bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal online deterministic algorithms and adaptive heuristics for energy and performance efficient dynamic consolidation of virtual machines in Cloud data centers
Authors: Beloglazov Anton , Buyya Rajkumar
Published: October 2011

The rapid growth in demand for computational power driven by modern service applications combined with the shift to the Cloud computing model have led to the establishment of large‐scale virtualized data centers. Such data centers consume enormous amounts of electrical energy resulting in high operating costs and carbon dioxide emissions. Dynamic consolidation of virtual machines (VMs) using live migration and switching idle nodes to the sleep mode allows Cloud providers to optimize resource usage and reduce energy consumption. However, the obligation of providing high quality of service to customers leads to the necessity in dealing with the energy‐performance trade‐off, as aggressive consolidation may lead to performance degradation. Because of the variability of workloads experienced by modern applications, the VM placement should be optimized continuously in an online manner. To understand the implications of the online nature of the problem, we conduct a competitive analysis and prove competitive ratios of optimal online deterministic algorithms for the single VM migration and dynamic VM consolidation problems. Furthermore, we propose novel adaptive heuristics for dynamic consolidation of VMs based on an analysis of historical data from the resource usage by VMs. The proposed algorithms significantly reduce energy consumption, while ensuring a high level of adherence to the service level agreement. We validate the high efficiency of the proposed algorithms by extensive simulations using real‐world workload traces from more than a thousand PlanetLab VMs. Copyright © 2011 John Wiley & Sons, Ltd.
Fast seismic modeling and reverse time migration on a graphics processing unit cluster
Authors: Abdelkhalek Rached , Calandra Henri , Coulaud Olivier , Latu Guillaume , Roman Jean
Published: October 2011

We designed a fast parallel simulator that solves the acoustic wave equation on a graphics processing unit (GPU) cluster. Solving the acoustic wave equation in an oil exploration industrial context aims at speeding up seismic modeling and reverse time migration (RTM). We considered a finite difference approach on a regular mesh, in both two‐dimensional and three‐dimensional cases. The acoustic wave equation is solved in a constant density or a variable density domain. All the computations were carried out in single precision (both in the CPU reference implementation and in the GPU implementation), because double precision was not required in our context. We used Compute Unified Device Architecture to take advantage of the GPU computational power. We studied different implementations and their impact on the application performance. The described application handles all the steps of seismic modeling and RTM and is used to solve real‐world problems in an industrial production context. We obtained a speedup of 16 for RTM and up to 43 for the modeling application over a sequential code running on general‐purpose CPUs. A CPU rack versus a GPU rack comparison was described and showed a 4.3 speedup. Copyright © 2011 John Wiley & Sons, Ltd.
Electronic Structures and Thermochemical Properties of the Small Silicon‐Doped Boron Clusters BnSi (n=1–7) and Their Anions
Authors: Tai Truong Ba , Kadłubański Paweł , Roszak Szczepan , Majumdar Devashis , Leszczynski Jerzy , Nguyen Minh Tho
Published: October 2011

We perform a systematic investigation on small silicon‐doped boron clusters BnSi (n=1–7) in both neutral and anionic states using density functional (DFT) and coupled‐cluster (CCSD(T)) theories. The global minima of these BnSi0/− clusters are characterized together with their growth mechanisms. The planar structures are dominant for small BnSi clusters with n≤5. The B6Si molecule represents a geometrical transition with a quasi‐planar geometry, and the first 3D global minimum is found for the B7Si cluster. The small neutral BnSi clusters can be formed by substituting the single boron atom of Bn+1 by silicon. The Si atom prefers the external position of the skeleton and tends to form bonds with its two neighboring B atoms. The larger B7Si cluster is constructed by doping Si‐atoms on the symmetry axis of the Bn host, which leads to the bonding of the silicon to the ring boron atoms through a number of hyper‐coordination. Calculations of the thermochemical properties of BnSi0/− clusters, such as binding energies (BE), heats of formation at 0 K (ΔHf0) and 298 K (ΔHf[298]), adiabatic (ADE) and vertical (VDE) detachment energies, and dissociation energies (De), are performed using the high accuracy G4 and complete basis‐set extrapolation (CCSD(T)/CBS) approaches. The differences of heats of formation (at 0 K) between the G4 and CBS approaches for the BnSi clusters vary in the range of 0.0–4.6 kcal mol−1. The largest difference between two approaches for ADE values is 0.15 eV. Our theoretical predictions also indicate that the species B2Si, B4Si, B3Si− and B7Si− are systems with enhanced stability, exhibiting each a double (σ and π) aromaticity. B5Si− and B6Si are doubly antiaromatic (σ and π) with lower stability.
Implementation of parallel zero‐voltage switching converter with series‐connected transformers
Authors: Lin Bor‐Ren , Cheng Chih‐Yuan
Published: October 2011

This paper presents a parallel zero‐voltage switching (ZVS) DC–DC converter with series‐connected transformers. In order to increase output power, two transformers connected in series are used in the proposed converter. Two buck‐type converters connected in parallel have the same switching devices. The primary windings of series‐connected transformers can achieve the balanced secondary winding currents. The current doubler rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding. Thus, the current ripple on the output capacitor is reduced, and the size of the output choke and output capacitor are reduced. Only two switches are used in the proposed circuit instead of four switches in the conventional parallel ZVS converter to achieve ZVS and output current sharing. Therefore, the proposed converter has less power switches. The ZVS turn‐on is implemented during the commutation stage of two complementary switches such that the switching losses and thermal stresses on the semiconductors are reduced. Experimental results for a 528‐W (48 V/11 A) prototype are presented to prove the theoretical analysis and circuit performance. Copyright © 2011 John Wiley & Sons, Ltd.
Switched‐capacitor‐voltage‐multiplier boost DC–AC inverter with adaptive stages
Authors: Chang Yuen‐Haw , Wu Ming‐Zong
Published: October 2011

