bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and reactivity of substituted α‐carbonylphosphonites and their derivatives
Authors: Prishchenko Andrey A. , Livantsov Mikhail V. , Novikova Olga P. , Livantsova Ludmila I. , Petrosyan Valery S.
Published: May 2012

Convenient methods for the synthesis of functionalized organophosphorus compounds containing carbonyl groups as well as di‐ or trialkoxymethyl fragments attached to phosphorus, and their derivatives, starting from the available derivatives of trivalent phosphorus acids, are proposed, and some properties of the new functionalized organophosphorus compounds are presented. So, the alkylation and acylation reaction of (dialkoxymethyl) phosphonites and their analogs have been studied. It is found that the Arbuzov rearrangement of these compounds was accompanied by the phosphorus–carbon bond cleavage with unique retention of the three‐coordinate phosphorus. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:352–372, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21024
The Evaluation of Double‐Layer Clothing in a Semiconductor Manufacturing Environment
Authors: Chen Te‐Hung , Lin Chih‐Long , Wang Mao‐Jiun J.
Published: May 2012

This study aims to investigate the influence of double‐layer clothing in a semiconductor manufacturing clean‐room environment. Twenty subjects including ten males and ten females participated in this study. Each subject completed four treatment combinations with four different inner pieces of clothing (i.e., 100% cotton, 70% cotton + 30% polyester, 65% polyester + 35% cotton, 100% polyester). The dependent measures included moisture absorption, skin temperature, and subjective responses in three body regions. The results indicate that wearing 100% polyester inner clothing caused a significant increase in inner microclimate relative humidity (RH; p < .01). Wearing 100% cotton inner clothing caused a significant increase in both inner microclimate RH (p < .01) and the inner clothing's moisture absorption. This was due to cotton fiber tends to trap more water molecules and allow less water vapor to pass through as compared to other types of fiber. Furthermore, wearing the blended fiber inner clothing caused lower RH in the inner and outer clothing microclimate (p < .05). Moreover, wearing 65% polyester + 35% cotton inner clothing had higher subjective comfort than did wearing 70% cotton + 30% polyester. In summary, the moisture absorption and water vapor transport characteristics of the inner clothing are the major factors affecting the comfort of wearing double‐layer clothing. © 2012 Wiley Periodicals, Inc.
Career Abandonment Intentions among Software Workers
Authors: Colomo‐Palacios Ricardo , Casado‐Lumbreras Cristina , Misra Sanjay , Soto‐Acosta Pedro
Published: May 2012

Within the software development industry, human resources have been recognized as one of the most decisive and scarce resources. Today, the retention of skilled IT (information technology) personnel is a major issue for employers and recruiters as well, since IT career abandonment is a common practice and means not only the loss of personnel, knowledge, and skills, but also the loss of business opportunities. This article seeks to discover the main motivations young practitioners abandon the software career. To achieve this objective, two studies were conducted. The first study was qualitative (performed through semistructured interviews) and intended to discover the main variables affecting software career abandonment. The second study was quantitative, consisting of a Web‐based survey developed from the output of the first study and administered to a sample of 148 IT practitioners. Results show that work‐related, psychological, and emotional variable are the most relevant group of variables explaining IT career abandonment. More specifically, the three most important variables that motivate employees to abandon the career are effort–reward imbalance, perceived workload, and emotional exhaustion. In contrast, variables such as politics and infighting, uncool work, and insufficient resources influence to a lesser extent the decision to leave the career. © 2012 Wiley Periodicals, Inc.
A multimodel assessment of the climate change effect on the drought severity–duration–frequency relationship
Authors: Lee Joo Heon , Kim Chang Joo
Published: May 2012

In this study, the patterns of past and future drought occurrences in the Seoul region were analysed using observed historical data from the Seoul weather station located in the Korean Peninsula and four different types of general circulation models (GCMs), namely, GFDL:CM2_1, CONS:ECHO‐G, MRI:CGCM2_3_2 and UKMO:HADGEM1. To analyse statistical properties such as drought frequency duration and return period, the Standardized Precipitation Index was used to derive the severity–duration–frequency (SDF) curve from the drought frequency analysis. In addition, a drought spell analysis was conducted to estimate the frequency and change of drought duration for each drought classification. The results of the analysis suggested a decrease in the frequency of mild droughts and an increase in the frequency of severe and extreme droughts in the future. Furthermore, the average duration of droughts is expected to increase. A comparison of the SDF relationship derived from the observed data with that derived via the GCMs indicated that the drought severity for each return period was reduced as drought duration increased and that the drought severity derived from the GCMs was severer than the severity obtained using the observed data for the same duration and return period. Furthermore, among the four types of GCMs used in this study, the MRI model predicted the most severe future drought for the Seoul region, and the SDF curve derived using the MRI model also resulted in the highest degree of drought severity compared with the other GCMs. Copyright © 2012 John Wiley & Sons, Ltd.
Unravelling changing sediment sources in a Mediterranean mountain catchment: a Bayesian fingerprinting approach
Authors: D'Haen Koen , Verstraeten Gert , Dusar Bert , Degryse Patrick , Haex Jill , Waelkens Marc
Published: May 2012

