bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Urbanization and the Growing Threat of Violence and Conflict: A 21st Century Crisis
Authors: Patel Ronak B. , Burkle Frederick M.
Published: May 2012

As the global population is concentrated into complex environments, rapid urbanization increases the threat of conflict and insecurity. Many fast-growing cities create conditions of significant disparities in standards of living, which set up a natural environment for conflict over resources. As urban slums become a haven for criminal elements, youth gangs, and the arms trade, they also create insecurity for much of the population. Specific populations, such as women, migrants, and refugees, bear the brunt of this lack of security, with significant impacts on their livelihoods, health, and access to basic services. This lack of security and violence also has great costs to the general population, both economic and social. Cities have increasingly become the battlefield of recent conflicts as they serve as the seats of power and gateways to resources. International agencies, non-governmental organizations, and policy-makers must act to stem this tide of growing urban insecurity. Protecting urban populations and preventing future conflict will require better urban planning, investment in livelihood programs for youth, cooperation with local communities, enhanced policing, and strengthening the capacity of judicial systems.

Patel RB, Burkle FM Jr. Rapid urbanization and the growing threat of violence and conflict: a 21st century crisis. Prehosp Disaster Med. 2012;27(2):1-4.
Value Generation and Health Reform in Emergency Medical Services
Authors: Munk Marc-David
Published: May 2012

American Emergency Medical Services (EMS) agencies largely have been untouched by the dramatic health care reform efforts underway, although change seems imminent. Clarifying the role of the modern EMS system, and the yardsticks used to evaluate its performance, will be a challenge.

This paper introduces the concept of value (or outcomes to cost ratio) in EMS, and offers value assessment as a means by which reform decisions can be framed. The best reform decisions are those that optimize both costs and outcomes. This includes: (1) attention to the patient experience; (2) disallowing the provision of unhelpful, harmful or disproven prehospital care; and (3) expanding patient dispositions beyond Emergency Departments. Costs of care will need to be tracked carefully and acknowledged. Value generation should serve as the goal of ongoing EMS reform efforts.

Munk MD. Value generation and health reform in emergency medical services. Prehosp Disaster Med. 2012;27(2):1-4.
Obsessive Compulsive Drinking Scale (OCDS-G): Psychometrische Kennwerte alkoholabhängiger Patienten in der Schweiz
Authors: Burren Yuliya , Wapp Manuela , Seitz Andrea , Ballinari Pietro , Moggi Franz
Published: May 2012

Fragestellung: Der Erfassung subjektiv empfundenen Alkoholverlangens (Craving) kommt eine wichtige Rolle in der Einschätzung der Rückfallgefährdung zu. Mann & Ackermann (2000) haben an einer deutschen Stichprobe Reliabilität und Validität der Obsessive Compulsive Drinking Scale (OCDS-G; Anton, Moak & Latham, 1995 ) vorgestellt. Um deren Verwendbarkeit in der deutschsprachigen Schweiz zu überprüfen, wurden die psychometrischen Kennwerte der OCDS-G an einer Schweizer Stichprobe alkoholabhängiger Patienten untersucht. Methodik: Insgesamt 153 Patienten füllten eine Woche nach ihrem Eintritt in ein stationäres, qualifiziertes Entzugsprogramm die OCDS-G aus. Davon füllten 30 Patienten die OCDS-G erneut vor Austritt aus. Ergebnisse: Die beiden Unterskalen „Gedanken“ und „Handlungen“ konnten durch die Hauptkomponentenanalyse zwar knapp bestätigt werden und zwei Drittel der Varianz erklären, aber die Ergebnisse der konfirmatorischen Faktorenanalyse legen eher eine Einfaktorenlösung nahe. Für die Gesamtskala ergab sich eine sehr gute innere Konsistenz, gute Test-Retest-Reliabilität und substanzielle Korrelationen mit dem Schweregrad der Abhängigkeit und deren Konsequenzen. Schlussfolgerungen: Für die OCDS-G ergeben sich in einer Deutschschweizer Stichprobe alkoholabhängiger Patienten gute psychometrische Kennwerte, so dass sie sich auch für die Anwendung in Klinik und Forschung sowie für internationale Vergleiche (z. B. Wirksamkeits- und Verlaufsstudien) eignet.
Cannabiskonsum im Studium
Authors: Pauly Anne , Klein Michael
Published: May 2012