A multistage switched‐capacitor‐voltage‐multiplier inverter (SCVMI) is proposed with a variable‐conversion‐ratio phase generator and a sinusoidal pulse‐width‐modulation controller for boost DC–AC conversion and high‐efficiency regulation. Its power unit contains: SCVM booster and H‐bridge. The SCVM booster includes two mc‐stage switched‐capacitor cells and two nc‐stage switched‐capacitor cells in the interleaving operation to realize DC–DC boost gain of mc × nc at most. Here, the variable‐conversion‐ratio phase generator is suggested and adopted to change the running stage number and topological path for a suitable gain level of m × n (m = 1, 2, ⋯,mc, n = 1, 2, ⋯,nc) to improve efficiency, especially for the lower AC output. The H‐bridge is employed for DC–AC conversion, where four switches are controlled by sinusoidal pulse‐width‐modulation not only for full‐wave output but also for output regulation as well as robustness to source/loading variation. Some theoretical analysis and design include: SCVMI model, steady‐state/dynamic analysis, conversion ratio, power efficiency, stability, capacitance selection, output filter, and control design. Finally, the closed‐loop SCVMI is simulated, and the hardware circuit is implemented and tested. All the results are illustrated to show the efficacy of this scheme. Copyright © 2011 John Wiley & Sons, Ltd.
Low‐power, low‐area preamplifier for ultra high‐speed multi‐channel optical communication system
Authors: Wang Xiaoxia , Wang Zhigong
Published: October 2011

A novel circuit technique was applied to the design of a preamplifier for ultra high‐speed short‐distance parallel optical communication system in standard 180‐nm CMOS technology. This circuit is featured by low power, low area as well as high gain bandwidth product, and suited for applications in low‐cost process. The restraint on voltage headroom as bottleneck in traditionally adopted regulated cascode configuration has been fundamentally analyzed and lifted by feed‐forward common gate stage to achieve high gain bandwidth product under limited fT and strict power restriction. Complex poles were carefully assigned to further attain bandwidth extension without sacrifice on power, noise, and chip area. No additional peaking techniques and subsequent gain‐boosting stages are adopted, which makes the design simple and favorable in low‐cost high‐density multi‐channel optical communication system. The preamplifier provides a trans‐impedance gain of up to 52 dBΩ and a 3‐dB bandwidth of 8.4 GHz. Operating under a 1.8‐V supply, the power dissipation is 8 mW, and the chip area is only 0.075×0.08 mm. The measured average input‐referred noise–current spectral density is . Copyright © 2011 John Wiley & Sons, Ltd.
Structural characterization of classical and memristive circuits with purely imaginary eigenvalues
Authors: Riaza Ricardo , Tischendorf Caren
Published: October 2011

The hyperbolicity problem in circuit theory concerns the existence of purely imaginary eigenvalues in the linearization of the time‐domain description of the circuit dynamics. In this paper, we characterize the circuit configurations that, in a strictly passive setting, yield purely imaginary eigenvalues for all values of the capacitances and inductances. Our framework is based on branch‐oriented, semistate (differential‐algebraic) circuit models that capture explicitly the circuit topology, and use several notions and results from digraph theory. So‐called P‐structures arising in the analysis turn out to be the key element supporting our results. The analysis is shown to hold not only for classical (RLC) circuits but also for nonlinear circuits including memristors and other mem‐devices. Copyright © 2011 John Wiley & Sons, Ltd.
Non‐idealities in linear CDR phase detectors
Authors: Cao Jun , Huang Sui , Green Michael M.
Published: October 2011

The effects of circuit non‐idealities in a “Hogge”‐type phase detector are examined. Using a behavioral model for each circuit block, it is shown that various circuit non‐idealities introduce static phase offset in the phase detector, reduce the monotonic range of its transfer characteristics and eventually degrade the capture range and jitter tolerance of the clock and data recovery (CDR) loop. Lower bounds on the bandwidths of the various blocks in the CDR are also established in order to avoid variations of the transfer characteristics. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation and comparison of GHz‐range LC oscillators using time‐varying root‐locus
Authors: Broussev Svetozar S. , Tchamov Nikolay T.
Published: October 2011

This paper presents a comprehensive comparison between complementary metal‐oxide‐semiconductor (CMOS) LC‐oscillator topologies often used in GHz‐range transceivers. The comparison utilizes the time‐varying root‐locus (TVRL) method to add new insights into the operation of different oscillators. The paper focuses on the treatment of the TVRL trajectories obtained for different oscillators and establishes links between the trajectories and physical phenomena in oscillators. The evaluation of the root trajectories shows the advantages of the TVRL method for comparing oscillator topologies, which is also extended towards the analysis of voltage‐controlled oscillators. The necessary circuit simplifications required in closed‐form root‐locus analysis are avoided by the TVRL, which allows precise oscillator comparison and reveals details on the topology specifics. The derived conclusions have been verified by the Cadence Spectre‐RF simulator on 130‐nm CMOS process. Copyright © 2011 John Wiley & Sons, Ltd.
1.5 V square‐root domain universal biquad filters
Authors: Laoudias C. , Psychalinos C. , Stoumpou E.
Published: October 2011

