bluuebunny/crossref_metadata_2025 huggingface dataset:
Short‐term temporal variation in gelatinous zooplankton populations over 48 hours in a coral reef at Redang Island, Malaysia
Authors: Nakajima Ryota , Lindsay Dhugal J. , Yoshida Teruaki , Othman Bin Haji Ross , Toda Tatsuki
Published: June 2013

Gelatinous zooplankton abundance and species composition were investigated at 3‐h intervals for a 48‐h period at a fringing reef in Malaysia. A total of 20 gelatinous zooplankton species were observed; the community was dominated by the calycophoran siphonophore Diphyes chamissonis (79.9%), followed by the trachymedusdae Aglaura hemistoma (5.6%) and Liriope tetraphylla (4.8%). The gelatinous zooplankton were not collected in the water column during most of the daytime hours (1200, 1500 and 1800 h) but were common during the night. However, an abrupt peak in abundance was found at 0900 h on the second day. The times of appearance at night were different depending on the species, and the number of species was also different depending on the hour of sampling. Sampling at 3‐h intervals over a 48‐h period revealed that the temporal variation (or sampling availability) was large in this study. Careful consideration should be given to the sampling variability in handling the gelatinous zooplankton samples in coral reef areas.
Influence of the YORP effect on rotation rates of near‐Earth asteroids
Authors: Lupishko Dmitrij , Tielieusova Iryna
Published: June 2013

The distribution of near‐Earth asteroid (NEA) rotation rates differs considerably from the similar distribution of Main Belt asteroids (MBAs) by the presence of excesses of fast and slow rotators, which are not observed or not so prominent in the distribution for MBAs. Among possible reasons for the difference, there can be influence of solar radiation on spin rate of small NEAs, the so‐called “YORP effect,” which appears due to reflection, absorption, and IR re‐emission of the sunlight by an irregularly shaped rotating asteroid. It is known that the YORP‐effect action strongly depends on the amount of solar energy obtained by the body (insolation), its size, and albedo. The analysis of observation data has shown that: (1) the mean diameter of NEAs decreases from the middle of the distribution to its ends, that is, the excesses of slow rotators (ω ≤ 2 rev day−1) and fast rotators (ω ≥ 8 rev day−1) are composed of smaller NEAs than in the middle of the distribution; (2) NEAs of both excesses are in the orbits where their insolation is about 8–10% larger than that of NEAs in the middle of the distribution; and (3) the objects in both excesses have a little lower albedo on average than that of objects in the middle of the distribution. All these results qualitatively agree well with the YORP‐effect action and may be considered as independent arguments in favor of it.
Intimate partner violence and infant feeding practices in India: a cross‐sectional study
Authors: Zureick‐Brown Sarah , Lavilla Kayla , Yount Kathryn M.
Published: June 2013

Intimate partner violence (IPV) is widespread; yet research is thin and equivocal regarding its potential adverse effects on infant feeding practices. With a national sample of 3552 mothers and infants aged 180 days or younger from the 2005–2006 National Family Health Survey for India, we used logistic regression to estimate the unadjusted and adjusted associations of maternal reported lifetime exposure to any IPV and to physical or sexual IPV with feeding practices at birth and in the prior 24 h. Compared with their unexposed counterparts, mothers exposed to any IPV and to any physical or sexual IPV had higher adjusted odds of giving their infant liquids [aOR 1.32, 95% confidence interval (CI) 1.04–1.66; aOR 1.37, 95% CI 1.08–1.75, respectively], and thus lower adjusted odds of exclusively breastfeeding their infant in the prior 24 h (aOR 0.78, 95% CI 0.62–0.98; aOR 0.74, 95% CI 0.58–0.95). Mothers exposed to physical or sexual IPV also had higher adjusted odds of feeding their infant solids in the prior 24 h (aOR 1.50, 95% CI 1.01–2.23). Exposure to IPV was not significantly associated with breastfeeding immediately after birth or with bottle feeding in the prior 24 h. Perinatal screening for IPV, and addressing IPV and feeding practices in exposed mothers, may improve maternal health and infant nutrition in similar settings.
Carer and staff perspectives on supplementary suckling for treating infant malnutrition: qualitative findings from Malawi
Authors: Lelijveld Natasha , Mahebere‐Chirambo Chawanangwa , Kerac Marko
Published: June 2013

