bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal and inter-annual variability of plankton chlorophyll and primary production in the Mediterranean Sea: a modelling approach
Authors: Lazzari P. , Solidoro C. , Ibello V. , Salon S. , Teruzzi A. , Béranger K. , Colella S. , Crise A.
Published: January 2012

Abstract. This study presents a model of chlorophyll and primary production in the pelagic Mediterranean Sea. A 3-D-biogeochemical model (OPATM-BFM) was adopted to explore specific system characteristics and quantify dynamics of key biogeochemical variables over a 6 yr period, from 1999 to 2004. We show that, on a basin scale, the Mediterranean Sea is characterised by a high degree of spatial and temporal variability in terms of primary production and chlorophyll concentrations. On a spatial scale, important horizontal and vertical gradients have been observed. According to the simulations over a 6 yr period, the developed model correctly simulated the climatological features of deep chlorophyll maxima and chlorophyll west-east gradients, as well as the seasonal variability in the main offshore regions that were studied. The integrated net primary production highlights north-south gradients that differ from surface net primary production gradients and illustrates the importance of resolving spatial and temporal variations to calculate basin-wide budgets and their variability. According to the model, the western Mediterranean, in particular the Alboran Sea, can be considered mesotrophic, whereas the eastern Mediterranean is oligotrophic. During summer stratified period, notable differences between surface net primary production variability and the corresponding vertically integrated production rates have been identified, suggesting that care must be taken when inferring productivity in such systems from satellite observations alone. Finally, specific simulations that were designed to explore the role of external fluxes and light penetration were performed. The subsequent results show that the effects of atmospheric and terrestrial nutrient loads on the total integrated net primary production account for less than 5 % of the its annual value, whereas an increase of 30 % in the light extinction factor impacts primary production by approximately 10 %.
Technical Notes: Calibration and validation of geophysical observation models
Authors: Salama M. S. , Van der Velde R. , van der Woerd H. J. , Kromkamp J. C. , Philippart C. J. M. , Joseph A. T. , O'Neill P. E. , Lang R. H. , Gish T. , Werdell P. J. , Su Z.
Published: January 2012

Abstract. We present a method to calibrate and validate observational models that interrelate remotely sensed energy fluxes to geophysical variables of land and water surfaces. Coincident sets of remote sensing observation of visible and microwave radiations and geophysical data are assembled and subdivided into calibration (Cal) and validation (Val) data sets. Each Cal/Val pair is used to derive the coefficients (from the Cal set) and the accuracy (from the Val set) of the observation model. Combining the results from all Cal/Val pairs provides probability distributions of the model coefficients and model errors. The method is generic and demonstrated using comprehensive matchup sets from two very different disciplines, soil moisture and water quality. The results demonstrate that the method provides robust model coefficients and quantitative measure of the model uncertainty. This approach can be adopted for the calibration/validation of satellite products of land and water surfaces and the resulting uncertainty can be used as input to data assimilation schemes.
Competence formation and post-graduate education in the public water sector in Indonesia
Authors: Kaspersma J. M. , Alaerts G. J. , Slinger J. H.
Published: January 2012

Abstract. A framework is introduced, describing three aggregate competences for technical issues, management and governance, and a meta-competence for continuous learning and innovation, for the water sector. The four competences are further organised in a T-shaped competence profile. The framework and an assessment methodology were tested in a case study on post-graduate water education for professional staff in the Directorate General Water Resources (DGWR) in Indonesia. Though DGWR professionals have a firmly "technical" orientation, both the surveys and interviews show strong interest in the other competences: in particular the learning meta-competence, as well as the aggregate competence for management. The aggregate competence for governance systematically scores lower. A discrepancy appears to exist between the competences that staff perceive as needed in daily work, and those that could be acquired during post-graduate water education. In both locally-based and international post-graduate water education, the aggregate competences for management as well as governance are reportedly addressed modestly, if at all. With only little competence in these disciplines, it will be difficult for professionals to communicate and collaborate effectively in an interdisciplinary way. As a result, the horizontal bar of the T-shaped profile remains weakly developed. In international post-graduate education, this seems partly compensated by the attention for continuous learning and innovation. The exposure to a different culture and learning format is reported as fundamentally formative. The policies of DGWR have gone through three distinct phases. In the first phase (1970–1987) technical competence and learning were valued highly and training was arranged effectively; in the current phase the need to develop new competences is raising new challenges.
Solution of the Lane-Emden Equation Using the Bernstein Operational Matrix of Integration
Authors: Kumar Narayan , Pandey Rajesh K. , Cattani Carlo
Published: January 2012

Lane-Emden's equation has fundamental importance in the recent analysis of many problems in relativity and astrophysics including some models of density profiles for dark matter halos. An efficient numerical method is presented for linear and nonlinear Lane-Emden-type equations using the Bernstein polynomial operational matrix of integration. The proposed approach is different from other numerical techniques as it is based on the Bernstein polynomial integration matrix. Some illustrative examples are given to demonstrate the efficiency and validity of the proposed algorithm.
Geometric Location Based on TDOA for Wireless Sensor Networks
Authors: Luo Xin-long , Li Wei , Lin Jia-ru
Published: January 2012