Square‐root domain universal biquad topologies are introduced in this paper. One of them is single input multiple output, while the other one is multiple input single output biquad. Important benefits offered by the proposed topologies are the electronic adjustment of the resonant frequency and the capability for operating in a low‐voltage environment; also, the resonant frequency could be adjusted without disturbing the Q factor and vice‐versa. Simulation results using the Spectre simulator of the Analog Design Environment of Cadence software validate the correct operation of the proposed topologies and provide important performance characteristics. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic OSR dithered sigma–delta modulation in solid state light dimming
Authors: Orcioni Simone , d'Aparo Rocco , Lobascio Armando , Conti Massimo
Published: October 2011

Pulse width modulation (PWM) is the most common way to control switching regulation and digital dimming. This paper presents a way to implement digital dimming by means of a dithered sigma–delta modulator with dynamic oversampling ratio. The system has been modeled in SystemC‐WMS and implemented in a board using a commercial microcontroller. Simulation results show conducted electromagnetic interference reduction compared to PWM and flickering reduction with respect to classic sigma‐delta modulation. Copyright © 2011 John Wiley & Sons, Ltd.
Optimization‐based method for shunt hybrid filter compensation in non‐stiff systems
Authors: Ramos‐Carranza Hugo , Medina Aurelio
Published: October 2011

In this contribution, a steady‐state approach for determining the optimal size and control of a shunt hybrid filter (SHF), to control harmonic current mitigation and to provide reactive power compensation, is proposed. The SHF topology is formed by a shunt active power filter (APF) and a shunt capacitor. The APF current injections are determined from the solution of a nonlinear programming problem formulated to meet permissible operation limits, with an optimal APF size. The formulation and control theory for the SHF is developed in the abc reference frame. An important practical aspect such as the application of SHF compensation in non‐stiff systems is included in the analysis and solution of the nonlinear programming problem, as well as in the current control technique, maintaining stringent performance requirements on the tracking of the filtering currents, by allowing the use of the shunt capacitor also as a filter for draining the ripple current inherent to the APF injection currents. Results obtained with matlab/Simulink (MathWorks, Inc., Natick, MA, USA) show that the proposed theory and the control of the optimal SHF compensation constitute an effective system to compensate reactive power and to control harmonic distortion under selected/permissible limits with an optimal APF injection current reducing the APF size. Copyright © 2011 John Wiley & Sons, Ltd.
Quasi‐active power factor correction on flyback‐based dc/dc converter
Authors: Athab H. S. , Lu Dylan Dah‐Chuan
Published: October 2011

This paper presents a novel input current shaper based on a quasi‐active power factor correction (PFC) scheme. In this method, high power factor and low harmonic content are achieved by providing an auxiliary PFC circuit with a driving voltage which is derived from a third winding of the transformer of a cascaded dc/dc flyback converter. It eliminates the use of active switch and control circuit for PFC. The auxiliary winding provides a controlled voltage‐boost function for bulk capacitor without inducing a dead angle in the line current. Since the dc/dc converter operates at high switching frequency, the driving voltage is also of high switching frequency, which results in reducing the size of the magnetic components. Operating principles, analysis and experimental results of the proposed method are presented. Copyright © 2011 John Wiley & Sons, Ltd.
A 12‐bit multi‐channel dual‐mode successive approximation ADC for power management bus (Pmbus) devices
Authors: Chiang Cheng‐Ta , Chang Wei‐Hsu
Published: October 2011

In this paper, a 12‐bit multi‐channel dual‐mode successive approximation ADC for PMBus devices is newly proposed. The proposed data converter is attractive because all the requirements of PMBus devices, which are high resolution, low‐cost, dual‐mode, and multi‐channel, are successfully matched. In measurement results, all the functions and performance of the proposed data converter are successfully verified and confirmed to be applied on PMBus devices. The area of this chip is 1.64 × 1.56 mm2, and the measured power consumption including digital output buffers is 1.683 mW. The proposed 12‐bit multi‐channel dual‐mode successive approximation ADC is suitable for power monitoring systems, such as PMBus devices. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic mixed serial–parallel content addressable memory (DMSP CAM)
Authors: Kang Mingu , Kim Jisu , Yang Young Hwi , Jung Seong‐Ook
Published: October 2011

A novel dynamic mixed serial–parallel content addressable memory (DMSP CAM) is proposed to achieve both low‐power consumption and high performance. The replica circuits provide optimal timings to enable and disable the matchline charge transistor, which maximizes performance and minimizes leakage current, respectively. The DMSP CAM does not suffer from charge sharing in the serial stage and achieves high performance by removing the predischarge or precharge operation of the matchline before every comparison. To guarantee the robustness of the proposed scheme, a statistical design methodology is also applied. Using the 45‐nm technology, the DMSP CAM achieves both energy saving and performance improvement, and thus over 53% energy‐delay product reduction compared with the other serial–parallel mixed CAMs. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of implicit HHT‐α integration algorithm for real‐time hybrid simulation
Authors: Chen Cheng , Ricles James M.
Published: October 2011