Ziel: Der vorliegende Beitrag beschäftigt sich mit der Frage, warum Studierende in weit höherem Umfang Cannabis konsumieren als die nicht studierende Bevölkerung. Methodik: Im Rahmen der vom BMBF geförderten Studie „Suchtverhalten von Studierenden“, die von September 2002 bis Februar 2004 am Deutschen Institut für Sucht und Präventionsforschung (ehemals: Forschungsschwerpunkt Sucht) der Katholischen Hochschule NRW durchgeführt wurde, wurden epidemiologische Daten zum Substanzkonsum bei 2.624 Studierenden aus NRW im Alter von 19 bis 30 Jahren erhoben. Zwei Befragungsmethoden (Fragebogen und anschließendes persönliches Interview) erbringen Erkenntnisse unter anderem zu den Substanzkonsumaspekten einer Querschnittsstichprobe von Studierenden an Universitäten und Fachhochschulen an den Studienstandorten Köln, Aachen und Paderborn. Ergebnisse: Insgesamt bietet die vorliegende Studie einen Überblick, wie Studierende im Vergleich mit der gleichaltrigen, nicht studierenden Bevölkerung Suchtmittel konsumieren und wie sich Suchtprobleme auf das Leben und das Studium auswirken. Die Daten weisen auf zum Teil gravierende Unterschiede zwischen Studierenden und Nicht-Studierenden der gleichen Altersgruppe hin. Die Prävalenzerhebung des Alkohol- und Drogenkonsums unter Nicht-Studierenden wurde durch die Reanalyse vorhandener früherer Datensätze (Drogenaffinitätsstudie BZgA, 2001; Repräsentativerhebung zum Gebrauch psychoaktiver Substanzen bei Erwachsenen in Deutschland IFT, Kraus & Bauernfeind, 1998 ) durchgeführt. Nach der Darstellung der Datenlage und methodischen Hinweisen erfolgen in der Diskussion anhand des Modells der Kritischen Lebensereignisse (vgl. Filipp, 1990 ) Überlegungen, warum Studierende riskanter konsumieren.
Psychometric Properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED) in Cypriot Children and Adolescents
Authors: Essau Cecilia A. , Anastassiou-Hadjicharalambous Xenia , Muñoz Luna C.
Published: May 2012

The Screen for Child Anxiety Related Emotional Disorders (SCARED) is a 41-item self-report questionnaire that measures symptoms of DSM-IV anxiety disorders (panic/somatic, generalized anxiety, separation anxiety, social phobia) and school phobia in children and adolescents. This study examined the psychometric properties of the Greek translation of SCARED in a large community sample of children and adolescents (N = 1,072), aged 12 to 17 years, in the nonoccupied territory of Cyprus. A subsample of these participants (N = 108) was retested an average of 8 weeks after the initial assessment. The SCARED demonstrated high internal consistency (α = .92) and test-retest reliability (r = .84, over 8 weeks). The SCARED total scores correlated significantly with the internalizing factor of the Youth Self-Report, the Columbia Impairment Scale, and with the emotional subscale of the Strength and Difficulty Questionnaire. Confirmatory factor analyses revealed the same five-factor structure as the original SCARED. The SCARED proved to be a reliable and valid measure of anxiety symptoms in the Cypriot context.
Impact of vegetation on land‐atmosphere coupling strength and its implication for desertification mitigation over East Asia
Authors: Myoung Boksoon , Choi Yong‐Sang , Choi Suk‐Jin , Park Seon Ki
Published: May 2012

Desertification of the East Asian drylands and the consequent dust transport have been serious concerns for adjacent Asian countries as well as the western United States. Tree planting has been considered one applicable strategy to mitigate the desertification. However, the desired effect of the tree planting would not be brought to fruition unless the newly planted trees change the coupling characteristics between the land and the atmosphere. Based on this perception, we attempt to clarify the effects of vegetation on the coupling strength between the atmosphere and land surface, and we suggest the most efficient areas of tree planting for desertification mitigation in East Asia. Using regional vegetation‐atmosphere coupled model simulations, coupling strength with and without vegetation was computed and compared with each other. An increased vegetation fraction reduces the coupling strength in June, July, and August (JJA), primarily due to decreased evapotranspiration variability. This effect is pronounced over the Manchurian Plains and the highly populated areas of Beijing and Tianjin. The reduced coupling strength tends to weaken feedback between soil moisture and precipitation as a maintenance mechanism of warm season droughts in the midlatitudes and subsequently decrease the probability of droughts, a finding that is reflected in the enhanced JJA mean soil moisture. However, some drylands like the eastern edges of the Gobi desert present marginal or even opposite changes in coupling strength, meaning a limited effect of vegetation on relieving droughts. Therefore, given limited financial and human resources, acupuncture‐like afforestation, i.e., concentrated tree planting in a particular region where the coupling strength can be substantially reduced by vegetation, is an effective strategy to secure long‐standing desertification mitigation.
California reanalysis downscaling at 10 km using an ocean‐atmosphere coupled regional model system
Authors: Li Haiqin , Kanamitsu Masao , Hong Song‐You
Published: May 2012

A fully coupled regional downscaling system based on the Regional Spectral Model (RSM) for atmosphere and the Regional Ocean Modeling System (ROMS) for the ocean was developed for the purpose of downscaling observed analysis or global model outputs. The two models share the same grid and resolution with efficient parallelization through the use of dual message passing interfaces. Coupled downscaling was performed using historical Simple Ocean Data Assimilation (SODA) oceanic reanalysis and NCEP/DOE (R‐2) atmospheric reanalysis in order to study the impact of coupling on the regional scale atmospheric analysis. The results were subsequently compared with the uncoupled downscaling forced by the prescribed observed sea surface temperature (SST). The coupled experiment yielded the SST and ocean current with realistic small‐scale oceanic features that are almost absent in the oceanic reanalysis. Upwelling over the California coast is well resolved and comparable to findings obtained from high‐resolution observations. The coupling impact on the atmospheric circulation mainly modulates the near surface atmospheric variables when compared to the simulation conducted without coupling. The duration of the Catalina Eddy detected in the coupled experiment increased by about 6.5% when compared to that in the uncoupled experiment. The offshore land breeze is enhanced by about 10%, whereas the change in the onshore sea breeze is very small during the summer.
Assessing the greenhouse impact of natural gas
Authors: Cathles L. M.
Published: May 2012