To determine the provenance of Holocene floodplain deposits of the Büğdüz catchment in southwest Turkey, a Bayesian fingerprinting approach was used. An important requirement for any provenance study is that the potential sediment sources show sufficient spatial and compositional heterogeneity. The spatial distribution of potential sources, in this case the various lithologies present within the catchment, was mapped using field observations and ASTER and Quickbird satellite images. To distinguish the source lithologies, a set of geochemical tracers was identified using linear discriminant analysis. This optimum fingerprint was then used in the mixing model to determine the sediment provenance. The Bayesian mixing model uses Markov chain Monte Carlo random walks to determine the most probable source composition and mixing proportions. The uncertainty associated with the input data can be incorporated into the model through prior probability distributions. The spread of the posterior probability distributions represents the uncertainty associated with the mixing proportion calculation. The main contrasts in the provenance of the floodplain deposits reflect the spatial distribution of potential sediment sources throughout the catchment. There are, however, also important temporal variations in sediment provenance and lateral differences due to the nature of floodplain build‐up. The observed spatial and temporal variability of sediment provenance gives a first indication that hill slope‐channel and within‐channel coupling relations are not uniform through the catchment and that different locations showed a distinct response to disturbances. Copyright © 2012 John Wiley & Sons, Ltd.
Sediment storage in the reach of the middle Yellow River located in the Fenwei Graben, China
Authors: Xu Jiongxin
Published: May 2012

Fenwei Graben is a famous sediment sink. The Longmen‐Sanmexia sediment sink of middle Yellow River is located in the middle part. Using the sediment budget based on annual data from the period 1920–2006 and flood‐event data from 154 flood events from the period 1950–1985, the variations in sediment storage, release and transport have been analysed. Data from different methods and sources indicate that, during an 1800‐year period, the variation of sedimentation rate in this sink has undergone a cycle from increase to decline; the cause for this can be found in the changes in the manner and intensity of human activities. Over 87 years, sediment storage in this sink can be separated into four stages which showed different trends, depending on changing human activities, such as reservoir construction, soil and water conservation and water diversion. Stepwise multiple regression shows that the runoff and sediment yield from three major source areas have differing influences on sediment storage in the sink. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of appropriate lags and temporal resolutions for low flow indicators in the River Rhine to forecast low flows with different lead times
Authors: Demirel Mehmet C. , Booij Martijn J. , Hoekstra Arjen Y.
Published: May 2012

The aim of this paper is to assess the relative importance of low flow indicators for the River Rhine and to identify their appropriate temporal lag and resolution. This is done in the context of low flow forecasting with lead times of 14 and 90 days. First, the Rhine basin is subdivided into seven sub‐basins. By considering the dominant processes in the sub‐basins, five low flow indicators were selected: precipitation, potential evapotranspiration, groundwater storage, snow storage and lake storage. Correlation analysis was then carried out to determine the relationship between observed low flows and preselected indicators with varying lags (days) and temporal resolutions (from 1 day to 7 months).

The results show that the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 14 days are potential evapotranspiration with a large lag and temporal resolution, and lake levels with a small lag and temporal resolution. In the other sub‐basins groundwater levels with a small lag and temporal resolution are important in addition to potential evapotranspiration with a large lag and temporal resolution. The picture is slightly different for forecasts with a lead time of 90 days. The snow storage in the Alpine sub‐basins and the precipitation in the other sub‐basins also become relevant for low flows. Consequently, the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 90 days are potential evapotranspiration with a large lag and temporal resolution, lake levels with a small lag and temporal resolution and snow storage with a small lag and large temporal resolution. The resultant correlation maps provide appropriate lags and temporal resolutions for indicators to forecast low flows in the River Rhine with different lead times. Copyright © 2012 John Wiley & Sons, Ltd.
Drug release and bone growth studies of antimicrobial peptide‐loaded calcium phosphate coating on titanium
Authors: Kazemzadeh‐Narbat Mehdi , Noordin Shahryar , Masri Bassam A. , Garbuz Donald S. , Duncan Clive P. , Hancock Robert E. W. , Wang Rizhi
Published: May 2012

