bluuebunny/crossref_metadata_2025 huggingface dataset:
Is pelvic pain associated with defecatory symptoms in women with pelvic organ prolapse?
Authors: Asfaw Tirsit S. , Saks Emily K. , Northington Gina M. , Arya Lily A.
Published: March 2011

Objective

To investigate the significance of pelvic pain and its association with defecatory symptoms in women with pelvic organ prolapse (POP).

Study Design

This is a cross sectional study of 248 women with stage II POP or greater. Women were stratified into “pain” and “no‐pain” groups based on their response to a question on the Pelvic Floor Distress Inventory short form. Associations between patient demographics, exam findings and responses to validated questionnaires were evaluated.

Results

In women with POP, defecatory symptoms are significantly more common in women with pelvic pain including straining with bowel movement (OR 2.4, 95% CI 1.3, 4.6), sense of incomplete emptying (OR 4.4, 95% CI 2.3, 8.2), pain with bowel movement (OR 5.3, 95% CI 1.2, 23.0) and splinting with bowel movement (OR 3.8, 95% CI 2.0, 7.5).

Conclusion

In women with POP, the symptom of pelvic pain is associated with the presence of defecatory symptoms. Neurourol. Urodynam. 30:1305–1308, 2011. © 2011 Wiley‐Liss, Inc.
Edge‐superconnectivity of semiregular cages with odd girth
Authors: Balbuena C. , González‐moreno D. , Salas J.
Published: March 2011

A graph is said to be edge‐superconnected if each minimum edge‐cut consists of all the edges incident with some vertex of minimum degree. A graph G is said to be a
$\{d,d+1\}$‐semiregular graph if all its vertices have degree either d or $d+1$. A smallest $\{d,d+1\}$‐semiregular graph G with girth g is said to be a $(\{d,d+1\};g)$‐cage. We show that every $(\{d,d+1\};g)$‐cage with odd girth g is edge‐superconnected. © 2011 Wiley Periodicals, Inc. NETWORKS, 2011
Approximation algorithms for distance constrained vehicle routing problems
Authors: Nagarajan Viswanath , Ravi R.
Published: March 2011

We study the distance constrained vehicle routing problem (DVRP) (Laporte et al., Networks 14 (1984), 47–61, Li et al., Oper Res 40 (1992), 790–799): given a set of vertices in a metric space, a specified depot, and a distance bound D, find a minimum cardinality set of tours originating at the depot that covers all vertices, such that each tour has length at most D. This problem is NP‐complete, even when the underlying metric is induced by a weighted star. Our main result is a 2‐approximation algorithm for DVRP on tree metrics; we also show that no approximation factor better than 1.5 is possible unless P = NP. For the problem on general metrics, we present a
$(O(\log {1 \over \varepsilon }),1 + \varepsilon )$‐bicriteria approximation algorithm: i.e., for any ε > 0, it obtains a solution violating the length bound by a 1 + ε factor while using at most $O(\log {1 \over \varepsilon })$ times the optimal number of vehicles. © 2011 Wiley Periodicals, Inc. NETWORKS, 2012
An auxiliary space preconditioner for linear elasticity based on the generalized finite element method
Authors: Brannick James , Cho Durkbin
Published: March 2011

We construct and analyze a preconditioner of the linear elasticity system discretized by conforming linear finite elements in the framework of the auxiliary space method. The auxiliary space preconditioner is based on two auxiliary spaces corresponding to discretizations of the scalar Poisson equation by linear finite elements and the generalized finite element method. Copyright © 2011 John Wiley & Sons, Ltd.
A new parallel sparse direct solver: Presentation and numerical experiments in large‐scale structural mechanics parallel computing
Authors: Guèye I. , Arem S. El , Feyel F. , Roux F.‐X. , Cailletaud G.
Published: March 2011

The main purpose of this work is to present a new parallel direct solver: Dissection solver. It is based on LU factorization of the sparse matrix of the linear system and allows to detect automatically and handle properly the zero‐energy modes, which are important when dealing with DDM. A performance evaluation and comparisons with other direct solvers (MUMPS, DSCPACK) are also given for both sequential and parallel computations. Results of numerical experiments with a two‐level parallelization of large‐scale structural analysis problems are also presented: FETI is used for the global problem parallelization and Dissection for the local multithreading. In this framework, the largest problem we have solved is of an elastic solid composed of 400 subdomains running on 400 computation nodes (3200 cores) and containing about 165 millions dof. The computation of one single iteration consumes less than 20 min of CPU time. Several comparisons to MUMPS are given for the numerical computation of large‐scale linear systems on a massively parallel cluster: performances and weaknesses of this new solver are highlighted. Copyright © 2011 John Wiley & Sons, Ltd.
The meshless Galerkin boundary node method for Stokes problems in three dimensions
Authors: Li Xiaolin
Published: March 2011

The Galerkin boundary node method (GBNM) is a boundary only meshless method that combines an equivalent variational formulation of boundary integral equations for governing equations and the moving least‐squares (MLS) approximations for generating the trial and test functions. In this approach, boundary conditions can be implemented directly and easily despite of the fact that the MLS shape functions lack the delta function property. Besides, the resulting formulation inherits the symmetry and positive definiteness of the variational problems. The GBNM is developed in this paper for solving three‐dimensional stationary incompressible Stokes flows in primitive variables. The numerical scheme is based on variational formulations for the first‐kind integral equations, which are valid for both interior and exterior problems simultaneously. A rigorous error analysis and convergence study of the method for both the velocity and the pressure is presented in Sobolev spaces. The capability of the method is also illustrated and assessed through some selected numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of drawing on the molecular orientation, polymorphism, and properties of melt‐spun nanocomposite fibers based on nylon 6 with polyhedral oligomeric silsesquioxane, montmorillonite, and their combination
Authors: Magniez Kevin , Fox Bronwyn Louise , Lonney Mark Graham
Published: March 2011