The global warming impact of substituting natural gas for coal and oil is currently in debate. We address this question here by comparing the reduction of greenhouse warming that would result from substituting gas for coal and some oil to the reduction which could be achieved by instead substituting zero carbon energy sources. We show that substitution of natural gas reduces global warming by 40% of that which could be attained by the substitution of zero carbon energy sources. At methane leakage rates that are ∼1% of production, which is similar to today's probable leakage rate of ∼1.5% of production, the 40% benefit is realized as gas substitution occurs. For short transitions the leakage rate must be more than 10 to 15% of production for gas substitution not to reduce warming, and for longer transitions the leakage must be much greater. But even if the leakage was so high that the substitution was not of immediate benefit, the 40%‐of‐zero‐carbon benefit would be realized shortly after methane emissions ceased because methane is removed quickly from the atmosphere whereas CO2 is not. The benefits of substitution are unaffected by heat exchange to the ocean. CO2 emissions are the key to anthropogenic climate change, and substituting gas reduces them by 40% of that possible by conversion to zero carbon energy sources. Gas substitution also reduces the rate at which zero carbon energy sources must eventually be introduced.
Formation of magnetite‐enriched zones in and offshore of a mesotidal estuarine lagoon: An environmental magnetic study of Tauranga Harbour and Bay of Plenty, New Zealand
Authors: Badesab Firoz , von Dobeneck Tilo , Bryan Karin R. , Müller Hendrik , Briggs Roger M. , Frederichs Thomas , Kwoll Eva
Published: May 2012

Magnetic iron minerals are widespread and indicative sediment constituents in estuarine, coastal and shelf systems. We combine environmental magnetic, sedimentological and numerical methods to identify magnetite‐enriched placer‐like zones in a complex coastal system and delineate their formation mechanisms. Magnetic susceptibility and remanence measurements on 245 surficial sediment samples collected in and around Tauranga Harbour, the largest barrier‐enclosed tidal estuary of New Zealand, reveal several discrete enrichment zones controlled by local hydrodynamic conditions. Active magnetite enrichment takes place in tidal channels, which feed into two coast‐parallel nearshore magnetite‐enriched belts centered at water depths of 6–10 m and 10–20 m. A close correlation between magnetite content and magnetic grain size was found, where higher susceptibility values are associated within coarser magnetic crystal sizes. Two key mechanisms for magnetite enrichment are identified. First, tide‐induced residual currents primarily enable magnetite enrichment within the estuarine channel network. A coast‐parallel, fine sand magnetite enrichment belt in water depths of less than 10 m along the barrier island has a strong decrease in magnetite content away from the southern tidal inlet and is apparently related to active coast‐parallel transport combined with mobilizing surf zone processes. A second, less pronounced, but more uniform magnetite enrichment belt at 10–20 m water depth is composed of non‐mobile, medium‐coarse‐grained relict sands, which have been reworked during post‐glacial sea level transgression. We demonstrate the potential of magnetic methods to reveal and differentiate coastal magnetite enrichment patterns and investigate their formative mechanisms.
Exploring the intermediates of photochemical CO2reduction: reaction of Re(dmb)(CO)3 COOH with CO2
Authors: Agarwal Jay , Sanders Brian C. , Fujita Etsuko , Schaefer III Henry F. , Harrop Todd C. , Muckerman James T.
Published: May 2012

An explicit pathway for the reactivity of CO2 with Re(dmb)(CO)3COOH is proposed from theoretical studies and further supported by experiment.
Molecular modification of coumarin dyes for more efficient dye sensitized solar cells
Authors: Sánchez-de-Armas Rocío , San-Miguel Miguel A. , Oviedo Jaime , Sanz Javier Fdez.
Published: May 2012

In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (–OH, –NH2, and –OCH3) and two different substituents with steric effect: –CH2–CH2–CH2– and –CH2–HC=CH–. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes. The introduction of a –NH2 group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of –CH2–CH2–CH2– does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, –CH2–HC=CH– produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.
High-output-power densities from molecular beam epitaxy grown n- and p-type PbTeSe-based thermoelectrics via improved contact metallization
Authors: Goodhue W. G. , Reeder R. E. , Vineis C. J. , Calawa S. D. , Dauplaise H. M. , Vangala S. , Walsh M. P. , Harman T. C.
Published: May 2012

Electrical power densities of up to 33 W/cm2 and up to 12 W/cm2 were obtained for n-type and p-type PbTeSe-based stand-alone thermoelectric devices, respectively, at modest temperature gradients of ∼200 °C (Tcold = 25 °C). These large power densities were enabled by greatly improving electrical contact resistivities in the thermoelectric devices. Electrical contacts with contact resistivities as low as 3.9 × 10−6 Ω cm2 and 4.0 × 10−6 Ω cm2 for n- and p-type telluride-based- materials, respectively, were developed by investigating several metallization schemes and contact layer doping/alloy combinations, in conjunction with a novel contact application process. This process exposes heated semiconductor surfaces to an atomic hydrogen flux under high vacuum for surface cleaning (oxide and carbon removal), followed immediately by an in-situ electron-beam evaporation of the metal layers.
Localization and electrical transport in onion-like carbon based composites
Authors: Macutkevic J. , Adomavicius R. , Krotkus A. , Banys J. , Kuznetsov V. , Moseenkov S. , Romanenko A. , Shenderova O.
Published: May 2012