Wireless sensor networks (WSNs) consist of a large number of low-cost miniature sensors, which can be applied to battlefield surveillance, environmental monitoring, target tracking, and other applications related to the positions of sensors. The location information of sensors is of great importance for wireless sensor networks. In this paper, we propose a new localization algorithm for the wireless sensor network based on time difference of arrival (TDOA), which is a typical algorithm in the wireless localization field. In order to improve the localization accuracy of a sensor, a new strategy is proposed for a localized sensor being upgraded to an anchor node, which is used to localize the position of the next sensor. Performance analysis and simulation results show that the revised TODA localization algorithm has the higher localization accuracy when compared with the original TDOA location method.
Reprogramming of Mouse, Rat, Pig, and Human Fibroblasts into iPS Cells
Authors: Rajarajan Kuppusamy , Engels Marc C. , Wu Sean M.
Published: January 2012

The induction of pluripotency in somatic cells by transcription‐factor overexpression has been widely regarded as one of the major breakthroughs in stem cell biology within this decade. The generation of these induced pluripotent stem cells (iPSCs) has enabled investigators to develop in vitro disease models for biological discovery and drug screening, and in the future, patient‐specific therapy for tissue or organ regeneration. While new technologies for reprogramming are continually being discovered, the availability of iPSCs from different species is also increasing rapidly. Comparison of iPSCs across species may provide new insights into key aspects of pluripotency and early embryonic development. iPSCs from large animals may enable the generation of genetically modified large animal models or potentially transplantable donor tissues or organs. This unit describes the procedure for the generation of iPSCs from mouse, rat, pig and human fibroblasts. Curr. Protoc. Mol. Biol. 97:23.15.1‐23.15.32. © 2012 by John Wiley & Sons, Inc.
Trends in hip fracture incidence and in the prescription of antiosteoporosis medications during the same time period in Belgium (2000–2007)
Authors: Hiligsmann Mickaël , Bruyère Olivier , Roberfroid Dominique , Dubois Cécile , Parmentier Yves , Carton Joëlle , Detilleux Johann , Gillet Pierre , Reginster Jean‐Yves
Published: January 2012

Objective

To examine the secular trend of hip fracture incidence in Belgium between 2000 and 2007 and the concomitant change in the prescriptions of antiosteoporosis medications.

Methods

The incidence of hip fractures and the number of prescriptions were determined using national databases. A logistic regression including years and 5‐year age range was performed to assess the secular trend of hip fracture incidence, and Pearson's correlation coefficient was calculated to examine the relationship between hip fracture incidence and the prescriptions of antiosteoporosis medications.

Results

The annual number of hip fractures increased in Belgium from 13,512 in 2000 to 14,744 in 2007, with a more marked increased in men (20.4%) than in women (5.7%). The age‐adjusted incidence of hip fractures was significantly decreased by 1.12% per year in women, but declined nonsignificantly by 0.34% per year in men. An increase in the prescriptions of antiosteoporosis medications in women was observed during the same time period.

Conclusion

Despite an increase in the number of hip fractures in Belgium between 2000 and 2007, there was a significant decrease in age‐adjusted incidence in women but not in men. Although our results suggest that the decrease may be related to the extent of antiosteoporosis medications, a causal relationship cannot be ascertained and many other factors may have contributed to the decrease in age‐adjusted incidence.
Disease severity and knee extensor force in knee osteoarthritis: Data from the Osteoarthritis Initiative
Authors: Berger Michael J. , Kean Crystal O. , Goela Aashish , Doherty Timothy J.
Published: January 2012

Objective

To determine whether the method of disease severity measurement influences the magnitude of knee extensor force deficits in knee osteoarthritis (OA).

Methods

Data from the Osteoarthritis Initiative (n = 659) were analyzed. Knee extensor force was assessed with isometric contractions. Clinical severity was measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Patients were stratified into tertiles of severity (i.e., moderate, mild, and severe OA) based on the lowest, middle, and highest WOMAC scores, respectively. Kellgren/Lawrence (K/L) grading was used to assess radiographic severity of the tibiofemoral compartment and patients were again stratified into mild (K/L grade <2), moderate (K/L grade 2), and severe (K/L grade >2) knee OA.

Results

When stratifying with the WOMAC, force was significantly lower in the severe group compared to the mild (∼18% lower; P < 0.001) and moderate groups (∼9% lower; P = 0.03), and in the moderate group compared to the mild group (∼10% lower; P = 0.03). When stratifying with K/L grade, small nonsignificant differences were observed in the severe (∼7% lower; P = 0.19) and moderate groups (∼8% lower; P = 0.08) compared to the mild group. Large intragroup variability was observed when comparing WOMAC scores across radiographic severity (coefficients of variation were 79.3%, 74.6%, and 61.6% for K/L grade <2, K/L grade 2, and K/L grade >2, respectively).