Severe acute malnutrition (SAM) in infants aged <6 months is a major global health problem. Supplementary suckling (SS) is widely recommended as an inpatient treatment technique for infant <6 months SAM. Its aim is to re‐establish effective exclusive breastfeeding. Despite widespread support in guidelines, research suggests that field use of SS is limited in many settings. In this study, we aimed therefore to describe and understand the barriers and facilitating factors to SS as a treatment technique for infant SAM. We conducted qualitative interviews and focus group discussions in a hospital setting in Blantyre, Malawi, with ward staff and caregivers of infants <2 years. We created a conceptual framework based on five major themes identified from the data: (1) motivation; (2) breastfeeding views; (3) practicalities; (4) understanding; and (5) perceptions of hospital‐based medicine. Within each major theme, more setting‐specific subthemes can also be developed. Other health facilities considering SS roll‐out could consider their own barriers and facilitators using our framework; this will facilitate the implementation of SS, improve staff confidence and therefore give SS a better chance of success. Used to shape and guide discussions and inform action plans for implementing SS, the framework has the potential to facilitate SS roll‐out in settings other than Malawi, where this study was conducted. We hope that it will help pave the way to more widespread SS, more research into its use and effectiveness, and a stronger evidence‐base on malnutrition in infants aged <6 months.
Identification of a serine protease inhibitor which causes inclusion vacuole reduction and is lethal to Chlamydia trachomatis
Authors: Gloeckl Sarina , Ong Vanissa A. , Patel Pooja , Tyndall Joel D. A. , Timms Peter , Beagley Kenneth W. , Allan John A. , Armitage Charles W. , Turnbull Lynne , Whitchurch Cynthia B. , Merdanovic Melisa , Ehrmann Michael , Powers James C. , Oleksyszyn Jozef , Verdoes Martijn , Bogyo Matthew , Huston Wilhelmina M.
Published: June 2013

The mechanistic details of the pathogenesis of Chlamydia, an obligate intracellular pathogen of global importance, have eluded scientists due to the scarcity of traditional molecular genetic tools to investigate this organism. Here we report a chemical biology strategy that has uncovered the first essential protease for this organism. Identification and application of a unique CtHtrA inhibitor (JO146) to cultures of Chlamydia resulted in a complete loss of viable elementary body formation. JO146 treatment during the replicative phase of development resulted in a loss of Chlamydia cell morphology, diminishing inclusion size, and ultimate loss of inclusions from the host cells. This completely prevented the formation of viable Chlamydia elementary bodies. In addition to its effect on the human Chlamydia trachomatis strain, JO146 inhibited the viability of the mouse strain, Chlamydia muridarum, both in vitro and in vivo. Thus, we report a chemical biology approach to establish an essential role for Chlamydia CtHtrA. The function of CtHtrA for Chlamydia appears to be essential for maintenance of cell morphology during replicative the phase and these findings provide proof of concept that proteases can be targeted for antimicrobial therapy for intracellular pathogens.
Boreal feather mosses secrete chemical signals to gain nitrogen
Authors: Bay Guillaume , Nahar Nurun , Oubre Matthieu , Whitehouse Martin J. , Wardle David A. , Zackrisson Olle , Nilsson Marie‐Charlotte , Rasmussen Ulla
Published: June 2013

Summary

The mechanistic basis of feather moss–cyanobacteria associations, a main driver of nitrogen (N) input into boreal forests, remains unknown. Here, we studied colonization by Nostoc sp. on two feather mosses that form these associations (Pleurozium schreberi and Hylocomium splendens) and two acrocarpous mosses that do not (Dicranum polysetum and Polytrichum commune). We also determined how N availability and moss reproductive stage affects colonization, and measured N transfer from cyanobacteria to mosses.

The ability of mosses to induce differentiation of cyanobacterial hormogonia, and of hormogonia to then colonize mosses and re‐establish a functional symbiosis was determined through microcosm experiments, microscopy and acetylene reduction assays. Nitrogen transfer between cyanobacteria and Pleurozium schreberi was monitored by secondary ion mass spectrometry (SIMS).

All mosses induced hormogonia differentiation but only feather mosses were subsequently colonized. Colonization on Pleurozium schreberi was enhanced during the moss reproductive phase but impaired by elevated N. Transfer of N from cyanobacteria to their host moss was observed.

Our results reveal that feather mosses likely secrete species‐specific chemo‐attractants when N‐limited, which guide cyanobacteria towards them and from which they gain N. We conclude that this signalling is regulated by N demands of mosses, and serves as a control of N input into boreal forests.
Interactions between sleep disorders and oral diseases
Authors: Huynh NT , Emami E , Helman JI , Chervin RD
Published: June 2013

Dental sleep medicine is a rapidly growing field that is in close and direct interaction with sleep medicine and comprises many aspects of human health. As a result, dentists who encounter sleep health and sleep disorders may work with clinicians from many other disciplines and specialties. The main sleep and oral health issues that are covered in this review are obstructive sleep apnea, chronic mouth breathing, sleep‐related gastroesophageal reflux, and sleep bruxism. In addition, edentulism and its impact on sleep disorders are discussed. Improving sleep quality and sleep characteristics, oral health, and oral function involves both pathophysiology and disease management. The multiple interactions between oral health and sleep underscore the need for an interdisciplinary clinical team to manage oral health‐related sleep disorders that are commonly seen in dental practice.
Why reregulation after the crisis is feeble: Shadow banking, offshore financial centers, and jurisdictional competition
Authors: Rixen Thomas
Published: June 2013