Real‐time hybrid simulation is a viable experiment technique to evaluate the performance of structures equipped with rate‐dependent seismic devices when subject to dynamic loading. The integration algorithm used to solve the equations of motion has to be stable and accurate to achieve a successful real‐time hybrid simulation. The implicit HHT α‐algorithm is a popular integration algorithm for conducting structural dynamic time history analysis because of its desirable properties of unconditional stability for linear elastic structures and controllable numerical damping for high frequencies. The implicit form of the algorithm, however, requires iterations for nonlinear structures, which is undesirable for real‐time hybrid simulation. Consequently, the HHT α‐algorithm has been implemented for real‐time hybrid simulation using a fixed number of substep iterations. The resulting HHT α‐algorithm with a fixed number of substep iterations is believed to be unconditionally stable for linear elastic structures, but research on its stability and accuracy for nonlinear structures is quite limited. In this paper, a discrete transfer function approach is utilized to analyze the HHT α‐algorithm with a fixed number of substep iterations. The algorithm is shown to be unconditionally stable for linear elastic structures, but only conditionally stable for nonlinear softening or hardening structures. The equivalent damping of the algorithm is shown to be almost the same as that of the original HHT α‐algorithm, while the period elongation varies depending on the structural nonlinearity and the size of the integration time‐step. A modified form of the algorithm is proposed to improve its stability for use in nonlinear structures. The stability of the modified algorithm is demonstrated to be enhanced and have an accuracy that is comparable to that of the existing HHT α‐algorithm with a fixed number of substep iterations. Both numerical and real‐time hybrid simulations are conducted to verify the modified algorithm. The experimental results demonstrate the effectiveness of the modified algorithm for real‐time testing. Copyright © 2011 John Wiley & Sons, Ltd.
Depression and frailty in later life: a synthetic review
Authors: Mezuk Briana , Edwards Lauren , Lohman Matt , Choi Moon , Lapane Kate
Published: October 2011

Background

Many of the symptoms, consequences, and risk factors for frailty are shared with late‐life depression. However, thus far, few studies have addressed the conceptual and empirical interrelationships between these conditions. This review synthesizes existing studies that examined depression and frailty among older adults and provides suggestions for future research.

Methods

A search was conducted using PubMed for publications through 2010. Reviewers assessed the eligibility of each report and abstracted information on study design, sample characteristics, and key findings, including how depression and frailty were conceptualized and treated in the analysis.

Results

Of 133 abstracted articles, 39 full‐text publications met inclusion criteria. Overall, both cross‐sectional (n = 16) and cohort studies (n = 23) indicate that frailty, its components, and functional impairment are risk factors for depression. Although cross‐sectional studies indicate a positive association between depression and frailty, findings from cohort studies are less consistent. The majority of studies included only women and non‐Hispanic Whites. None used diagnostic measures of depression or considered antidepressant use in the design or analysis of the studies.

Conclusions

A number of empirical studies support for a bidirectional association between depression and frailty in later life. Extant studies have not adequately examined this relationship among men or racial/ethnic minorities, nor has the potential role of antidepressant medications been explored. An interdisciplinary approach to the study of geriatric syndromes such as late‐life depression and frailty may promote cross‐fertilization of ideas leading to novel conceptualization of intervention strategies to promote health and functioning in later life. Copyright © 2011 John Wiley & Sons, Ltd.
PRODUCTIVITY COSTS REVISITED: TOWARD A NEW US POLICY
Authors: Nyman John A.
Published: October 2011

In 1996, the Washington Panel recommended that the productivity costs that are not directly related to obtaining care be captured in the quality‐of‐life weights used to construct the quality‐adjusted life years (QALYs) in American cost–utility analyses. This paper revisits the original justification of the Panel and the critiques that appeared in the literature at the time. It then analyzes how productivity costs would be viewed from a cost–benefit analysis perspective to identify their welfare implications and then translates these implications into what they mean for how to express productivity costs in a cost–utility analysis. Next, three consistency issues are identified: (i) consistency between the welfare implications and the health status questionnaires used to construct the QALYs; (ii) consistency between the productivity costs from morbidity and mortality; and (iii) consistency between the measurement of productivity costs and the societal perspective. Finally, after reviewing the productivity costs policies of other countries, the paper makes a modest proposal for a new US policy. Copyright © 2011 John Wiley & Sons, Ltd.
An Efficient Synthesis of Mono and Bis‐1,2,3‐triazole AZT Derivatives via Copper(I)‐catalyzed Cycloaddition
Authors: Yuan Jin‐Wei , Qu Ling‐Bo , Chen Xiao‐Lan , Qu Zhi‐Bo , Liu Xiang‐Qian , Ke Dian‐Dian
Published: October 2011

An efficient synthesis of novel mono and bis‐1,2,3‐triazoles 3′‐azido‐2′‐deoxythymidine (AZT) derivatives via copper(I)‐catalyzed 1,3‐dipolar cycloaddition reaction is described. Starting from AZT and terminal alkyne derivatives, mono and bis‐1,2,3‐triazole AZT derivatives are regioselectively obtained in good yields under mild conditions using CuSO4·5H2O and sodium ascorbate as a catalyst system, and t‐BuOH/H2O (1:1, v/v) as a co‐solvent. The structures of these compounds were elucidated by IR, HR MS and NMR.
Synthesis and Biological Activity of a Series of Novel N‐Substituted β‐Lactams Derived from Natural Gallic Acid
Authors: Cao Xiu‐Fang , Wang Yun‐Shen , Li Shao‐Wei , Chena Chang‐Shu , Ke Shao‐Yong
Published: October 2011

A series of novel β‐lactams derived from natural gallic acid were conveniently synthesized via classical Staudinger ketene‐imine cycloaddition reaction. Their structures were confirmed by satisfactory analytical and spectroscopic methods. The preliminary bioassay showed that some of the target compounds exhibited obvious insecticidal activity against Heliothis armigera at the dosage of 0.2 mg/mL.
Zinc(II) and Cadmium(II) Metal Complexes with Bis(tetrazole) Ligands: Synthesis and Crystal Structures
Authors: Bai Mei , Zhang Jian‐Bin , Cao Ling‐Hua , Li Yan‐Ping , Wang Duo‐Zhi
Published: October 2011