Electrical transport properties of onion-like carbon (OLC) based composites over a wide (20 Hz–4 THz) frequency range are reported. The dependencies of dc conductivity on temperature can be approximated by the Mott law for one-dimensional variable range hopping below 130 K and by the typical law for fluctuation induced tunneling within the range of 130–300 K. The critical frequency at low temperatures also decreases according to the Mott law for one-dimensional variable range hopping. It was demonstrated that OLC annealing temperature plays a high role on the dielectric and electrical properties of composites at low temperatures. In the terahertz frequency range, the main contribution to the complex electrical conductivity is due to the phonon contribution while the contribution from hopping conduction vanishes at these frequencies.
Magnetohydrodynamic spin waves in degenerate electron-positron-ion plasmas
Authors: Mushtaq A. , Maroof R. , Ahmad Zulfiaqr , Qamar A.
Published: May 2012

Low frequency magnetosonic waves are studied in magnetized degenerate electron-positron-ion plasmas with spin effects. Using the fluid equations of magnetoplasma with quantum corrections due to the Bohm potential, temperature degeneracy, and spin magnetization energy, a generalized dispersion relation for oblique magnetosonic waves is derived. Spin effects are incorporated via spin force and macroscopic spin magnetization current. For three different values of angle θ, the generalized dispersion relation is reduced to three different relations under the low frequency magnetohydrodynamic assumptions. It is found that the effect of quantum corrections in the presence of positron concentration significantly modifies the dispersive properties of these modes. The importance of the work relevant to compact astrophysical bodies is pointed out.
Improved multiferroic properties in Sm-doped BiFeO3 thin films deposited using chemical solution deposition method
Authors: Singh S. K. , Tomy C. V. , Era T. , Itoh M. , Ishiwara H.
Published: May 2012

Sm-substituted (0% to 10%) BiFeO3 thin films were fabricated by chemical solution deposition on Pt/Ti/SiO2/Si substrates. X-ray diffraction analysis revealed that no secondary phase appeared even if Bi atoms were substituted with Sm atoms up to 10 at. %. 7.5 at. % Sm-substituted films show improved electrical properties and substitution was effective in improving the coercive field in the films. Sm-substitution shows improved ferroelectric as well as magnetic properties of the films. There is a noticeable reduction in the leakage current density (10−4 A/cm2) and increase in the polarization (70 μC/cm2) when the Sm concentration is kept around 7.5%. The magnetic moment obtained from the saturated magnetization curves shows a value of 0.3 μB/Fe compared to 0.04 μB/Fe for the parent compound. The results are important since it increases the potential of the material as a multiferroic compound.
Deposition of stress free c-axis oriented LiNbO3 thin film grown on (002) ZnO coated Si substrate
Authors: Shandilya Swati , Tomar Monika , Gupta Vinay
Published: May 2012

C-axis oriented lithium niobate thin films have been deposited on Si substrate using RF sputtering technique. A thin buffer layer of c-axis (002) oriented ZnO on Si substrate has been used as a nucleating layer to promote the growth of (006) oriented LiNbO3 film. The processing gas composition and pressure are found to be very critical in obtaining stress free LiNbO3 film having desired (006) orientation. The LiNbO3 films deposited under unique combination of sputtering pressure (10 mTorr) and argon percentage (80%) in reactive gas (Ar + O2) composition become almost stress free having lattice parameter (1.3867 Å) close to the bulk value. The observed variation in the structural properties and optical phonon modes observed by Raman spectroscopic studies of the oriented LiNbO3 thin film with stress has been correlated with growth kinetics.
Metamaterial metal-based bolometers
Authors: Niesler F. B. P. , Gansel J. K. , Fischbach S. , Wegener M.
Published: May 2012

We demonstrate metamaterial metal-based bolometers, which take advantage of resonant absorption in that a spectral and/or polarization filter can be built into the bolometer. Our proof-of-principle gold-nanostructure-based devices operate around 1.5 μm wavelength and exhibit room-temperature time constants of about 134 μs. The ultimate detectivity is limited by Johnson noise, enabling room-temperature detection of 1 nW light levels within 1 Hz bandwidth. Graded bolometer arrays might allow for integrated spectrometers with several octaves bandwidth without the need for gratings or prisms and for integrated polarization analysis without external polarization optics.
Laser-driven proton acceleration using a conical nanobrush target
Authors: Yu Jinqing , Zhao Zongqing , Jin Xiaolin , Wu Fengjuan , Yan Yonghong , Zhou Weimin , Cao Leifeng , Li Bin , Gu Yuqiu
Published: May 2012

A conical nanobrush target is proposed to improve the total proton energy-conversion efficiency in proton beam acceleration and investigated by two-dimensional particle-in-cell (2D-PIC) simulations. Results indicate a significant enhancement of the number and energies of hot electrons through the target rear side of the conical nanobrush target. Compared with the plain target, the field increases several times. We observe enhancements of the average proton energy and total laser-proton energy conversion efficiency of 105%. This enhancement is attributed to both nanobrush and conical configurations. The proton beam is well collimated with a divergence angle less than 28°. The proposed target may serve as a new method for increasing laser to proton energy-conversion efficiency.
Enhancement of magnetocaloric properties near room temperature in Ga-doped Ni50Mn34.5In15.5 Heusler-type alloy
Authors: Takeuchi A. Y. , Guimarães C. E. , Passamani E. C. , Larica C.
Published: May 2012