In this work, binary and ternary nanocomposite systems based on nylon 6 with montmorillonite (MMT), polyhedral oligomeric silsesquioxane (POSS), and their combination were prepared using a melt‐compounding process. In the transmission electron microscope (TEM) images, the MMT was found to be generally well dispersed in all materials resulting in its good chemical compatibility with nylon 6, affording intercalated disordered microstructures. On the other hand, the TEM images showed that POSS formed micron‐size crystalline agglomerates possibly resulting from a lack in chemical compatibility with nylon 6. These nanocomposite systems were melt‐spun into fibers, and the relevant structure–property relationships that occur during the cold drawing process was established by correlating the tensile properties to the changes in crystallinity, polymorphic crystal forms, and molecular orientation. The properties of the resulting fibers were found to be rather skewed and significantly affected by the polymer/nanoparticles interface. The agglomeration of POSS and POSS–MMT particles coupled with the weak nylon 6/POSS interface, reflected on the tensile properties of the nylon 6/POSS and nylon 6/MMT‐POSS fibers which underperformed. Some nanocomposite fiber systems offered significant improvements in modulus without excessively compromising the extensibility of the fibers. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Maternal serum adiponectin at 11 to 13 weeks of gestation in the prediction of macrosomia
Authors: Nanda Surabhi , Akolekar Ranjit , Sarquis Rita , Mosconi Ana Paula , Nicolaides Kypros H.
Published: March 2011

Objective

To examine the potential role of maternal serum level of adiponectin in the first trimester of pregnancy in the prediction of neonatal macrosomia.

Methods

Maternal serum adiponectin concentration was measured in a case–control study of singleton pregnancies at 11 to 13 weeks' gestation, which included 50 cases that subsequently delivered macrosomic neonates with birth weight above the 95th percentile for gestation at delivery and 300 controls who delivered appropriate for gestational age neonates. The median multiple of the median (MoM) serum adiponectin in the two outcome groups was compared and the bivariate Gaussian distributions were simulated in a screened population of 33 344 pregnancies to estimate the performance of screening for macrosomia by a combination of maternal characteristics and obstetric history with serum adiponectin.

Results

In the macrosomic group the median serum adiponectin [0.82, interquartile range (IQR): 0.56–1.02 MoM] was significantly lower than in the non‐macrosomic controls (1.02, IQR: 0.70–1.29 MoM; p = 0.001). The estimated detection rate of macrosomia, at fixed false positive rate of 10%, from maternal characteristics and obstetric history was 34.6% and this increased to 38.2% with the addition of serum adiponectin.

Conclusion

Maternal serum adiponectin at 11 to 13 weeks is a useful biomarker for early prediction of macrosomia. Copyright © 2011 John Wiley & Sons, Ltd.
The work of a dedicated inpatient diabetes care team in a district general hospital
Authors: Brooks AP , Li Voon Chong JSW , Grainger‐Allen S , McDonald M , Nero S , Atkin M , Deshmukh S
Published: March 2011

We describe the work of a multidisciplinary inpatient diabetes care team in a 400 bed district general hospital over a four‐year period. Also included are some observations on a positive contribution to reduced length of stay for people with diabetes in hospital, and low incidences of prescription and management errors in the first National Diabetes Inpatient Audit in 2009.

Specifically between 2005 and 2007 the average length of stay in days for all patients whose diagnosis included diabetes fell from 9.39 to 3.76 days despite the total number of patients increasing from 507 to 633 over the same quarter each year. The inpatient team provided almost 1000 visits to patients with diabetes in the first six months of each year 2008 and 2009, and at the first National Diabetes Inpatient Audit had only 5% prescription errors and 3% management errors (versus 19% and 14% respectively nationally) with 100% appropriate blood glucose testing.

We suggest that a dedicated inpatient diabetes care team raises the quality of care for patients and enhances patient and professional education; we also suggest that audit standards should be developed for inpatient diabetes care and assessed in future national audits. Copyright © 2011 John Wiley & Sons.
The surgical panacea for diabetes: time for diabetologists to discriminate facts from fiction and flights of fantasy
Authors: Pinkney J
Published: March 2011

Bariatric surgery is an important treatment for obesity and most patients enjoy substantial improvements in coexisting type 2 diabetes (T2D). As a result of the historic failure to establish relevant long‐term controlled trials, however, there is a need to separate evidence from unfounded belief. The short‐term impact, operative morbidity and mortality rates, and potential long‐term surgical and metabolic side effects of most (but not all) of the common forms of bariatric surgery are reasonably well described. In contrast, the longer‐term evidence base for applying bariatric surgery as an approach to treating T2D is much weaker. While bariatric surgery may have a prolonged beneficial effect on hyperglycaemia, it also has risks, and its economics and sustainability are unproven. At the more fanciful end of opinion is a mismatch between expectation and reality, with the risk that patients' expectations may be unrealistically raised. Long‐term relapse of weight and hyperglycaemia are well‐recognised and patients who choose these treatments will never be free of medical supervision.

