bluuebunny/crossref_metadata_2025 huggingface dataset:
Dopamine receptor D3 (DRD3) genotype and allelic variants and risk for essential tremor
Authors: García‐Martín Elena , Martínez Carmen , Alonso‐Navarro Hortensia , Benito‐León Julián , Puertas Inmaculada , Rubio Lluisa , López‐Alburquerque Tomás , Agúndez José A. G. , Jiménez‐Jiménez Félix Javier
Published: July 2009

To investigate the possible association between dopamine receptor D3 genotype (DRD3) and allelic variants and the risk for developing essential tremor (ET). Leukocytary DNA from 201 patients with ET and 282 healthy controls was studied for the genotype DRD3 and the occurrence of DRD3 allelic variants by using allele‐specific PCR amplification and MslI‐RFLP's analyses. A meta‐analysis of previous studies was performed. The frequencies of the DRD3Ser/Gly genotype and of the allelic variant DRDGly were significantly higher in patients with ET than in controls (P < 0.017 and <0.005, respectively), These findings were especially relevant in women (OR = 1.73, 95% CI: 1.15–2.59, P = 0.008), and in patients with earlier onset of the disease with (P = 0.014). The frequencies of the DRD3Ser/Gly and DRD3Gly/Gly genotypes and of the allelic variant DRD3Gly in patients were significantly higher in patients with voice tremor, but not with head, tongue, or chin tremor, than in controls. The meta‐analysis indicated association of variant genotypes with ET risk (OR = 1.18, 95% CI 1.01–1.38). These results suggest that DRD3 genotype and the variant DRD3Gly allelic variant is associated with the risk for and age at onset of ET, and with the risk for voice tremor, in Caucasian Spanish people. © 2009 Movement Disorder Society
Least energy quaternionic regular Lagrange interpolation
Authors: Perotti Alessandro
Published: July 2009

We revisit the concept of a totally regular variable of functions in one quaternionic variable and its application to Lagrange interpolation. We consider left‐regular functions in the kernel of a modified Cauchy–Fueter operator. For every imaginary unit p, let ℂp be the complex plane generated by 1 and p and let Jp be the corresponding complex structure on ℍ. We identify totally regular variables with real‐affine holomorphic functions from (ℍ, Jp) to (ℂp, Lp), where Lp is the complex structure defined by left multiplication by p. We show that every Jp‐biholomorphic map gives rise to a family of Lagrange interpolation formulas for any set of N distinct points in ℍ. In the case of quaternionic regular polynomials of degree at most N, there exists a unique regular interpolating polynomial that minimizes the Dirichlet energy on a domain containing the points. Copyright © 2009 John Wiley & Sons, Ltd.
Introducing INSPIRE, a scholarly component in Undergraduate Medical education
Authors: Zier Karen , Coplit Lisa D.
Published: July 2009

Individualized learning is a fundamental tenet of the Carnegie Foundation's new recommendations for physician training. A primary goal of Mount Sinai School of Medicine's new curriculum is to train self‐directed physicians who have mastered lifelong learning skills. The Individual Scholarly Project and Independent Research Experience (INSPIRE) was created to enable fourth‐year students to conduct mentored, independent scholarly projects to develop critical thinking skills and intellectual independence. Four students were accepted into the 2008 12‐week pilot. Two did clinical research, 1 conducted medical education research, and 1 continued a basic science project. INSPIRE featured weekly sessions in which students shared their progress, heard about the careers of physician‐scientists, and participated in presentation skills workshops. Mentors gave feedback using a form based on the program goals. Anonymous evaluations showed that all participants believed their goals were successfully fulfilled, that the likelihood of including research in their careers increased, and that they felt more skilled at writing abstracts and presenting their work orally. Students agreed that INSPIRE was a valuable opportunity for acquiring in‐depth knowledge on a topic and building research and presentation skills. Helping students shape an individualized scholarly experience may help to produce doctors who are self‐directed, are personally fulfilled, are able to serve society with diverse expertise, and have the tools to become leaders in their fields. Mt Sinai J Med 76:387–391, 2009. © 2008 Mount Sinai School of Medicine
Direct Observation in Medical Education: A Review of the Literature and Evidence for Validity
Authors: Fromme H. Barrett , Karani Reena , Downing Steven M.
Published: July 2009

In 2000, the Accreditation Council for Medical Education introduced a new initiative that substantively changed the method by which residency programs are evaluated. In this new competency‐based approach to residency education, assessment of performance became a main area of interest, and direct observation was offered as a tool to assess knowledge and skills. Despite being an inherent part of medical education as faculty and learners work together in clinical experiences, direct observation has traditionally been an informal and underused assessment method across all specialties. Residents and students report rarely being observed during their educational process, even though they value the experience. Reasons for this include a lack of faculty time, a lack of faculty skills, a potential stressful effect on the learner, and a perceived lack of validation of the assessment. This article examines the literature regarding the use of direct observation in medical education with a focus on validity evidence. We performed a PubMed search of articles pertaining to direct observation, using key words such as direct observation, performance observation, clinical observation, students, and residents. A subsequent search was conducted in known articles, focusing on variations of the term observation in the titles of articles and introducing the concept of clinical competence. In conclusion, direct observation is a unique and useful tool in the assessment of medical students and residents. Assessing learners in natural settings offers the opportunity to see beyond what they know and into what they actually do, which is fundamentally essential to training qualified physicians. Although the literature identifies several threats to its validity as an assessment, it also demonstrates methods to minimize those threats. Based on the current recommendations and need for performance assessment in education and with attention paid to the development and design, direct observation can and should be included in medical education curricula. Mt Sinai J Med 76:365–371, 2009. © 2008 Mount Sinai School of Medicine
The Risk of Upper Aero Digestive Tract Cancer associated with Smoking, with and without Concurrent Alcohol Consumption
Authors: Ansary‐Moghaddam Alireza , Huxley Rachel R. , Lam Tai Hing , Woodward Mark
Published: July 2009

Background Smoking and alcohol are major causal factors for upper aerodigestive tract cancer, but reliable quantification of the combined impact of smoking and alcohol on this cancer and its major subtypes has not been performed.