Preventing infection is one of the major challenges in total hip and joint arthroplasty. The main concerns of local drug delivery as a solution have been the evolution of antibiotic‐resistant bacteria and the potential inhibition of osseointegration caused by the delivery systems. This work investigated the in vitro drug release, antimicrobial performance, and cytotoxicity, as well as the in vivo bone growth of an antimicrobial peptide loaded into calcium phosphate coated Ti implants in a rabbit model. Two potent AMP candidates (HHC36: KRWWKWWRR, Tet213: KRWWKWWRRC) were first investigated through an in vitro cytotoxicity assay. MTT absorbance values revealed that HHC36 showed much lower cytotoxicity (minimal cytotoxic concentration 200 μg/mL) than Tet 213 (50 μg/mL). The AMP HHC36 loaded onto CaP (34.7 ± 4.2 μg/cm2) had a burst release during the first few hours followed by a slow and steady release for 7 days as measured spectrophotometrically. The CaP‐AMP coatings were antimicrobial against Staphylococcus aureus and Pseudomonas aeruginosa strains in colony‐forming units (CFU) in vitro assays. No cytotoxicity was observed on CaP‐AMP samples against MG‐63 osteoblast‐like cells after 5 days in vitro. In a trabecular bone growth in vivo study using cylindrical implants, loading of AMP HHC36 did not impair bone growth onto the implants. Significant bone on‐growth was observed on CaP‐coated Ti with or without HHC36 loading, as compared with Ti alone. The current AMP‐CaP coating thus offers in vivo osteoconductivity to orthopedic implants. It also offers in vitro antimicrobial property, with its in vivo performance to be confirmed in future animal infection models. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Transient receptor potential vanilloid 1 receptors mediate acid‐induced mucin secretion via Ca2+ influx in human airway epithelial cells
Authors: Yu Hongmei , Li Qi , Zhou Xiangdong , Kolosov Victor P. , Perelman Juliy M.
Published: May 2012

Mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. Previous studies have reported that acids (gastroesophageal reflux or environmental exposure) induce many respiratory symptoms and are implicated in the pathophysiology of obstructive airway diseases. To understand these mechanisms, we measured acid‐induced mucin secretion in human bronchial epithelial cells. In the present study, acid induced inward currents of transient receptor potential vanilloid (TRPV)1 and mucin 5AC (MUC5AC) secretion dose dependently, which were inhibited by TRPV1 antagonist capsazepine in a concentration‐dependent manner. TRPV1 agonist capsaicin mediated a concentration‐dependent increase in TRPV1 inward currents and MUC5AC secretion. Furthermore, capsaicin enhanced acid‐induced TRPV1 inward currents and MUC5AC secretion. Acid‐induced Ca2+ influx was prevented by capsazepine dose dependently and enhanced by capsaicin. Pretreatment only with capsaicin also increased the Ca2+ concentration in a concentration‐dependent manner. These data suggest that pharmacological inhibition of calcium‐permeable TRPV1 receptors could be used to prevent acid‐induced mucin secretion, thereby providing a potential mechanism to reduce their toxicity. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:179–186, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20413
Measurement of infant tongue thickness using ultrasound: A technical note
Authors: Capilouto Gilson J. , Frederick Eric D. , Challa Harigovinda
Published: May 2012

Novel uses of ultrasound include obtaining images of intra‐oral structures to further research in speech production and feeding. In this technical note we describe a noninvasive, cost‐effective, and reliable method for measuring infant tongue muscle thickness. The current pilot study demonstrates high reliability of a trained ultrasonographer to obtain adequate images of the infant tongue and the ability to measure reliably between two anatomic landmarks to determine tongue thickness and investigate a potential relationship between tongue size and tongue force. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
The effect of displacement on the mechanical properties of human cadaver subsynovial connective tissue
Authors: Vanhees Matthias , Morizaki Yutaka , Thoreson Andrew R. , Larson Dirk , Zhao Chunfeng , An Kai‐Nan , Amadio Peter C.
Published: May 2012

The subsynovial connective tissue (SSCT) in the carpal tunnel may participate in the origin of carpal tunnel syndrome (CTS), yet material properties of the SSCT have not been well‐characterized. We investigated the response of the SSCT to repeated ramp stretch tests. Eight human cadaver wrists were used. The physiological excursion of the flexor digitorum superficialis of the third digit (FDS 3) was measured, starting from a neutral position to maximal flexion of the metacarpophalangeal and proximal interphalangeal joints. The FDS 3 tendon was pulled to 40%, 60%, 90%, and 120% of the physiological excursion. Two “ramp stretch” cycles were performed at every excursion level, except for 120% of excursion, where three cycles were performed. The ratio of energy absorbed between the second (E2) and first (E1) ramp stretch was 0.94 (SD = 0.07) for 60%, 0.84 (SD = 0.11) for 90%, and 0.68 (SD = 0.11) for 120% of the physiological excursion. A significant decrease occurred in energy absorbed after the first ramp stretch cycle at 90% and 120% of the physiological excursion, which was not seen at 60%. Our data are consistent with a stepwise damage occurring in the SSCT. Furthermore, the damage seems to initiate within the physiological range of tendon excursion. This finding may be important in understanding the pathophysiology of conditions that are associated with SSCT pathology, such as carpal tunnel syndrome. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1732–1737, 2012
Shoot cadmium concentration of soil‐grown plants as related to their root properties
Authors: Stritsis Christos , Steingrobe Bernd , Claassen Norbert
Published: May 2012