A crucial element in the complex chain of factors that caused the recent financial crisis was the lack of regulation and oversight in the shadow banking sector, which is largely incorporated in offshore financial centers (OFCs), but instead of swift and radical regulatory reform in that sector after the crisis, we observe only incremental and ineffective measures. Why? This paper develops an explanation based on a two‐level game. On the international level, governments are engaged in competition for financial activity. On the domestic level, governments are prone to capture by financial interest groups, but also susceptible to demands for stricter regulation by the electorate. Governments try to square the circle between the conflicting demands by adopting incremental and symbolic, but largely ineffective, reforms. The explanation is put to empirical scrutiny by tracing the regulatory initiatives on shadow banks andOFCsat the international level and within theUnitedStates and theEuropeanUnion, where I focus onFrance,Germany, and theUnitedKingdom.
Politics of private regulation:ISEALand the shaping of transnational sustainability governance
Authors: Loconto Allison , Fouilleux Eve
Published: June 2013

Scholars describe the proliferation of sustainability standards by multi‐stakeholder initiatives as part of an organizational field for sustainability. The aim of this article is to gain a better understanding of the institutionalization process of this global organizational field by focusing on the case of theISEAL Alliance (the global association for sustainability standards). We show howISEALputs specific strategies into place to both reinforce and expand the role and influence of sustainability standards. This institutional entrepreneurship consists primarily of two dimensions: institutionalizing macro‐standards based on a market‐driven and procedural vision of sustainability; and simultaneously legitimating both the tools andISEALthrough internal and external enrolments and entanglements. The characterization ofISEAL's activities in this way brings politics back into the analysis of sustainability standard‐related technical debates and extends our understanding of how the micro‐dynamics within organizational fields are interdependent upon macro‐dynamics outside organizational fields.
A new objective histological scale for studying human photoaged skin
Authors: Kawabata K. , Kobayashi M. , Kusaka‐Kikushima A. , Akasaka E. , Mabuchi T. , Fukui T. , Sugiyama Y. , Takekoshi S. , Miyasaka M. , Ozawa A. , Sakai S.
Published: June 2013

Background

A quantitative understanding of the histological alteration of the skin is important for assessing the severity of photoaging.

Methods

We performed Elastica‐van Gieson staining and immunohistochemistry for decorin on 34 facial skin sections. We evaluated the alteration of collagen fibers and decorin (a modulator for collagen fibrillogenesis), according to the 5 grades of morphological change in elastic fibers that was established by Kligman (1969). The objectivity of a stage (Stages I–VI), which was established in this study, was evaluated using weighted kappa statistical analysis based on the degree of agreement in stage determination by 11 observers using a blind procedure. Correlation between the crow's‐feet‐area wrinkles grades of another 26 women and stages was also analyzed.

Results

The initial alteration of elastic fibers was observed in the deep dermis. Decorin was not detected in very severely altered skin. Based on the combination of changes in the elastic fibers, collagenic fibers, and decorin, skin tissues were categorized into 6 stages according to severity. The statistical analysis showed almost perfect agreement between observers. Significant positive correlation between stages and wrinkle scores was found.

Conclusions

We propose a new objective histological scale that is useful for assessing the severity of photoaging.
Enhanced pathogenicity of biofilm‐negative Staphylococcus epidermidis isolated from platelet preparations
Authors: Hodgson Scott D. , Greco‐Stewart Valerie , Jimenez Celine S. , Sifri Costi D. , Brassinga Ann Karen C. , Ramirez‐Arcos Sandra
Published: June 2013

Background

The platelet (PLT) storage environment triggers the formation of surface‐attached aggregates known as biofilms by the common PLT contaminant Staphylococcus epidermidis. The biofilm matrix is largely composed of polysaccharide intercellular adhesin (PIA) mediated by the icaADBC operon. However, PIA‐negative S. epidermidis has been reported to form biofilms in PLT concentrates (PCs). Since biofilm formation is associated with increased virulence, this study was aimed at determining if PIA‐negative S. epidermidis grown in PCs presents enhanced virulence using the nematode Caenorhabditis elegans as a host model for bacterial pathogenesis.

Study Design and Methods

Biofilm‐positive S. epidermidis ATCC 35984 and 9142, which carry the icaADBC operon, and biofilm‐negative S. epidermidis ATCC 12228 and 9142 ΔicaA were grown in regular media and in PCs and biofilm formation was quantified using a crystal violet assay. The virulence of these strains after passage through PCs was tested using nematode killing assays. Nematode survival was calculated using the Kaplan‐Meier method and statistical differences were determined by log‐rank analysis.

Results

All S. epidermidis strains were able to form biofilms in PCs. Although persistence of a biofilm‐positive phenotype in the biofilm‐negative strains grown in PCs was not observed after passage in regular medium, the virulence of all strains was significantly increased as demonstrated by shortened life spans of the nematodes in C. elegans killing assays.