Two new metal complexes [Zn(L1)]n (1) and [Cd3(L2)2Cl2(H2O)6]n (2) (H2L1 = 1,5‐bis(tetrazol‐5‐yl)‐3‐oxapentane, H2L2 = bis(tetrazol‐5‐yl)methane) have been synthesized and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction analysis. Complex 1 was a 2‐D sheet constructed by L1 and Zn(II) center, further assembled to form a three‐dimensional (3‐D) supramolecular networks through weak hydrogen‐bonding interactions. In the complex 2, there were two unequivalent Cd(II) centers, and some of ligands L2 adopted chelate coordination mode, and others adopted bridge coordination mode linking the Cd1 center and simultaneously bridging the Cd2 center, the Cl‐ anions adopted μ2 bridging mode, ligands L2 and the Cl‐ anions linked the Cd(II) centers to form a 3‐D supramolecular networks.
Hypervalent Iodine(III) Reagent Mediated Synthesis of 2‐Methylbenzofuran Derivatives by Pummerer‐type Reaction in Ionic Liquid
Authors: Chung Chi‐Lin , Han Chein‐Hwa , Wang Huey‐Min , Hou Rei‐Sheu , Chen Ling‐Ching
Published: October 2011

An efficient route for the synthesis of 2‐methylbenzofuran derivatives utilizing hypervalent iodine(III) reagent and a‐(methylthio)acetone via Pummerer‐type reaction in ionic liquid is described.
Investigating the last deglaciation of the Scandinavian Ice Sheet in southwest Sweden with 10Be exposure dating
Authors: Larsen Nicolaj Krog , Linge Henriette , Håkansson Lena , Fabel Derek
Published: October 2011

In this study we have obtained 17 cosmogenic exposure ages from three well‐developed moraine systems – Halland Coastal Moraines (HCM), Göteborg Moraine (GM) and Levene Moraine (LM) – which were formed during the last deglaciation in southwest Sweden by the Scandinavian Ice Sheet (SIS). The inferred ages of the inner HCM, GM and LM are 16.7 ± 1.6, 16.1 ± 1.4 and 13.6 ± 1.4 ka, respectively, which is slightly older than previous estimates of the deglaciation based on the minimum limiting radiocarbon ages and pollen stratigraphy. During this short interval from 16.7 ± 1.6 to 13.6 ± 1.4 ka a large part (100–125 km) of the marine‐based sector of the SIS in southwest Sweden was deglaciated, giving an average ice margin retreat between 20 to 50 m a−1. The inception of the deglaciation pre‐dated the Bølling/Allerød warming, the rapid sea level rise at 14.6 cal. ka BP and the first inflow of warm Atlantic waters into Skagerrak. We suggest that ice retreat in southwest Sweden is mainly a dynamical response governed by the disintegration of the Norwegian Channel Ice Stream and not primarily driven by climatic changes. Copyright © 2011 John Wiley & Sons, Ltd.
Vitamin D3 regulation of body fat, cytokines, and calpain gene expression
Authors: Choi Hyuck , Myung Kyuho
Published: October 2011

BACKGROUND: We conducted an in vivo experiment to determine whether vitamin D3 acts as a fat synthesizer and/or meat tenderizer in mice. At 6 weeks of age, 20 male C57BL/6 wild‐type mice were randomly divided into two groups (10 mice per group) and fed a modified AIN93G diet with (vitamin D3 diet) or without (basal diet) 10 IU 25‐OH‐cholecalciferol kg−3 for 3 weeks.

RESULTS: When vitamin D3 was fed to mice for 3 weeks, body fat was significantly increased compared to mice fed a basal diet. There was, however, no difference in body weight between the two groups. Vitamin D3 increased the gene expressions of pro‐inflammatory cytokines and peroxisome proliferator‐activated receptor gamma, but decreased interleukin‐15 in adipose tissue through nuclear vitamin D receptor and uncoupling protein‐2 signals. The muscle inducible nitrate oxide synthase content of mice fed vitamin D3 was higher than those fed a basal diet, while muscle arginase l showed a reverse phenomenon. longissimuss dorsi muscle of vitamin D3‐fed mice showed more severe fat deposition than those fed a basal diet. Vitamin D3 amplified muscle u‐ and m‐calpain protein content and suppressed muscle calpastatin protein content.

CONCLUSION: These findings suggest that vitamin D3 can be used as a fat synthesizer and meat tenderizer in meat‐producing animals. Copyright © 2011 Society of Chemical Industry
An investigation into gamma‐ray treatment of shellfish using electron paramagnetic resonance spectroscopy
Authors: Bhatti Ijaz A , Akram Kashif , Kwon Joong‐Ho
Published: October 2011

BACKGROUND: Gamma irradiation is a safe method for the decontamination of shellfish, and its technical feasibility and safety have been endorsed (FAO/IAEA/WHO). In order to implement proper food‐processing regulations, the identification of radiation treatment is required. In this study, electron paramagnetic resonance (EPR) spectroscopy was employed to identify the irradiation of seven different types of commonly consumed shellfish.

