bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of adipocyte hyperplasia in subcutaneous fat depot alleviated type 2 diabetes symptoms in obese mice
Authors: Lu Qiqi , Li Mingming , Zou Yu , Cao Tong
Published: January 2014

Objective

The role of subcutaneous adipose tissue (SAT) in the pathogenesis of type 2 diabetes is still under controversy. In this study, the metabolic effects of inducing adipocyte hyperplasia in SAT depots in obese mice were investigated.

Methods

High fat diet was used to induce obesity and type 2 diabetes symptoms in C57BL6/J mice. To induce SAT expansion through hyperplasia, acellular adipogenic cocktails were injected around the SAT depots in high fat diet‐induced obese mice.

Results

Ten weeks after injections, significant neoadipogenesis was induced, which not only obviously expanded the volume of SATs but also significantly increased the adipocyte density within the whole SAT depots. Importantly, these mice exhibited improved glucose tolerance and insulin sensitivity (homeostatic model assessment) when compared to control group. Further studies suggested that these beneficial metabolic effects were associated with elevation of serum high‐molecular‐weight adiponectin level and reduction of ectopic lipid accumulation in liver.

Conclusions

These findings not only further supported the protective role of SAT in the pathogenesis of type 2 diabetes but also highlighted the importance of adipocyte hyperplasia in this protective effect.
Intravenous magnesium for pediatric sickle cell vaso‐occlusive crisis: Methodological issues of a randomized controlled trial
Authors: Badaki‐Makun Oluwakemi , Scott J. Paul , Panepinto Julie A. , Casper T. Charles , Hillery Cheryl A. , Dean J. Michael , Brousseau David C. ,   for the Pediatric Emergency Care Applied Research Network (PECARN) Magnesium in Sickle Cell Crisis (MAGiC) Study Group
Published: January 2014

Multiple recent Sickle Cell Disease studies have been terminated due to poor enrollment. We developed methods to overcome past barriers and utilized these to study the efficacy and safety of intravenous magnesium for vaso‐occlusive crisis (VOC). We describe the methods of the Intravenous Magnesium in Sickle Vaso‐occlusive Crisis (MAGiC) trial and discuss methods used to overcome past barriers. MAGiC was a multi‐center randomized double‐blind placebo‐controlled trial of intravenous magnesium versus normal saline for treatment of VOC. The study was a collaboration between Pediatric Hematologists and Emergency Physicians in the Pediatric Emergency Care Applied Research Network (PECARN). Eligible patients were randomized within 12 hours of receiving intravenous opioids in the Emergency Department (ED) and administered study medication every 8 hours. The primary outcome was hospital length of stay. Associated plasma studies elucidated magnesium's mechanism of action and the pathophysiology of VOC. Health‐related quality of life was measured. Site‐, protocol‐, and patient‐related barriers from prior studies were identified and addressed. Limited study staff availability, lack of collaboration with the ED, and difficulty obtaining consent were previously identified barriers. Leveraging PECARN resources, forging close collaborations between Sickle Cell Centers and EDs of participating sites, and approaching eligible patients for prior consent helped overcome these barriers. Participation in the PECARN network and establishment of collaborative arrangements between Sickle Cell Centers and their affiliated EDs are major innovative features of the MAGiC study that allowed improved subject capture. These methods could serve as a model for future studies of VOCs. Pediatr Blood Cancer 2014;61:1049–1054. © 2014 Wiley Periodicals, Inc.
Mandibular condyle erosion and sclerosis in pediatric patients treated with radiotherapy to the head and neck region
Authors: Mercado Catherine E. , Little Stephen B. , Mazewski Claire , Schwaibold Frederick P. , Esiashvili Natia
Published: January 2014

Head and neck radiotherapy in children is associated with significant acute and late morbidities. Temporomandibular joint dysfunction and trismus has been widely reported in patients receiving radiotherapy for sarcomas and nasopharyngeal carcinoma; however, erosion of the mandibular condyle is a rare sequela of modern radiotherapy techniques. In this report, we present three cases of erosion of the temporomandibular joint amongst pediatric patients treated with radiotherapy for distinct head, neck and brain malignancies. Pediatr Blood Cancer 2014; 61:1479–1480. © 2014 Wiley Periodicals, Inc.
Outcome of children treated for relapsed acute myeloid leukemia in Central America
Authors: Marjerrison Stacey , Antillon Federico , Bonilla Miguel , Fu Ligia , Martinez Roxana , Valverde Patricia , Vasquez Roberto , Howard Scott C. , Ribeiro Raul C. , Sung Lillian
Published: January 2014

Background

Relapsed childhood acute myeloid leukemia (AML) outcomes have not been documented in resource‐limited settings. We examined survival after relapse for children with AML (non‐APML) and acute promyelocytic leukemia (APML) in Central America.

Procedure

We retrospectively evaluated outcomes of children with first relapse of AML (non‐APML) and APML in Guatemala, Honduras, or El Salvador diagnosed between 1997 and 2011. Predictors of subsequent event‐free survival (EFS) and overall survival (OS) were examined.

Results

We identified 140 children with relapsed AML (non‐APML), and 24 with relapsed APML. Two‐year subsequent EFS and OS (±SE) were 7.0 ± 2.5% and 9.1 ± 2.8%, respectively. Worse outcomes were associated with Hispanic or Indigenous heritage, white blood cell count at diagnosis ≥50 × 109/L, and time to relapse <18 months. For those with relapsed APML, subsequent 2‐year EFS and OS were 36.7 ± 10.8% and 43.4 ± 12.1%, although few patients survived beyond 3 years. 15.2% of all patients were managed solely with palliative intent following first relapse.