Conclusion

Our findings highlight the potential of an increased risk of nosocomial infections caused by S. epidermidis in transfusion recipients since PC storage conditions promote biofilm formation, and possibly pathogenicity, of strains traditionally known to be attenuated for virulence.
Measurements of Adiabatic Film and Overall Cooling Effectiveness on a Turbine Vane Pressure Side With a Trench
Authors: Albert Jason E. , Bogard David G.
Published: June 2013

Film cooling performance is typically quantified by separating the external convective heat transfer from the other components of the conjugate heat transfer that occurs in turbine airfoils. However, it is also valuable to assess the conjugate heat transfer in terms of the overall cooling effectiveness, which is a parameter of importance to airfoil designers. In the current study, adiabatic film effectiveness and overall cooling effectiveness values were measured for the pressure side of a simplified turbine vane model with three rows of showerhead cooling at the leading edge and one row of body film cooling holes on the pressure side. This was done by utilizing two geometrically identical models made from different materials. Adiabatic film effectiveness was measured using a very low thermal conductivity material, and the overall cooling effectiveness was measured using a material with a higher thermal conductivity selected such that the Biot number of the model matched that of a turbine vane at engine conditions. The theoretical basis for this matched-Biot number modeling technique is discussed in some detail. Additionally, two designs of pressure side body film cooling holes were considered in this study: a standard design of straight, cylindrical holes and an advanced design of “trenched” cooling holes in which the hole exits were situated in a recessed, transverse trench. This study was performed using engine representative flow conditions, including a coolant-to-mainstream density ratio of DR = 1.4 and a mainstream turbulence intensity of Tu = 20%. The results of this study show that adiabatic film and overall cooling effectiveness increase with blowing ratio for the showerhead and pressure side trenched holes. Performance decreases with blowing ratio for the standard holes due to coolant jet separation from the surface. Both body film designs have similar performance at a lower blowing ratio when the standard hole coolant jets remain attached. Far downstream of the cooling holes both designs perform similarly because film effectiveness decays more rapidly for the trenched holes.
Thermodynamic Study of Advanced Supercritical Carbon Dioxide Power Cycles for Concentrating Solar Power Systems
Authors: Turchi Craig S. , Ma Zhiwen , Neises Ty W. , Wagner Michael J.
Published: June 2013

Supercritical CO2 (s-CO2) operated in a closed-loop Brayton cycle offers the potential of higher cycle efficiency versus superheated or supercritical steam cycles at temperatures relevant for concentrating solar power (CSP) applications. Brayton-cycle systems using s-CO2 have a smaller weight and volume, lower thermal mass, and less complex power blocks versus Rankine cycles due to the higher density of the fluid and simpler cycle design. The simpler machinery and compact size of the s-CO2 process may also reduce the installation, maintenance, and operation cost of the system. In this work we explore s-CO2 Brayton cycle configurations that have attributes that are desirable from the perspective of a CSP application, such as the ability to accommodate dry cooling and achieve greater than 50% efficiency, as specified for the U.S. Department of Energy SunShot goal. Recompression cycles combined with intercooling and/or turbine reheat appear able to hit this efficiency target, even when combined with dry cooling. In addition, the intercooled cycles expand the temperature differential across the primary heat exchanger, which is favorable for CSP systems featuring sensible-heat thermal energy storage.
A New Approach to Stable Optimal Control of Complex Nonlinear Dynamical Systems
Authors: Udwadia Firdaus E.
Published: June 2013

This paper gives a simple approach to designing a controller that minimizes a user-specified control cost for a mechanical system while ensuring that the control is stable. For a user-given Lyapunov function, the method ensures that its time rate of change is negative and equals a user specified negative definite function. Thus a closed-form, optimal, nonlinear controller is obtained that minimizes a desired control cost at each instant of time and is guaranteed to be Lyapunov stable. The complete nonlinear dynamical system is handled with no approximations/linearizations, and no a priori structure is imposed on the nature of the controller. The methodology is developed here for systems modeled by second-order, nonautonomous, nonlinear, differential equations. The approach relies on some recent fundamental results in analytical dynamics and uses ideas from the theory of constrained motion.
Optimization of electron beam induced deposition process for the fabrication of diode-like Pt/SiO2/W devices
Authors: Taurino Antonietta , Farella Isabella , Cola Adriano , Lomascolo Mauro , Quaranta Fabio , Catalano Massimo
Published: June 2013

Pt/SiO2/W devices of controlled size, thickness, and interfaces were fabricated by electron beam induced deposition (EBID) in a focused ion beam (FIB) system, for possible applications as metal-insulator-metal diodes. A systematic study of the deposition parameters used for the fabrication of the devices was carried out by scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmission electron microscopy (TEM). In particular, the morphological and structural quality of the deposited layers, their mutual interfaces, and the thickness of the insulating layer were accurately investigated, being key issues for the application of these multilayer structures as tunneling diodes; to this aim, a novel TEM sample preparation approach was developed, which allows the in situ FIB preparation of ready-to-be-observed multilayer structures; by using this approach, TEM samples can be directly made, by depositing the structures in the same conditions used for the device fabrication, in the correct geometry for the cross sectional investigations and, without any further preparation steps. The capability of the EBID technique to fabricate submicrometer electronic devices with promising electrical properties, such as asymmetry and nonlinearity, was demonstrated.
In vivo dosimetry in brachytherapy
Authors: Tanderup Kari , Beddar Sam , Andersen Claus E. , Kertzscher Gustavo , Cygler Joanna E.
Published: June 2013