A martensitic Ni50Mn34.5In15.5 Heusler-type alloy doped with Ga was studied by x-ray diffractometry and magnetization measurements. Ga-doping does not affect the austenitic phase transition but shifts the martensitic phase transformation towards room temperature, producing an enhancement of the magnetic entropy change (ΔSM) in that temperature region. Large ΔSM-values in the Ga-doped samples are attained for an applied field of 30 kOe as opposed to the field of 50 kOe commonly found for the un-doped cases. These effects (enhancement of ΔSM-values, shift to temperatures close to 300 K, and large ΔSM-values at lower applied fields) make the Ga-doped Ni50Mn34.5In15.5 Heusler-type alloys good candidates for technological applications as a solid refrigerant.
Fiber-optic liquid level sensor based on coupling optical path length variation
Authors: Nath Pabitra , Kumarjit Singh Hidam , Tiwari Dhananjay , Basumatry Tenisen
Published: May 2012

The concept for a new and simple fiber-optic liquid level sensor is presented and experimental results are shown to demonstrate the principle. The sensing principle is based on light intensity modulation when rising and falling mode of liquid level causes coupling optical path distance variation between two optical fibers. Near continuous mode of liquid level variation could be monitored with resolution as low as 1 mm can be measured in the length scale of 25 cm.
Surface sensing behavior and band edge properties of AgAlS2: Experimental observations in optical, chemical, and thermoreflectance spectroscopy
Authors: Ho Ching-Hwa , Pan Chia-Chi
Published: May 2012

Optical examination of a chaocogenide compound AgAlS2 which can spontaneously transfer to a AgAlO2 oxide has been investigated by thermoreflectance (TR) spectroscopy herein. The single crystals of AgAlS2 were grown by chemical vapor transport (CVT) method using ICl3 as a transport agent sealed in evacuated quartz tubes. The as-grown AgAlS2 crystals essentially possess a transparent and white color in vacuum. The crystal surface of AgAlS2 becomes darkened and brownish when putting AgAlS2 into atmosphere for reacting with water vapor or hydrogen gas. Undergoing the chemical reaction process, oxygen deficient AgAlO2-2x with brownish and reddish-like color on surface of AgAlS2 forms. The transition energy of deficient AgAlO2-2x was evaluated by TR experiment. The value was determined to be ∼2.452 eV at 300 K. If the sample is kept dry and moved away from moisture, AgAlS2 crystal can stop forming more deficient AgAlO2-2x surface oxides. The experimental TR spectra for the surface-reacted sample show clearly two transition features at EW=2.452 eV for deficient AgAlO2-2x and EU=3.186 eV for AgAlS2, respectively. The EU transition belongs to direct band-edge exciton of AgAlS2. Alternatively, for surface-oxidation process of AgAlS2 lasting for a long time, a AgAlO2 crystal with yellowish color will eventually form. The TR measurements show mainly a ground-state band edge exciton of ${\rm E}{}_{{\rm OX}}^{\rm 1}$E OX 1 detected for AgAlO2. The energy was determined to be ${\rm E}{}_{{\rm OX}}^{\rm 1}$E OX 1=2.792 eV at 300 K. The valence-band electronic structure of AgAlS2 has been detailed characterized using polarized-thermoreflectance (PTR) measurements in the temperature range between 30 and 340 K. Physical chemistry behaviors of AgAlS2 and AgAlO2 have been comprehensively studied via detailed analyses of PTR and TR spectra. Based on the experimental analyses, optical and chemical behaviors of the AgAlS2 crystals under atmosphere are realized. A possible optical-detecting scheme for using AgAlS2 as a humidity sensor has also been proposed.
Development of a proof-of-concept hybrid electric fuel cell vehicle
Authors: Strahs Peter , Weaver Jordan , Breziner Luis , Garant Christophe , Shaffer Keith , Diloyan Georgiy , Hutapea Parsaoran
Published: May 2012

The demand for fuel-efficient vehicles is on the rise due to the rising costs of gasoline and increasing environmental concerns. Zero tailpipe emission vehicles that run on electricity or hydrogen lack infrastructure to have a significant impact, while some successful hybrid electric vehicles achieve little more than eliminating idling time and capturing small percentages of braking energy. One possible solution that addresses these problems is a series hybrid electric powertrain with range extending capabilities using hydrogen and gasoline. The described powertrain was designed and modeled to simulate performance and fuel economy. In order to further prove the concept of this design, a 2000 Audi TT was converted to a plug-in hybrid electric vehicle with a 90 kW AC electric motor, LiFePO4 batteries, 10 kW internal combustion generator, and 5 kW hydrogen PEM fuel cell. Using the U.S. Environmental Protection Agency’s standard city and highway driving tests, the vehicle has a simulated increase in fuel economy from 20/29 miles per gallon, respectively, to 230/173 miles per gallon gasoline equivalent.
Microfluidic device for studying cell migration in single or co-existing chemical gradients and electric fields
Authors: Li Jing , Zhu Ling , Zhang Michael , Lin Francis
Published: May 2012