Conclusions

Children with relapsed AML in Central America rarely survive, so palliative strategies should be considered following relapse in this population. However, children with late relapse or with APML may have a prolonged period of remission with second treatment, and consideration of re‐treatment may be appropriate. Pediatr Blood Cancer 2014;61:1222–1226. © 2014 Wiley Periodicals, Inc.
Influence of applying microwave radiation on the LDPE/MWCNTs nanocomposite
Authors: Al‐Harthi Mamdouh A.
Published: January 2014

Low density polyethylene (LDPE) and multiwall carbon nanotube (MWCNT) nanocomposites of varying MWCNT contents were prepared by melt blending and compression molding. The sample sheets were exposed to microwave irradiation and the effect on chemical, mechanical, and thermal properties as well as the sheets' morphology were determined and compared with that of nonirradiated samples with similar compositions. The percentage crystallinity of the LDPE/MWCNT nanocomposites declined after irradiation due to the degradation of polymeric chains. However, the melting temperature was hardly changed. The chemical degradation due to irradiation was also verified from the increase in the carbonyl index as determined from the Fourier transformed‐infrared spectroscopy study and the decline in the storage modulus of the dynamic mechanical analysis study. The microcalorimetry study revealed that the MWCNT nanofillers were effectively acting as a heat absorption shield by reducing the heat release rate of polymer during combustion. The Raman spectra and scanning electron microscopy photographs demonstrated improved interaction of MWCNT with the LDPE matrix after microwave irradiation. POLYM. COMPOS., 35:2036–2042, 2014. © 2014 Society of Plastics Engineers
Investigating the acoustical properties of carbon fiber‐, glass fiber‐, and hemp fiber‐reinforced polyester composites
Authors: Mehdi Jalili Mohammad , Yahya Mousavi Seyyed , Pirayeshfar Amir Soheil
Published: January 2014

Wood is one of the main materials used for making musical instruments due to its outstanding acoustical properties. Despite such unique properties, its inferior mechanical properties, moisture sensitivity, and time‐ and cost‐consuming procedure for making instruments in comparison with other materials (e.g., composites) are always considered as its disadvantages in making musical instruments. In this study, the acoustic parameters of three different polyester composites separately reinforced by carbon fiber, glass fiber, and hemp fiber are investigated and are also compared with those obtained for three different types of wood specimens called poplar, walnut, and beech wood, which have been extensively used in making Iranian traditional musical instruments. The acoustical properties such as acoustic coefficient, sound quality factor, and acoustic conversion factor were examined using some non‐destructive tests based on longitudinal and flexural free vibration and also forced vibration methods. Furthermore, the water absorption of these polymeric composites was compared with that of the wood samples. The results reveal that the glass fiber‐reinforced composites could be used as a suitable alternative for some types of wood in musical applications while the carbon fiber‐reinforced composites are high performance materials to be substituted with wood in making musical instruments showing exceptional acoustical properties. POLYM. COMPOS., 35:2103–2111, 2014. © 2014 Society of Plastics Engineers
Role of the second‐trimester ‘genetic sonogram’ for Down syndrome screen in the era of first‐trimester screening and noninvasive prenatal testing
Authors: Odibo Anthony O. , Ghidini Alessandro
Published: January 2014

Ultrasonography for the screening of Down syndrome was first introduced about 25 years ago. Different combinations of markers detectable at second‐trimester ultrasonography have been proposed under the banner of ‘genetic sonogram’. In recent years, several developments in first‐trimester screening and the recent introduction of noninvasive prenatal testing for aneuploidy screening have had important implications for the prevalence of these conditions in the second‐trimester and the screening performance of a genetic sonogram. Several second‐trimester sonographic markers for Down syndrome have been reported; meta‐analysis has shown that the most powerful predictors are mild ventriculomegaly, increased nuchal fold, hyperechoic bowel, and absent or hypoplastic nasal bone. Whereas use of individual markers should be discouraged and scoring systems of multiple markers are now obsolete, use of combined likelihood ratio and logistic regression analysis formulae provides better accuracy. However, there is significant heterogeneity in results among studies. Despite such limitations, the genetic sonogram will continue to have a place in prenatal screening, particularly in twin and higher‐order multiple pregnancies, in countries with limited access to the most recent genetic screening tests, in cases with borderline results at maternal serum screening tests, and as noninvasive supplementary test for high‐risk women reluctant to undergo invasive diagnostic testing. © 2014 John Wiley & Sons, Ltd.
Through‐space interactions in enshrouded m‐terphenylsilanes
Authors: Romanato Paola , Duttwyler Simon , Linden Anthony , Baldridge Kim K. , Siegel Jay S.
Published: January 2014

A series of m‐terphenyl‐substituted silanes was prepared and studied with regard to the steric and electronic interactions between the silyl core and the terphenyl shroud. Only weak conformational preferences were observed for the core, but the π‐basicity of the lateral rings led to distinct nuclear magnetic resonance shifts, and o‐fluorine atoms led to through‐space coupling effects. Copyright © 2014 John Wiley & Sons, Ltd.
The nano‐mechanics and magnetic properties of high moment synthetic antiferromagnetic particles
Authors: Forrester Michael , Kusmartsev Feodor
Published: January 2014