Methods A meta‐analysis of studies that had published quantitative estimates of smoking and upper aerodigestive tract cancer by January 2007 was performed. Pooled estimates of relative risks were obtained. Publication bias was investigated through funnel plots and corrected if found to be present.

Results Overall, 85 studies with information on 53,940 individuals with upper aerodigestive tract cancer were included. The pooled estimate for the association between smoking and the risk of this cancer was 3.47 (95% confidence interval, 3.06–3.92). The risk remained elevated for a decade after smoking cessation but declined thereafter. Individuals who both smoked and consumed alcohol had double the risk of upper aerodigestive tract cancer in comparison with those who only smoked: the relative risk was 6.93 (95% confidence interval, 4.99–9.62) for the former and 2.56 (95% confidence interval, 2.20–2.97) for the latter (P < 0.001).

Conclusions Public health interventions that simultaneously discourage smoking and heavy drinking would have greater benefits than would be expected from those that target only one of these risk factors. Mt Sinai J Med 76:392–403, 2009. © 2008 Mount Sinai School of Medicine
Evaluating the Impact of the Humanities in Medical Education
Authors: Schwartz Andrea Wershof , Abramson Jeremy S. , Wojnowich Israel , Accordino Robert , Ronan Edward J. , Rifkin Mary R.
Published: July 2009

The inclusion of the humanities in medical education may offer significant potential benefits to individual future physicians and to the medical community as a whole. Debate remains, however, about the definition and precise role of the humanities in medical education, whether at the premedical, medical school, or postgraduate level. Recent trends have revealed an increasing presence of the humanities in medical training. This article reviews the literature on the impact of humanities education on the performance of medical students and residents and the challenges posed by the evaluation of the impact of humanities in medical education. Students who major in the humanities as college students perform just as well, if not better, than their peers with science backgrounds during medical school and in residency on objective measures of achievement such as National Board of Medical Examiners scores and academic grades. Although many humanities electives and courses are offered in premedical and medical school curricula, measuring and quantifying their impact has proven challenging because the courses are diverse in content and goals. Many of the published studies involve self‐selected groups of students and seek to measure subjective outcomes which are difficult to measure, such as increases in empathy, professionalism, and self‐care. Further research is needed to define the optimal role for humanities education in medical training; in particular, more quantitative studies are needed to examine the impact that it may have on physician performance beyond medical school and residency. Medical educators must consider what potential benefits humanities education can contribute to medical education, how its impact can be measured, and what ultimate outcomes we hope to achieve. Mt Sinai J Med 76:372–380, 2009. © 2008 Mount Sinai School of Medicine
A higher‐order discontinuous enrichment method for the solution of high péclet advection–diffusion problems on unstructured meshes
Authors: Farhat C. , Kalashnikova I. , Tezaur R.
Published: July 2009

A higher‐order discontinuous enrichment method (DEM) with Lagrange multipliers is proposed for the efficient finite element solution on unstructured meshes of the advection–diffusion equation in the high Péclet number regime. Following the basic DEM methodology, the usual Galerkin polynomial approximation is enriched with free‐space solutions of the governing homogeneous partial differential equation (PDE). In this case, these are exponential functions that exhibit a steep gradient in a specific flow direction. Exponential Lagrange multipliers are introduced at the element interfaces to weakly enforce the continuity of the solution. The construction of several higher‐order DEM elements fitting this paradigm is discussed in detail. Numerical tests performed for several two‐dimensional benchmark problems demonstrate their computational superiority over stabilized Galerkin counterparts, especially for high Péclet numbers. Copyright © 2009 John Wiley & Sons, Ltd.
Activists playing a dual role: identities, organizational goals, and public relations practices
Authors: Jiang Hua , Ni Lan
Published: July 2009

This study explores the relationship among identities, goals, and public relations practices of an activist organization through in‐depth interviews and document analysis. Findings suggest different levels of the participant organization's identity in communication with its different audiences. In playing its dual role (as a “public” to its target organizations and a “public communicator” to its own publics), the organization acts as an honest representative voice and a credible source of information to both parties, a process that requires a balance position compatible with its mission. Its public relations practices were found to be consistent with the identities it appropriates and the values it respects.

Copyright © 2009 John Wiley & Sons, Ltd.
Characterisation of melt‐processed poly(ethylene terephthalate)/synthetic mica nanocomposite sheet and its biaxial deformation behaviour
Authors: Soon Kok H , Harkin‐Jones Eileen , Rajeev Rajvihar S , Menary Gary , McNally Tony , Martin Peter J , Armstrong Cecil
Published: July 2009

BACKGROUND: Poly(ethylene terephthalate) (PET) is widely used in the packaging industry. In order to enhance the mechanical and barrier properties, nanoscale fillers are added to PET matrices to form nanocomposites. In the work reported here, a melt‐processed PET/synthetic mica nanocomposite sheet was characterised to determine the effect of the incorporation of synthetic mica on the sheet properties and also to see if these properties are an indicator of subsequent performance under high‐speed, high‐temperature biaxial deformation, typical of processes such as stretch blow moulding.