Cell migration is involved in physiological processes such as wound healing, host defense, and cancer metastasis. The movement of various cell types can be directed by chemical gradients (i.e., chemotaxis). In addition to chemotaxis, many cell types can respond to direct current electric fields (dcEF) by migrating to either the cathode or the anode of the field (i.e., electrotaxis). In tissues, physiological chemical gradients and dcEF can potentially co-exist and the two guiding mechanisms may direct cell migration in a coordinated manner. Recently, microfluidic devices that can precisely configure chemical gradients or dcEF have been increasingly developed and used for chemotaxis and electrotaxis studies. However, a microfluidic device that can configure controlled co-existing chemical gradients and dcEF that would allow quantitative cell migration analysis in complex electrochemical guiding environments is not available. In this study, we developed a polydimethylsiloxane-based microfluidic device that can generate better controlled single or co-existing chemical gradients and dcEF. Using this device, we showed chemotactic migration of T cells toward a chemokine CCL19 gradient or electrotactic migration toward the cathode of an applied dcEF. Furthermore, T cells migrated more strongly toward the cathode of a dcEF in the presence of a competing CCL19 gradient, suggesting the higher electrotactic attraction. Taken together, the developed microfluidic device offers a new experimental tool for studying chemical and electrical guidance for cell migration, and our current results with T cells provide interesting new insights of immune cell migration in complex guiding environments.
Identification and characterisation of a novel class I endo-β-1,3-glucanase regulated by salicylic acid, ethylene and fungal pathogens in strawberry
Authors: Zamora Martín G. Martínez , Bournonville Carlos Grellet , Castagnaro Atilio P. , Ricci Juan C. Díaz
Published: May 2012

The identification of a full length cDNA encoding an endo-β-1,3-glucanase (FaOGBG-5) from strawberry (Fragaria × ananassa Duch) is reported. The analysis of the deduced amino acid sequence of FaOGBG-5 showed that it shares typical structural features and a high degree of identity with other plant β-1,3-glucanases of the class I. The expression of FaOGBG-5 in plants infected with a virulent isolate of Colletotrichum acutatum and an avirulent isolate of Colletotrichum fragariae was examined. Induction of expression was observed with both pathogens but exhibited a delayed high expression with the virulent one. Additionally, the accumulation of FaOGBG-5 transcripts was also observed after treatments with the stress related hormones salicylic acid and ethylene. Results obtained suggest that the β-1,3-glucanase encoded by FaOGBG-5 may be implicated in plant defence against biotic and abiotic stress.
Critical role of soluble amyloid-β for early hippocampal hyperactivity in a mouse model of Alzheimer’s disease
Authors: Busche Marc Aurel , Chen Xiaowei , Henning Horst A. , Reichwald Julia , Staufenbiel Matthias , Sakmann Bert , Konnerth Arthur
Published: May 2012

Alzheimer’s disease (AD) is characterized by a progressive dysfunction of central neurons. Recent experimental evidence indicates that in the cortex, in addition to the silencing of a fraction of neurons, other neurons are hyperactive in amyloid-β (Aβ) plaque-enriched regions. However, it has remained unknown what comes first, neuronal silencing or hyperactivity, and what mechanisms might underlie the primary neuronal dysfunction. Here we examine the activity patterns of hippocampal CA1 neurons in a mouse model of AD in vivo using two-photon Ca
2+
imaging. We found that neuronal activity in the plaque-bearing CA1 region of older mice is profoundly altered. There was a marked increase in the fractions of both silent and hyperactive neurons, as previously also found in the cortex. Remarkably, in the hippocampus of young mice, we observed a selective increase in hyperactive neurons already before the formation of plaques, suggesting that soluble species of Aβ may underlie this impairment. Indeed, we found that acute treatment with the γ-secretase inhibitor LY-411575 reduces soluble Aβ levels and rescues the neuronal dysfunction. Furthermore, we demonstrate that direct application of soluble Aβ can induce neuronal hyperactivity in wild-type mice. Thus, our study identifies hippocampal hyperactivity as a very early functional impairment in AD transgenic mice and provides direct evidence that soluble Aβ is crucial for hippocampal hyperactivity.
Homeoprotein hhex-induced conversion of intestinal to ventral pancreatic precursors results in the formation of giant pancreata in
Xenopus
embryos
Authors: Zhao Hui , Han Dandan , Dawid Igor B. , Pieler Tomas , Chen Yonglong
Published: May 2012

Liver and ventral pancreas develop from neighboring territories within the endoderm of gastrulae.
ventral pancreatic precursor 1 (vpp1)
is a marker gene that is differentially expressed in a cell population within the dorsal endoderm in a pattern partially overlapping with that of
hematopoietically expressed homeobox
(
hhex
) during gastrulation. In tail bud embryos,
vpp1
expression specifically demarcates two ventral pancreatic buds, whereas
hhex
expression is mainly restricted to the liver diverticulum. Ectopic expression of a critical dose of
hhex
led to a greatly enlarged
vpp1
-positive domain and, subsequently, to the formation of giant ventral pancreata, putatively by conversion of intestinal to ventral pancreatic precursor cells. Conversely, antisense morpholino oligonucleotide-mediated knockdown of hhex resulted in a down-regulation of
vpp1
expression and a specific loss of the ventral pancreas. Furthermore, titration of hhex with a dexamethasone-inducible hhex-VP16GR fusion construct suggested that endogenous hhex activity during gastrulation is essential for the formation of ventral pancreatic progenitor cells. These observations suggest that, beyond its role in liver development,
hhex
controls specification of a
vpp1
-positive endodermal cell population during gastrulation that is required for the formation of the ventral pancreas.
INVOLVED IN DE NOVO 2-containing complex involved in RNA-directed DNA methylation in
Arabidopsis
Authors: Ausin Israel , Greenberg Maxim V. C. , Simanshu Dhirendra K. , Hale Christopher J. , Vashisht Ajay A. , Simon Stacey A. , Lee Tzuu-fen , Feng Suhua , Española Sophia D. , Meyers Blake C. , Wohlschlegel James A. , Patel Dinshaw J. , Jacobsen Steven E.
Published: May 2012