RESULTS: Characteristics (g factor and signal intensity) of the EPR spectra of control and irradiated samples were recorded in order to clarify the gamma‐ray treatment of shellfish. Radiation‐specific signals around g = 2.0038 ± 0.0006 (g1) and g = 1.9996 ± 0.0002 (g2 and g3) were observed for all shellfish samples irradiated with absorbed doses of 3 and 6 kGy. The X‐ray diffraction (XRD) spectra of some shellfish samples were recorded to investigate their mineral profiles.

CONCLUSION: The EPR spectroscopic results indicated that carbonate minerals were the source of the paramagnetic species that were produced upon irradiation, entrapped in the shellfish and showed radiation‐specific asymmetric signals whose intensities increased quantitatively with the absorbed radiation dose. The XRD analysis revealed that aragonite and calcite minerals were present in the shells of shellfish. Copyright © 2011 Society of Chemical Industry
Aroma characterization of tangerine hybrids by gas‐chromatography–olfactometry and sensory evaluation
Authors: Miyazaki Takayuki , Plotto Anne , Baldwin Elizabeth A , Reyes‐De‐Corcuera José I , Gmitter Jr Fred G
Published: October 2011

BACKGROUND: Tangerines have a distinct flavor among citrus fruit. However, information on tangerine volatiles remains limited. Volatile compounds from a breeding population of tangerines were earlier identified by gas chromatography–mass spectrometry. In this study, five hybrids with a distinct volatile profile were analyzed by gas‐chromatography–olfactometry (GC‐O) and descriptive sensory analysis.

RESULTS: Forty‐nine aroma active compounds were found in a consensus by GC‐O. Aldehydes were the most important group with odor activity, as well as monoterpenes, esters, alcohols and ketones. 1,8‐Cineole, β‐myrcene, (E,E)‐2,4‐nonadienal, hexanal, ethyl‐2‐methylbutanoate, and linalool were perceived with high intensity in most samples. Two ‘Clementine’ × ‘Minneola’ and one ‘Fortune’ × ‘Murcott’ hybrids with tangerine, sulfury and woody/spicy flavors had aroma active compounds with terpeney, fatty/vegetable and metallic/rubber descriptors. A tangerine with ‘Valencia’ orange in its parentage had a characteristic orange flavor, which could be explained by esters and ketones, high in fruity and floral odor intensities. A hybrid of unknown origin had a distinct fruity–non‐citrus and pumpkin/fatty flavor; that sample had the lowest amount of aroma‐active volatiles, with the least compounds with terpeney odors.

CONCLUSION: There was no one compound characteristic of tangerine flavor. Nevertheless, each sample sensory characteristic could be explained by a set of aroma‐active volatile compounds. Published 2011 by John Wiley & Sons, Ltd.
Notch1 regulates chemotaxis and proliferation by controlling the CC‐chemokine receptors 5 and 9 in T cell acute lymphoblastic leukaemia
Authors: Mirandola Leonardo , Chiriva‐Internati Maurizio , Montagna Daniela , Locatelli Franco , Zecca Marco , Ranzani Marco , Basile Andrea , Locati Massimo , Cobos Everardo , Kast W Martin , Asselta Rosanna , Paraboschi Elvezia Maria , Comi Paola , Chiaramonte Raffaella
Published: October 2011

Tumour cells often express deregulated profiles of chemokine receptors that regulate cancer cell migration and proliferation. Notch1 pathway activation is seen in T cell acute lymphoblastic leukaemia (T‐ALL) due to the high frequency of Notch1 mutations affecting approximately 60% of patients, causing ligand‐independent signalling and/or prolonging Notch1 half‐life. We have investigated the possible regulative role of Notch1 on the expression and function of chemokine receptors CCR5, CCR9 and CXCR4 that play a role in determining blast malignant properties and localization of extramedullary infiltrations in leukaemia. We inhibited the pathway through γ‐Secretase inhibitor and Notch1 RNA interference and analysed the effect on the expression and function of chemokine receptors. Our results indicate that γ‐Secretase inhibitor negatively regulates the transcription level of the CC chemokine receptors 5 and 9 in T‐ALL cell lines and patients' primary leukaemia cells, leaving CXCR4 expression unaltered. The Notch pathway also controls CCR5‐ and CCR9‐mediated biological effects, ie chemotaxis and proliferation. Furthermore, engaging CCR9 through CCL25 administration rescues proliferation inhibition associated with abrogation of Notch activity. Finally, through RNA interference we demonstrated that the oncogenic isoform in T‐ALL, Notch1, plays a role in controlling CCR5 and CCR9 expression and functions. These findings suggest that Notch1, acting in concert with chemokine receptors pathways, may provide leukaemia cells with proliferative advantage and specific chemotactic abilities, therefore influencing tumour cell progression and localization. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Focal adhesion kinase and tumour angiogenesis
Authors: Lechertier Tanguy , Hodivala‐Dilke Kairbaan
Published: October 2011

Angiogenesis, the formation of new blood vessels from pre‐existing ones, is essential for tumour development. It is initiated and regulated by growth factors via their surface receptors, which activate several intracellular signalling pathways in endothelial cells. Cell adhesion molecules, such as integrins, also regulate angiogenesis. Despite these facts, inhibitors of endothelial cell growth factor receptors or integrins have not been as effective as initially hoped in the long‐term inhibition of angiogenesis in cancer patients. Signalling downstream of growth factor receptors and integrins converge on the ubiquitously expressed non‐receptor tyrosine kinase focal adhesion kinase (FAK). FAK is involved in endothelial cell proliferation, migration and survival, is up‐regulated in many cancers and has recently been shown to control tumour angiogenesis. Indeed, FAK inhibitors are presently being developed for the treatment of cancer. However, recent studies have indicated the complexities of understanding the precise role for FAK in angiogenesis. Here we have summarized some of the key features of FAK, addressed some of the apparently contradictory roles of this molecule in angiogenesis and provided some perspectives for future studies. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Electromagnetic activation of a shape memory copolymer matrix incorporating ferromagnetic nanoparticles
Authors: Yang Dan , Huang Wei , He Xiaohua , Xie Meiran
Published: October 2011