The only way to guarantee that appropriate patients with T2D are safely selected for bariatric surgery, offered an appropriate choice of evidence‐based procedures, and receive appropriate immediate and long‐term postoperative medical care is for diabetologists to take on this mantle of responsibility. Copyright © 2011 John Wiley & Sons.
The implications of propensity score variable selection strategies in pharmacoepidemiology: an empirical illustration
Authors: Patrick Amanda R. , Schneeweiss Sebastian , Brookhart M. Alan , Glynn Robert J. , Rothman Kenneth J. , Avorn Jerry , Stürmer Til
Published: March 2011

Purpose

To examine the effect of variable selection strategies on the performance of propensity score (PS) methods in a study of statin initiation, mortality, and hip fracture assuming a true mortality reduction of < 15% and no effect on hip fracture.

Methods

We compared seniors initiating statins with seniors initiating glaucoma medications. Out of 202 covariates with a prevalence > 5%, PS variable selection strategies included none, a priori, factors predicting exposure, and factors predicting outcome. We estimated hazard ratios (HRs) for statin initiation on mortality and hip fracture from Cox models controlling for various PSs.

Results

During 1 year follow‐up, 2693 of 55 610 study subjects died and 496 suffered a hip fracture. The crude HR for statin initiators was 0.64 for mortality and 0.46 for hip fracture. Adjusting for the non‐parsimonious PS yielded effect estimates of 0.83 (95%CI:0.75–0.93) and 0.72 (95%CI:0.56–0.93). Including in the PS only covariates associated with a greater than 20% increase or reduction in outcome rates yielded effect estimates of 0.84 (95%CI:0.75–0.94) and 0.76 (95%CI:0.61–0.95), which were closest to the effects predicted from randomized trials.

Conclusion

Due to the difficulty of pre‐specifying all potential confounders of an exposure‐outcome association, data‐driven approaches to PS variable selection may be useful. Selecting covariates strongly associated with exposure but unrelated to outcome should be avoided, because this may increase bias. Selecting variables for PS based on their association with the outcome may help to reduce such bias. Copyright © 2011 John Wiley & Sons, Ltd.
Transcriptional and proteomic profiling of flatfish (Solea senegalensis) spermatogenesis
Authors: Forné Ignasi , Castellana Bárbara , Marín‐Juez Rubén , Cerdà Joan , Abián Joaquín , Planas Josep V.
Published: March 2011

The Senegalese sole (Solea senegalensis) is a marine flatfish of high economic value and a target species for aquaculture. The efforts to reproduce this species in captivity have been hampered by the fact that farmed males (F1) often show lower sperm production and fertilization capacity than wild‐type males (F0). Our knowledge on spermatogenesis is however limited to a few studies. In a previous work, we identified by 2‐D DIGE several potential protein markers in testis for the poor reproductive performance of F1 males. Therefore, the objectives of the present study were, first, to investigate changes in genes and proteins expressed in the testis throughout spermatogenesis in F0 males by using a combination of transcriptomic and proteomic approaches and, second, to further compare the testis proteome between late spermatogenic stages of F0 and F1 fish to identify potential indicators of hampered reproductive performance in F1 fish. We identified approximately 400 genes and 49 proteins that are differentially expressed during the progression of spermatogenesis and that participate in processes such as transcriptional activation, the ubiquitin–proteasome system, sperm maturation and motility or cytoskeletal remodeling. Interestingly, a number of these proteins differed in abundance between F0 and F1 fish, pointing toward alterations in cytoskeleton, sperm motility, the ubiquitin–proteasome system and the redox state during spermiogenesis as possible causes for the decreased fertility of F1 fish.
Comparative proteomic analysis of canola leaves under salinity stress
Authors: Bandehagh Ali , Salekdeh Ghasem Hosseini , Toorchi Mahmoud , Mohammadi Abolghasem , Komatsu Setsuko
Published: March 2011

Although canola is a moderately salt‐tolerant species, its growth, seed yield, and oil production are markedly reduced under salt stress, particularly during the early vegetative growth stage. To identify the mechanisms of salt responsiveness in canola, the proteins expressed in the second and third newly developed leaves of salt‐tolerant, Hyola 308, and salt‐sensitive, Sarigol, cultivars were analyzed. Plants were exposed to 0, 175, and 350 mM NaCl during the vegetative stage. An increase in the Na content and a reduction in growth were observed in the third leaves compared to the second leaves. The accumulation of Na was more pronounced in the salt‐sensitive compared with the salt‐tolerant genotype. Out of 900 protein spots detected on 2‐DE gels, 44 and 31 proteins were differentially expressed in the tolerant and susceptible genotypes, respectively. Cluster analysis based on the expression level of total and responsive proteins indicated that the second leaves had a discriminator role between the two genotypes at both salinity levels. Using MS analysis, 46 proteins could be identified including proteins involved in responses to oxidative stress, energy production, electron transport, translation, and photosynthesis. Our results suggest that these proteins might play roles in canola adaptation to salt stress.
Dynamics of post‐translational modifications and protein stability in the stroma of Chlamydomonas reinhardtii chloroplasts
Authors: Bienvenut Willy V. , Espagne Christelle , Martinez Aude , Majeran Wojetec , Valot Benoît , Zivy Michel , Vallon Olivier , Adam Zach , Meinnel Thierry , Giglione Carmela
Published: March 2011