At least three pathways control maintenance of DNA cytosine methylation in
Arabidopsis thaliana
. However, the RNA-directed DNA methylation (RdDM) pathway is solely responsible for establishment of this silencing mark. We previously described INVOLVED IN DE NOVO 2 (IDN2) as being an RNA-binding RdDM component that is required for DNA methylation establishment. In this study, we describe the discovery of two partially redundant proteins that are paralogous to IDN2 and that form a stable complex with IDN2 in vivo. Null mutations in both genes, termed
IDN2-LIKE 1
and
IDN2-LIKE 2
(
IDNL1
and
IDNL2
), result in a phenotype that mirrors, but does not further enhance, the
idn2
mutant phenotype. Genetic analysis suggests that this complex acts in a step in the downstream portion of the RdDM pathway. We also have performed structural analysis showing that the IDN2 XS domain adopts an RNA recognition motif (RRM) fold. Finally, genome-wide DNA methylation and expression analysis confirms the placement of the IDN proteins in an RdDM pathway that affects DNA methylation and transcriptional control at many sites in the genome. Results from this study identify and describe two unique components of the RdDM machinery, adding to our understanding of DNA methylation control in the
Arabidopsis
genome.
Brown Trout Spawning Migration in Fragmented Central European Headwaters: Effect of Isolation by Artificial Obstacles and the Moon Phase
Authors: Slavík Ondřej , Horký Pavel , Randák Tomáš , Balvín Pavel , Bílý Michal
Published: May 2012

The spawning migrations of 123 brown troutSalmo truttawere studied in six highland streams in the Elbe River catchment area, Czech Republic, in central Europe. Trout were observed by using radiotelemetry from August to November in headwater stretches isolated by artificial obstacles without fish ladders. The length of isolated headwater stretches ranged between 5.7 and 16.1 km. Migration distance per day and total migration length over the study period (total migration) were analyzed. In total, 1,957 individual fish positions were recorded. In general, the brown trout spawning migration reflected the seasonality with respect to temperature. Migration distance per day was low in August, reached a maximum in October, and then decreased in November. In isolated headwaters, trout adapted their migrations to the length of available free migration stretches, as both migration descriptors (migration distance per day and total migration) increased according to this variable. Moon phase appeared to be the key factor that influenced the timing of brown trout migration activity on a daily basis. High migration distance per day occurred during the eclipse of the moon, whereas the lowest migration distance per day occurred during the full moon. Furthermore, migration distance per day decreased with increasing river slope. The other variables tested (sex and physicochemical parameters, such as flow, pH, conductivity, and dissolved oxygen) did not affect brown trout migration activity. The results indicated that despite the restrictions of upstream migrations by lateral obstacles without fish ladders, brown trout migration activity in artificially isolated headwaters with pristine morphology is preserved. Furthermore, the analyses revealed a significant impact of the moon phase on brown trout migration that has not been previously described for this species. Although the observed migration occurred over a short period of time, brown trout did not adopt sedentary behavior, as has been described in the river stretches upstream from natural obstacles, such as waterfalls.
Encomium on Helen as Advertisement: Political Life According to Gorgias the Barbarian
Authors: Pfau Michael William
Published: May 2012

In this paper I develop a speculative reading of Gorgias's Encomium on Helen that begins from several common assumptions about the work—especially its status as a “pretext” for Gorgias's hidden purposes and its character as a sort of advertisement. Beginning from these common assumptions I propose that the Encomium is appropriately read as an allegorical representation of Athenian political life. By way of this allegory Gorgias was able to advertise his conception of persuasion despite its highly controversial political implications. I refer to Gorgias as a “barbarian” due to the fundamental incompatibility of the model of political persuasion implicit in the Encomium with democratic Athenian political culture.
Microtubules regulate GEF-H1 in response to extracellular matrix stiffness
Authors: Heck Jessica N. , Ponik Suzanne M. , Garcia-Mendoza Maria G. , Pehlke Carolyn A. , Inman David R. , Eliceiri Kevin W. , Keely Patricia J.
Published: May 2012

Breast epithelial cells sense the stiffness of the extracellular matrix through Rho-mediated contractility. In turn, matrix stiffness regulates RhoA activity. However, the upstream signaling mechanisms are poorly defined. Here we demonstrate that the Rho exchange factor GEF-H1 mediates RhoA activation in response to extracellular matrix stiffness. We demonstrate the novel finding that microtubule stability is diminished by a stiff three-dimensional (3D) extracellular matrix, which leads to the activation of GEF-H1. Surprisingly, activation of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway did not contribute to stiffness-induced GEF-H1 activation. Loss of GEF-H1 decreases cell contraction of and invasion through 3D matrices. These data support a model in which matrix stiffness regulates RhoA through microtubule destabilization and the subsequent release and activation of GEF-H1.
In silico identification software (ISIS): a machine learning approach to tandem mass spectral identification of lipids
Authors: Kangas Lars J. , Metz Thomas O. , Isaac Giorgis , Schrom Brian T. , Ginovska-Pangovska Bojana , Wang Luning , Tan Li , Lewis Robert R. , Miller John H.
Published: May 2012