RESULTS: The incorporation of synthetic mica was found to enhance the modulus, particularly above the glass transition temperature, and barrier properties of the extruded sheet and it significantly altered the deformation behaviour of PET under biaxial deformation. The plastic flow of PET during biaxial deformation was found to diminish for the nanocomposites, and strain hardening occurred earlier.

CONCLUSION: The modulus and barrier properties of PET were enhanced by the incorporation of synthetic mica. Clay loading also altered the biaxial deformation behaviour of PET. Copyright © 2009 Society of Chemical Industry
Wheezing, sleeping, and worrying: The hidden risks of asthma and obesity in school‐age children
Authors: Fiese Barbara H. , Everhart Robin S. , Wildenger Leah
Published: July 2009

The present study investigated the co‐occurrence of asthma and obesity in a sample of 193 children (mean age = 7.76 years). Specifically, this study was interested in delineating the associated comorbidities of internalizing symptoms and sleep disruptions among younger (younger than 7 years) and older elementary age children with asthma who were also overweight. Information about child internalizing symptoms (among other areas of functioning) was collected from teacher ratings of child behavior. Data regarding nighttime waking, morning symptoms, and school days missed were obtained from parent reports. Findings suggest that older elementary age children with asthma who are overweight are more likely to experience internalizing symptoms and more nighttime waking than their average weight peers. Implications include the important role of teachers in identifying these children who might be at increased risk for internalizing symptoms and the consequences of such symptoms. © 2009 Wiley Periodicals, Inc.
Reactivity of mixed organozinc and mixed organocopper reagents. Part 4: a kinetic study of group transfer selectivity in CC coupling of mixed diorganocuprates
Authors: Erdik Ender , Özkan Duygu
Published: July 2009

The competitive rate data and Taft relationships for the coupling of bromomagnesium n‐butyl (substituted phenyl) cuprates with alkyl bromides show that selective n‐butyl transfer can be explained by an oxidative addition mechanism. Taft reaction constants also show that the residual group FG‐C6H4 in the mixed cuprate n‐Bu(FG‐C6H4)CuMgBr changes the ability of the copper nucleophile to react with the electrophile RBr. These results provide support for the commonly accepted hypothesis regarding the dependence of the R1 group transfer ability on the strength of R2Cu bond in reactions of R1R2CuMgBr reagents. Copyright © 2009 John Wiley & Sons, Ltd.
A proteomic approach combining MS and bioinformatic analysis for the detection and identification of biomarkers of administration of exogenous human growth hormone in humans
Authors: Boateng Joshua , Kay Richard , Lancashire Lee , Brown Pamela , Velloso Cristiana , Bouloux Pierre , Teale Phil , Roberts Jane , Rees Robert , Ball Graham , Harridge Stephen , Goldspink Geoffrey , Creaser Colin
Published: July 2009

An integrated MS‐based proteomic approach is described that combines MALDI‐MS and LC‐MS with artificial neural networks for the identification of protein and peptide biomarkers associated with recombinant human growth hormone (rhGH) administration. Serum from exercised males administered with rhGH or placebo was analysed using ELISA to determine insulin‐like growth factor‐I concentrations. Diluted serum from rhGH‐ and placebo‐treated subjects was analysed for protein biomarkers by MALDI‐MS, whereas LC‐MS was used to analyse tryptically digested ACN‐depleted serum extracts for peptide biomarkers. Ion intensities and m/z values were used as inputs to artificial neural networks to classify samples into rhGH‐ and placebo‐treated groups. Six protein ions (MALDI‐MS) correctly classified 96% of samples into their respective groups, with a sensitivity of 91% (20 of 22 rhGH treated) and specificity of 100% (24 of 24 controls). Six peptide ions (LC‐MS) were also identified and correctly classified 93% of samples with a sensitivity of 90% (19 of 21 rhGH treated) and a specificity of 95% (20 of 21 controls). The peptide biomarker ion with the highest significance was sequenced using LC‐MS/MS and database searching and found to be associated with leucine‐rich α‐2‐glycoprotein.
Proteomics‐based characterization of hemagglutinins in different strains of influenza virus
Authors: Getie‐Kebtie Melkamu , Chen David , Eichelberger Maryna , Alterman Michail
Published: July 2009