Cadmium (Cd) is toxic to plants, animals, and humans. However, different plant species growing on the same soil may have very different shoot Cd concentrations depending on properties such as size of the root system, Cd net influx, shoot‐growth rate, Cd translocation from root to shoot, and the ability to affect Cd availability in the soil. To investigate possible reasons for different shoot Cd concentrations maize, sunflower, flax, and spinach were grown on an acid sandy soil (pH<$>_{{\rm{(CaCl}}_{\rm{2}} {\rm)}<$> 4.5, and Corg 2.8%) in a growth chamber with Cd additions as Cd(NO3)2 of none, 14, and 40 μmol (kg soil)–1 resulting in Cd soil‐solution concentrations of 0.04, 0.68, and 2.5 μM. Only the high Cd addition caused a significant growth reduction of flax and spinach. The shoot Cd concentration was up to 30 times higher in spinach than in maize; the other species were intermediate. Of the plant properties studied only the variation of the Cd net influx explained the differences in shoot Cd concentrations. This was due to a decreased (maize, sunflower) or increased (flax) Cd concentration in soil solution or more effective uptake kinetics (spinach).
First bite syndrome: Incidence, risk factors, treatment, and outcomes
Authors: Linkov Gary , Morris Luc G. T. , Shah Jatin P. , Kraus Dennis H.
Published: May 2012

Objectives/Hypothesis:

First bite syndrome (FBS) refers to facial pain characterized by a severe cramping or spasm in the parotid region with the first bite of each meal that diminishes over the next several bites.1, 2 It is a potential sequela of surgery involving the infratemporal fossa (ITF), parapharyngeal space (PPS), and/or deep lobe of the parotid gland. The incidence, risk factors, treatment options, and outcomes of FBS are poorly understood. We hypothesized that certain clinical and tumor variables independently predict the development of FBS.

Study Design:

Retrospective cohort study.

Methods:

We reviewed the records of 499 patients (mean age, 50 years; range, 12–81 years) undergoing surgery of the deep lobe of the parotid gland, PPS, and/or ITF between 1992 and 2010. Minimum follow‐up time was 3 months (median, 39 months). Patient, tumor, and FBS characteristics were analyzed. Incidence was calculated using the Kaplan–Meier method. Univariate analyses and multivariate logistic regression were used to identify independent risk factors for FBS. Patients developing FBS were interviewed to assess the efficacy of various treatment modalities.

Results:

FBS developed in 45 patients (incidence, 9.6%), at a mean time of 97 (range, 6–877) days from surgery. On multivariate analysis, three variables were significant independent risk factors for FBS: sympathetic chain sacrifice (odds ratio [OR], 4.7; P = .008), PPS dissection (OR, 8.7; P = .001), and resection of only the deep lobe of the parotid gland (OR, 4.2; P = .002). FBS developed in 48.6% of patients undergoing sympathetic chain sacrifice, 22.4% of patients undergoing PPS dissection, 38.4% of patients undergoing isolated deep lobe parotid resection, and 0.8% of patients undergoing total parotidectomy. Partial resolution of FBS symptoms occurred in 69% and complete resolution in 12%. Of 45 FBS patients, 15 (33%) underwent at least one type of treatment for symptomatic relief. No treatment consistently provided effective symptomatic relief.

Conclusions:

The strongest independent risk factors for FBS are PPS dissection, deep lobe of parotid resection, and sympathetic chain sacrifice. Patients undergoing surgery with dissection and/or manipulation in these anatomical sites and structures should be thoroughly counseled about the risk of developing FBS. Laryngoscope, 2012
On The Incompatibility of Dextran and Pullulan in Aqueous Solutions and Its Modeling
Authors: Eckelt Anja , Eckelt John , Schärtl Wolfgang , Wolf Bernhard A.
Published: May 2012

Joint aqueous solutions of branched dextran and linear pullulan are investigated with respect to their phase separation. The experiments demonstrate that the polymers are – depending on the molar mass of dextran – incompatible in aqueous solutions despite their chemical similarity. This finding can be modeled on the basis of an approach accounting for chain connectivity and conformational relaxation of the components. According to these calculations, the polymers exhibit a miscibility gap in joint solutions despite the favorable interactions between them. Using information on the subsystems H2O/dextran and H2O/pullulan, the assumption of complete miscibility of the polysaccharides is required to model the observed phase separation. This analysis predicts the existence of two islands of immiscibility for the ternary system.
Efficient derivation of bovine embryonic stem cells needs more than active core pluripotency factors
Authors: Maruotti Julien , Muñoz Marta , Degrelle Severine A. , Gómez Enrique , Louet Claire , Monforte Carmen Díez , de Longchamp Priscille Huot , Brochard Vincent , Hue Isabelle , Caamaño José Nestor , Jouneau Alice
Published: May 2012