Conclusion

The method of disease severity stratification influences the magnitude of knee extensor force deficits because no difference in force between disease subgroups was observed when stratifying with K/L grade. Furthermore, there was large variability in the WOMAC score within each radiographic subgroup, highlighting the limitations in using radiographic measures to reflect symptom severity.
Predictors of health‐related quality of life in children and adolescents with juvenile idiopathic arthritis: Results from a web‐based survey
Authors: Haverman L. , Grootenhuis M. A. , van den Berg J. M. , van Veenendaal M. , Dolman K. M. , Swart J. F. , Kuijpers T. W. , van Rossum M. A. J.
Published: January 2012

Objective

Children with juvenile idiopathic arthritis (JIA) experience functional impairment due to joint manifestations of the disease. The aim of our present study was to assess health‐related quality of life (HRQOL) and its predictors in a group of children and adolescents with JIA.

Methods

The study sample includes all JIA patients (ages 6–18 years) who consulted a pediatric rheumatologist in Amsterdam, The Netherlands, between February 2009 and March 2010. HRQOL was measured using the Paediatric Quality of Life Inventory 4.0 (ages 6–18 years). Functional ability was measured using the Childhood Health Assessment Questionnaire, and medical and sociodemographic parameters were assessed. The study sample was compared to a Dutch youth norm population including children with other chronic health conditions. The proportion of children with JIA with an impaired HRQOL (<1 SD) was evaluated and multivariate regression analyses were performed to predict HRQOL outcome.

Results

Of the eligible patients, 64.1% (n = 152) participated. Both children (ages 6–12 years) and adolescents (ages 13–18 years) with JIA reported a significantly lower HRQOL in almost all domains compared to either healthy controls or children with other chronic health conditions. Approximately half of the children with JIA showed an impaired HRQOL. The main predictors of HRQOL were functional ability, pain, subjective burden of medication use, and school absence.

Conclusion

The HRQOL is severely affected in children and adolescents with JIA. These findings underline the necessity to systematically monitor HRQOL in daily clinical practice.
Potential impact on patient residence to hospital travel distance and access to care under a policy of preferential referral to high‐volume knee replacement hospitals
Authors: FitzGerald John D. , Soohoo Nelson F. , Losina Elena , Katz Jeffrey N.
Published: January 2012

Objective

To examine the potential impact of a policy of selective referral to high‐volume knee replacement hospitals on patients' travel distance to hospitals and access to care for patients seeking total knee replacement (TKR) in urban and rural settings.

Methods

The travel distance required for patients to reach their hospital of service and the additional travel distance required to reach the nearest high‐volume hospital were analyzed using a 100% sample of Medicare fee‐for‐service patients undergoing TKR in 2001.

Results

Of the 183,174 TKRs performed in the US during 2001, 95% of the patients selected underwent TKR at a hospital that was located within 50 miles of their residence. There were 11,550 patients who had their TKR performed at a low‐volume hospital (LVH) where there was no nearer high‐volume hospital. The impact of a policy that would direct patients to high‐volume hospitals varied by region. In urban areas, the nearest high‐volume hospital was a median of 3.8 miles further than the LVH of service. The patient factors race and poverty were associated with selection of LVHs in urban areas. In rural areas and urban clusters, 1,506 patients would have had to travel >50 miles and 259 patients would have had to travel >100 miles to reach a high‐volume hospital.

Conclusion

A policy to direct patients away from LVHs could increase patients' travel time to hospitals in rural areas and restrict access for minority and low‐income patients in urban areas. Any implementation of selective referral to high‐volume centers should address access to hospitals for rural patients and urban minority and low‐income patients.
Inactive disease and remission in childhood‐onset systemic lupus erythematosus
Authors: Mina Rina , Klein‐Gitelman Marisa S. , Ravelli Angelo , Beresford Michael W. , Avcin Tadej , Espada Graciela , Eberhard B. Anne , Schanberg Laura E. , O'Neil Kathleen M. , Silva Clovis A. , Higgins Gloria C. , Onel Karen , Singer Nora G. , von Scheven Emily , Imundo Lisa F. , Nelson Shannen , Giannini Edward H. , Brunner Hermine I.
Published: January 2012

Objective

To define inactive disease (ID) and clinical remission (CR) and to delineate variables that can be used to measure ID/CR in childhood‐onset systemic lupus erythematosus (cSLE).

Methods

Delphi questionnaires were sent to an international group of pediatric rheumatologists. Respondents provided information about variables to be used in future algorithms to measure ID/CR. The usefulness of these variables was assessed in 35 children with ID and 31 children with minimally active lupus (MAL).

Results

While ID reflects cSLE status at a specific point in time, CR requires the presence of ID for >6 months and considers treatment. There was consensus that patients in ID/CR can have <2 mild nonlimiting symptoms (i.e., fatigue, arthralgia, headaches, or myalgia) but not Raynaud's phenomenon, chest pain, or objective physical signs of cSLE; antinuclear antibody positivity and erythrocyte sedimentation rate elevation can be present. Complete blood count, renal function testing, and complement C3 all must be within the normal range. Based on consensus, only damage‐related laboratory or clinical findings of cSLE are permissible with ID. The above parameters were suitable to differentiate children with ID/CR from those with MAL (area under the receiver operating characteristic curve >0.85). Disease activity scores with or without the physician global assessment of disease activity and patient symptoms were well suited to differentiate children with ID from those with MAL.