In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high‐gradient BT dose distribution and the large range of dose and dose rate. Due to these challenges, the sensitivity and specificity toward error detection has been limited, and IVD has mainly been restricted to detection of gross errors. Given these factors, routine use of IVD is currently limited in many departments. Although the impact of potential errors may be detrimental since treatments are typically administered in large fractions and with high‐gradient‐dose‐distributions, BT is usually delivered without independent verification of the treatment delivery. This Vision 20/20 paper encourages improvements within BT safety by developments of IVD into an effective method of independent treatment verification.
A mass‐conserving 4D XCAT phantom for dose calculation and accumulation
Authors: Williams Christopher L. , Mishra Pankaj , Seco Joao , James Sara St. , Mak Raymond H. , Berbeco Ross I. , Lewis John H.
Published: June 2013

Purpose:

The XCAT phantom is a realistic 4D digital torso phantom that is widely used in imaging and therapy research. However, lung mass is not conserved between respiratory phases of the phantom, making detailed dosimetric simulations and dose accumulation unphysical. A framework is developed to correct this issue by enforcing local mass conservation in the XCAT lung. Dose calculations are performed to assess the implications of neglecting mass conservation, and to demonstrate an application of the phantom to calculate the accumulated delivered dose in an irregularly breathing patient.

Methods:

A displacement vector field (DVF) between each respiratory state and a reference image is generated from the XCAT motion model and its divergence is calculated and used to correct the lung density. A series of phantoms with regular and irregular breathing (based on patient data) are generated and modified to conserve mass. Monte Carlo methods are used to simulate conventional and SBRT treatment delivery. The calculated dose is deformed and accumulated using the DVF. Results from the mass‐conserving and original XCAT are compared. A 4DCT is simulated for the irregularly breathing patient, and a 4DCT‐based dose estimate is compared with the accumulated delivered dose.

Results:

The presented framework successfully conserves mass in the XCAT lung. The spatial distribution of the lung dose was qualitatively changed by the use of a mass conservation in the XCAT; however, the corresponding DVH did not change significantly. The comparison of the delivered dose with the 4DCT‐based prediction shows similar lung metric results, however dose differences of 10% can be seen in some spatial regions.

Conclusions:

The XCAT phantom has been successfully modified so that it conserves lung mass during respiration, enabling it to be used as a tool to perform dose accumulation studies in the lung without relying on deformable image registration. Neglecting mass conservation can result in erroneous spatial distributions of the dose in the lung. Using this tool to simulate patient treatments reveals differences between the planned dose and the calculated delivered dose for the full treatment. The software is freely available from the authors.
In vivo dosimetry in external beam radiotherapy
Authors: Mijnheer Ben , Beddar Sam , Izewska Joanna , Reft Chester
Published: June 2013

In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large‐scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation‐induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors’ opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.
Reducing the Level of Undecaprenyl Pyrophosphate Synthase Has Complex Effects on Susceptibility to Cell Wall Antibiotics
Authors: Lee Yong Heon , Helmann John D.
Published: June 2013

Undecaprenyl pyrophosphate synthase (UppS) catalyzes the formation of the C
55
lipid carrier (UPP) that is essential for bacterial peptidoglycan biosynthesis. We selected here a vancomycin (VAN)-resistant derivative of
Bacillus subtilis
W168 that contains a single-point mutation in the ribosome-binding site of the
uppS
gene designated
uppS1
. Genetic reconstruction experiments demonstrate that the
uppS1
allele is sufficient to confer low-level VAN resistance and causes reduced UppS translation. The decreased level of UppS renders
B. subtilis
slightly more susceptible to many late-acting cell wall antibiotics, including β-lactams, but significantly more resistant to fosfomycin and
d
-cycloserine, antibiotics that interfere with the very early steps of cell wall synthesis. We further show that the
uppS1
allele leads to slightly elevated expression of the σ
M
regulon, possibly helping to compensate for the stress caused by a decrease in UPP levels. Notably, the
uppS1
mutation increases resistance to VAN, fosfomycin, and
d
-cycloserine in wild-type cells, but this effect is greatly reduced or eliminated in a
sigM
mutant background. Our findings suggest that, although UppS is an attractive antibacterial target, incomplete inhibition of UppS function may lead to increased resistance to some cell wall-active antibiotics.
Daptomycin
In Vitro
Activity against Methicillin-Resistant Staphylococcus aureus Is Enhanced by
d
-Cycloserine in a Mechanism Associated with a Decrease in Cell Surface Charge
Authors: Gasch O. , Pillai S. K. , Dakos J. , Miyakis S. , Moellering R. C. , Eliopoulos G. M.
Published: June 2013

The killing activity of daptomycin against an isogenic pair of daptomycin-susceptible and daptomycin-nonsusceptible (DNS) methicillin-resistant
Staphylococcus aureus
(MRSA) strains was enhanced by the addition of certain cell wall agents at 1× MIC. However, when high inocula of the DNS strain were used, no significant killing was observed in our experiments. Cytochrome
c
binding assays revealed
d
-cycloserine as the only agent associated with a reduction in the cell surface charge for both strains at the concentrations used.
Targeting the “Rising DAMP” during a Francisella tularensis Infection
Authors: D'Elia Riccardo V. , Laws Thomas R. , Carter Alun , Lukaszewski Roman , Clark Graeme C.
Published: June 2013

