bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small‐size WWAN monopole slot antenna with dual‐band band‐stop matching circuit for tablet computer application
Authors: Wong Kin‐Lu , Ma Pei‐Ji 
Published: February 2012

AbstractA monopole slot antenna printed on a small‐size FR4 substrate of 40 × 10 mm2 to provide two wide operating bands of 824–960 and 1710–2170 MHz for the wireless wide area network operation in the tablet computer is presented. The monopole slot is folded to achieve a compact configuration and is fed by a microstrip feedline loaded with a dual‐band band‐stop matching circuit on the same FR4 substrate. The band‐stop matching circuit can generate two separate parallel resonances at about 1050 and 2250 MHz, which respectively leads to additional resonance occurred nearby the resonant frequencies of the quarter‐wavelength slot mode at about 850 MHz and higher‐order slot mode at about 1900 MHz, thereby resulting in dual‐resonance excitation of the two excited slot modes to respectively cover the GSM850/900 and GSM1800/1900/UMTS operation. The bandwidth‐enhancement technique of using a dual‐band band‐stop matching circuit is reported for the first time in published articles, and its detailed operating principle is described in this study. Performances of the proposed antenna are also discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:875–879, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26723
Microstrip patch array antenna with high isolation characteristic
Authors: Jang Hyeong‐Seok , Lim Won‐Gyu , Son Wang‐Ik , Cha Sung‐Yong , Yu Jong‐Won 
Published: February 2012

AbstractThe design of an integrated rectangular microstrip patch array antenna with enhanced isolation characteristic between transmitter and receiver is presented to produce a full‐duplex transceiver with transmit and receive operation at the same frequency and with the same polarization. This integrated circulator‐like antenna has potential uses in both short‐range communication systems and radar systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:973–976, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26727
Transient absorption spectroscopy of a single lateral InGaAs quantum dot molecule
Authors: Wolpert Christian , Wang Lijuan , Rastelli Armando , Schmidt Oliver G. , Giessen Harald , Lippitz Markus 
Published: February 2012

AbstractLateral quantum dot molecules promise a scalable approach to quantum registers. The individual neutral exciton states can be controlled by a lateral bias voltage. In this way radiative emission of localized excitons can be switched between the two quantum dots in the molecule. Here, we report on coherent absorption spectroscopy of a single quantum dot molecule. By transient reflection spectroscopy we demonstrate that not only the emission but also the absorption switches from one dot to the other when varying the applied electric field. This result is consistent with Rabi flopping showing a radically suppressed dipole moment for the non‐emitting exciton transition
Affordance‐based indirect task communication for astronaut‐robot cooperation
Authors: Heikkilä Seppo S. , Halme Aarne , Schiele André 
Published: February 2012

AbstractThe problem with human–robot task communication is that robots cannot understand complex human speech, whereas humans cannot efficiently use the fixed task request utterances required by robots. However, future planetary exploration missions will require astronauts on extravehicular activities to communicate task requests to robot assistants by using speech‐ and gesture‐type user interfaces that can be easily embedded in their space suits. The solution proposed in this paper is indirect task communication based on the humanlike ability to utilize object–action relationships in task communication. A conventional task communication method, in which the astronaut needs to communicate all the task parameters explicitly, is compared with communication methods where affordances, i.e., action possibilities, are used to complete the task communication. This comparison is done with three user experiments: one performed with a fully autonomous centauroid robot in a geological exploration work context and two with a simulated robot in a lander assembly work context. The experiments indicate that affordance‐based indirect task communication methods can be used to decrease both the human workload and the task communication times in a planetary exploration type of work context, and that combined direct and indirect task communication methods seem to be preferable from a human point of view. © 2012 Wiley Periodicals, Inc.
On the use of mutations and testing for debugging
Authors: Nica Mihai , Nica Simona , Wotawa Franz 
Published: February 2012