With nanomagnets increasingly being used and proposed as functional units for in vivo applications, it is vital to understand how to optimize their structure, geometry, and size, and their responses to electromagnetic stimulation. Herein, we predicate how to do so for synthetic antiferromagnetic structures that are subjected to external magnetic control. Because the structures are on the scale of biological entities, interactions with cells and molecular constituents can be extreme and careful design must be undertaken to avoid detrimental effects. Thus, the magnetic responses of multilayers, as demonstrated in experiments by Koh et al. [e.g., Hu et al., Adv. Mater. 20, 1479 (2008) and Koh et al., J. Appl. Phys. 107, 09B522 (2010)], are understood using a fully dynamical investigation based on Landau–Lifshitz–Gilbert equations. We find that during the fabrication of the structures the axial positions of the nanomagnets become offset from each other, leading to the characteristic magnetic hysteresis shapes witnessed. We then find the magnetic nano‐mechanical forces generated by such structures.

The conical synthetic antiferromagnetic nanoparticles with two magnetic layers – Left: the magnetic flux density is shown on the surface of the structure in a magnetic flux density of B = 0.08 T. Middle and right: orientations of the magnetic moments of the two magnetic layers.
Balance and randomness in sequential clinical trials: the dominant biased coin design
Authors: Antognini Alessandro Baldi , Zagoraiou Maroussa
Published: January 2014

Efron's biased coin design (BCD) is a well‐known randomization technique that helps neutralize selection bias, while keeping the experiment fairly balanced for every sample size. Several extensions of this rule have been proposed, and their properties were analyzed from an asymptotic viewpoint and compared via simulations in a finite setup. The aim of this paper is to push forward these comparisons by taking also into account the adjustable BCD, which is never considered up to now. Firstly, we show that the adjustable BCD performs better than Efron's coin with respect to both loss of precision and randomness. Moreover, the adjustable BCD is always more balanced than the other coins and, only for some sample sizes, slightly more predictable. Therefore, we suggest the dominant BCD, namely a new and flexible class of procedures that can change the allocation rule step by step in order to ensure very good performance in terms of both balance and selection bias for any sample size. Our simulations demonstrate that the dominant BCD is more balanced and, at the same time, less or equally predictable than Atkinson's optimum BCD. Copyright © 2014 John Wiley & Sons, Ltd.
Obtaining K‐obfuscation for profile privacy in social networks
Authors: Liu Xiangyu , Wang Bin , Yang Xiaochun , Yu Meng , Zang Wanyu
Published: January 2014

The increasing popularity of social networks in various application domains has raised privacy concerns for the individuals involved. In this work, we formally present the definition of profile privacy leakage, which is a newly identified privacy leakage in social networks. However, applying existing methods straightforwardly cannot provide efficient privacy protection for the profiles meanwhile incurring a large amount of information loss. We propose k‐obfuscation to protect profiles against graph property based attacks. We develop a general framework for obtaining k‐obfuscation. In this framework, we propose a novel safe vertex‐profile mapping mechanism, named as k‐mapping. We also design a number of techniques to make the k‐mapping method efficient meanwhile maintaining the data utilities. Extensive experiments on real datasets show the satisfactory performance of our methods in terms of privacy protection, efficiency, and practical utilities. Copyright © 2014 John Wiley & Sons, Ltd.
Cryptanalysis and improvement of password‐authenticated key agreement for session initiation protocol using smart cards
Authors: Zhang Liping , Tang Shanyu , Cai Zhihua
Published: January 2014

Session Initiation Protocol (SIP) is one of the most commonly used protocols for handling sessions for over Internet Protocol based communications, and the security of SIP is becoming increasingly important. Recently, Zhang et al. proposed a password‐authenticated key agreement protocol for SIP by using smart cards to protect the VoIP communications between users. Their protocol provided some unique features, such as mutual authentication, no password table needed, and password updating freely. In this study, we performed cryptanalysis of Zhang et al.'s protocol and found that their protocol was vulnerable to the impersonation attack although the protocol could withstand several other attacks. A malicious attacker could compute other users' privacy keys and then impersonated the users to cheat the SIP server. Furthermore, we proposed an improved password‐authentication key agreement protocol for SIP, which overcame the weakness of Zhang et al.'s protocol and was more suitable for Voice over Internet Protocol communications. Copyright © 2014 John Wiley & Sons, Ltd.
SecureTCG: a lightweight cheating‐detection protocol for P2P multiplayer online trading card games
Authors: Simplicio Marcos A. , Santos Mateus A.S. , Leal Rodrigo R. , Gomes Marco A.L. , Goya Walter A.
Published: January 2014

Online gaming is today a very lucrative market, with millions of users all around the globe. At the same time, the increasing popularity and complexity of such games implies the need of deploying cheating‐detection mechanisms for ensuring the continuous interest of honest users in playing. The development of secure and efficient solutions for online games is, however, a challenging issue. This is especially true in P2P environments, in which the lack of a central trusted entity monitoring the game greatly facilitates the activity of malicious players. Aiming to tackle this issue, this paper presents SecureTCG, a protocol for detecting cheating attempts in P2P multiplayer card games where the players use their own decks to play, such as the so‐called trading card games. In summary, SecureTCG allows the multiple players participating in a trading card game match to detect cheating attempts as soon as they are made and without the intervention of third parties, supports multiple players and different game styles, displays tolerance to players’ dropouts during a match, prevents collusion among any number of players, provides (optional) after‐match auditability mechanisms, and has a reduced computational cost. Copyright © 2014 John Wiley & Sons, Ltd.
Known‐plaintext attack on secure kNN computation on encrypted databases
Authors: Chunsheng Gu , Jixing Gu
Published: January 2014