Antibiotic efficacy is greatly enhanced the earlier it is administered following infection with a bacterial pathogen. However, in a clinical setting antibiotic treatment usually commences following the onset of symptoms, which in some cases (e.g., biothreat agents) may be too late. In a BALB/c murine intranasal model of infection for
Francisella tularensis
SCHU S4 infection, we demonstrate during a time course experiment that proinflammatory cytokines and the damage-associated molecular pattern HMGB1 were not significantly elevated above naive levels in tissue or sera until 72 h postinfection. HMGB1 was identified as a potential therapeutic target that could extend the window of opportunity for the treatment of tularemia with antibiotics. Antibodies to HMGB1 were administered in conjunction with a delayed/suboptimal levofloxacin treatment of
F. tularensis
. We found in the intranasal model of infection that treatment with anti-HMGB1 antibody, compared to an isotype IgY control antibody, conferred a significant survival benefit and decreased bacterial loads in the spleen and liver but not the lung (primary loci of infection) 4 days into infection. We also observed an increase in the production of gamma interferon in all tested organs. These data demonstrate that treatment with anti-HMGB1 antibody is beneficial in enhancing the effectiveness of current antibiotics in treating tularemia. Strategies of this type, involving antibiotics in combination with immunomodulatory drugs, are likely to be essential for the development of a postexposure therapeutic for intracellular pathogens.
DARK MATTER INVESTIGATION BY DAMA AT GRAN SASSO
Authors: BERNABEI R. , BELLI P. , d'ANGELO S. , DI MARCO A. , MONTECCHIA F. , CAPPELLA F. , d'ANGELO A. , INCICCHITTI A. , CARACCIOLO V. , CASTELLANO S. , CERULLI R. , DAI C. J. , HE H. L. , MA X. H. , SHENG X. D. , WANG R. G. , YE Z. P.
Published: June 2013

Experimental observations and theoretical arguments at Galaxy and larger scales have suggested that a large fraction of the Universe is composed by Dark Matter particles. This has motivated the DAMA experimental efforts to investigate the presence of such particles in the galactic halo by exploiting a model independent signature and very highly radiopure setup in deep underground. Few introductory arguments are summarized before presenting a review of the present model independent positive results obtained by the DAMA/NaI and DAMA/LIBRA setups at the Gran Sasso National Laboratory of the INFN. Implications and model dependent comparisons with other different kinds of results will be shortly addressed. Some arguments put forward in literature will be confuted.
ON EXOTIC SPHERE FIBRATIONS, TOPOLOGICAL PHASES, AND EDGE STATES IN PHYSICAL SYSTEMS
Authors: LIN HAI , YAU SHING-TUNG
Published: June 2013

We suggest that exotic sphere fibrations can be mapped to band topologies in condensed matter systems. These fibrations can correspond to geometric phases of two double bands or state vector bases with second Chern numbers m+n and -n, respectively. They can be related to topological insulators, magnetoelectric effects, and photonic crystals with special edge states. We also consider time-reversal symmetry breaking perturbations of topological insulator, and heterostructures of topological insulators with normal insulators and with superconductors. We consider periodic TI/NI/TI/NI′ heterostructures, and periodic TI/SC/TI/SC′ heterostructures. They also give rise to models of Weyl semimetals which have thermal and electrical transports.
APPLICATION OF BLOCK THEORY MODELING ON SPATIAL BLOCK TOPOLOGICAL IDENTIFICATION TO ROCK SLOPE STABILITY ANALYSIS
Authors: WANG SHUHONG , NI PENGPENG
Published: June 2013

Rock slopes stability has been one of the fundamental issues facing geotechnical engineering researchers. Due to the pre-existing joints, the intactness of the rock is weakened. The mechanical characteristics are changed correspondingly along with joint-induced stress redistribution within the rock mass if the sliding limit at the joint or part of it is exceeded. In this study, spatial block topological identification techniques are applied to distinguish all blocks cut by 3D finite random or fixed discontinuities. Based on the available photographic information of rock slopes, the sliding forces and the corresponding factor of safety are evaluated through limit equilibrium conditions by the classic block theory. The rock slope stability analysis software, GeoSMA-3D (Geotechnical Structure and Model Analysis), satisfying the requirements of spatial block modeling, joint plane simulation, key block identification and analysis and sliding process display, was developed. The application of such a software on the analysis of a rock slope, which is located near the inlet of Daiyuling No. 1 tunnel on the Zhuanghe–Gaizhou highway networks, was performed. The assessed results were compared with the monitored data to validate the effectiveness of such software.
LONG TIME SOLUTIONS FOR WAVE MAPS WITH LARGE DATA
Authors: WANG JINHUA , YU PIN
Published: June 2013