Pluripotency can be captured in vitro, providing that the culture environment meets the requirements that avoid differentiation while stimulating self‐renewal. From studies in the mouse embryo, two kinds of pluripotent stem cells have been obtained from the early and late epiblast, embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs), representing the naive and primed states, respectively. All attempts to derive convincing ESCs in ungulates have been unsuccessful, although all attempts were based on the assumption that the conditions used to derive mouse ESCs or human ESC could be applied in other species. Pluripotent cells derived in primates, rabbit, and pig strongly indicate that the state of pluripotency of these cells is, in fact, closer to EpiSCs than to ESCs, and thus depend on fibroblast growth factor (FGF) and Activin signaling pathways. Based on this observation, we have tried to derive EpiSC from the epiblast of bovine elongated embryos as well as ESCs from Day‐8 blastocysts. We here show that the core transcription factors Oct4/Sox2/Nanog can be used as markers of pluripotency in the bovine since their expression was restricted to the developing epiblast after Day 8, and disappeared following differentiation of both the ESC‐like and EpiSC‐like cultures. Although FGF and Activin pathways are indeed present and active in the bovine, it is not sufficient/enough to maintain a long‐term pluripotency ex vivo, as was reported for mouse and pig EpiSCs. Mol. Reprod. Dev. 79:461–477, 2012. © Wiley Periodicals, Inc.
Effect of simvastatin on passive strain‐induced skeletal muscle injury in rats
Authors: Tomazoni Shaiane Silva , Leal‐Junior Ernesto Cesar Pinto , Pallotta Rodney Capp , De Godoi Vanessa , Rossi Rafael Paolo , Frigo LÚcio , Leonardo Patrícia Sardinha , De Almeida Patrícia , Lopes‐Martins Rodrigo Álvaro Brandão
Published: May 2012

Introduction: HMG‐CoA reductase inhibitors are the most frequently prescribed drugs for treatment of lipid imbalance, but they have side effects, such as myopathy. Our aim was to assess the effect of simvastatin on the inflammatory process induced by skeletal muscle injury. Methods: Rats were divided into experimental groups [control group, simvastatin (20 mg/kg) group, group treated with simvastatin (20 mg/kg) and subjected to injury, and group subjected to injury only]. Histological analysis and analyses of creatine kinase activity and C‐reactive protein were performed. Results: Animals treated with simvastatin exhibited significantly greater morphological and structural skeletal muscle damage in comparison to the control group and injured animals without treatment. Conclusions: Although simvastatin has a small anti‐inflammatory effect in the early stage after a muscle strain injury, the overall picture is negative, as simvastatin increases the extent of damage to muscle morphology. Further studies are needed. Muscle Nerve, 2012
Optimal time‐point for neural stem cell transplantation to delay denervated skeletal muscle atrophy
Authors: Lin Sen , Xu Lei , Hu Shaonan , Zhang Changqing , Wang Yang , Xu Jianguang
Published: May 2012

Introduction:

Transplantation of neural stem cells (NSCs) is a promising treatment to delay denervated skeletal muscle atrophy; however, the optimal time‐point between peripheral nerve injury and NSC transplantation needs to be determined.

Methods:

Improvement in rat gastrocnemius muscle function was evaluated after NSCs were transplanted into sectioned distal tibial nerves. We also assessed survival and differentiation. ANOVA was used to compare the mean value of the number of neuron‐like cells, cross‐sectional area amelioration, the amount of activated fibers, and latency and amplitude of the gastrocnemius compound muscle action potential.

Results:

The group in which the NSCs were transplanted 1 week after tibial nerve transection had the largest number of neuron‐like cells, maximum cross‐sectional area amelioration, and maximum amount of activated gastrocnemius fibers compared with all other groups (P < 0.01).

Conclusions:

The optimal time‐point for NSC transplantation for delaying denervated skeletal muscle atrophy is 1 week after severing the nerve. Muscle Nerve, 2013
Robust quantized feedback stabilization of linear systems based on sliding mode control
Authors: Zheng Bo‐Chao , Yang Guang‐Hong
Published: May 2012

This paper investigates the robust quantized feedback stabilization problem for a class of single‐input linear uncertain systems on the basis of sliding mode control schemes. It is assumed that the system signals including the system state and control input are quantized before being transmitted through digital communication channels. A static adjustment policy of the quantization parameter for dynamic quantizers is developed. With the adjustment of the quantization parameter, a sliding mode control strategy is designed to ensure the reachability of the sliding manifold, and then, the system is induced into the stable sliding motion thereafter. Finally, an example is provided to illustrate the effectiveness of the proposed approach. Copyright © 2012 John Wiley & Sons, Ltd.
Origin of trisomy: no evidence to support the ovarian mosaicism theory
Authors: Morris Charlotte Rose , Haigh Shaun , Cuthbert Gavin , Crosier Moira , Harding Fiona , Wolstenholme John
Published: May 2012

Objective

Trisomy is the most common type of chromosome abnormality, affecting 4% of clinically recognised pregnancies, of which, trisomies 16, 21 and 22 are the most prevalent. It has been suggested that a large proportion of maternally derived trisomic pregnancies, specifically trisomy 21, are the result of low‐level ovarian mosaicism. In this study, we aimed to reproduce these previously published results on trisomy 21 and investigate the other common maternally derived trisomies (i.e. trisomies 16 and 22) by determining chromosome copy number in fetal ovarian and control skin cells.

Methods

Ovarian and control skin tissue was collected from eight karyotypically normal female fetuses of between 10 and 14 weeks gestation, which were terminated for social reasons. Tissues were dissociated and fluorescence in situ hybridisation was performed with break‐apart probes: CBFβ (16q22), RUNX1 (21q22) and EWSR1 (22q12).

Results

A small number of trisomic cells, 13 out of 51 146 cells examined (0.025%), were identified in both ovarian and control skin samples. Only three of these trisomic cells were present in the fetal ovarian tissue.