Infection with influenza A (subtypes H1N1 and H3N2) or B viruses results in over half a million deaths worldwide every year. Frequent antigenic changes (drift) in two major viral surface proteins hemagglutinin (HA) and neuraminidase lead to the constant emergence of antigenically distinct virus strains against which there is sub‐optimal immunity in the population. Consequently the suitability of the viral strains included in the trivalent influenza vaccine (TIV) has to be re‐evaluated annually. While virus seeds selected for vaccine manufacture are very well characterized, there is no assay in place to identify the source of HA in the formulated trivalent vaccine. Our study describes a proteomics‐based method to identify the HA strain (not just subtype) and more fully characterize the final vaccine product. Unique and shared tryptic peptides of HAs were predicted by in silico tryptic digest of different influenza A and B virus strains. Recombinant HA and whole virus preparations of selected strains were then digested to identify the peptides detected by MS. Both subtype and strain‐specific peptides were observed. The feasibility of this method to accurately identify HA strains in an inactivated TIV was tested using a 2006/2007 formulation. Each of the three HAs in the vaccine was identified in addition to a number of other viral and non‐viral proteins. In summary, MS is a powerful method that is both specific and inclusive; in a single analysis, HAs of individual virus strains can be identified and the composition of the TIV fully characterized.
Effect of Leucine and Lysine substitution on the antimicrobial activity and evaluation of the mechanism of the HPA3NT3 analog peptide
Authors: Gopal Ramamourthy , Park Seong‐Cheol , Ha Kyeoung‐Ju , Cho Seung Joo , Kim Si Wouk , Song Peter I. , Nah Jae‐Woon , Park Yoonkyung , Hahm Kyung‐Soo
Published: July 2009

In this study, a HPA3NT3‐analog (FKKLKKLFKKILKLK‐NH2) peptide was designed. In this analog, two Trp residues (positions 12, 14) were replaced with Leu, and Arg and Asn (positions 3, 13) were replaced with Lys to investigate the role of amino acid substitution and increased cationicity on antimicrobial and hemolytic activities. In fungal and Gram‐negative bacterial cells, HPA3NT3‐analog activity was unchanged or slightly enhanced when compared to the HPA3NT3 peptide. In addition, a twofold decrease in activity against Gram‐positive bacteria was observed. The HPA3NT3‐analog also induced less hemolysis (4.2%) than the HPA3NT3 peptide (71%) at 200 µM. Circular dichroism (CD) spectra revealed that the HPA3NT3‐analog peptide had an unordered structure in buffer and egg yolk L‐2‐phosphatidyl choline (EYPC), but adapted an α‐helical conformation in 50% 2,2,2‐trifluoroethanol (TFE) and negatively charged egg yolk L‐2‐phosphatidyl glycerol (EYPG), while the parent peptide showed an ordered structure in the EYPC. Additionally, the HPA3NT3‐analog peptide induced the leakage of calcein from egg yolk L‐2‐phosphatidyl ethanolamine (EYPE)/EYPG (7:3 w/w) large unilamellar vesicles (LUVs); however, the activity was slightly weaker than that of the HPA3NT3 peptide. The molecular dynamics (MD) structures revealed that the amino acid substitutions induced a significant variation in peptide structure. These results suggest that the substitutions of Arg and Asn with Lys and two Trp with Leu resulted in small changes in HPA3NT3‐analog activity and significant decreases in hemolytic activity. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Electron momentum distribution in SnS
Authors: Sharma G. , Sharma M. , Mishra M. C. , Joshi K. B. , Kothari R. K. , Sharma B. K.
Published: July 2009

A study of electron momentum density distribution in SnS by means of Compton profiles is presented. The measurement on polycrystalline sample of SnS is performed employing 59.54 keV gamma‐rays emanating from an Am241 radioisotope. The calculations are performed on the basis of density‐functional theory based ab‐initio linear combination of atomic orbitals method embodied in the CRYSTAL program. The correlation scheme proposed by von Barth and Hedin is adopted. The generalized gradient approximation proposed by Perdew and Wang is also considered to treat the correlation. The exchange is treated following the Becke scheme. Both the correlation schemes are in good agreement with the measurement. The better agreement with experimental result is, however, observed with the von Barth and Hedin correlation that also gives lower ground‐state energy than the Perdew–Wang generalized gradient approximation. Ionic model calculations for a number of configurations of Sn+xS−x (0.0 ≤ x ≤ 2) are also performed utilizing free‐atom profiles. The ionic model suggests transfer of 2.0 electrons from the valence 5p state of Sn to the 3p state of S.
Temperature dependence of the noise amplitude in graphene and graphene oxide
Authors: Goldsmith B. R. , Lu Ye , Luo Zhengtang , Johnson A. T.
Published: July 2009

Graphene and related materials such as carbon nanotubes and graphene oxide are promising materials for future applications in chemical sensing and electronics. Electronic noise in these materials is typically very high due to the low number of carriers and the inverse dependence of 1/f noise on the number of carriers. We have investigated the changes in 1/f noise amplitude with temperature in exfoliated graphene and reduced graphene oxide devices. We show that using reduced graphene oxide results in an intriguing environmental coupling to noise amplitude. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of chemical bonds in metalloenzymes XIII: Singlet and triplet diradical mechanisms of hydroxylations with iron‐oxo species and P450 are revisited
Authors: Yamaguchi Kizashi , Yamanaka Syusuke , Isobe Hiroshi , Shoji Mitsuo , Saito Toru , Kitagawa Yasutaka , Okumura Mitsutaka , Shimada Jiro
Published: July 2009