SUMMARYTools for automated fault localization usually generate too many bug candidates depending on the underlying technique. Hence, more information is required in order to further restrict the number of bug candidates. Approaches that rely on specific knowledge of the program to be debugged, such as variable values at specific positions in the source code, are not easily accessible for users especially in the case of software maintenance. In order to avoid this problem, we suggest integrating testing to restrict the number of bug candidates. In particular, we propose computing possible corrections of the program and from this distinguishing test cases. A distinguishing test case is a test that reveals different output values for two program variants given the same input values. Besides the formal definitions and algorithms, we extend the first empirical results of our approach in this paper. The obtained empirical results show that the use of mutations and distinguishing test cases reduces the number of bug candidates by more than 90% on average. Copyright © 2012 John Wiley & Sons, Ltd.
Genome shuffling of Bacillus amyloliquefaciens for improving antimicrobial lipopeptide production and an analysis of relative gene expression using FQ RT-PCR
Authors: Zhao Junfeng , Li Yuanhong , Zhang Chong , Yao Zhengying , Zhang Li , Bie Xiaomei , Lu Fengxia , Lu Zhaoxin 
Published: February 2012

Abstract
Genome shuffling is an efficient approach for the rapid improvement of the yield of secondary metabolites. This study was undertaken to enhance the yield of surfactin produced by Bacillus amyloliquefaciens ES-2-4 using genome shuffling and to examine changes in SrfA expression of the improved phenotype at the transcriptional level. Six strains with subtle improvements in lipopeptide yield were obtained from populations generated by ultraviolet irradiation, nitrosoguanidine, and ion beam mutagenesis. These strains were then subjected to recursive protoplast fusion. A strain library that was likely to yield positive colonies was created by fusing the lethal protoplasts obtained from both ultraviolet irradiation and heat treatments. After two rounds of genome shuffling, a high-yield recombinant F2-38 strain that exhibited 3.5- and 10.3-fold increases in surfactin production in shake flask and fermenter respectively, was obtained. Comparative analysis of synthetase gene expression was conducted between the initial and shuffled strains using FQ (fluorescent quantitation) RT-PCR. Delta CT (threshold cycle) relative quantitation analysis revealed that surfactin synthetase gene (srfA) expression at the transcriptional level in the F2-38 strain was 15.7-fold greater than in the ES-2-4 wild-type. The shuffled strain has a potential application in food and pharmaceutical industries. At the same time, the analysis of improved phenotypes will provide more valuable data for inverse metabolic engineering.
Stability of reactive interfaces in saturated porous media under gravity in the presence of transverse flows
Authors: Hejazi S. H. , Azaiez J. 
Published: February 2012

AbstractThe stability of a horizontal interface between a solution of reactant $A$ on top of another solution of reactant $B$ is analysed. A chemical product $C$ is generated at the interface as a result of a bimolecular chemical reaction $A+ B\ensuremath{\rightarrow} C$. In general, all chemical components are assumed to have different densities and viscosities, and a transverse velocity is introduced parallel to the interface between the reactants. Although the transverse flow is known for its stabilizing effect in viscously unstable non-reactive systems in the presence of an injection velocity, it is shown here that it can actually destabilize an initially stable reactive front. An expression for the critical transverse velocity beyond which an initially stable interface is destabilized is derived in the case of an initial sharp interface for reactants of the same viscosity. The analysis is extended to a diffused profile, and purely buoyancy-driven flows are analysed first in the absence of viscosity contrast and then in the presence of transverse flows and viscosity contrast. Various possible density fingering scenarios are determined based on the relative contribution of each chemical component to the density profile. It is found that the chemical reaction can destabilize a buoyancy-stable initial interface by generating a non-monotonic density profile. Unlike the viscous fingering of a reactive interface, a symmetry in the stability characteristics with respect to density increase or decrease by chemical reaction product is observed in the case of chemically buoyancy-driven flows for identical reactants.
ON ODD PERFECT NUMBERS
Authors: CHEN FENG-JUAN , CHEN YONG-GAO 
Published: February 2012

