity of CYP 3A isozymes, which are the principal cocaine N ‐demethylators in humans, inhibition of CYP 3A by troleandomycin in the rat may be useful as a model of the human cocaine “poor metabolizer” phenotype.
Characteristics of Japanese alcoholics with inactive aldehyde dehydrogenase: clinical features of alcoholics with ALDH2*2
Authors: Nakamura Kazuhiko , Iwahashi Kazuhiko , Itoh Masahiro , Ameno Kiyoshi , Yoshihara Eiji , Fukunishi Isao , Suwaki Hiroshi 
Published: October 2006

AbstractIn a person with inactive ALDH2 (ALDH2*2) the blood aldehyde concentration tends to rise faster and higher and there are flushing responses which are considered to be a restraint against excessive alcohol drinking. The subjects in this study comprised 71 Japanese alcoholics. Psychiatrists interviewed the patients concerning the clinical features. Alcoholics homozygous (n = 59) for ALDH2*1/ALDH2*1 (Group I) and those heterozygous (n = 12) for ALDH2*1/ALDH2*2 (Group II) were compared. Group II alcoholics included significantly more cases of guilt or personality disorder. These findings indicate that alcoholics with the ALDH2*2 genotype showed generally typical clinical features.