Electronic structures of the Compound I (CpdI) in P450 are investigated on the basis of spin coupling forms of iron‐oxo (Fe(IV)O) cores and radical ligand (•L) groups to generalize previous singlet and triplet diradical (TD) mechanisms for oxygenations of alkanes with Fe( IV)O. Orbital interaction schemes for four lower‐lying spin configurations of CpdI with HC bond of substrate are examined to elucidate how magnetic coupling modes correlate with radical reaction pathways for hydroxylation reactions on the basis of the broken symmetry (BS) molecular orbital (MO) model. The configuration correlation diagrams for the four configurations model are depicted on the basis of the isoelectronic analogy among O, O2, and Fe( IV)O, in addition to Coulomb exchange energy on the iron site, which determines its local spin configuration. Important role of ligand spin (•L) of CpdI for regulation of hydroxylation mechanisms is clarified with the aid of the spin coupling forms. Transition states for one quartet and three doublet configurations under the BS MO approximation are examined on the basis of potential curve crossings along reaction pathways. The four transition structures and corresponding radical intermediates for methane and trimethyl methane with CpI are located by the BS hybrid Kohn–Sham density functional theory (DFT) (B3LYP) method to confirm the orbital interaction schemes. Spin density populations obtained by the BS B3LYP calculations are found to be consistent with the theoretical predictions based on the four configurations model. The configuration and state correlation diagrams by BS B3LYP before and after spin projection are also consistent with the BS MO interaction schemes, which provide local SD and TD mechanisms of hydroxylation with CpdI. The present BS MO‐theoretical framework is useful for systematic understanding of a lot of recent BS hybrid DFT computational results for hydroxylation reactions with CpdI and configuration correlation diagrams reported by several groups. Implications of the present theoretical and computational results are discussed in relation to several experimental characteristics of hydroxylation reactions with iron‐oxo species and P450. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The host‐defence skin peptide profiles of Peron's Tree Frog Litoria peronii in winter and summer. Sequence determination by electrospray mass spectrometry and activities of the peptides
Authors: Bilusich Daniel , Jackway Rebecca J. , Musgrave Ian F. , Tyler Michael J. , Bowie John H.
Published: July 2009

Positive and negative ion electrospray mass spectrometry together with Edman sequencing (when appropriate) has been used to sequence the host‐defence peptides secreted from skin glands of the tree frog Litoria peronii. The peptide profiles are different in winter and summer. In winter, the frog produces small amounts of the known caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL‐NH2] (a wide‐spectrum antibiotic) and caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA‐OH], a narrow‐spectrum antibiotic and an inhibitor of neuronal nitric oxide synthase. The major peptides produced throughout the year are the pGlu‐containing peroniins 1.1 to 1.5 (e.g. peroniin 1.1 [pEPWLPFG‐NH2], a smooth muscle contractor from 10−7 M), and caerulein [pEQDY(SO3H)TGWMDF‐NH2], a known and potent smooth muscle contractor from 10−10 M. There are also some precursors to the peroniin 1 peptides, only detected in the skin secretion in summer, which are inactive and appear to be all (or part) of the spacer peroniin 1 peptides, e.g. peroniin 1.1b [SEEEKRQPWLPFG‐NH2]. There are three members of the Litoria peronii Group of tree frogs classified in Australia, namely, L. peronii, L. rothii and L.tyleri. A comparison of the skin peptide profiles of L. peronii with those reported previously for L. rothii suggests that either these two species of tree frog are not as closely related as determined previously on morphological grounds, or that skin peptide divergence in tree frogs of this Group is more extensive than in others that have been studied. Copyright © 2009 John Wiley & Sons, Ltd.
Efficient rekeying algorithms for WiMAX networks
Authors: Brown Jeremy , Du Xiaojiang , Guizani Mohsen
Published: July 2009

In this paper, we study the rekeying issue in IEEE 802.16e WiMAX networks. The existing rekeying scheme—the Multicast and Broadcast Rekeying Algorithm (MBRA) unicasts new keys to each subscriber station (SS). This scheme does not scale well since it incurs large communication overheads when the number of SSs increase. In our work, first we propose a general tree‐based rekeying scheme, which is more efficient than the MBRA. We also formulate an optimization problem to determine the optimal tree structure for given number of SSs. Furthermore, we present a novel and efficient rekeying scheme for WiMAX networks. Our new rekeying scheme utilizes efficient security schemes and the WiMAX network application feature. Both analysis and performance evaluation show that our rekeying scheme can significantly reduce the communication overheads. Copyright © 2009 John Wiley & Sons, Ltd.
Year of birth determination using radiocarbon dating of dental enamel
Authors: Buchholz B. A. , Spalding K. L.
Published: July 2009

Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently, however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite, and carbon‐14 (14C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, 14C levels in the enamel represent 14C levels in the atmosphere at the time of its formation. In this paper, we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases, police will try to match particulars of the unidentified individual, which is often only gender and/or an estimate of age, with particulars from missing persons lists. Copyright © 2009 John Wiley & Sons, Ltd.
A hierarchical model for binary data with dependence between the design and outcome success probabilities
Authors: Todem David , Williams Karen Patricia
Published: July 2009

Statistical theory requires that analysis of study outcomes be conducted conditional on the design process. Ignoring this process may result in severely biased estimates, leading to false inferences, especially when the outcome variable is associated with design variables. We propose in this paper a class of hierarchical models to investigate the dependence between the design process and the study outcomes of primary interest. We discuss a fully parametric and a semi‐parametric formulation of the hypothesized model and propose the EM algorithm to obtain maximum likelihood estimates. Our numerical results show that the semi‐parametric approach outperforms the fully parametric model with respect to some key features of the model. The methodology is used to gain insight into the mechanism that generates breast cancer literacy outcomes in a study conducted among medically underserved females in Michigan. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of fidelity of implementation on science achievement gains among english language learners
Authors: Lee Okhee , Penfield Randall , Maerten‐Rivera Jaime
Published: July 2009