The proteome of any system is a dynamic entity dependent on the intracellular concentration of the entire set of expressed proteins. In turn, this whole protein concentration will be reliant on the stability/turnover of each protein as dictated by their relative rates of synthesis and degradation. In this study, we have investigated the dynamics of the stromal proteome in the model organism Chlamydomonas reinhardtii by characterizing the half‐life of the whole set of proteins. 2‐DE stromal proteins profiling was set up and coupled with MS analyses. These identifications featuring an average of 26% sequence coverage and eight non‐redundant peptides per protein have been obtained for 600 independent samples related to 253 distinct spots. An interactive map of the global stromal proteome, of 274 distinct protein variants is now available on‐line at http://www.isv.cnrs‐gif.fr/gel2dv2/. N‐α‐terminal‐Acetylation (NTA) was noticed to be the most frequently detectable post‐translational modification, and new experimental data related to the chloroplastic transit peptide cleavage site was obtained. Using this data set supplemented with series of pulse‐chase experiments, elements directing the relationship between half‐life and N‐termini were analyzed. Positive correlation between NTA and protein half‐life suggests that NTA could contribute to protein stabilization in the stroma.
VAT‐1 is a novel pathogenic factor of progressive benign prostatic hyperplasia
Authors: Mori Fumitaka , Tanigawa Kiyoshi , Endo Kanji , Minamiguchi Kazuhisa , Abe Masaaki , Yamada Shizuo , Miyoshi Kazuhisa
Published: March 2011

BACKGROUND

Benign prostatic hyperplasia (BPH), arising from prostatic stromal hyperplasia (STH), is a progressive disease associated with bothersome lower urinary tract symptoms (LUTS). The mechanism of this STH remains unclear because there is no suitable model to study BPH pathology. Previously, we reported a new experimental BPH model that is clinically relevant to STH (the STH model). To elucidate prostatic STH mechanism, we used a compound found to be effective in the STH model.

METHODS

A binding protein specific for the effective compound in the STH model was pulled down using a compound‐conjugated affinity matrix and identified by mass spectrometry. The RNA interference (RNAi) method was used to confirm the participation of the binding protein in cell proliferation. The binding protein expression in the prostate was assessed by immunohistochemistry.

RESULTS

A benzimidazole derivative (Benz) significantly suppressed growth of implanted urogenital sinuses (UGS; 37.1%) in the STH model and inhibited the proliferation of human prostate stromal cells (PrSC) in a concentration‐dependent manner (IC50 = 0.43 µM). Vesicle amine transport protein‐1 (VAT‐1) was identified as a specific binding protein of Benz. Immunohistochemical analysis showed that the VAT‐1 expression level was higher in both epithelial and stromal cells of rat UGS and human BPH tissue than in normal prostate. VAT‐1 siRNA markedly inhibited proliferation of PrSC, two androgen‐independent prostate cancer cell lines (PC3 and DU145), and suppressed UGS growth (28.2%) in the STH model.

CONCLUSIONS

Here, we demonstrate that VAT‐1 is a novel pathogenic factor in BPH associated with cell proliferation. Prostate 71:1579–1586, 2011. © 2011 Wiley‐Liss, Inc.
Enhancing habitat to help the plight of the bumblebee
Authors: Blake Robin J , Westbury Duncan B , Woodcock Ben A , Sutton Peter , Potts Simon G
Published: March 2011

Modern farming has caused considerable declines in UK bumblebee populations, and, while options exist for farmers to increase the quantity of bee‐friendly habitat, uptake has been low. Robin Blake explains how existing habitats on farms could be enhanced for the benefit of bumblebees. Copyright © 2011 Society of Chemical Industry
Pyrethroid resistance and thiacloprid baseline susceptibility of European populations of Meligethes aeneus (Coleoptera: Nitidulidae) collected in winter oilseed rape
Authors: Zimmer Christoph T , Nauen Ralf
Published: March 2011

BACKGROUND: Pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae), is a major pest in European winter oilseed rape. Recently, control failures with pyrethroid insecticides commonly used to control this pest have been reported in many European countries. For resistance management purposes, the neonicotinoid insecticide thiacloprid was widely introduced as a new mode of action for pollen beetle control.

RESULTS: A number of pollen beetle populations collected in Germany, France, Austria, Great Britain, Sweden, Denmark, Finland, Poland, Czech Republic and Ukraine were tested for pyrethroid resistance using lambda‐cyhalothrin‐coated glass vials (adult vial test). Most of the populations tested exhibited substantial levels of resistance to lambda‐cyhalothrin, and resistance ratios ranged from < 10 to > 2000. A similar resistance monitoring bioassay for the neonicotinoid insecticide thiacloprid was developed and validated by assessing baseline susceptibility data for 88 European pollen beetle populations. A variation of less than fivefold in response to thiacloprid was detected. The thiacloprid adult vial bioassay is based on glass vials coated with an oil‐dispersion‐based formulation of thiacloprid, resulting in a much better bioavailability compared with technical material. Analytical measurements revealed a > 56 and 28 day stability of thiacloprid and lambda‐cyhalothrin in coated glass vials at room temperature, respectively. No cross‐resistance between thiacloprid and lambda‐cyhalothrin based on log‐dose probit–mortality data was detected.