Modified magnetite (Fe3O4) was easily mixed in a matrix of a polynorbornene‐based copolymer to realize a nanocomposite of organic polymer and inorganic metal oxide nanoparticles. The crystalline structure and the diameter of the modified Fe3O4 were evaluated with X‐ray diffraction and atomic force microscopy, revealing the crystalline Fe3O4 nanoparticles in the nanometer size range with an average diameter of 55 nm, a value close to that indicated by dynamic light scattering (68 nm). The transition temperature of the composite of 51 °C was determined using differential scanning calorimetry and the thermal stability and dynamic mechanical properties of the easily formed composite were investigated using thermogravimetry and dynamic mechanical analysis. The shape memory effect was evaluated in terms of shape recovery rate and speed, while thermally and electromagnetically triggered shape memory properties were documented. The recovery time triggered by Fe3O4 is 186 s. Copyright © 2011 Society of Chemical Industry
Cancer survivors' exercise barriers, facilitators and preferences in the context of fatigue, quality of life and physical activity participation: a questionnaire–survey
Authors: Blaney J. M. , Lowe‐Strong A. , Rankin‐Watt J. , Campbell A. , Gracey J. H.
Published: October 2011

Objective

To investigate the exercise barriers, facilitators and preferences of a mixed sample of cancer survivors as well as fatigue levels, quality of life (QoL) and the frequency and intensity of exercise that cancer survivors typically engage in.

Methods

An anonymous, postal questionnaire–survey with a convenience sample of 975 cancer survivors was used. Standardised measures were used to establish fatigue (Multidimensional Fatigue Symptom Inventory‐Short Form), QoL (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire‐C30), exercise frequency and intensity (Leisure Score Index).

Results

A 52.3% response rate (n = 456) was achieved. A total of 76.0% were female, with stage I (18.3%) or stage II (21.0%) breast cancer (64.4%), and 62.3% were ≥3 years post treatment. A total of 73.5% reported fatigue with 57.2% experiencing fatigue on a daily basis. A total of 68.1% had never been given any advice on how to manage fatigue. A total of 9.4% reported to engage in strenuous physical activity, 43.5% in moderate physical activity and 65.5% in mild physical activity. Respondents experienced difficulties with emotional, cognitive and social functioning and the symptoms of fatigue, insomnia and pain. Barriers that interfered with exercise ‘often/very often’ were mainly related to respondents' health and environmental factors. A total of 50.2% were interested in exercise and 52.5% felt able to exercise. Exercise facilitators, preferences and motivators provide some insight into cancer survivors' needs in terms of becoming more physically active.

Conclusions

Although cancer survivors continue to experience fatigue and QoL issues long after treatment completion, over half are willing and feel able to participate in exercise. Exercise barriers were mainly health related or environmental issues, however, the main barriers reported were those that had the potential to be alleviated by exercise. Copyright © 2011 John Wiley & Sons, Ltd.
Genetic testing for hereditary melanoma and pancreatic cancer: a longitudinal study of psychological outcome
Authors: Aspinwall Lisa G. , Taber Jennifer M. , Leaf Samantha L. , Kohlmann Wendy , Leachman Sancy A.
Published: October 2011

Objective

CDKN2A/p16 mutations confer 76% lifetime risk of melanoma and up to 17% lifetime risk of pancreatic cancer. Our objective was to determine the short‐ and long‐term impact of CDKN2A/p16 genetic counseling and test reporting on psychological distress, cancer worry, and perceived costs and benefits of testing.

Methods

Prospective changes in anxiety, depression, and cancer worry following CDKN2A/p16 counseling and test reporting were evaluated at multiple assessments over 2 years among 60 adult members of melanoma‐prone families; 37 participants completed the 2‐year follow‐up. Quantitative and qualitative assessments of the costs and benefits of testing were carried out. Outcomes were evaluated among unaffected noncarriers (n = 27), unaffected carriers (n = 15), and affected carriers (n = 18).

Results

Reported anxiety and depression were low. For carriers and noncarriers, anxiety decreased significantly throughout the 2‐year period, whereas depression and melanoma worry showed short‐term decreases. Worry about pancreatic cancer was low and decreased significantly. In all groups, test‐related distress and uncertainty were low, regret was absent, and positive experiences were high. All participants (>93% at each assessment) reported at least one perceived benefit of genetic testing; only 15.9% listed any negative aspect. Carriers reported increased knowledge about melanoma risk and prevention (78.3%) and increased prevention and screening behaviors for self and family (65.2%). Noncarriers reported increased knowledge (95.2%) and emotional benefits (71.4%).

Conclusion

Among US participants familiar with their hereditary melanoma risk through prior epidemiological research participation, CDKN2A/p16 genetic testing provides multiple perceived benefits to both carriers and noncarriers without inducing distress in general or worry about melanoma or pancreatic cancer. Copyright © 2011 John Wiley & Sons, Ltd.
Acaricidal activities of the active component of Lycopus lucidus oil and its derivatives against house dust and stored food mites (Arachnida: Acari)
Authors: Yang Ji‐Yeon , Lee Hoi‐Seon
Published: October 2011

BACKGROUND: Recent studies have focused on materials derived from plant extracts as mite control products against house dust and stored food mites because repeated use of synthetic acaricides had led to resistance and unwanted activities on non‐target organisms. The aim of this study was to evaluate the acaricidal activity of materials derived from Lycopus lucidus against Dermatophagoides farinae, D. pteronyssinus and Tyrophagus putrescentiae.