Conclusion

This study found no evidence of fetal ovarian mosaicism for trisomies 16, 21 and 22. © 2012 John Wiley & Sons, Ltd and Crown copyright.
Strain rate and temperature dependence of a nanoparticle‐filled poly(dimethylsiloxane) undergoing shear deformation
Authors: Yan Lei , Dillard David A. , West Robert L. , Rubis Kenneth J. , Gordon Glenn V.
Published: May 2012

The mechanical properties in shear of unfilled and nanoparticle‐filled polydimethylsiloxane (PDMS) networks are reported. The effect of silicate‐based nanoparticles on the mechanical response was studied as functions of rate and temperature using the time–temperature superposition principle. An apparent yielding phenomenon was observed in the filled polymer in spite of the more typical elastomeric behavior exhibited by the pure PDMS network. The time–temperature superposition principle was applied to capture the shear strain rate (10−4–10−1 s−1) and temperature (−40 to 60°C) dependence of the stress response of the filled PDMS at different strains and at the yield point. A power‐law relationship was found to adequately describe the resulting master curves for yield stress in shear. Using a triangular shear displacement profile at 10−2 s−1, the effect of temperature (−20 to 80°C) on the recovery from a particularly pronounced Mullins effect was investigated as a function of rest time. Given adequate rest time (between 10 and 102 min), recovery was observed for the temperature range studied. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
N‐terminal acetylation of α‐synuclein induces increased transient helical propensity and decreased aggregation rates in the intrinsically disordered monomer
Authors: Kang Lijuan , Moriarty Gina M. , Woods Lucy A. , Ashcroft Alison E. , Radford Sheena E. , Baum Jean
Published: May 2012

The conformational properties of soluble α‐synuclein, the primary protein found in patients with Parkinson's disease, are thought to play a key role in the structural transition to amyloid fibrils. In this work, we report that recombinant 100% N‐terminal acetylated α‐synuclein purified under mild physiological conditions presents as a primarily monomeric protein, and that the N‐terminal acetyl group affects the transient secondary structure and fibril assembly rates of the protein. Residue‐specific NMR chemical shift analysis indicates substantial increase in transient helical propensity in the first 9 N‐terminal residues, as well as smaller long‐range changes in residues 28–31, 43–46, and 50–66: regions in which the three familial mutations currently known to be causative of early onset disease are found. In addition, we show that the N‐terminal acetylated protein forms fibrils that are morphologically similar to those formed from nonacetylated α‐synuclein, but that their growth rates are slower. Our results highlight that N‐terminal acetylation does not form significant numbers of dimers, tetramers, or higher molecular weight species, but does alter the conformational distributions of monomeric α‐synuclein species in regions known to be important in metal binding, in association with membranes, and in regions known to affect fibril formation rates.
How cells process information: Quantification of spatiotemporal signaling dynamics
Authors: Ganesan Ambhighainath , Zhang Jin
Published: May 2012

Arguably, one of the foremost distinctions between life and non‐living matter is the ability to sense environmental changes and respond appropriately—an ability that is invested in every living cell. Within a single cell, this function is largely carried out by networks of signaling molecules. However, the details of how signaling networks help cells make complicated decisions are still not clear. For instance, how do cells read graded, analog stress signals but convert them into digital live‐or‐die responses? The answer to such questions may originate from the fact that signaling molecules are not static but dynamic entities, changing in numbers and activity over time and space. In the past two decades, researchers have been able to experimentally monitor signaling dynamics and use mathematical techniques to quantify and abstract general principles of how cells process information. In this review, the authors first introduce and discuss various experimental and computational methodologies that have been used to study signaling dynamics. The authors then discuss the different types of temporal dynamics such as oscillations and bistability that can be exhibited by signaling systems and highlight studies that have investigated such dynamics in physiological settings. Finally, the authors illustrate the role of spatial compartmentalization in regulating cellular responses with examples of second‐messenger signaling in cardiac myocytes.
Open quantum dots: Physics of the non‐Hermitian Hamiltonian
Authors: Ferry D.K. , Akis R. , Burke A.M. , Knezevic I. , Brunner R. , Bird J.P. , Meisels R. , Kuchar F. , Bird J.P.
Published: May 2012

Quantum dots provide a natural system in which to study both classical and quantum features of transport, as they possess a very rich set of eigenstates.When coupled to the environment through a pair of quantum point contacts, these dots possess a mixed phase space which yields families of closed, regular orbits as well as an expansive sea of chaos. In this latter case, many of the eigenstates are decohered through interaction with the environment, but many survive and are referred to as the set of pointer states. These latter states are described by a projected, non‐Hermitian Hamiltonian which describes their dissipation through many‐body interactions with particles in the external environment.
Contact‐free reactions between micropipes in bulk SiC growth
Authors: Gutkin Mikhail Yu. , Sheinerman Alexander G. , Kohn Victor G. , Argunova Tatiana S. , Smirnov Mikhail A. , Je Jung Ho
Published: May 2012

It has been generally accepted that any reaction between micropipes in silicon carbide (SiC) crystals requires a direct contact of the micropipes. We propose a new model of contact‐free reactions that are realized through the emission and absorption of full‐core dislocations by micropipes.