CONCLUSION: Pyrethroid resistance in many European populations of M. aeneus was confirmed, whereas all populations are susceptible to thiacloprid when tested in a newly designed and validated monitoring bioassay based on glass vials coated with oil‐dispersion‐formulated thiacloprid. Based on the homogeneous results, it is concluded that thiacloprid could be an important chemical tool for pollen beetle resistance management strategies in European winter oilseed rape. Copyright © 2011 Society of Chemical Industry
Contribution of Pt layer to hydrogen mediation in ZnCoO
Authors: Shin Jong Moon , Cho Yong Chan , Cha Su‐Young , Lee Seunghun , Kim Sung‐Jin , Kim Sung‐Kyu , Park Sungkyun , Cho Chae Ryong , Jeong Se‐Young
Published: March 2011

We succeeded in injecting large amounts of hydrogen into Co‐doped ZnO (ZnCoO) thin films by coating the films with a Pt layer, which facilitated the dissociation of molecular hydrogen into hydrogen ions. Because of the hydrogen mediation effect in ZnCoO, the ferromagnetic spin ordering between the Co ions was proportional to the injected thin film. Hydrogenation of the ZnCoO films was carried out by a post plasma treatment process. The thin Pt layer fabricated on the ZnCoO films helped in enhancing the adsorption rate of hydrogen near the film surface up to 50 nm of depth. The Pt layer evaporated during the plasma process because of the weak adhesion between Pt and ZnCoO, and therefore, we could not optimize the hydrogen injection efficiency. To increase the number of applications based on the hydrogen mediation effect, it is necessary to gain a thorough understanding of the behavior of hydrogen ions in transition metal‐doped ZnO films and the role of the Pt layer in hydrogen mediation.
Ferroelectric and piezoelectric properties of Aurivillius phase intergrowth ferroelectrics and the underlying materials design
Authors: Yi Z. G. , Li Y. X. , Liu Y.
Published: March 2011

Ferroelectric and piezoelectric properties of the La‐doped intergrowth Aurivillius phase ceramics Bi5−xLaxTiNbWO15 and Bi7−xLaxTi4NbO21 (x = 0.00–1.75) were studied. It was found that the La doping is in favour of the domain switching. Owing to the impact of defects, the P–E hysteresis loops of the La‐doped Bi5TiNbWO15 ceramics are un‐symmetrical and the piezoelectric coefficients are quite low. Enhanced ferro‐/piezoelectric properties, such as 2Pr of 24.4 µC/cm2 (x = 0.50) and d33 of 16.6 pC/N (x = 0.75), were obtained in the Bi7−xLaxTi4NbO21 ceramics. The high temperature electrical behaviour indicates that the Bi5−xLaxTiNbWO15 ceramics are semiconducting whereas the La‐doped Bi7Ti4NbO21 ceramics are worthy to be further studied toward high temperature piezoelectric applications. Finally, the underlying materials design is discussed.
Improvement of resistance switching properties for metal/La0.7Ca0.3MnO3/Pt devices
Authors: Yang Rui , Li Xiaomin
Published: March 2011

On the polycrystalline La0.7Ca0.3MnO3 (LCMO) film, various top electrodes (TEs) have been prepared to form metal/LCMO/Pt devices, including Al, Ag and Ag–Al alloy with the atomic ratio of Ag/Al = 2:1. It is found that the switching polarity of the devices with Al as TE is opposite to those with Ag as TE. For the Al layered devices, the endurance and switching speed have been effectively improved by decreasing the thickness of the Al electrode from 50 to 10 nm. Meanwhile, the endurance and yield of the resistance switching behaviour observed at Ag layered structure have been improved by alloying some Al into Ag electrode. The present work suggests a possible way to improve the resistance switching properties by adjusting the microstructure of the electrodes to modulate the interface structure of the metal/LCMO interface.
Demands of highly piezoelectric materials for radio frequency acoustic wave devices
Authors: Hashimoto Ken‐ya
Published: March 2011

This paper is aimed at making it clear why we device engineers are keen to have high quality and highly piezoelectric materials for sophisticated radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) devices to be used in future communication systems. First, RF SAW/BAW resonators and their filter application are introduced, and it is shown how the resonator properties directly reflect to achievable filter performances. Discussions are also provided on how the acoustic and piezoelectric properties of base materials influence the total device performances. An emphasis is given to the fact that use of high quality and highly piezoelectric materials is essential for the applications. It is also demonstrated how high performance devices are achievable by the use of high coupling materials such as a single‐crystalline LiNbO3 substrate with specific crystallographic orientation with extremely large electromechanical coupling. Further discussions are given on new applications of extremely wideband SAW/BAW resonators employing ferroelectric materials with extremely large electromechanical coupling.
Density functional theoretical study of pKa of RCOOH (RH, CH3, and C2H5) using the combination of the extended clusters‐continuum model
Authors: Du Dongmei , Qin Mei , Zhou Zhengyu , Fu Aiping
Published: March 2011