To protect user privacy and data security in cloud computing, a secure k‐nearest neighbor computation‐enhanced scheme on encrypted database has been proposed by Wong, Cheung, Kao and Mamoulis. The scheme is proven resistant to the known‐plaintext attack. We show that contrary to claims, the enhanced asymmetric scalar‐product‐preserving encryption cannot resist known‐plaintext attack by directly solving a secret key from a set of known plaintext–ciphertext pairs. Copyright © 2014 John Wiley & Sons, Ltd.
Investigation of silica nanoparticles by Auger electron spectroscopy (AES)
Authors: Rades S. , Wirth T. , Unger W.
Published: January 2014

High‐priority industrial nanomaterials like SiO2, TiO2, and Ag are being characterized on a systematic basis within the framework of the EU FP7 research project NanoValid. Silica nanoparticles from an industrial source have been analyzed by Auger electron spectroscopy. Point, line, and map spectra were collected. Material specific and methodological aspects causing the special course of Auger line scan signals will be discussed. Copyright © 2014 John Wiley & Sons, Ltd.
RIOS: efficient I/O in reverse direction
Authors: Willkomm Johannes , Bischof Christian , Martin Bücker H.
Published: January 2014

The reverse mode of automatic differentiation executes the adjoint statements induced by each statement in the original program in the reverse order of the original program flow. This program flow reversal commonly requires storage of information on the control flow of the original program. In addition, intermediate values of variables that are overwritten have to be recorded, as these values may later be needed to compute the partial derivatives of the corresponding statement. The stored information will be accessed in reverse order of being written. This runs contrary to many assumptions made in standard implementations of file systems, operating systems, and input/output (I/O) libraries. A common buffering strategy aimed at speeding up future read requests is to employ read‐ahead. This strategy is useful for accesses in forward direction but is considered to be harmful to the performance of the reverse mode. To increase the performance of the reverse mode, it is also advantageous to interleave computations with the data storage and retrieval operations, which can be achieved using multithreading. To this end, we design and implement a novel software called reverse‐mode I/O stream (RIOS) that is adapted to these particular requirements of the reverse mode. We show the advantages of RIOS in two empirical case studies, an artificially constructed example of a typical I/O pattern in the reverse mode and a real‐world example arising from fluid mechanics, which is studied in Fortran90 and in Matlab where the reverse mode is generated via the automatic differentiation tools Tapenade and ADiMat, respectively. Copyright © 2014 John Wiley & Sons, Ltd.
DIN EN 1993‐1‐1‐konforme integrierte Stabilitätsanalysen für 2D/3D‐Stahlkonstruktionen (Teil 1)
Authors: Papp Ferenc , Rubert Achim , Szalai Josef
Published: January 2014

Dieser Aufsatz beschreibt – als erster einer Serie von drei Teilen – im Wesentlichen die Details der so genannten “Allgemeinen Methode” von DIN EN 1993‐1‐1/Abschnitt 6.3.4. Diese softwarebasierte Methode für beliebige 2D‐ und 3D‐Stahlstrukturen benutzt ein integriertes Nachweiskonzept der Stabilitätsanalyse und ‐nachweise. Sie wird mit der klassischen Ersatzstabmethode für Stabilitätsnachweise einfacher Stabmodelle verglichen, bei der im Allgemeinen unterschiedliche Berechnungsmodelle (wie auch gegebenenfalls entsprechende Software) zur Schnittgrößenberechnung in der Ebene und den Stabilitätsnachweisen verwendet werden. Für die numerische Analyse – das ist ein entscheidender Kernpunkt der Methode – wird die auf der Basis von EC 3 entwickelte Software ConSteel eingesetzt, die ein leistungsfähiges 3D finites Balken‐Stützenelement mit zwei Knoten und jeweils sieben Verformungsfreiheitsgraden verwendet, dessen Qualität mit relevanten Benchmark‐Tests nachgewiesen wird. Nach der soeben erst publizierten Methodik der Klassifikation von Software zur Anwendung der Theorie 2. Ordnung ist ConSteel in die höchste Kategorie 5 (TH. II.O.‐3WS) einzuordnen. Die “Allgemeine Methode” führt zu einer robusten und vor allem verständlichen computerunterstützten Nachweismethodik gegen globales Stabilitätsversagen.

DIN EN 1993‐1‐1 based integrated stability analysis of 2D/3D steel structures (Part 1). This paper – as the first one of a series of three parts – presents the details and use of the “General method” of DIN EN 1993‐1‐1/clause 6.3.4. This method is a model based design procedure for steel structures using integrated stability analysis and standard check. The method is compared to the classical method where different calculation models as well as suitable software are used for the stress analysis and for the stability analysis and check. Also the alternative method of 3D calculations with the theory 2nd order using equivalent initial deformations, which are derived from the eigenform analysis, is presented.