RESULTS: The LD50 values of L. lucidus oil were 2.19, 2.25 and 8.45 µg cm−2 against D. farinae, D. pteronyssinus and T. putrescentiae. The acaricidal constituent of L. lucidus was isolated by chromatographic techniques and identified as 1‐octen‐3‐ol. In a fumigant method against D. farinae, the acaricidal activity of 1‐octen‐3‐ol (0.25 µg cm−2) was more toxic than N,N‐diethyl‐m‐toluamide (DEET) (36.84 µg cm−2), followed by 3,7‐dimethyl‐1‐octen‐3‐ol (0.29 µg cm−2), 1‐octen‐3‐yl butyrate (2.32 µg cm−2), 1‐octen‐3‐yl acetate (2.42 µg cm−2), 3,7‐dimethyl‐1‐octene (9.34 µg cm−2) and benzyl benzoate (10.02 µg cm−2). In a filter paper bioassay against D. farinae, 1‐octen‐3‐ol (0.63 µg cm−2) was more effective than DEET (20.64 µg cm−2), followed by 3,7‐dimethyl‐1‐octen‐3‐ol (1.09 µg cm−2).

CONCLUSION: 1‐Octen‐3‐ol and 3,7‐dimethyl‐1‐octen‐3‐ol could be useful as natural agents for the management of three mite species. Copyright © 2011 Society of Chemical Industry
Binding energy of singlet excitons and charge transfer complexes in MDMO‐PPV:PCBM solar cells
Authors: Kern Julia , Schwab Sebastian , Deibel Carsten , Dyakonov Vladimir
Published: October 2011

The influence of an external electric field on the photoluminescence intensity of singlet excitons and charge transfer complexes is investigated for a poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene] (MDMO‐PPV) diode and a bulk heterojunction of the PPV in combination with [6,6]‐phenyl‐C61 butyric acid methylester (PCBM), respectively. The experimental data is related to the dissociation probability derived from the Onsager–Braun model. In this way, a lower limit for the singlet exciton binding energy of MDMO‐PPV is determined as $ (327 \pm 30) $ meV, whereas a significantly lower value of $ (203 \pm 18) $ meV is extracted for the charge transfer complex in a MDMO‐PPV:PCBM blend. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical study of slantwise circulations in a strongly sheared prefrontal environment
Authors: Fantini M. , Malguzzi P. , Buzzi A.
Published: October 2011

The simultaneous presence of convective, symmetric and inertial instability in a prefrontal region of strong vertical wind shear was simulated with the non‐hydrostatic model MOLOCH. Model diagnostics of absolute vorticity, pseudo‐angular momentum, saturated equivalent potential temperature and vorticity reveal a sequence of events that includes ‘ΔM‐adjustment’, followed by slanted ascent in symmetrically unstable regions, becoming saturated in the later stages. An idealized experiment without orography was performed to isolate the presence and role of instabilities characterizing the development. The diagnosed circulation is reminiscent of a wavenumber‐two normal mode of dry symmetric instability, while moist symmetric instability is confined to a very limited region, despite the appearance of wider areas of negative moist potential vorticity. The evaluation of moist thermodynamic quantities which give proper account of condensate loading is suggested as a possible resolution of this apparent inconsistency. Copyright © 2011 Royal Meteorological Society
Open vs robot‐assisted laparoscopic gastric resection with D2 lymph node dissection for adenocarcinoma: a case‐control study
Authors: Caruso Stefano , Patriti Alberto , Marrelli Daniele , Ceccarelli Graziano , Ceribelli Cecilia , Roviello Franco , Casciola Luciano
Published: October 2011

Background

A population‐based case‐control study was conducted in order to investigate the advantages of robot‐assisted gastric resection (RGR) for gastric cancer as opposed to traditional open gastrectomy (OG).

Methods

Data were collected in two prospectively maintained databases on patients who underwent a D2 gastrectomy with curative intent for primary gastric adenocarcinoma. All (n = 29) the first consecutive gastric cancer patients submitted to RGR from a referral centre for minimally invasive surgery were matched to control cancers (n = 120) extrapolated from a high volume centre database including patients submitted to OG.

Results

Robot‐assisted laparoscopic procedures implied increased operative time (290 vs 222 min, p = 0.004), decreased blood loss (197.6 vs 386.1 mL, p = 0.0001) and shorter hospital stay (9.6 vs 13.4 days, p < 0.0009). There was no difference in the mean number of harvested lymph nodes between the two groups (28.0 vs 31.7, p = 0.023). The total morbidity rate, including major complications such as anastomotic and duodenal suture failure, was comparable between groups (41.4% vs 42.5%; in the RGR and OG, respectively, p = 0.764). Preliminary data on overall survival did not show prognostic differences between the two groups (p = 0.615).

Conclusions

Robot‐assisted surgery fulfils oncologic criteria for D2 dissection and has an oncologic outcome comparable with that of OG. RGR resulted in shorter hospital stays, the loss of less blood and morbidity comparable with that of OG. Randomized clinical trials and longer follow‐up are needed to evaluate whether RGR achieves long‐term survival rates equivalent to that of open and laparoscopic surgery. Copyright © 2011 John Wiley & Sons, Ltd.