For (2 + 1)-dimensional wave maps with 𝕊2as the target, we show that for all positive numbers T0> 0 and E0> 0, there exist Cauchy initial data with energy at least E0, so that the solution's life-span is at least [0, T0]. We assume neither symmetry nor closeness to harmonic maps.
MHD BOUNDARY-LAYER FLOW AND HEAT TRANSFER OVER PERMEABLE PLATE WITH CONVECTIVE SURFACE BOUNDARY CONDITION
Authors: IBRAHIM WUBSHET , SHANKER BANDARI
Published: June 2013

A numerical analysis has been carried out to investigate the problem of magnetohydrodynamic (MHD) boundary-layer flow and heat transfer of a viscous incompressible fluid over a fixed plate. Convective surface boundary condition is taken into account for thermal boundary condition. A problem formulation is developed in the presence of thermal radiation, magnetic field and heat source/sink parameters. A similarity transformation is used to reduce the governing boundary-layer equations to couple higher-order nonlinear ordinary differential equations. These equations are numerically solved using Keller–Box method. The effect of the governing parameters such as radiation, Prandtl number, Hartman number, heat source/sink parameter on velocity and temperature profile is discussed and shown by plotting graphs. It is found that the temperature is an increasing function of convective parameter A, radiation and heat source parameters. Besides, the numerical results for the local skin friction coefficient and local Nusselt number are computed and presented in tabular form. Finally a comparison with a previously published results on a special case of the problem has done and shows excellent agreement.
OPTIMIZATION DESIGN FOR A DIELECTRIC ELASTOMER MEMBRANE ACTUATOR
Authors: HE TIANHU , LI YANYAN , LI HUIMIN , CHEN CHENG
Published: June 2013

Due to the large voltage-induced strain along with other unique attributes, dielectric elastromers are being developed as transducers for broad applications in soft robots, adaptive structures, medical devices, energy harvesting and so on. Due to nonlinear large deformation and diverse modes of failure, it has been challenging to model dielectric transducers. This paper focuses on the optimization design of an actuator made of a layer of dielectric elastomer membrane and deformed into an out-of plane axisymmetric shape. The optimization procedure is demonstrated by examining the effect of three designing parameters, originated from the pre-stretch of the membrane, on the performance of the actuator, and by determining the region of allowable states in terms of several typical modes of failure. The equations of state are solved numerically by shooting method and the obtained numerical results indicate that the considered variables are sensitive to the designing parameters and that it is feasible to improve the performance of the actuator by choosing the designing parameters judiciously and averting the modes of failure. The approach presented here provides some guidelines in optimizing such actuators.
Lava–sediment interactions in an Old Red Sandstone basin, NE Scotland
Authors: Hole Malcolm , Jolley David , Hartley Adrian , Leleu Sophie , John Nadine , Ball Michael
Published: June 2013

The early Devonian, Old Red Sandstone succession at St. Cyrus, NE Scotland, includes the exceptional preservation of a lava field and its associated fluvial drainage system. The lava field developed through punctuated eruptions of low-volume pāhoehoe lava, fed by lava tubes. During periods of rapid effusion, groundwater systems were able to transmit most of the recharge in the subsurface, probably by springs, and where there were areas of localized low permeability, ephemeral lakes developed. Subsequent lava flows underwent significant interaction with the partly consolidated lacustrine sediment, forming peperite deposits. Fluvial conglomerates, with extra-basinal clasts, are interbedded with the lava flows. The maturity of the fluvial system suggests a long-lived catchment that transported sediment westwards. Drainage was periodically deflected away from the lava field by the positive topographic relief created by the lava flows, and was re-established during periods of volcanic dormancy. The lava field developed over periods of decades, but the fluvial systems were longer-lived by three or four orders of magnitude. A key feature of this lava field and its drainage is that the establishment and abandonment of fluvial systems immediately adjacent to the lava field was primarily controlled by the eruption dynamics of the magmatic system.
Bin Packing via Discrepancy of Permutations
Authors: Eisenbrand Friedrich , Pálvölgyi Dömötör , Rothvoß Thomas
Published: June 2013

A well-studied special case of
bin packing
is the
3-partition problem
, where
n
items of size > 1/4 have to be packed in a minimum number of bins of capacity one. The famous
Karmarkar-Karp algorithm
transforms a fractional solution of a suitable LP relaxation for this problem into an integral solution that requires at most
O
(log
n
) additional bins.

The
three-permutations-problem
of Beck is the following. Given any three permutations on
n
symbols, color the symbols red and blue, such that in any interval of any of those permutations, the number of red and blue symbols is roughly the same. The necessary difference is called the
discrepancy
.

We establish a surprising connection between bin packing and Beck’s problem: The additive integrality gap of the 3-partition linear programming relaxation can be bounded by the discrepancy of three permutations.