This study examined the effect of fidelity of implementation (FOI) on the science achievement gains of third grade students broadly and students with limited literacy in English specifically. The study was conducted in the context of a professional development intervention with elementary school teachers to promote science achievement of ELL students in urban schools. As the criterion for measuring FOI, we focused on the quality of instructional delivery in teaching science to ELL students. We measured FOI using both teachers' self‐reports and classroom observations during the first year of the intervention. Science achievement was measured by a pretest and posttest over the school year. The results indicate that none of the measures of FOI using teachers' self‐reports or classroom observations had significant effects on science achievement gains. The results are discussed in terms of issues about conceptualization and measurement of FOI in educational interventions. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 836–859, 2009
Keyhole sign: how specific is it for the diagnosis of posterior urethral valves?
Authors: Bernardes L. S. , Aksnes G. , Saada J. , Masse V. , Elie C. , Dumez Y. , Lortat‐Jacob S. L. , Benachi A.
Published: July 2009

Objectives

Posterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. Although antenatal suspicion of this pathology has become quite common in recent years, prenatal diagnosis remains challenging. The aim of this study was to evaluate the predictive value of different ultrasound criteria currently used to diagnose PUV.

Methods

We reviewed the antenatal and postnatal files of 54 male patients referred to our center from 2000 to 2006 after detection of fetal bilateral hydronephrosis. The following ultrasound criteria were evaluated in relation to the postnatal diagnosis of PUV: amniotic fluid volume, bladder wall thickness, bladder dilatation and the presence of the ‘keyhole sign’.

Results

Forty‐two fetuses (77.8%) were suspected to have PUV on prenatal examination. Out of these, 29 (69.0%) had PUV confirmed postnatally. The sensitivity and specificity of the antenatal diagnosis of PUV were 94% and 43%, respectively. Increased bladder wall thickness and bladder dilatation were highly associated with the diagnosis of PUV (P < 0.001). However, a thick‐walled bladder was observed in 39.1% and a dilated bladder in 47.8% of the infants with a postnatal diagnosis other than PUV. The presence of the keyhole sign was not found to predict a diagnosis of PUV (P = 0.27).

Conclusion

In this series the use of classical prenatal ultrasound signs to diagnose PUV showed high sensitivity but low specificity. The best diagnostic indicators were increased bladder wall thickness and dilatation of the bladder. The keyhole sign was not found to be a reliable predictor of PUV. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Performance study for HARQ–ARQ interaction of LTE
Authors: Chuang Ching‐Hsiang , Lin Phone
Published: July 2009

The 3GPP working group proposes the Long‐Term Evolution (LTE) system as the 4G mobile communications technology. To reduce the transmission latency in the radio access network, Evolved Universal Terrestrial Radio Access Network (E‐UTRAN), of LTE, the base station and radio network controller are merged into a single network node, namely eNB. In E‐UTRAN, the Stop‐And‐Wait Hybrid ARQ (SAW‐HARQ) protocol in the Media Access Control (MAC) layer deals with transmission errors without the need to engage the ARQ protocol in the Radio Link Control (RLC) layer. The HARQ and ARQ protocols interact only in case of dealing HARQ residual errors. In this paper, we propose an analytical model to model the behavior of the HARQ–ARQ Interaction. Our analytical model is validated against the simulation experiments that provide more performance metrics (which cannot be obtained through our analytical model). Finally, we investigate the impacts of the HARQ–ARQ Interaction on the Protocol Data Unit (PDU) transmission delay based on our simulation experiments. Copyright © 2009 John Wiley & Sons, Ltd.
The Methyl Group at C2 Carbon in {(2‐C4H3S)–C2(Me)=N–NH–C1(=S)NH2} Alters Iodide‐Bridging to Sulfur‐Bridging in Copper(I) Iodide Complexes
Authors: Lobana Tarlok S. , Sharma Rekha
Published: July 2009

The presence of methyl group at C2 carbon in {(2‐C4H3S)–C2(Me)=N–NH–C1(=S)NH2} leads to the formation of a sulfur‐bridged dinuclear complex [Cu2(μ‐S–Hattsc)2(η1‐I)2(Ph3P)2]·2H2O (1), in reaction of copper(I) iodide with the 2‐acetylthiophene thiosemicarbazone (Hattsc), unlike the usual iodo‐bridging in the absence of methyl substituent at C2 carbon. Water molecules are entrapped in eighteen membered cavities of 1D network.
Dimorphic Modification of the Trinuclear Nickel(II) Complex [Ni3(NCS)6(pdz)6]: Synthesis, Crystal Structure, Thermal, Magnetic and Spectroscopic Properties
Authors: Wriedt Mario , Näther Christian
Published: July 2009