This model can explain the correlated reduction in micropipe radii in the samples with low micropipe densities which has been observed in synchrotron radiation (SR) phase contrast images supported by computer simulations. We provide a theoretical description of a contact‐free reaction between two parallel micropipes.
Linear response function approach for the boundary problem of QM/MM methods
Authors: Ueda Koki , Yamanaka Shusuke , Nakata Kazuto , Ehara Masahiro , Okumura Mitsutaka , Yamaguchi Kizashi , Nakamura Haruki
Published: May 2012

We present a simple approach to treat the boundary problem in quantum mechanics and molecular mechanical (QM/MM) methods. The method is based on ab initio calculations of linear response functions, which indicate nonlocal polarization of densities due to the perturbations at the specific site. We describe basic ideas as well as some numerical results. The computational results will be discussed with the boundary problem in QM/MM methods. © 2012 Wiley Periodicals, Inc.
Semiquantal molecular dynamics simulations of hydrogen‐bond dynamics in liquid water using spherical gaussian wave packets
Authors: Ono Junichi , Hyeon‐Deuk Kim , Ando Koji
Published: May 2012

A semiquantal (SQ) molecular dynamics (MD) simulation method using spherical Gaussian wave packets (WPs) is applied to a microscopic analysis of hydrogen‐bond (H‐bond) exchange dynamics in liquid water. We focus on the molecular jump mechanism of H‐bond reorientation dynamics proposed from a classical MD simulation by Laage and Hynes (Science 2006, 311, 832). As a notable quantum effect, broadenings of both the oxygen and hydrogen WPs of jumping water are observed associated with the H‐bond switching events. Nonetheless, quantum effects on averaged trajectories of structural parameters measured with respect to the WP centers are rather minor. A 1/f fluctuation of local H‐bond number is observed in both SQ and classical simulations. This is obtained straightforwardly from the real‐time trajectories, in contrast with the originally found 1/f fluctuation (Sasai et al., J. Chem. Phys. 1992, 96, 3045) of the total potential energies collected at quenched inherent structures. The quantum effects are found to accelerate the relaxation of H‐bond number fluctuation, which is reflected in the region near the lower bound of the 1/f behavior in the power spectra. New developments in the implementation of SQMD simulations including all atoms are also described. © 2012 Wiley Periodicals, Inc.
Some formal properties of ensemble density functionals
Authors: Joubert Daniel P.
Published: May 2012

Formal properties of ensemble density functionals are examined. Expressions for the difference between energy functionals where the particle number differs by one are constructed in terms of their first functional derivatives for the universal energy functional, the electron–electron repulsion energy functional, and the interacting kinetic energy functional. Equations that must be satisfied by second and higher order functional derivatives are derived. It is also shown that the shape of
${\delta V_{ee}[\rho]\over\delta\rho({\bf r})}$
and ${\delta K[\rho]\over\delta\rho({\bf r})}$, the functional derivatives of the mutual electron–electron repulsion, and kinetic energy, respectively, are separately particle number independent for particle numbers between successive integers. © 2013 Wiley Periodicals, Inc.
Disturbance‐driven model predictive control by means of Youla–Kučera parameter switching with an application to drainage canal control
Authors: Blanchini Franco , Pellegrino Felice Andrea , Miani Stefano
Published: May 2012

Motivated by applications such as drainage canal control, where the disturbance acting on a system can be predicted on the basis of weather forecast, we propose a model predictive control technique consisting in the online tuning of a Youla–Kučera parameter. Essentially, the optimal control sequence is supplied to the system by properly setting the coefficients of the Youla–Kučera parameter taken as a finite impulse response, whose length depends on that of the optimal trajectory. Stability is guaranteed for any arbitrary choice of the time‐varying coefficients that are adapted to the current forecast of disturbance. The approach is illustrated by numerical simulations of a drainage canal control system. Copyright © 2012 John Wiley & Sons, Ltd.
Mediation Effects of Environmental Cooperation on the Relationship between Sustainable Design and Performance Improvement among Chinese Apartment Developers
Authors: Zhu Qinghua , Zhao Tielin , Geng Yong
Published: May 2012

Due to increasing pressure for energy saving and emission reduction, Chinese apartment developers have initiated sustainable design practices. This paper develops a conceptual model which proposes that cooperation with construction stakeholders and customers is a mediator, necessary for apartment developers to realize environmental, economic and even competitive performance improvement through sustainable design practices. The paper examines the current practice situations of sustainable design, cooperation with construction stakeholders and customers as well as related performance improvement among Chinese apartment developers based on 92 questionnaires conducted by the authors. The mediation effects are further analysed through hierarchical regression analysis. Statistical results indicate that sustainable design should be further promoted by the Chinese governments and implemented by Chinese apartment developers. Policy implications are discussed to provide detailed suggestions on improving the cooperation with Chinese apartment developers and their construction stakeholders/customers. Such cooperation can help apartment developers to improve environmental, competitive and economic performance through sustainable design practices. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
A generic static analyzer for multithreaded Java programs
Authors: Ferrara P.
Published: May 2012