The accurate pKa determinations for three carboxylic acids have been investigated using the combination of the extended clusters‐continuum model at B3LYP/6‐31+g(d,p) and B3LYP/6‐311++g(d,p) levels. To take into account of the effect of the water combined with carboxylic acids in different positions, eleven molecular clusters were considered. Among these clusters, the one involving the carboxylic acid wrapped up with water molecules and saturated with hydrogen bonds (four hydrogen bonds around COOH) leads to the best B3LYP pKa results compared to the experimental data. For those clusters saturated with hydrogen bonds, when n = 3 (the number of water molecules), the average absolute errors between the calculated pKa results and experimental data of these three carboxylic acids were 0.19 (0.23) and 0.12 (0.22) pKa at B3LYP/6‐31+g(d,p)//PCM (IEFPCM) and B3LYP/6‐311++g(d,p)//PCM (IEFPCM) levels, respectively; when n = 4, they are 0.53 (1.23) and 1.09 (1.03) pKa, respectively. On the basis of the above results, the molecular cluster saturated with four hydrogen bonds formed by three waters and one carboxylic acid molecule was the chief existence in the carboxylic acid solution. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Ab initio and semiempirical computational studies on 1‐{(2E)‐2‐[(aminocarbonothioyl)hydrazono]‐2‐(3‐mesityl‐3‐methylcyclobutyl)ethyl}‐pyrrolidine‐2,5‐dione
Authors: Karakurt Tuncay , Dinçer Muharrem , Çukurovali Alaaddin
Published: March 2011

The molecular geometry, vibrational frequencies, and gauge including atomic orbital (GIAO) 1H‐ and 13C NMR chemical shift values of the title compound in the ground state have been calculated using the Hartree‐Fock (HF) and density functional theory (DFT) methods with 6‐31G(d) basis sets, and compared with the experimental data. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters and the theoretical vibrational frequencies, and 1H‐ and 13C NMR chemical shift values show good agreement with experimental data. To determine conformational flexibility, the molecular energy profile of the title compound was obtained by semiempirical (AM1) calculations with respect to the selected torsion angle, which was varied from −180° to +180° in steps of 10°. The energetic behavior of the title compound in solvent media was examined using the B3LYP method with the 6‐31G(d) basis set by applying the Onsager and the polarizable continuum model (PCM). The results obtained with these methods reveal that the PCM method provided more stable structure than Qnsager's method. By using TD‐DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD‐DFT method and the experimental one is determined. The predicted nonlinear optical properties of the title compound are much greater than ones of urea. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, NBO analysis and thermodynamic properties of the title compound were investigated using theoretical calculations. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
An elliptic curve secret sharing key management scheme for mobile ad hoc networks
Authors: Dahshan Hisham , Irvine James
Published: March 2011

In mobile ad hoc networks (MANETs), traditional security solutions are not adequate due to the infrastructureless nature and the absence of centralized administration. In this paper, a threshold key management scheme for MANETs is presented. The proposed scheme is implemented using elliptic curve dlog‐based cryptosystem. In this scheme, an off‐line central authority (CA) is required in the initialization phase before network deployment. The CA creates and preloads the shares matrix for each mobile node in the network initialization phase. Each session member generates its private/public key pair, and the session public key by collaborating with its trusted neighbors. The generation of the node private/public key pair, and the session public key is performed without any prior communication between session members. The advantages of the proposed scheme are justified through extensive timing and network simulations. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient distributed key management scheme for group‐signature based anonymous authentication in VANET
Authors: Sun Yipin , Feng Zhenqian , Hu Qiaolin , Su Jinshu
Published: March 2011

Group signature is one of the well‐known cryptographic primitives for anonymous authentication which is the fundamental requirement for securing vehicular ad hoc networks (VANETs), but it is prone to cause huge revocation overhead in VANETs with millions of nodes and serious security risk. To solve this problem, we develop an efficient distributed key management scheme (DKM) where the whole domain of VANET is divided into several sub‐regions, and any vehicle has to update its group secret key periodically from the regional group manager who manages the region where the vehicle stays. Unlike the previously reported works, DKM prevents vehicles from leaking the value of the updated group secret key to the regional group manager during the group key updating process. Subsequently, it is capable of identifying either the compromised regional authorities or the malicious vehicles. Moreover, performance analysis demonstrates that DKM can reduce the revocation cost significantly while the communication cost for key updating is small. Copyright © 2011 John Wiley & Sons, Ltd.
Modelling security message propagation in delay tolerant networks
Authors: Jia Zhongtian , Li Shudong , Peng Haipeng , Yang Yixian , Guo Shize
Published: March 2011

Delay tolerant networks (DTNs) are new emerging technologies aiming to solve communication issues in challenged network environments. In such networks, any real‐time interactive key agreement protocol does not work due to the intermittent connectivity and long time delay in message round trips. In the context of specific applications, such as single hop authentication, manual public key exchange is the most direct method because single hop authentication can be achieved by holding a small part of node's public key. To evaluate how many public keys should be maintained by each node to achieve a high propagation speed while single hop authentication scheme is used, in this paper, we proposed a security message propagation model for DTNs formed by vehicles where the extended graph theory and rumor spreading terminology in complex networks were harnessed. We find that holding 8–10 public keys by each node is optimal. And decay rate threshold is 0.16 under which message can be disseminated throughout the whole network. Copyright © 2011 John Wiley & Sons, Ltd.
Combined Characterization of microRNA and mRNA Profiles Delineates Early Differentiation Pathways of CD133+ and CD34+ Hematopoietic Stem and Progenitor Cells
Authors: Bissels Ute , Wild Stefan , Tomiuk Stefan , Hafner Markus , Scheel Hartmut , Mihailovic Aleksandra , Choi Yeong-Hoon , Tuschl Thomas , Bosio Andreas
Published: March 2011