AbstractLet q be an odd prime. In this paper, we prove that if N is an odd perfect number with qα∥N then σ(N/qα)/qα≠p,p2,p3,p4,p1p2,p21p2, where p,p1, p2 are primes and p1≠p2. This improves a result of Dris and Luca [‘A note on odd perfect numbers’, arXiv:1103.1437v3 [math.NT]]: σ(N/qα)/qα≠1,2,3,4,5. Furthermore, we prove that for K≥1 , if N is an odd perfect number with qα ∥N and σ(N/qα)/qα ≤K, then N≤4K8.
AFRICAN COUNTRIES IN THE WORLD TRADING SYSTEM: INTERNATIONAL TRADE, DOMESTIC INSTITUTIONS AND THE ROLE OF INTERNATIONAL LAW
Authors: Desta Melaku Geboye , Hirsch Moshe 
Published: February 2012

AbstractThis article addresses an important and complex subject relating to the link between international law and economic development. There is broad agreement that trade liberalization and participation in foreign markets play an important role in economic development. Countries in Sub-Saharan Africa (SSA) have generally pursued a liberalization route over the past two decades, but their economic performance has been deeply disappointing. In this article, we look at seven countries in the Horn of Africa and examine, from legal and institutional perspectives, the central question of why these countries have failed to translate their comparative advantage, particularly in the livestock sector, into meaningful trade-led economic growth. In order to answer this question, we have reviewed the relevant legal and policy instruments and the literature, visited five of the seven countries, and interviewed different players in the livestock value chain. Analysis of the evidence reveals that the main impediments to trade relate to rising sanitary import requirements in foreign markets and weak institutional capacity within the Horn. The limited technical and financial resources available to these countries also reduce their capacity to meet these standards. Meaningful institutional change requires substantial involvement of local actors and it takes place incrementally and over the long term. International law can play a role in this process by promoting the rule of law and tackling corruption, facilitating capacity-building, and encouraging regional integration.
EU COMPETITION LAW ENFORCEMENT: IS BRUSSELS I SUITED TO DEALING WITH ALL THE CHALLENGES?
Authors: Danov Mihail 
Published: February 2012

AbstractThere are arguments indicating that Brussels I could be applicable to cross-border competition law proceedings before a National Competition Authority located in one Member State and private EU competition law proceedings before another Member State court. However, an analysis of the current private international law framework appears to indicate that Brussels I is not well suited to deal with the difficulties that could arise in this context. Given the fact that, in the new proposal for a regulation on jurisdiction and the recognition and enforcement of judgments there is no indication that special jurisdictional bases for competition law actions in the successor to Brussels I are on anyone's agenda, an option for a reform may be setting up a new and special regulation to be applicable with regard to EU competition law claims only.
A comparison ofToxocara canisembryonation under controlled conditions in soil and hair
Authors: Keegan J. Devoy , Holland C.V. 
Published: February 2012

AbstractToxocaraspp. eggs require a period of time under appropriate environmental conditions to become infective to definitive and paratenic hosts. Temperature and humidity are important factors known to affect the levels of development in soil. We aimed to investigate whether the eggs ofT. caniscould embryonate in dog hair under controlled conditions of temperature and humidity and, if so, to what degree. No previous work had been carried out on embryonation in hair under controlled conditions. Soil samples exposed to the same conditions as the hair samples were considered a suitable comparison in order to investigate differing levels of development. Development at two temperatures (10°C and 20°C) and the addition of water to samples was investigated over a period of 8 weeks. Importantly, we demonstrated that unembryonatedT. caniseggs are capable of development in hair under controlled conditions. The rate of development is lower than that observed in soil, but remains biologically significant in terms of the overall numbers of potentially infective embryonated eggs present. Temperature is responsible for the rate of embryonation while moisture is essential for encouraging development and maintaining egg viability in general. In light of these findings the transmission ofToxocaraspp. as a result of direct contact with well-cared-for owned dogs seems unlikely, but should not be ignored.
New advances in thein-vitroculture ofDientamoeba fragilis
Authors: MUNASINGHE VARUNI S. , STARK D. , ELLIS J. T. 
Published: February 2012