For the numerical analysis (as it is the crucial point of the method) the 14 DOF beam‐column finite element of ConSteel is described and its quality is shown by relevant benchmarks. According to the recently published methodology for the classification of 2nd order theory software ConSteel belongs to the highest category 5 (TH.II.O.‐3WS). Finally it is shown that the “General method” leads to an easy to use, robust and understandable computer aided design methodology against loss of global stability.
Subdiffractive microscopy: techniques, applications, and challenges
Authors: Long Brian R. , Robinson Danielle C. , Zhong Haining
Published: January 2014

Cellular processes rely on the precise orchestration of signaling and effector molecules in space and time, yet it remains challenging to gain a comprehensive picture of the molecular organization underlying most basic biological functions. This organization often takes place at length scales below the resolving power of conventional microscopy. In recent years, several ‘superresolution’ fluorescence microscopic techniques have emerged that can surpass the diffraction limit of conventional microscopy by a factor of 2–20. These methods have been used to reveal previously unknown organization of macromolecular complexes and cytoskeletal structures. The resulting high‐resolution view of molecular organization and dynamics is already changing our understanding of cellular processes at the systems level. However, current subdiffractive microscopic techniques are not without limitations; challenges remain to be overcome before these techniques achieve their full potential. Here, we introduce three primary types of subdiffractive microscopic techniques, consider their current limitations and challenges, and discuss recent biological applications. WIREs Syst Biol Med 2014, 6:151–168. doi: 10.1002/wsbm.1259

This article is categorized under:

Laboratory Methods and Technologies > Imaging
Preparation, Crystal Structure and Physical Properties of the Superconducting Cage Compound Ba3Ge16Ir4
Authors: Duong Nguyen Hong , Prots Yurii , Schnelle Walter , Böhme Bodo , Baitinger Michael , Paschen Silke , Grin Yuri
Published: January 2014

The cage compound Ba3Ge16Ir4 crystallizes with the Ba3Ge16Rh4 type of crystal structure, which represents a hierarchical derivative of the BaAl4 type. The crystal structure [Pearson symbol tI46, space group I4/mmm; a = 6.5312(2) Å, c = 22.2845(6) Å] was refined from single‐crystal X‐ray diffraction data. The phase was obtained after 10 d at 910 °C with small impurities of clathrate‐I, BaGe7Ir2 and α‐Ge remaining at the grain boundaries. Ba3Ge16Ir4 is a Pauli‐paramagnetic metal, which becomes superconducting below Tc = 5.1 K. Electronic structure and analysis of the chemical bonding were performed based on density functional theory calculations. The physical properties are discussed in comparison to the isotypic phase Ba3Ge16Rh4.
Electric/magnetic duality and RG flows in AdS4/CFT3
Authors: Tarrío Javier , Varela Oscar
Published: January 2014

Abstract

A large set of relevant deformations of the ABJM field theory defined on a stack of M2 branes is captured holographically by D = 4
$ \mathcal{N} $
= 8 SO(8)-gauged supergravity, which has accordingly been applied to study renormalisation group (RG) flows of the field theory between distinct superconformal phases. Recently, it has been discovered that this supergravity is not unique, and that a one-parameter family of gaugings of maximal supergravity exists. The parameter is an angle that measures the mixture of electric and magnetic vectors that gauge SO(8) dyonically. We construct and comprehensively characterise all domain walls between the critical points of the new supergravities with at least SU(3) invariance, which are expected to be dual to RG flows of new field theories defined at least at large N. We also construct some walls running off to infinity in scalar space, which we expect to be dual to Coulomb branch flows of these field theories.
Elliptic genera and real Jacobi forms
Authors: Ashok Sujay K. , Troost Jan
Published: January 2014

Abstract

We construct real Jacobi forms with matrix index using path integrals. The path integral expressions represent elliptic genera of two-dimensional
$ \mathcal{N} $
= (2, 2) supersymmetric theories. They arise in a family labeled by two integers N and k which determine the central charge of the infrared fixed point through the formula c = 3N (1 + 2N/k). We decompose the real Jacobi form into a mock modular form and a term arising from the continuous spectrum of the conformal field theory. For a given N and k we argue that the Jacobi form represents the elliptic genus of a theory defined on a 2N dimensional linear dilaton background with U(N) isometry, an asymptotic circle of radius
$ \sqrt{{k\alpha \prime }} $
and linear dilaton slope
$ N\sqrt{{{2 \left/ {k} \right.}}} $
. We also present formulas for the elliptic genera of their orbifolds.
Wilson loops and the geometry of matrix models in AdS4/CFT3
Authors: Farquet Daniel , Sparks James
Published: January 2014

Abstract

We study a general class of supersymmetric AdS4 × Y
7 solutions of M-theory that have large N dual descriptions as
$ \mathcal{N} $
= 2 Chern-Simons-matter theories on S
3. The Hamiltonian function h

M
for the M-theory circle, with respect to a certain contact structure on Y
7, plays an important role in the duality. We show that an M2-brane wrapping the M-theory circle, giving a fundamental string in AdS4, is supersymmetric precisely at the critical points of h

M
, and moreover the value of this function at the critical point determines the M2-brane action. Such a configuration determines the holographic dual of a BPS Wilson loop for a Hopf circle in S
3, and leads to an effective method for computing the Wilson loop on both sides of the correspondence in large classes of examples. We find agreement in all cases, including for several infinite families, and moreover we find that the image h

M
(Y
7) determines the range of support of the eigenvalues in the dual large N matrix model, with the critical points of h