MicroRNAs (miRNAs) have been shown to play an important role in hematopoiesis. To elucidate the role of miRNAs in the early steps of hematopoiesis, we directly compared donor-matched CD133+ cells with the more differentiated CD34+CD133− and CD34−CD133− cells from bone marrow on the miRNA and mRNA level. Using quantitative whole genome miRNA microarray and sequencing-based profiling, we found that between 109 (CD133+) and 216 (CD34−CD133−) miRNAs were expressed. Quantification revealed that the 25 highest expressed miRNAs accounted for 73% of the total miRNA pool. miR-142-3p was the highest expressed miRNA with up to 2,000 copies per cell in CD34+CD133− cells. Eighteen miRNAs were significantly differentially expressed between CD133+ and CD34+CD133− cells. We analyzed their biological role by examining the coexpression of miRNAs and its bioinformatically predicted mRNA targets and luciferase-based reporter assays. We provide the first evidence for a direct regulation of CD133 by miR-142-3p as well as tropomyosin 1 and frizzled homolog 5 by miR-29a. Overexpression of miRNAs in CD133+ cells demonstrated that miR-142-3p has a negative influence on the overall colony-forming ability. In conclusion, the miRNAs expressed differentially between the CD133+ and CD34+CD133− cells are involved in inhibition of differentiation, prevention of apoptosis, and cytoskeletal remodeling. These results are highly relevant for stem cell-based therapies with CD133+ cells and delineate for the first time how the stem cell character of CD133+ cells is defined by the expression of specific miRNAs.
Snail and the microRNA-200 Family Act in Opposition to Regulate Epithelial-to-Mesenchymal Transition and Germ Layer Fate Restriction in Differentiating ESCs
Authors: Gill Jennifer G. , Langer Ellen M. , Lindsley R. Coleman , Cai Mi , Murphy Theresa L. , Kyba Michael , Murphy Kenneth M.
Published: March 2011

The reprogramming of somatic cells to inducible pluripotent stem cells requires a mesenchymal-to-epithelial transition. While differentiating ESCs can undergo the reverse process or epithelial-to-mesenchymal transition (EMT), little is known about the role of EMT in ESC differentiation and fate commitment. Here, we show that Snail homolog 1 (Snail) is expressed during ESC differentiation and is capable of inducing EMT on day 2 of ESC differentiation. Induction of EMT by Snail promotes mesoderm commitment while repressing markers of the primitive ectoderm and epiblast. Snail's impact on differentiation can be partly explained through its regulation of a number of ESC-associated microRNAs, including the microRNA-200 (miR-200) family. The miR-200 family is normally expressed in ESCs but is downregulated in a Wnt-dependent manner during EMT. Maintenance of miR-200 expression stalls differentiating ESCs at the epiblast-like stem cell (EpiSC) stage. Consistent with a role for activin in maintaining the EpiSC state, we find that inhibition of activin signaling decreases miR-200 expression and allows EMT to proceed with a bias toward neuroectoderm commitment. Furthermore, miR-200 requires activin to efficiently maintain cells at the epiblast stage. Together, these findings demonstrate that Snail and miR-200 act in opposition to regulate EMT and exit from the EpiSC stage toward induction of germ layer fates. By modulating expression levels of Snail, activin, and miR-200, we are able to control the order in which cells undergo EMT and transition out of the EpiSC state.
Beyond 2°C: redefining dangerous climate change for physical systems
Authors: Lenton Timothy M.
Published: March 2011

Most efforts to define a level of dangerous anthropogenic interference (DAI) with the climate system are framed in terms of global annual mean surface temperature change, with 2°C above preindustrial being the most widely accepted climate policy ‘target’. Yet, no actual large‐scale threshold (or ‘tipping point’) in the climate system (of which there are probably several) has been clearly linked to 2°C global warming. Of those that can be indirectly linked to global temperature change, the dangerous levels are necessarily imprecise and vary, with estimates ranging from ∼1°C above preindustrial upwards. Some potential thresholds cannot be meaningfully linked to global temperature change, others are sensitive to rates of climate change, and some are most sensitive to spatial gradients of climate change. In some cases, the heterogeneous distributions of reflective (sulfate) aerosols, absorbing (black carbon) aerosols, and land use could be more dangerous than changes in globally well‐mixed greenhouse gases. Hence, the framing of Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC), in terms of stabilization of greenhouse gas concentrations (within a time frame), is too narrow to prevent some types of DAI. To address this, a reframed policy objective is proposed; to limit the overall magnitude, rate of change, and spatial gradients of anthropogenic radiative forcing, and resultant climate change, through restriction of emissions of anthropogenic aerosols, patterns of land use, and concentrations of short‐lived, as well as long‐lived, greenhouse gases. WIREs Clim Change 2011 2 451–461 DOI: 10.1002/wcc.107

This article is categorized under:

Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change
Image steganography and steganalysis
Authors: Bachrach Mayra , Shih Frank Y.
Published: March 2011