Reaction of nickel(II) thiocyanate and pyridazine (pdz) as organic spacer ligand leads to the formation of the ligand‐rich 1:2 (1:2 = metal to ligand ratio) trinuclear nickel(II) complex of composition [Ni3(NCS)6(pdz)6]. Depending on the reaction solvent, different polymorphic modifications are obtained: Reaction in acetonitrile leads to the formation of the new modification 1I and reaction in ethanol leads to the formation of modification 1II reported recently. In their crystal structures discrete [Ni3(NCS)6(pdz)6] units are found, in which each of the Ni2+ cations exhibits a NiN6 distorted octahedral arrangement. The central Ni2+ cation is coordinated by four bridging pdz ligands and two thiocyanato anions in trans positions. Both thiocyanato anions exhibit the end‐on bridging mode. The peripheral Ni2+ cations are bridged by one thiocyanato anion and by two pdz ligands with the central Ni2+ cation. Further they are coordinated by two terminal N‐bonded thiocyanato anions and one terminal N‐bonded pdz ligand. The structure of 1I was determined by X‐ray single crystal structure investigation and emphasized by infrared spectroscopy. Magnetic measurements revealed a quasi Curie behavior with net ferromagnetic interactions for 1I and net antiferromagnetic interactions for 1II. Solvent‐mediated conversion experiments clearly show that modification 1I represents the thermodynamic most stable form at room temperature and that modification 1II is metastable. On thermal decomposition, both modification transform quantitatively in a new ligand‐deficient intermediate. Elemental analysis revealed a 3:4 compound of composition [Ni3(NCS)6(pdz)4]. A structure model supported by IR spectroscopic investigations was assumed, in which three coordination modes of the thiocyanato anion exist, resulting in a 2D polymeric network.
Torsional wave dispersion relations in a pre‐stressed bi‐material compounded cylinder
Authors: Ozturk A. , Akbarov S.D.
Published: July 2009

Within the framework of the piecewise homogeneous body model and through the application of the three‐dimensional linearized theory of elastic waves in an initially stressed body, the torsional wave dispersion in pre‐stretched bi‐material compounded cylinders is investigated. It is assumed that the elasticity relations of the materials of the components of the cylinders are given through the Murnaghan potential. The numerical investigations are made for steel (St) (as a material for the solid cylinder) and bronze (Br) (as a material for a hollow covering cylinder). According to the numerical results obtained, the influence of the problem parameters such as the initial stresses in the components of the bi‐material compounded cylinder, the values of the mechanical and physical constants of the components, and the geometrical parameters (such as the relation of the thickness of the covering cylinder with the radius of the inner solid cylinder on the dispersion curves) are analyzed.
Iterative solvers within sequences of large linear systems in non‐linear structural mechanics
Authors: Hartmann S. , Duintjer Tebbens J. , Quint K.J. , Meister A.
Published: July 2009

This article treats the computation of discretized constitutive models of evolutionary‐type (like models of viscoelasticity, plasticity, and viscoplasticity) with quasi‐static finite elements using diagonally implicit Runge‐Kutta methods (DIRK) combined with the Multilevel‐Newton algorithm (MLNA). The main emphasis is on promoting iterative methods, as opposed to the more traditional direct methods, for solving the non‐symmetric systems which occur within the DIRK/MLNA. It is shown that iterative solution of the arising sequences of linear systems can be substantially accelerated by various techniques that aim at sharing part of the computational effort throughout the sequence. In this way iterative solution becomes attractive at clearly lower dimensions than the dimensions where direct solvers start to fail for memory reasons. The applications are related to small strain viscoplasticity of a smooth constitutive model for plastics and a finite strain plasticity model with non‐linear kinematic hardening developed for metals.
Discrepancy Between the Extent of Pancreatic Necrosis and Multiple Organ Failure Score in Severe Acute Pancreatitis
Authors: Mole Damian J. , McClymont Katie L. , Lau Sarah , Mills Rosamund , Stamp‐Vincent Christopher , Garden O. James , Parks Rowan W.
Published: July 2009

Background

Whether pancreatic necrosis is a prerequisite for the development of multiorgan failure (MOF) in severe acute pancreatitis (AP) is not clear and has implications for the rational design of translational therapies. This study was designed to investigate the magnitude of any association between MOF and radiologically evident pancreatic or extrapancreatic complications of AP.

Methods

Data regarding 276 patients with AP were analyzed retrospectively with regard to clinical presentation, MOF severity, computerized tomography (CT) evidence of pancreatic necrosis, and modified CT severity index (MCTSI).

Results

Agreement between the presence of necrosis and MOF status was seen in 160 of 276 patient episodes (58%; 95% confidence intervals (CI), 52.1–63.8%). In 116 of 276 episodes, the MCTSI and MOF scores disagreed (42%; 95% CI, 36.2–47.9%). CT evidence of pancreatic necrosis was present in 21 of 104 (20.2%) patients without any evidence of MOF, and there was no evidence of necrosis on CT scan in 95 of 176 (54%) patients with MOF. Full‐factorial univariate analysis suggested that extrapancreatic complications seen on CT, in particular intra‐abdominal fluid collections (effect size = 0.02; P = 0.016) and abnormal liver enhancement (effect size = 0.035; P = 0.031) were associated with severity of MOF, and exerted an even greater effect when they occurred synchronously.