M
mapping to points where the derivative of the eigenvalue density is discontinuous.
Non-Abelian vortices with an Aharonov-Bohm effect
Authors: Evslin Jarah , Konishi Kenichi , Nitta Muneto , Ohashi Keisuke , Vinci Walter
Published: January 2014

Abstract

The interplay of gauge dynamics and flavor symmetries often leads to remarkably subtle phenomena in the presence of soliton configurations. Non-Abelian vortices — vortex solutions with continuous internal orientational moduli — provide an example. Here we study the effect of weakly gauging a U(1)
R
subgroup of the flavor symmetry on such BPS vortex solutions. Our prototypical setting consists of an SU(2) × U(1) gauge theory with N

f
= 2 sets of fundamental scalars that break the gauge symmetry to an “electromagnetic” U(1). The weak U(1)
R
gauging converts the well-known CP
1 orientation modulus |B| of the non-Abelian vortex into a parameter characterizing the strength of the magnetic field that is responsible for the Aharonov-Bohm effect. As the phase of B remains a genuine zero mode while the electromagnetic gauge symmetry is Higgsed in the interior of the vortex, these solutions are superconducting strings.
Key climate indices in Switzerland; expected changes in a future climate
Authors: Zubler Elias M. , Scherrer Simon C. , Croci-Maspoli Mischa , Liniger Mark A. , Appenzeller Christof
Published: January 2014

Climate indices facilitate the interpretation of expected climate change impacts for many sectors in society, economy, and ecology. The new localized data set of climatic change signals for temperature and precipitation presented by Zubler et al. (Clim Change, 2013) is applied for an analysis of frequently used climate indices in Switzerland. The indices considered are: number of summer days and tropical nights, growing season length, number of frost days and ice days, heating and cooling degree days, and the number of days with fresh snow. For the future periods 2020-49, 2045-74 and 2070–2099 the indices are computed using a delta-change approach based on the reference period 1980–2009 for the emission scenarios A1B, A2, and RCP3PD. The scenario data suggest the following relevant findings: (1) a doubling of the number of summer days by the end of the century under the scenarios A1B and A2, (2) an appearance of tropical nights even above 1500 m asl, (3) a possible reduction of the number of frost days by more than 3 months at altitudes higher than 2500 m asl, (4) a decline of heating degree days by about 30 % until the end of the century, and (5) the near disappearance of days with fresh snow at low altitudes. It is also shown that the end-of-the-century projections of all indices strongly depend on the chosen emission scenario.
Sugar‐Based Ester Quaternary Ammonium Compounds and Their Surfactant Properties
Authors: Gan Changsheng , Wang Haoshu , Zhao Zhenzhen , Yin Binbin
Published: January 2014

Two sugar‐based ester quaternary ammonium compounds were synthesized and their surface behavior and antimicrobial activity were investigated. The compatibility with anionic surfactant sodium dodecyl sulfate (SDS) was further studied. Results indicated that the synthesized cationic surfactants showed high surface activity and good synergistic effects with SDS.
Corrosion Inhibition Efficiency, Electrochemical and Quantum Chemical Studies of Some New Nonionic Surfactants for Carbon Steel in Acidic Media
Authors: Noor El‐Din Mahmoud R. , Khamis Eman A.
Published: January 2014

In this work, three types of nonionic surfactant as corrosion inhibitors were synthesized. The chemical structure of the prepared inhibitors was confirmed using FT‐IR and 1H‐NMR spectroscopy. The surface tension and thermodynamic properties of these inhibitors were investigated. The corrosion inhibition efficiency of these surfactants was investigated on a carbon steel surface in 1 M HCl solution by weight loss and electrochemical measurements. Untreated and treated steel surfaces were characterized by scanning electron microscopy. Results show that the inhibition efficiency of the prepared inhibitors increases with increasing the ethylene oxide units. Also, the potentiodynamic polarization curves indicated that the investigated inhibitors behave as a mixed type inhibitor. Adsorption of these surfactants on the carbon steel surface was found to obey Langmuir's adsorption isotherm. The computed quantum chemical properties viz., electron affinity (EA), highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO), energy gap ΔE = EHOMO − ELUMO, dipole moment (μ), polarizability and total energy (ET) show good correlation with experimental inhibition efficiency.
Involucramiento de producto y lealtad de marca para productos de consumo masivo en Bogotá D.C.
Authors: Ramírez Angulo Pedro Julián , Duque Oliva Edison Jair
Published: January 2014

Mediante este artículo se busca validar algunas hipótesis referentes a la relación entre Involucramiento de Producto y Lealtad de Marca para productos de consumo masivo en Bogotá (Colombia). Para tal fin, se recolectó información acerca de las percepciones de involucramiento de producto y lealtad de marca para 478 consumidores bogotanos, que posteriormente fue analizada mediante Modelos de Ecuaciones Estructurales. A través de la información recolectada, se determinó la existencia de relación directa entre involucramiento de producto y lealtad de marca, no solo como conceptos, sino para cada una de las dimensiones de cada concepto. También se encontraron diferencias en el comportamiento de estas variables para distintas tipologías de producto.
El capital social organizacional de la pequeña empresa innovadora. Un ensayo de medición en las ciudades de Cali y Medellín
Authors: Román Castillo Ruth Esperanza , Gómez Mejía Alina , Smida Alí
Published: January 2014