SUMMARYDientamoeba fragilisis an intestinal protozoan in humans that is commonly associated with diarrhoea and other gastrointestinal complaints. Studies conducted to investigate the biology of this parasite are limited by methods forin vitrocultivation. The objective of this study was to improve a biphasic culture medium, based on the Loeffler's slope, by further supplementation in order to increase the yield of trophozoites in culture. The currentin vitroculture ofD. fragilisis a xenic culture with a mix of bacteria. Three different liquid overlays were evaluated including Earle's balanced salt solution (EBSS), PBS and Dulbecco's modified PBS (DPBS), for their ability to support thein vitrogrowth ofD. fragilistrophozoites. Out of these 3 overlays EBSS gave the highest increase in the trophozoite numbers. The effect of supplementation was analysed by supplementing EBSS with ascorbic acid, ferric ammonium citrate, L-cysteine, cholesterol and alpha-lipoic acid and quantification ofin vitrogrowth by cell counts. A new liquid overlay is here described based upon EBSS supplemented with cholesterol and ferric ammonium citrate that, in conjunction with the Loeffler's slope, supports the growth ofD. fragilistrophozoitesin vitro. This modified overlay supported a 2-fold increase in the numbers of trophozoite in culture from all 4D. fragilisisolates tested, when compared to a PBS overlay. These advances enable the harvest of a larger number of trophozoites needed for further studies on this parasite.
Pangloss revisited: a critique of the dilution effect and the biodiversity-buffers-disease paradigm
Authors: RANDOLPH S. E. , DOBSON A. D. M. 
Published: February 2012

SUMMARYThe twin concepts of zooprophylaxis and the dilution effect originated with vector-borne diseases (malaria), were driven forward by studies on Lyme borreliosis and have now developed into the mantra “biodiversity protects against disease”. The basic idea is that by diluting the assemblage of transmission-competent hosts with non-competent hosts, the probability of vectors feeding on transmission-competent hosts is reduced and so the abundance of infected vectors is lowered. The same principle has recently been applied to other infectious disease systems – tick-borne, insect-borne, indirectly transmitted via intermediate hosts, directly transmitted. It is claimed that the presence of extra species of various sorts, acting through a variety of distinct mechanisms, causes the prevalence of infectious agents to decrease. Examination of the theoretical and empirical evidence for this hypothesis reveals that it applies only in certain circumstances even amongst tick-borne diseases, and even less often if considering the correct metric – abundance rather than prevalence of infected vectors. Whether dilution or amplification occurs depends more on specific community composition than on biodiversityper se. We warn against raising a straw man, an untenable argument easily dismantled and dismissed. The intrinsic value of protecting biodiversity and ecosystem function outweighs this questionable utilitarian justification.
Interleukin-6, C-reactive protein and interleukin-10 after antidepressant treatment in people with depression: a meta-analysis
Authors: Hiles S. A. , Baker A. L. , de Malmanche T. , Attia J. 
Published: February 2012

BackgroundCross-sectional studies support an association between depression and inflammatory markers. However, little is known of their relationship in the context of antidepressant treatment. Our aim was to explore via meta-analysis whether antidepressant treatment is associated with a reduction in three inflammatory markers associated with depression.MethodA computerized search of EMBASE, Medline, PsycINFO and Cochrane Library databases was completed using subject headings for depression and either interleukin-6, C-reactive protein or interleukin-10, selecting studies which reported circulating levels of inflammatory markers before and after antidepressant treatment for people with depression. Outcome and moderator variables were coded for analysis, including inflammatory marker change, depression severity change, age, gender ratio, assay brand, treatment response and weight change.ResultsPooled effect sizes showed a significant decrease in interleukin-6 (n=14, d=−0.42, p=0.02), marginally significant decrease in C-reactive protein (n=8, d=−0.57, p=0.05) and a non-significant decrease in interleukin-10 (n=3, d=−0.45, p=0.14) after treatment. High levels of heterogeneity were observed, which may be associated with clinical variations between the studies such as weight gain, anxiety, incomplete remission and other individual differences and co-morbidities.ConclusionsThe findings of this meta-analysis indicate that there may be a normalization of overactive inflammatory processes following antidepressant treatment.
A note on Borel–Cantelli lemmas for non-uniformly hyperbolic dynamical systems
Authors: HAYDN NICOLAI , NICOL MATTHEW , PERSSON TOMAS , VAIENTI SANDRO 
Published: February 2012