Conclusions

The discrepancy between the presence of necrosis and the occurrence of MOF favors association but not cause in AP. A complex, systems‐based, pleiotropic inflammatory network with a common root, in which the extent of pancreatic necrosis influences the severity of MOF in certain individuals and MOF exacerbates the development of pancreatic necrosis in others, seems more likely.
Life‐history variation following habitat degradation associated with differing fine‐scale spatial genetic structure in a rainforest cycad
Authors: Lopez‐Gallego Cristina , O'Neil Pamela
Published: July 2009

Habitat degradation can result in drastic environmental changes potentially affecting the life‐history of populations and aspects of the reproductive biology and the genetic structure within and among populations. Here, we explore how life‐history differences between subpopulations from contrasting habitats may affect mating availability, which in turn will indirectly affect the strength of spatial genetic structure within populations of a tropical rainforest cycad (Zamia fairchildiana). Subpopulations exposed to higher light availability in degraded‐forest habitats had male individuals that grew faster, reproduced earlier, and invested more in reproduction than in native‐forest habitat subpopulations. These differences in life history resulted in degraded‐habitat subpopulations showing a higher proportion of reproductive adults and greater mate availability in a reproductive season. Subpopulations in the degraded habitat showed weaker SGS, i.e., a smaller slope in the linear regression of genetic relatedness on linear distance. Environmentally induced changes in life history and subsequent changes in the strength of the SGS after habitat degradation may have important consequences for population viability and should be of concern in conservation.
Synthesis and Characterization of ZnO Nanowire–CdO Composite Nanostructures
Authors: Senthil Karuppanan , Tak Youngjo , Seol Minsu , Yong Kijung
Published: July 2009

ZnO nanowire–CdO composite nanostructures were fabricated by a simple two-step process involving ammonia solution method and thermal evaporation. First, ZnO nanowires (NWs) were grown on Si substrate by aqueous ammonia solution method and then CdO was deposited on these ZnO NWs by thermal evaporation of cadmium chloride powder. The surface morphology and structure of the synthesized composite structures were analyzed by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The optical absorbance spectrum showed that ZnO NW–CdO composites can absorb light up to 550 nm. The photoluminescence spectrum of the composite structure does not show any CdO-related emission peak and also there was no band gap modification of ZnO due to CdO. The photocurrent measurements showed that ZnO NW–CdO composite structures have better photocurrent when compared with the bare ZnO NWs.
Mikrozephaliesyndrome und geistige Behinderung
Authors: Wieczorek D.
Published: July 2009

Die Ursachenabklärung der mentalen Retardierung, die mit einer Prävalenz von 2–3% in der Bevölkerung vorliegt, ist eine häufige Fragestellung in der klinisch-genetischen Sprechstunde. Ausgehend vom Leitsymptom Mikrozephalie, die ebenfalls mit einer Prävalenz von 2–3% angegeben wird, soll anhand der zugrunde liegenden Erbgänge ein Überblick über verschiedene Krankheitsbilder mit Mikrozephalie und Entwicklungsverzögerung/mentaler Retardierung gegeben werden. Die Winter-Baraitser-Dysmorphology-Database führt in der aktuellen Version 558 Krankheitsbilder mit diesen beiden klinischen Zeichen auf. Dies macht deutlich, dass die nachfolgende Übersicht nur einen Ausschnitt dieses umfassenden Gebiets der klinischen Genetik/Dysmorphologie wiedergeben kann.
Genetik der nichtsyndromalen geistigen Behinderung
Authors: Tzschach A.
Published: July 2009

Die meisten Patienten mit mentaler Retardierung (MR) sind von nichtsyndromaler MR (NS-MR) betroffen, d. h. sie weisen entweder überhaupt keine zusätzlichen klinischen, radiologischen oder metabolischen Merkmale auf oder die weiteren Auffälligkeiten sind für die Zuordnung zu einem etablierten Fehlbildungssyndrom nicht spezifisch genug. In den letzten Jahren wurden erhebliche Fortschritte bei der Aufklärung X-chromosomal vererbter Formen der NS-MR erzielt, und auch bei der Erforschung autosomaler NS-MR sind erste Erfolge zu verzeichnen. Beide Formen sind durch ausgeprägte genetische Heterogenität gekennzeichnet. Eine routinemäßige Mutationsanalyse in den bekannten NS-MR-Genen ist derzeit bei sporadischen Patienten nur begrenzt möglich und wird erst mit der Einführung neuer Sequenziertechnologien breite Anwendung finden. Im Gegensatz dazu können Patienten mit familiärer NS-MR bereits jetzt in molekulargenetische Screeningprogramme eingeschlossen werden. In der aktuellen Routinediagnostik sind aufgrund klinischer Überlappungen mit syndromalen MR-Formen auch mehrere Gene für die X-chromosomale NS-MR von Bedeutung.
Angeborene Hirnfehlbildungen und geistige Behinderung
Authors: Uyanik G. , Hehr U.
Published: July 2009

Hirnfehlbildungen sind klinisch und genetisch bedeutsame Ursachen für psychomotorische Entwicklungsstörungen und Epilepsien. Die diagnostische Einordnung erfolgt durch bildgebende Verfahren und ist die Grundlage für eine individuelle genetische Abklärung und für zuverlässige prognostische Aussagen. Für einen beträchtlichen Teil der Hirnfehlbildungen sind die molekularen Ursachen bereits bekannt. Mutationen in diesen Genen können mit milden Verlaufsformen assoziiert sein, bis hin zur geistigen Behinderung ohne strukturelle Hirnfehlbildungen. Die Aufklärung der molekulargenetischen Ursachen von Hirnfehlbildungen trägt zum besseren Verständnis der Gehirnentwicklung bei und eröffnet gleichzeitig neue Einsichten in die Pathophysiologie von geistiger Behinderung und Epilepsie. Darüber hinaus ermöglicht sie die Erkennung und individuelle genetische Beratung von Anlageträgern und ist eine Voraussetzung für die pränatale molekulargenetische Diagnostik in Risikofamilien.