Conclusion

Consensus has been reached on common definitions of ID/CR with cSLE and relevant patient characteristics with ID/CR. Further studies must assess the usefulness of the data‐driven candidate criteria for ID in cSLE.
Patient handling and musculoskeletal disorders among hospital workers: Analysis of 7 years of institutional workers' compensation claims data
Authors: Kim Hyun , Dropkin Jonathan , Spaeth Kenneth , Smith Francine , Moline Jacqueline
Published: January 2012

Objectives

Musculoskeletal disorders (MSDs) are the most common occupational injuries and illnesses among hospital workers in the United States. To date, there is little in the literature examining the principal effect of patient handling on MSDs. The primary objective of this study was to investigate and confirm the principal effect of patient handling on hospital worker MSDs.

Methods

Workers' Compensation (WC) claims related to MSDs filed during 2003–2009 by employees in a large US healthcare system were classified using ICD‐9. Patient handling, demographic, work, and injury characteristics were obtained. Two multivariable Poisson regression models were compared to evaluate association between risk factors and MSDs. One model contained all risk factors, excluding patient handling; the other model included patient handling.

Results

Among 3,452 claims from 24,824 FTEs, 76% were MSDs. About half of the MSDs involved patient handling. In the regression model without patient handling, EMS workers, women, 50–59 years of age, union members, evening shift workers, and fulltime workers showed associations with MSDs. However, all the observed associations disappeared when patient handling was included in the second regression model; patient handling was the only factor showing an association with MSDs, although the effect was not strong (RR = 1.2, 95% CI = 1.2–1.3).

Conclusions

All the observed associations of risk factors disappeared and were further away from patient handling on the causal pathway to MSDs. Patient handling involves numerous work elements and dynamic physical activities. Understanding the work elements of patient handling and conducting interventions based on specific patient handling tasks can substantially reduce MSDs among hospital workers. Am. J. Ind. Med. 55:683–690, 2012. © 2012 Wiley Periodicals, Inc.
Dorsal Fronto‐Parietal Connections of the Human Brain: A Fiber Dissection Study of Their Composition and Anatomical Relationships
Authors: Maldonado Igor L. , Mandonnet Emmanuel , Duffau Hugues
Published: January 2012

Fiber dissection of the deep white matter of a human left cerebral hemisphere (lateral view). See Figure 2 in Maldonado et al., on page 189, in this issue.
Interferon‐γ release assay versus tuberculin skin test prior to treatment with golimumab, a human anti–tumor necrosis factor antibody, in patients with rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis
Authors: Hsia Elizabeth C. , Schluger Neil , Cush John J. , Chaisson Richard E. , Matteson Eric L. , Xu Stephen , Beutler Anna , Doyle Mittie K. , Hsu Benjamin , Rahman Mahboob U.
Published: January 2012

Objective

To evaluate the performance of an interferon‐γ release assay (IGRA) versus the standard tuberculin skin test (TST) as a screening tool for latent tuberculosis (TB) infection prior to the initiation of anti–tumor necrosis factor therapy in patients with autoimmune inflammatory diseases.

Methods

This integrated analysis involved screening of patients with rheumatoid arthritis, those with psoriatic arthritis, and those with ankylosing spondylitis from phase III trials of golimumab. The IGRA used to screen for latent TB was the QuantiFERON‐TB Gold In‐Tube test.

Results

In this pooled analysis, 2,282 patients underwent both IGRA and TST screening prior to golimumab treatment. Among these patients, 13.8% had at least one test yielding positive findings for latent TB, including 9.4% with positive results by TST, 7.0% with positive results by IGRA, and 2.6% with positive results on both tests. The rate of indeterminate results for TB on IGRA was 1.8%. Agreement between the TST and IGRA results, measured by the kappa coefficient, was 0.22 (95% confidence interval 0.157–0.279; P = 0.021). Among the patients with positive IGRA findings, 36.9% had positive TST findings. Among the patients with positive TST findings, 27.4% had positive IGRA findings. Overall, 781 (34.2%) of the 2,282 patients had previously received the bacillus Calmette‐Guérin (BCG) vaccine; among this vaccinated group, the rate of positivity for latent TB by TST was 15.2% (119 of 781), compared to a rate of positivity of 9.1% (71 of 781) by IGRA (P = 0.0002). Among patients who had not received the BCG vaccine, the rate of positivity by TST was 5.0% (62 of 1,248) and the rate of positivity by IGRA was 5.8% (72 of 1,248) (P = 0.3745). When the IGRA was repeated in patients whose results were initially indeterminate, the rate of indeterminate IGRA findings for latent TB was much lower than has been previously reported.