Image steganography is used to embed covert messages in the form of files, text, or other images in digital images. The intent is to transmit hidden information. Steganalysis is the process used to detect hidden messages in images. Although steganography is not a new discipline, it has become increasingly important in today's digital world where information is often and easily exchanged through the Internet, email, and other means using computers. The need for better methods and techniques which can be used both to embed hidden information in images and to detect messages hidden in images is driving new research in the area of steganography and steganalysis. This article surveys image steganography and steganalysis. The aim is to introduce the uninformed reader to image steganography and steganalysis. The key concepts behind image steganography and steganalysis are explained. The history and origin of steganography are outlined. Steganography is compared with watermarking in technique and intent. Details of how images are represented are explained. Methods and algorithms used to embed messages in images and to detect embedded messages are explored. Currently available steganography and steganalysis tools are explained. A demonstration of how to embed hidden information in an image using available steganography tools is provided. WIREs Comp Stat 2011 3 251–259 DOI: 10.1002/wics.152

This article is categorized under:

Data: Types and Structure > Image and Spatial Data
Total laparoscopic hysterectomy versus total abdominal hysterectomy with bilateral salpingo-oophorectomy for endometrial carcinoma: a randomised controlled trial with 5-year follow-up
Authors: Kluivers Kirsten B. , Ten Cate Florien A. , Bongers Marlies Y. , Brölmann Hans A. M. , Hendriks Jan C. M.
Published: March 2011

This report is on recovery and long-term outcomes in a small-scale randomised controlled trial (RCT) after total laparoscopic hysterectomy versus total abdominal hysterectomy in (potential) endometrial carcinoma patients. An RCT was performed among women with atypical endometrial hyperplasia and endometrial carcinoma scheduled for hysterectomy in a teaching hospital in The Netherlands. Women were randomised to total laparoscopic hysterectomy versus total abdominal hysterectomy both with bilateral salpingo-oophorectomy and were followed until 5 years after the intervention. Patients completed the RAND 36-Item Short Form Health Survey (RAND-36), Quality of Recovery-40 (QoR-40) and Recovery Index-10 (RI-10) until 12 weeks after surgery. Main outcome measure was quality of life and recovery in the first 12 weeks after surgery. A linear mixed model was used for statistical analysis while accounting for baseline values where applicable. Seventeen women were included, of whom 11 allocated to the laparoscopic arm and 6 to the abdominal arm. Laparoscopic hysterectomy performed better on all scales and subscales used in the study. A statistically significant treatment effect, favouring laparoscopic hysterectomy, was found in the total RAND-36 (difference between groups 142 units, 95% confidence interval 46; 236). Clinical follow-up was completed after median 60 months, but this study was too small for conclusions regarding the safety and survival. Laparoscopic hysterectomy results in better postoperative quality of life in the first 12 weeks after surgery when compared with abdominal hysterectomy.
Arthroscopic Avulsion Repair of a Pediatric ACL with an Anomalous Primary Insertion into the Lateral Meniscus
Authors: Toy Jason O. , Feeley Brian T. , Gulotta Lawrence V. , Warren Russell F.
Published: March 2011

Background

Injury to the anterior cruciate ligament (ACL) in the pediatric population is becoming more common, with the majority of ruptures occurring at the tibial insertion site. However, to our knowledge, there are no reports of avulsion in which the primary ACL insertion site is the anterior lateral meniscal root.

Methods

We report a rare case of a pediatric ACL/anterior horn of the lateral meniscus avulsion, which was successfully repaired arthroscopically.

Results

In this patient, neither a mid-substance tear, nor a tibial eminence fracture was noted. Instead, the patient avulsed the tibial insertion of the ACL from its small footprint, which included an extensive attachment to the lateral meniscus.

Conclusions

We believe this developmental anomaly may provide further support of the shared embryological origin between the ACL and menisci. In this case report, we review the literature on anterior cruciate ligament injury and repair in the pediatric population.
Synthesis and Surface Active Properties of Gemini Cationic Surfactants and Interaction with Anionic Azo Dye (AR52)
Authors: Abdel‐Salam Fatma H. , El‐Said Asrar G.
Published: March 2011

A homologous series of new gemini cationic surfactants were synthesized and characterized using micro elemental analysis, FTIR, 1H‐NMR and mass spectra. The surface activities of these amphiphiles were determined based on the data of surface tension. Critical micelle concentration, effectiveness of the surface tension reduction, efficiency of adsorption, maximum surface excess, minimum surface area and critical packing parameter were evaluated. The effect of cationic micelles on solubilization of anionic azo dye, sulforhodamine B (Acid Red 52) in aqueous micellar solution of the synthesized gemini cationic surfactants was studied at pH 6.9 ± 0.5 and 25 °C. The results showed that the solubility of dye rose with increasing surfactant concentration as a consequence of some association between the dye and the micelles. It was also observed that the aggregation of surfactant and dye takes place at a surfactant concentration below the CMC of the individual surfactant. The partition coefficients between the bulk water and surfactant micelles as well as the Gibbs energies of distribution of dye between the bulk water and surfactant micelles were calculated using a pseudo‐phase model. The effect of the hydrophobic chain length of Gemini cationic surfactants on the distribution parameters was also reported. The results show favorable solubilization of dye in cationic micelles.
The analytic index of elliptic pseudodifferential operators on a singular foliation
Authors: Androulidakis Iakovos , Skandalis Georges
Published: March 2011

In previous papers ([1, 2]) we defined the C*-algebra and the longitudinal pseudodifferential calculus of any singular foliation (M,). In the current paper we construct the analytic index of an elliptic operator as a KK-theory element, and prove that this element can be obtained from an “adiabatic foliation” on M×ℝ, which we introduce here.