AbstractLet (Bi) be a sequence of measurable sets in a probability space (X,ℬ,μ) such that ∑ ∞n=1μ(Bi)=∞. The classical Borel–Cantelli lemma states that if the sets Bi are independent, then μ({x∈X:x∈Bi infinitely often})=1. Suppose (T,X,μ) is a dynamical system and (Bi) is a sequence of sets in X. We consider whether Tix∈Bi infinitely often for μ almost every x∈X and, if so, is there an asymptotic estimate on the rate of entry? If Tix∈Bi infinitely often for μ almost every x, we call the sequence (Bi) a Borel–Cantelli sequence. If the sets Bi :=B(p,ri) are nested balls of radius ri about a point p, then the question of whether Tix∈Bi infinitely often for μ almost every x is often called the shrinking target problem. We show, under certain assumptions on the measure μ, that for balls Bi if μ(Bi)≥i−γ, 0<γ<1, then a sufficiently high polynomial rate of decay of correlations for Lipschitz observables implies that the sequence is Borel–Cantelli. If μ(Bi)≥C1 /i, then exponential decay of correlations implies that the sequence is Borel–Cantelli. We give conditions in terms of return time statistics which quantify Borel–Cantelli results for sequences of balls such that μ(Bi)≥C/i. Corollaries of our results are that for planar dispersing billiards and Lozi maps, sequences of nested balls B(p,1/i) are Borel–Cantelli. We also give applications of these results to a variety of non-uniformly hyperbolic dynamical systems.
A molecular method to assess bioburden embedded within silicon-based resins used on modern spacecraft materials
Authors: Stam Christina N. , Bruckner James , Spry J. Andy , Venkateswaran Kasthuri , La Duc Myron T. 
Published: February 2012

AbstractCurrent assessments of bioburden embedded in spacecraft materials are based on work performed in the Viking era (1970s), and the ability to culture organisms extracted from such materials. To circumvent the limitations of such approaches, DNA-based techniques were evaluated alongside established culturing techniques to determine the recovery and survival of bacterial spores encapsulated in spacecraft-qualified polymer materials. Varying concentrations ofBacillus pumilusSAFR-032 spores were completely embedded in silicone epoxy. An organic dimethylacetamide-based solvent was used to digest the epoxy and spore recovery was evaluated viagyrB-targeted qPCR, direct agar plating, most probably number analysis, and microscopy. Although full-strength solvent was shown to inhibit the germination and/or outgrowth of spores, dilution in excess of 100-fold allowed recovery with no significant decrease in cultivability. Similarly, qPCR (quantitative PCR) detection sensitivities as low as ∼103CFU ml−1were achieved upon removal of inhibitory substances associated with the epoxy and/or solvent. These detection and enumeration methods show promise for use in assessing the embedded bioburden of spacecraft hardware.
The galactic habitable zone in elliptical galaxies
Authors: Suthar Falguni , McKay Christopher P. 
Published: February 2012

AbstractThe concept of a Galactic Habitable Zone (GHZ) was introduced for the Milky Way galaxy a decade ago as an extension of the earlier concept of the Circumstellar Habitable Zone. In this work, we consider the extension of the concept of a GHZ to other types of galaxies by considering two elliptical galaxies as examples, M87 and M32. We argue that the defining feature of the GHZ is the probability of planet formation which has been assumed to depend on the metallicity. We have compared the metallicity distribution of nearby stars with the metallicity of stars with planets to document the correlation between metallicity and planet formation and to provide a comparison to other galaxies. Metallicity distribution, based on the [Fe/H] ratio to solar, of nearby stars peaks at [Fe/H]≈−0.2 dex, whereas the metallicity distribution of extrasolar planet host stars peaks at [Fe/H]≈+0.4 dex. We compare the metallicity distribution of extrasolar planet host stars with the metallicity distribution of the outer star clusters of M87 and M32. The metallicity distribution of stars in the outer regions of M87 peaks at [Fe/H]≈−0.2 dex and extends to [Fe/H]≈+0.4 dex, which seems favourable for planet formation. The metallicity distribution of stars in the outer regions of M32 peaks at [Fe/H]≈−0.2 dex and extends to a much lower [Fe/H]. Both elliptical galaxies met the criteria of a GHZ. In general, many galaxies should support habitable zones.