Conclusion

In the absence of a true gold standard test for latent TB infection, results of this comparison of IGRA and TST in a large cohort of patients with rheumatic diseases suggest that the IGRA provides greater specificity and possibly greater sensitivity than the TST.
Anatomical Sciences Education Vol. 5, Issue 1, 2012 Cover Image
Authors: Griksaitis Michael J. , Sawdon Marina A. , Finn Gabrielle M.
Published: January 2012

Medical students at Durham University, United Kingdom receive instructions using ultrasound
echocardiography. In this issue of ASE Dr. Finn and her colleagues compare the efficacy of ultrasound and cadaveric prosections for teaching gross anatomy of the heart.
Second‐order performance analysis of discrete‐time queues fed by DAR(2) sources with a focus on the marginal effect of the additional traffic parameter
Authors: Miao Daniel Wei‐Chung , Lee Hsou‐Chun
Published: January 2012

Discrete autoregressive process of order 1 (DAR(1)) has been used as a popular stochastic model for correlated traffic sources because it parsimoniously uses a single parameter to capture the desirable correlation structure. In contrast with DAR(1), discrete autoregressive process of order 2 (DAR(2)) uses one more parameter to provide a much richer pattern in the autocorrelation function and is able to capture slower decay rate and longer memory. To investigate how the additional traffic parameter in DAR(2) influences the queueing performance, this paper provides an analysis of the discrete‐time DAR(2)/D/1 queue. The performance measures concerned are the mean and second‐order statistics of queue size, which are both important in the queueing systems seen in telecommunication networks. Under a mild condition, these performance indices are derived in closed form that allows for efficient computing. An approximate version of these results is also developed to relax the condition and cover more general sources, and both versions serve as a simple tool set for performance evaluation. The numerical examples use this tool to demonstrate that the DAR(2) source may cause up to 30% poorer performance than DAR(1) when the traffic is heavy, bursty, and highly correlated. This indicates that the effect from slower decay rate in autocorrelation is not negligible and using the extra parameter is necessary particularly when the queue is heavily loaded with correlated traffic. Copyright © 2012 John Wiley & Sons, Ltd.
Tuning the Activity of Mitochondria‐Penetrating Peptides for Delivery or Disruption
Authors: Horton Kristin L. , Pereira Mark P. , Stewart Kelly M. , Fonseca Sonali B. , Kelley Shana O.
Published: January 2012

Mitochondrially targeted agents have the capacity to be both vehicles for the delivery of bioactive agents and mitochondrial disrupters and show promise for the treatment of various diseases. Engineering these agents to specifically accumulate or disrupt the mitochondrion is challenging, as there is a fine line between characteristics of the molecules that accomplish each task. Here, we assess the physicochemical properties governing mitochondrial matrix accumulation or membrane disruption caused by mitochondria‐penetrating peptides. Increases in peptide length and hydrophobicity were uncovered as the dominant factors in deriving membrane disruptive activity. Shorter, less hydrophobic peptides did not disrupt the mitochondrial membrane, but rather accumulated in the mitochondrial matrix without interfering with cellular activity. These shorter peptides, however, can trigger cytochrome c release through activation of the permeability transition pore complex (PTPC), but only at very high concentrations. This study illustrates that the activity of a mitochondria‐localizing agent can be controlled through alterations in peptide hydrophobicity and dosing concentrations.
Carbodiphosphorane Analogues E(PPh3)2 with E=C–Pb: A Theoretical Study with Implications for Ligand Design
Authors: Takagi Nozomi , Tonner Ralf , Frenking Gernot
Published: January 2012

Quantum‐chemical calculations at the BP86/TZVPP level have been carried out for the heavy Group 14 homologues of carbodiphosphorane E(PPh3)2, where E=Si, Ge, Sn, Pb, which are experimentally unknown so far. The results of the theoretical investigation suggest that the tetrelediphosphoranes E(PPh3)2 (1 E) are stable compounds that could become isolated in a condensed phase. The molecules possess donor–acceptor bonds Ph3P→E←PPh3 to a bare tetrele atom E, which retains its four valence electrons as two electron lone pairs. The analysis of the bonding situation and the calculation of the chemical reactivity indicate that the molecules 1 E belong to the class of divalent E(0) compounds (ylidones). All molecules 1 C–1 Pb have very large first but also very large second proton affinities, which distinguishes them from the N‐heterocyclic carbene homologues, in which the donor atom is a divalent E(II) species that possesses only one electron lone pair. Compounds 1 E are powerful double donors that strongly bind Lewis acids such as BH3 and AuCl in the complexes 1 E(BH3)n and 1 E(AuCl)n (n=1, 2). The bond dissociation energies (BDEs) of the second BH3 and AuCl molecules are only slightly less than the BDE of the first BH3 and AuCl. The results of this work are a challenge for experimentalists.
A Versatile Ru Catalyst for the Asymmetric Transfer Hydrogenation of Both Aromatic and Aliphatic Sulfinylimines
Authors: Pablo Óscar , Guijarro David , Kovács Gábor , Lledós Agustí , Ujaque Gregori , Yus Miguel
Published: January 2012