Este artículo realiza una aplicación del concepto de capital social a nivel organizacional. Se propone un instrumento de medición de los aspectos culturales de este capital inmaterial empleando una escala tipo Likert. El cuestionario fue aplicado a una muestra de pequeñas empresas con perfil innovador de Cali y Medellín (Colombia). Las mediciones promedio obtenidas y el análisis de la correlación entre diferentes variables del estudio permiten concluir que las empresas analizadas tienen una percepción positiva de la calidad de sus relaciones sociales internas, así como de aquellas sostenidas con las partes interesadas del entorno. No obstante, se identifican debilidades sobre las cuales puede trabajarse para mejorar sus competencias colectivas y convertir este capital en un vehículo más efectivo para la innovación y en una base sostenible de competitividad.
Asimetría y curtosis en el modelo binomial para valorar opciones reales: caso de aplicación para empresas de base tecnológica
Authors: Milanesi Gastón Silverio
Published: January 2014

El trabajo propone un modelo de valoración de opciones reales con base al modelo binomial utilizando la transformación de Edgeworth (Rubinstein, 1998) para incorporar momentos estocásticos de orden superior, especialmente para ciertos tipos de organizaciones, como empresas de base tecnológica, donde no se dispone de cartera de activos financieros gemelos, comparables de mercado y procesos estocásticos no Gaussianos. Primero se presenta el desarrollo formal del modelo, luego su aplicación sobre la valuación de spin-off tecnológico universitario, sensibilizando asimetría - curtosis y exponiendo el impacto en el valor del proyecto. Finalmente se concluye sobre limitaciones y ventajas de la propuesta de valoración que resume la simplicidad del modelo binomial e incorporando momentos de orden superior, en subyacentes con procesos no normales.
A simple method for the determination of reduction potentials in heme proteins
Authors: Efimov Igor , Parkin Gary , Millett Elizabeth S. , Glenday Jennifer , Chan Cheuk K. , Weedon Holly , Randhawa Harpreet , Basran Jaswir , Raven Emma L.
Published: January 2014

We describe a simple method for the determination of heme protein reduction potentials. We use the method to determine the reduction potentials for the PAS‐A domains of the regulatory heme proteins human NPAS2 (E
m
= −115 mV ± 2 mV, pH 7.0) and human CLOCK (E
m
= −111 mV ± 2 mV, pH 7.0). We suggest that the method can be easily and routinely applied to the determination of reduction potentials across the family of heme proteins.
Experimental evidence for a 9‐binding subsite of Bacillus licheniformis thermostable α‐amylase
Authors: Tran Phuong Lan , Lee Jin-Sil , Park Kwan-Hwa
Published: January 2014

The action pattern of Bacillus licheniformis thermostable α‐amylase (BLA) was analyzed using a series of 14C‐labeled and non‐labeled maltooligosaccharides from maltose (G2) to maltododecaose (G12). Maltononaose (G9) was the preferred substrate, and yielded the smallest K
m
= 0.36 mM, the highest k
cat
= 12.86 s−1, and a k
cat/K
m value of 35.72 s−1
mM−1, producing maltotriose (G3) and maltohexaose (G6) as the major product pair. Maltooctaose (G8) was hydrolyzed into two pairs of products: G3 and maltopentaose (G5), and G2 and G6 with cleavage frequencies of 0.45 and 0.30, respectively. Therefore, we propose a model with nine subsites: six in the terminal non‐reducing end‐binding site and three at the reducing end‐binding site in the binding region of BLA.
New insights into the substrate specificities of proton‐coupled oligopeptide transporters from E. coli by a pH sensitive assay
Authors: Prabhala Bala K. , Aduri Nanda G. , Jensen Johanne M. , Ernst Heidi A. , Iram Nida , Rahman Moazur , Mirza Osman
Published: January 2014

Proton‐coupled oligopeptide transporters (POTs) are secondary active transporters that facilitate di‐ and tripeptide uptake by coupling it to an inward directed proton electrochemical gradient. Here the substrate specificities of Escherichia coli POTs YdgR, YhiP and YjdL were investigated by means of a label free transport assay using the hydrophilic pH sensitive dye pyranine and POT overexpressing E. coli cells. The results confirm and extend the functional knowledge on E. coli POTs. In contrast to previous assumptions, alanine and trialanine appears to be substrates of YjdL, albeit poor compared to dipeptides. Similarly tetraalanine apparently is a substrate of both YdgR and YhiP.
Attenuation of hydrogen peroxide‐mediated oxidative stress by Brassica juncea annexin‐3 counteracts thiol‐specific antioxidant (TSA1) deficiency in Saccharomyces cerevisiae
Authors: Dalal Ahan , Vishwakarma Abhaypratap , Singh Naveen Kumar , Gudla Triveni , Bhattacharyya Mrinal Kanti , Padmasree Kollipara , Viehhauser Andrea , Dietz Karl-Josef , Kirti Pulugurtha Bharadwaja
Published: January 2014