This connection yields an alternative method to establish an
O
(log
n
) bound on the additive integrality gap of the 3-partition. Conversely, making use of a recent example of three permutations, for which a discrepancy of Ω(log
n
) is necessary, we prove the following: The
O
(log
2
n
) upper bound on the additive gap for bin packing with arbitrary item sizes cannot be improved by any technique that is based on rounding up items. This lower bound holds for a large class of algorithms including the Karmarkar-Karp procedure.
Delivering fairness and priority enforcement on asymmetric multicore systems via OS scheduling
Authors: Sáez Juan Carlos , Castro Fernando , Chaver Daniel , Prieto Manuel
Published: June 2013

Symmetric-ISA (instruction set architecture) asymmetric-performance multicore processors (AMPs) were shown to deliver higher performance per watt and area than symmetric CMPs for applications with diverse architectural requirements. So, it is likely that future multicore processors will combine big power-hungry fast cores and small low-power slow ones. In this paper, we propose a novel thread scheduling algorithm that aims to improve the throughput-fairness trade-off on AMP systems. Our experimental evaluation on real hardware and using scheduler implementations on a general-purpose operating system, reveals that our proposal delivers a better throughput-fairness trade-off than previous schedulers for a wide variety of multi-application workloads including single-threaded and multithreaded applications.
Temperature aware workload management in geo-distributed datacenters
Authors: Xu Hong , Feng Chen , Li Baochun
Published: June 2013

Datacenters consume an enormous amount of energy with significant financial and environmental costs. For geo-distributed datacenters, a workload management approach that routes user requests to locations with cheaper and cleaner electricity has been shown to be promising lately. We consider two key aspects that have not been explored in this approach. First, through empirical studies, we find that the energy efficiency of the cooling system depends directly on the ambient temperature, which exhibits a significant degree of geographical diversity. Temperature diversity can be used by workload management to reduce the overall cooling energy overhead. Second, energy consumption comes from not only interactive workloads driven by user requests, but also delay tolerant batch workloads that run at the back-end. The elastic nature of batch workloads can be exploited to further reduce the energy cost. In this work, we propose to make workload management for geo-distributed datacenters
temperature aware
. We formulate the problem as a joint optimization of request routing for interactive workloads and capacity allocation for batch workloads. We develop a distributed algorithm based on an m-block
alternating direction method of multipliers
(ADMM) algorithm that extends the classical 2-block algorithm. We prove the convergence and rate of convergence results under general assumptions. Trace-driven simulations demonstrate that our approach is able to provide 5%--20% overall cost savings for geo-distributed datacenters.
A mean field model for a class of garbage collection algorithms in flash-based solid state drives
Authors: Van Houdt Benny
Published: June 2013

Garbage collection (GC) algorithms play a key role in reducing the write amplification in flash-based solid state drives, where the write amplification affects the lifespan and speed of the drive. This paper introduces a mean field model to assess the write amplification and the distribution of the number of valid pages per block for a class C of GC algorithms. Apart from the Random GC algorithm, class C includes two novel GC algorithms: the d-Choices GC algorithm, that selects d blocks uniformly at random and erases the block containing the least number of valid pages among the $d$ selected blocks, and the Random++ GC algorithm, that repeatedly selects another block uniformly at random until it finds a block with a lower than average number of valid blocks. Using simulation experiments we show that the proposed mean field model is highly accurate in predicting the write amplification (for drives with $N=50000$ blocks). We further show that the d-Choices GC algorithm has a write amplification close to that of the Greedy GC algorithm even for small d values, e.g., d = 10, and offers a more attractive trade-off between its simplicity and its performance than the Windowed GC algorithm introduced and analyzed in earlier studies. The Random++ algorithm is shown to be less effective as it is even inferior to the FIFO algorithm when the number of pages $b$ per block is large (e.g., for b ≥ 64).
Practical conflict graphs for dynamic spectrum distribution
Authors: Zhou Xia , Zhang Zengbin , Wang Gang , Yu Xiaoxiao , Zhao Ben Y. , Zheng Haitao
Published: June 2013

Most spectrum distribution proposals today develop their allocation algorithms that use conflict graphs to capture interference relationships. The use of conflict graphs, however, is often questioned by the wireless community because of two issues. First, building conflict graphs requires significant overhead and hence generally does not scale to outdoor networks, and second, the resulting conflict graphs do not capture accumulative interference. In this paper, we use large-scale measurement data as ground truth to understand just how severe these issues are in practice, and whether they can be overcome. We build "practical" conflict graphs using measurement-calibrated propagation models, which remove the need for exhaustive signal measurements by interpolating signal strengths using calibrated models. These propagation models are imperfect, and we study the impact of their errors by tracing the impact on multiple steps in the process, from calibrating propagation models to predicting signal strength and building conflict graphs. At each step, we analyze the introduction, propagation and final impact of errors, by comparing each intermediate result to its ground truth counterpart generated from measurements. Our work produces several findings. Calibrated propagation models generate location-dependent prediction errors, ultimately producing conservative conflict graphs. While these "estimated conflict graphs" lose some spectrum utilization, their conservative nature improves reliability by reducing the impact of accumulative interference. Finally, we propose a graph augmentation technique that addresses any remaining accumulative interference, the last missing piece in a practical spectrum distribution system using measurement-calibrated conflict graphs.