A highly efficient Ru catalyst based on an achiral, very simple, and inexpensive amino alcohol ligand (2‐amino‐2‐methylpropan‐1‐ol) has been developed for the asymmetric transfer hydrogenation (ATH) of chiral N‐(tert‐butylsulfinyl)imines. This complex is able to catalyze the ATH of both aromatic and the most challenging aliphatic sulfinylimines by using isopropyl alcohol as the hydrogen source. The diastereoselective reduction of aromatic, heteroaromatic, and aliphatic sulfinylketimines, including sterically congested cases, over short reaction times (1–4 h), followed by desulfinylation of the nitrogen atom, affords the corresponding highly enantiomerically enriched (ee up to >99 %) α‐branched primary amines in excellent yields. The same ligand was equally effective for the synthesis of both (R)‐ and (S)‐amines by using the appropriate absolute configuration in the iminic substrate. DFT mechanistic studies show that the hydrogen‐transfer process is stepwise. Moreover, the origin of the diastereoselectivity has been rationalized.
Analysis of distributed multiperiodic systems to achieve consistent data matching
Authors: Pontisso Nadège , Quéinnec Philippe , Padiou Gérard
Published: January 2012

The distributed real‐time architecture of an embedded system is often described as a set of communicating components. Such a system is dataflow (for its description) and time triggered (for its execution). The architecture forms a graph of communicating components, where more than one path can link two components. Because the characteristics of the network and the behavior of intermediate components may vary or are only partially known, these paths often have different timing characteristics, and the flows of information that transit on these paths reach their destination at independent times. However, an application that seeks consistent values will require these flows to be temporally matched so that a component uses inputs that all (directly or indirectly) depend on the same computation step of another component. In this paper, we define this temporal data‐matching property, both in a strict sense and in a relaxed way allowing approximately consistent values. Then, we show how to analyze a system architecture to detect situations that result in data‐matching inconsistencies. In the context of multiperiodic systems, where components do not necessarily share a common period, we also describe an approach to manage data matching that uses queues to delay too fast paths and timestamps to recognize consistent data sets. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis and Implementation of an Interleaved ZVS Converter with High Input Voltage
Authors: Lin B. R. , Chao C. H.
Published: January 2012

An interleaved half‐bridge converter is presented for high input voltage application. The features of the proposed converter are zero voltage switching (ZVS) turn‐on for all active switches, ripple current reduction at output side, load current sharing and load voltage regulation. Two half‐bridge converters connected in series and two split capacitors are used to limit the voltage stress of each power switch at one‐half of input DC bus voltage. Thus, active switches with low voltage stress can be used at high input voltage application. On the other hand, the output sides of two half‐bridge converters are connected in parallel to share the load current and reduce the current stresses of the secondary windings and the rectifier diodes. Since two half‐bridge converters are operated with interleaved pulse‐width modulation (PWM), the output ripple current can partially cancel each other such that the resultant ripple current at output side is reduced and the size of output inductors can be reduced. In each half‐bridge converter, asymmetrical PWM scheme is used to regulate the output voltage. Based on the resonant behavior by the output capacitance of MOSFETs and the leakage inductance (or external inductance) of transformers, active switches can be turned on at ZVS during the transition interval. Thus, the switching losses of power MOSFETs are reduced. The proposed converter can be applied for high input voltage applications such as three‐phase 380‐V utility system. Finally, experiments based on a laboratory prototype with 960‐W rated power are provided to demonstrate the performance of proposed converter. Copyright © 2012 John Wiley & Sons, Ltd.
CRMP4 suppresses apical dendrite bifurcation of CA1 pyramidal neurons in the mouse hippocampus
Authors: Niisato Emi , Nagai Jun , Yamashita Naoya , Abe Takaya , Kiyonari Hiroshi , Goshima Yoshio , Ohshima Toshio
Published: January 2012

Collapsin response mediator proteins (CRMPs) are a family of cytosolic phosphoproteins that consist of 5 members (CRMP 1–5). CRMP2 and CRMP4 regulate neurite outgrowth by binding to tubulin heterodimers, resulting in the assembly of microtubules. CRMP2 also mediates the growth cone collapse response to the repulsive guidance molecule semaphorin‐3A (Sema3A). However, the role of CRMP4 in Sema3A signaling and its function in the developing mouse brain remain unclear. We generated CRMP4−/− mice in order to study the in vivo function of CRMP4 and identified a phenotype of proximal bifurcation of apical dendrites in the CA1 pyramidal neurons of CRMP4−/− mice. We also observed increased dendritic branching in cultured CRMP4−/− hippocampal neurons as well as in cultured cortical neurons treated with CRMP4 shRNA. Sema3A induces extension and branching of the dendrites of hippocampal neurons; however, these inductions were compromised in the CRMP4−/− hippocampal neurons. These results suggest that CRMP4 suppresses apical dendrite bifurcation of CA1 pyramidal neurons in the mouse hippocampus and that this is partly dependent on Sema3A signaling. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2012
A New Type of Lanthanide Complex – Two Divalent Ytterbium Species Assembled from Cation–π Interactions
Authors: Pan Cheng‐Ling , Sheng Shao‐Ding , Hou Chang‐Min , Pan Yu‐Song , Wang Jing , Fan Yong
Published: January 2012

A new divalent ytterbium complex, [{(LPh)YbII(Et2O)(thf)}2(μ‐KI)] {LPh = Ph2Si(NAr)2, Ar = 2,6‐iPr2C6H3} (3), was synthesized by the reaction of [(LPh)YbIIII(thf)2] (2) and an excess of potassium. The bimetallic ytterbium(II) species with bulky diamido ligands are bridged by a KI molecule with cation–π interactions. These two complexes have been fully characterized, particularly by X‐ray crystallography.
Generation of an Organotellurium(II) Cation
Authors: Sugamata Koh , Sasamori Takahiro , Tokitoh Norihiro
Published: January 2012