In this paper, we present heckmate, the first generic static analyzer of multithreaded Java programs based on abstract interpretation. heckmate can be tuned at different levels of precision and efficiency in order to prove various properties (e.g., absence of divisions by zero and data races), and it is sound for multithreaded programs. It supports all the most relevant features of Java multithreading, such as dynamic thread creation, runtime creation of monitors, and dynamic allocation of memory. The experimental results demonstrate that heckmate is accurate and efficient enough to analyze programs with some thousands of statements and a potentially infinite number of threads. Copyright © 2012 John Wiley & Sons, Ltd.
An unequal clustering algorithm based on energy balance for wireless sensor networks
Authors: Xu Guangwei , Zhu Ming , Luo Xin , Wu Min , Ren Fuji
Published: May 2012

Sensor nodes in sensor networks often gather data and deliver them to the sink. However, the energy and radio range constraints force them to cooperate in transmitting the data to the destination with multihop communication. To achieve this, nodes have to be clustered and some of them are elected as the cluster head nodes to transmit the aggregated data. Unfortunately, the clustering brings extra traffic load to the cluster head nodes, particularly those closer to the sink. These nodes die faster than before as their energy is drained at a high rate. Therefore, some clustering and cluster head election algorithms were suggested to use the unequal clustering size to extend the lifetime of cluster head nodes. However, it is difficult to obtain the accurate cluster size in the process of unequal clustering. Moreover, some cluster head nodes with the overfull cluster members may die early. We propose an enhanced unequal clustering size algorithm to optimize the unequal cluster size in the different layers and balance the dissipation energy of all cluster head nodes. Simulation results show that our algorithm dissipates approximately the same energy of cluster head nodes in the different layers per round and obviously increases the number of rounds of data gathering and transmission. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Serotonin signaling in eating disorders
Authors: Compan Valérie , Laurent Laetitia , Jean Alexandra , Macary Céline , Bockaert Joël , Dumuis Aline
Published: May 2012

The brain serotonin (5‐hydroxytryptamine, 5‐HT) system is implicated in the neurobiological control of feeding and appears to be dysfunctional in patients suffering from feeding disorders, such as anorexia, bulimia, and obesity. Thanks to the identification and cloning of 5‐HT receptors, the production of agonist and antagonist compounds, and the generation of 5‐HT receptor knock‐out mice, our knowledge on the implication of different 5‐HT receptor subtypes in feeding behavior has greatly increased. A number of studies have demonstrated an involvement of the hypothalamic 5‐HT1B and 5‐HT2C receptors in food intake and body weight control, but the downstream events induced by such signaling remain to be explored. Moreover, little is known about the influence of 5‐HT on the rewarding value of eating. Such value may not necessarily be linked to food consumption, but rather to voluntary reduction of food intake, as recently demonstrated upon activation of the 5‐HT4 receptors in the nucleus accumbens. Thus, abnormalities in the reward system in addition to those in the central control of the autonomic nervous system might contribute to the anorexic behavior. Recent studies have also reported an involvement of the 5‐HT6 and 5‐HT7 receptors in feeding behavior. Potential 5‐HT receptor agonists/antagonists could then be developed and used in association with psychological treatment to better cope with the stressors that trigger anorexia and drug dependence. WIREs Membr Transp Signal 2012, 1:715–729. doi: 10.1002/wmts.45

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Serotonergic signaling: multiple effectors and pleiotropic effects
Authors: Masson Justine , Emerit Michel Boris , Hamon Michel , Darmon Michèle
Published: May 2012

Serotonin (5‐HT) is a neurotransmitter which exerts both central and peripheral control on numerous physiological functions such as sleep/wake cycle, thermoregulation, food intake, nociception, locomotion, sexual behavior, gastrointestinal motility, blood coagulation, and cardiovascular homeostasis. These multiple effects are mediated by a family of serotonin receptors which comprises at least 13 distinct G‐protein‐coupled receptors (GPCRs) of the A type and a combination of ligand‐gated cation channel heteropentameric receptors of the conserved 5‐HT3 Cys‐loop type. Many of these receptors are targets of pharmaceutical drugs justifying the wide interest to elucidate their functioning. Over the past decades, substantial investigations have led to the current understanding of the complex signal transduction mechanisms which these receptors initiate. The idea of a unique coupling of a receptor to a linear pathway has evolved into a multiplicity of alternative bifurcations and feedback mechanisms. The emerging signaling model includes the capacity of 5‐HT receptors GPCR superfamily to couple and initiate transduction through several G proteins depending on the tissue and/or the presence of interacting proteins. In turn, these G proteins may activate many effectors. On the other hand, the complexity increases further with the capacity of 5‐HT receptors to transduce signals through G‐protein‐independent pathways. These multiple couplings often participate in the control of gene transcription, thereby resulting in 5‐HT‐mediated long‐term (neuroplastic) adaptive functional changes. WIREs Membr Transp Signal 2012, 1:685–713. doi: 10.1002/wmts.50

For further resources related to this article, please visit the WIREs website.