Brassica juncea annexin‐3 (BjAnn3) was functionally characterized for its ability to modulate H2O2‐mediated oxidative stress in Saccharomyces cerevisiae. BjAnn3 showed a significant protective role in cellular‐defense against oxidative stress and partially alleviated inhibition of mitochondrial respiration in presence of exogenously applied H2O2. Heterologous expression of BjAnn3 protected membranes from oxidative stress‐mediated damage and positively regulated antioxidant gene expression for ROS detoxification. We conclude that, BjAnn3 partially counteracts the effects of thioredoxin peroxidase 1 (TSA1) deficiency and aids in cellular‐protection across kingdoms. Despite partial compensation of TSA1 by BjAnn3 in cell‐viability tests, the over‐complementation in ROS‐related features suggests the existence of both redundant (e.g. ROS detoxification) and distinct features (e.g. membrane protection versus proximity‐based redox regulator) of both proteins.
Consensus among multiple trophic levels during high- and low-water stands over the last two millennia in a northwest Ontario lake
Authors: Karmakar Moumita , Kurek Joshua , Haig Heather , Cumming Brian F.
Published: January 2014

We investigated the modern distribution of fossil midges within a dimictic lake and explored downcore patterns of inferred lake depths over the last 2000 years from previously published proxies. Modern midge distribution within Gall Lake showed a consistent and predictable pattern related to the lake-depth gradient with recognizable assemblages characteristic of shallow-water, mid-depth and profundal environments. Interpretations of downcore changes in midge assemblages, in conjunction with quantitative lake-depth inferences across a priori defined (based on diatom data) ~ 500-yr wet and dry periods, demonstrated that both invertebrate and algal assemblages exhibited similar timing and nature of ecological responses. Midges were quantified by their relative abundance, concentrations and an index of Chaoborus to chironomids, and all showed the greatest differences between the wet and dry periods. During the low lake-level period of the Medieval Climate Anomaly (MCA: AD 900 to 1400), profundal chironomids declined, shallow-water and mid-depth chironomids increased, chironomid-inferred lake level declined and the Chaoborus-to-chironomid index decreased. The coherence between multiple trophic levels provides strong evidence of lower lake levels in Gall Lake during the MCA.
Statistics and compression of scl
Authors: CALEGARI DANNY , MAHER JOSEPH
Published: January 2014

We obtain sharp estimates on the growth rate of stable commutator length on random (geodesic) words, and on random walks, in hyperbolic groups and groups acting non-degenerately on hyperbolic spaces. In either case, we show that with high probability stable commutator length of an element of length$n$is of order$n/ \log n$. This establishes quantitative refinements of qualitative results of Bestvina and Fujiwara and others on the infinite dimensionality of two-dimensional bounded cohomology in groups acting suitably on hyperbolic spaces, in the sense that we can control the geometry of the unit balls in these normed vector spaces (or rather, in random subspaces of their normed duals). As a corollary of our methods, we show that an element obtained by random walk of length$n$in a mapping class group cannot be written as a product of fewer than$O(n/ \log n)$reducible elements, with probability going to$1$as$n$goes to infinity. We also show that the translation length on the complex of free factors of a random walk of length$n$on the outer automorphism group of a free group grows linearly in$n$.
Is transition to disability pension in young people associated with changes in risk of attempted suicide?
Authors: Mittendorfer-Rutz E. , Alexanderson K. , Westerlund H. , Lange T.
Published: January 2014

Background

The aim of the present study was to investigate trajectories of suicide attempt risks before and after granting of disability pension in young people.

Method

The analytic sample consisted of all persons 16–30 years old and living in Sweden who were granted a disability pension in the years 1995–1997; 2000–2002 as well as 2005–2006 (n = 26 624). Crude risks and adjusted odds ratios for suicide attempt were computed for the 9-year window around the year of disability pension receipt by repeated-measures logistic regressions.

Results

The risk of suicide attempt was found to increase continuously up to the year preceding the granting of disability pension in young people, after which the risk declined. These trajectories were similar for women and men and for disability pension due to mental and somatic diagnoses. Still, the multivariate odds ratios for suicide attempts for women and for disability pension due to mental disorders were 2.5- and 3.8-fold increased compared with the odds ratios for men and disability pension due to somatic disorders, respectively. Trajectories of suicide attempts differed for young individuals granted a disability pension during 2005–2006 compared with those granted during 1995–1997 and 2000–2002.

Conclusions

We found an increasing risk of suicide attempt up until the granting of a disability pension in young individuals, after which the risk decreased. It is of clinical importance to monitor suicide attempt risk among young people waiting for the granting of a disability pension.
The effects of dialect variation on speech intelligibility in a multitalker background
Authors: JACEWICZ EWA , FOX ROBERT ALLEN
Published: January 2014

Speech intelligibility in a multitalker background can be affected by the language of both the talker and the interfering speech. This study investigated whether this interaction is modulated by dialect variations of the same language. American English listeners were presented with target sentences in either their own General American English (GAE) or a different accent (Southern American English [SAE]) masked by either GAE or SAE two-talker babble at three sound to noise ratios (SNRs): +3, 0, and –3 dB. All speech materials were produced by male talkers. Across all conditions, SAE target was more intelligible than GAE. Intelligibility of either target decreased as the level of the interfering babble noise increased. Target accent interacted with masking accent: at +3 dB SNR, GAE (and not SAE) was the more effective masker. The target-masker interaction was different as listening conditions deteriorated: at 0 and –3 dB SNR, masking accent did not affect GAE target, but when the target was SAE, the SAE masker (and not GAE) was more effective. Thus, at increased noise levels, listeners benefited from the mismatch between the target and masking accents only when the target was in a nonnative accent. These results demonstrate that dialect variation can influence listeners’ performance in a multitalker environment. The apparent asymmetry in intelligibility of accents may be in part related to dialect-specific prosodic and phonetic features.