We expected that the chemical trapping products of low‐coordinated tellurenyl cation species can also be kinetically stabilized by the Tbt or Bbt group. Recently, we have reported the halogenation reactions of Bbt‐substituted ditelluride, BbtTeTeBbt, leading to the formation of the TeII–TeIV mixed‐valent tellurenyl fluoride, BbtTeTe(F)2Bbt, and tellurenyl halides, BbtTeX (X = Cl, Br, I). During the dehalogenation reactions of these tellurium halides, it is rational to postulate the formation of a tellurenyl cation species as an intermediate. In this paper, we report the successful trapping of tellurenyl cation species with butadienes or triphenylphosphane, and the regeneration of the tellurenyl cation species by thermal retro [1+4] cycloaddition of the diene adducts.
Microbial production of conjugated linoleic and linolenic acids in fermented foods: Technological bottlenecks
Authors: Gorissen Lara , Raes Katleen , De Smet Stefaan , De Vuyst Luc , Leroy Frédéric
Published: January 2012

Several food‐grade bacteria are known to produce conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) from linoleic acid (LA) and α‐linolenic acid (ALA), respectively. Therefore, bifidobacteria and a Lactobacillus sakei strain, able to produce CLA and CLNA in vitro, were applied as starter cultures for the fermentation of milk and meat, respectively. However, for both the fermented milk and meat no increase in CLA and CLNA content was obtained. Although LA and ALA were present in sufficient amounts in milk, their availability as free fatty acids was likely too low. During meat fermentation, the prevailing temperature and pH conditions most probably were the limiting factors for conversion of LA and ALA.

Practical applications: The market interest in CLA and CLNA has increased because of their potential health‐promoting properties. It has been suggested that increased levels of CLA and CLNA isomers in fermented food products might be obtained through the use of appropriate starter cultures. From the present study, it became clear that this approach is not straightforward and more research is needed to investigate the possibility of using selected bacterial strains to increase the levels of CLA and CLNA in fermented foods.
Concave Annelated Terpyridines
Authors: Lüning Ulrich , Liebig Timo
Published: January 2012

Bimacrocyclic concave annelated terpyridines were generated from a U‐shaped nonmacrocyclic tetraalkene precursor by ring closing metathesis followed by hydrogenation. The U‐shaped precursor was synthesized by condensing two aryl‐tetrahydroquinolones with Eschenmoser's salt. The quinolones themselves were accessible by coupling a 2‐chloroquinolone with a bis‐alkenyloxy‐substituted boronic acid. The concave terpyridine was tested for reactivity and stereoselectivity in a copper(I)‐catalyzed cyclopropanation.
Voltammetric Immunoassay for the Detection of Protein Biomarkers
Authors: Dou Yue‐Hua , Haswell Stephen J. , Greenman John , Wadhawan Jay
Published: January 2012

A strategy for a fast (ca. 20 min), specific, electrochemical immunoassay for the cardiac biomarker creatine kinase (CK) and the human cytokine interleukin 10 (IL10) has been developed in this paper. The polyaniline modified gold surface formed from electrochemical reduction of diazonium salt supplies a solid substrate to link the activated carboxylic acid groups from the antibodies, which were labelled with ferrocene. The direct electrochemistry of ferrocene allows the analysis of protein markers with good sensitivity. The creatine kinase sensor demonstrates limit of detection of 0.5 pg mL−1 in a physiological Krebs‐Henseleit solution. The anti‐IL10 antibody retained fluorescence activity after further coupling to ferrocene and covalent immobilization on to a gold electrode, showing a linear detection range for IL‐10 from 0.001 ng mL−1 to 50 ng mL−1 in PBS. We attribute the high sensitivity to the well‐controlled modified surface which results in end–on antibodies that can specifically capture the antigen with ease.
A marker‐and‐cell approach to free surface 2‐D multiphase flows
Authors: Santos F. L. P. , Ferreira V. G. , Tomé M. F. , Castelo A. , Mangiavacchi N. , McKee S.
Published: January 2012

This work describes a methodology to simulate free surface incompressible multiphase flows. This novel methodology allows the simulation of multiphase flows with an arbitrary number of phases, each of them having different densities and viscosities. Surface and interfacial tension effects are also included. The numerical technique is based on the GENSMAC front‐tracking method. The velocity field is computed using a finite‐difference discretization of a modification of the Navier–Stokes equations. These equations together with the continuity equation are solved for the two‐dimensional multiphase flows, with different densities and viscosities in the different phases. The governing equations are solved on a regular Eulerian grid, and a Lagrangian mesh is employed to track free surfaces and interfaces. The method is validated by comparing numerical with analytic results for a number of simple problems; it was also employed to simulate complex problems for which no analytic solutions are available. The method presented in this paper has been shown to be robust and computationally efficient. Copyright © 2012 John Wiley & Sons, Ltd.
Estimating suspended sediment concentrations in areas with limited hydrological data using a mixed‐effects model
Authors: Araujo H. Andres , Cooper Andrew B. , Hassan Marwan A. , Venditti Jeremy
Published: January 2012