Motivation: Liquid chromatography–mass spectrometry-based metabolomics has gained importance in the life sciences, yet it is not supported by software tools for high throughput identification of metabolites based on their fragmentation spectra. An algorithm (ISIS: in silico identification software) and its implementation are presented and show great promise in generating in silico spectra of lipids for the purpose of structural identification. Instead of using chemical reaction rate equations or rules-based fragmentation libraries, the algorithm uses machine learning to find accurate bond cleavage rates in a mass spectrometer employing collision-induced dissociation tandem mass spectrometry.

Results: A preliminary test of the algorithm with 45 lipids from a subset of lipid classes shows both high sensitivity and specificity.

Contact:  lars.kangas@pnnl.gov

Supplementary information:  Supplementary data are available at Bioinformatics online.
Identifying mechanistic similarities in drug responses
Authors: Zhao Chen , Hua Jianping , Bittner Michael L. , Ivanov Ivan , Dougherty and Edward R.
Published: May 2012

Motivation: In early drug development, it would be beneficial to be able to identify those dynamic patterns of gene response that indicate that drugs targeting a particular gene will be likely or not to elicit the desired response. One approach would be to quantitate the degree of similarity between the responses that cells show when exposed to drugs, so that consistencies in the regulation of cellular response processes that produce success or failure can be more readily identified.

Results: We track drug response using fluorescent proteins as transcription activity reporters. Our basic assumption is that drugs inducing very similar alteration in transcriptional regulation will produce similar temporal trajectories on many of the reporter proteins and hence be identified as having similarities in their mechanisms of action (MOA). The main body of this work is devoted to characterizing similarity in temporal trajectories/signals. To do so, we must first identify the key points that determine mechanistic similarity between two drug responses. Directly comparing points on the two signals is unrealistic, as it cannot handle delays and speed variations on the time axis. Hence, to capture the similarities between reporter responses, we develop an alignment algorithm that is robust to noise, time delays and is able to find all the contiguous parts of signals centered about a core alignment (reflecting a core mechanism in drug response). Applying the proposed algorithm to a range of real drug experiments shows that the result agrees well with the prior drug MOA knowledge.

Availability: The R code for the RLCSS algorithm is available at http://gsp.tamu.edu/Publications/supplementary/zhao12a.

Contact:  edward@ece.tamu.edu
Fast computation for genome-wide association studies using boosted one-step statistics
Authors: Voorman Arend , Rice Ken , Lumley Thomas
Published: May 2012

Motivation: Statistical analyses of genome-wide association studies (GWAS) require fitting large numbers of very similar regression models, each with low statistical power. Taking advantage of repeated observations or correlated phenotypes can increase this statistical power, but fitting the more complicated models required can make computation impractical.

Results: In this article, we present simple methods that capitalize on the structure inherent in GWAS studies to dramatically speed up computation for a wide variety of problems, with a special focus on methods for correlated phenotypes.

Availability: The R package ‘boss’ is available on the Comprehensive R Archive Network (CRAN) at http://cran.r-project.org/web/packages/boss/

Contact:  voorma@u.washington.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Deep sequencing reveals persistence of intra- and inter-host genetic diversity in natural and greenhouse populations of zucchini yellow mosaic virus
Authors: Simmons H. E. , Dunham J. P. , Stack J. C. , Dickins B. J. A. , Pagán I. , Holmes E. C. , Stephenson A. G.
Published: May 2012

The genetic diversity present in populations of RNA viruses is likely to be strongly modulated by aspects of their life history, including mode of transmission. However, how transmission mode shapes patterns of intra- and inter-host genetic diversity, particularly when acting in combination with de novo mutation, population bottlenecks and the selection of advantageous mutations, is poorly understood. To address these issues, this study performed ultradeep sequencing of zucchini yellow mosaic virus in a wild gourd, Cucurbita pepo ssp. texana, under two infection conditions: aphid vectored and mechanically inoculated, achieving a mean coverage of approximately 10 000×. It was shown that mutations persisted during inter-host transmission events in both the aphid vectored and mechanically inoculated populations, suggesting that the vector-imposed transmission bottleneck is not as extreme as previously supposed. Similarly, mutations were found to persist within individual hosts, arguing against strong systemic bottlenecks. Strikingly, mutations were seen to go to fixation in the aphid-vectored plants, suggestive of a major fitness advantage, but remained at low frequency in the mechanically inoculated plants. Overall, this study highlights the utility of ultradeep sequencing in providing high-resolution data capable of revealing the nature of virus evolution, particularly as the full spectrum of genetic diversity within a population may not be uncovered without sequence coverage of at least 2500-fold.
Imunocompetent Mice Model for Dengue Virus Infection
Authors: Gonçalves Denise , de Queiroz Prado Rafael , Almeida Xavier Eric , Cristina de Oliveira Natália , da Matta Guedes Paulo Marcos , da Silva João Santana , Moraes Figueiredo Luiz Tadeu , Aquino Victor Hugo
Published: May 2012

Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV). DENV belongs to the familyFlaviviridae, genusFlavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease) in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγand TNFαcytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.