Sediment rating curves are commonly used to estimate the suspended sediment load in rivers and streams under the assumption of a constant relation between discharge (Q) and suspended sediment concentrations (SSC) over time. However, temporal variation in the sediment supply of a watershed results in shifts in this relation by increasing variability and by introducing nonlinearities in the form of hysteresis or a path‐dependent relation. In this study, we used a mixed‐effects linear model to estimate an average SSC–Q relation for different periods of time within the hydrologic cycle while accounting for seasonality and hysteresis. We tested the performance of the mixed‐effects model against the standard rating curve, represented by a generalized least squares regression, by comparing observed and predicted sediment loads for a test case on the Chilliwack River, British Columbia, Canada. In our analyses, the mixed‐effects model reflected more accurate patterns of interpolated SSC from Q data than the rating curve, especially for the low‐flow summer months when the SSC–Q relation is less clear. Akaike information criterion scores were lower for the mixed‐effects model than for the standard model, and the mixed‐effects model explained nearly twice as much variance as the standard model (52% vs 27%). The improved performance was achieved by accounting for variability in the SSC–Q relation within each month and across years for the same month using fixed and random effects, respectively, a characteristic disregarded in the sediment rating curve. Copyright © 2012 John Wiley & Sons, Ltd.
Maternal Sensitivity: Evidence of Stability across Time, Contexts, and Measurement Instruments
Authors: Behrens Kazuko Y. , Hart Sybil L. , Parker Andrea C.
Published: January 2012

Although maternal sensitivity is widely understood as having a direct impact on the quality of the mother–child relationship, empirical evidence supporting this has been inconsistent, possibly because of varied definitions of the construct and limitations of measurements. The Maternal Behavior Q‐Set (MBQS) appears to be a promising measure of sensitivity, showing associations with attachment security (r = .60) higher than those reported (r = .24) in a highly‐regarded meta‐analysis of other sensitivity measures. The present study aimed to further establish the validity and utility of the MBQS by exploring its consistency with a contingency‐based measure of sensitivity, while also seeking evidence of stability across contexts and times. Seventy‐two mothers and their 10‐month‐olds participated in a procedure that included two episodes of Floor Play and Reunions following maternal differential treatment. Mothers were scored on contingent responsivity and warmth. At 12 months, the dyads underwent the Strange Situation Procedure where sensitivity was assessed using a 72‐item version of the MBQS. The findings revealed the stability of maternal sensitivity across times, contexts, and measures. However, linkages applied only to 10‐month scores from reunion, not play, episodes, supporting Pederson and Moran's (1995) assertion that high‐demand circumstances reveal more meaningful differences in maternal sensitivity. Copyright © 2012 John Wiley & Sons, Ltd.
Evidence for Website Claims about the Benefits of Teaching Sign Language to Infants and Toddlers with Normal Hearing
Authors: Nelson Lauri H. , White Karl R. , Grewe Jennifer
Published: January 2012

The development of proficient communication skills in infants and toddlers is an important component to child development. A popular trend gaining national media attention is teaching sign language to babies with normal hearing whose parents also have normal hearing. Thirty‐three websites were identified that advocate sign language for hearing children as a way of promoting better developmental outcomes. These sites make several claims about the positive benefits of teaching hearing infants and toddlers to sign, such as earlier communication, improved language development, increased IQ, reduced tantrums, higher self‐esteem, and improved parent–child bonding. Without endorsing or disparaging these claims, the purpose of this article was to evaluate the strength of evidence cited on websites that promote products to teach young children to use sign language. Cumulatively, 82 pieces of evidence were cited by the websites as supporting research. However, over 90% of these citations were opinion articles without any supporting data or descriptions of products and only eight were empirical research studies relevant to the benefits of teaching sign language to young children with normal hearing. Unfortunately, there is not enough high‐quality evidence cited on these websites to draw research‐based conclusions about whether teaching sign language to young children with normal hearing results in better developmental outcomes. Copyright © 2012 John Wiley & Sons, Ltd.
2011 panel on developing a biomaterials curriculum
Authors: Reichert William M. , Harris Thomas R. , Lemons Jack , Mikos Antonios G. , Puleo David A. , Schoen Frederick J. , Temenoff Johnna S.
Published: January 2012

This article provides the transcript for the Panel on Developing a Biomaterials Curriculum held at the 2011 annual meeting of the Society for Biomaterials in Orlando, FL. The panelists were Thomas R. Harris of Vanderbilt University, Jack Lemons of the University of Alabama, Birmingham, Antonios G. Mikos of Rice University, David A. Puleo on the University of Kentucky, Frederick J. Schoen of Harvard Medical School, and Johnna S. Temenoff of Georgia Tech/Emory. The panelists, each an expert in engineering education and textbook author, presented their perspectives on key issues of developing undergraduate and graduate curricula that contain a biomaterials focus. The presentations were followed by a lively and informative discussion with the audience. A redacted portion of this discussion is included. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.