bluuebunny/crossref_metadata_2025 huggingface dataset:
Risikoberechnungen beim autosomal-rezessiven Erbgang
Authors: Grimm T. , Fischer C. , Langer S. , Rudnik-Schöneborn S. , Zerres K.
Published: September 2011

Die Risikoberechnungen bei autosomal-rezessiven Erkrankungen können mithilfe des Bayesschen Rechentableaus durchgeführt werden. Die Hardy-Weinberg-Regel ist eine wichtige Grundlage, um A-priori-Wahrscheinlichkeiten zu bestimmen. Es wird demonstriert, wie sich gesunde Angehörige, Ergebnisse molekularer Tests und komplexe genetische Modelle berücksichtigen lassen und wie diese Parameter sich auf das Risiko auswirken. Als Beispiele für den autosomal-rezessiven Erbgang sind die zystische Fibrose (CF) und die infantile spinale Muskelatrophie (SMA) gewählt worden.
Confucianism and Youth Suicide in Rural China
Authors: Zhang Jie , Liu Eric Y.
Published: September 2011

This study examined the relationship between core Confucian ethics and suicide. We used a proxy sample of youths randomly selected from rural areas of three provinces in China. The proxy sample consisted of 382 completed suicides and 414 community living controls, all aged 15–34 years. Logistic regression analyses showed that among the Chinese youths (1) the Confucian ethic of filial piety was negatively associated with suicide; (2) the Confucian ethic of harmony moderated the estimated net effect of negative life events on suicide; and (3) the Confucian ethic of female subordination was positively linked with suicide. We also discussed implications of our study for future research.
Intergenerational transmission and continuity of stress and depression: depressed women and their offspring in 20 years of follow-up
Authors: Hammen C. , Hazel N. A. , Brennan P. A. , Najman J.
Published: September 2011

Background

Children of depressed mothers not only have higher risk of depression, but also may experience both elevated and continuing exposure to stressful experiences. The study tested hypotheses of the intergenerational transmission of stress and depression and examined the role of early childhood adversity and maternal depression in the interplay between youth depression and stress over 20 years.

Method

In a longitudinal community study of 705 families selected for history or absence of maternal depression, mothers and youth were studied from pregnancy to age 5 years and at youth ages 15 and 20 years. Youth and maternal depression were assessed with diagnostic interviews, acute and chronic interview-based stress assessment in the youth and contemporaneous measures of childhood adversity obtained between pregnancy and youth age 5 years.

Results

Regression analyses indicated evidence of intergenerational transmission and continuity of depression over time, continuity of acute and chronic stress and reciprocal predictive associations between depression and stress. Maternal depression and exposure to adversities by child's age 5 years contributed to the youth's continuing experiences of depression and stress. An overall path model was consistent with stress continuity and intergenerational transmission and highlighted the mediating role of age 15 youth chronic interpersonal stress.

Conclusions

Youth of depressed mothers are at risk not only for depression but also for continuing experiences of acute and chronic stress from childhood to age 20. The associations among depression and stress are bidirectional and portend continuing experiences of depression and further stress.
Cross-language effects in written word recognition: The case of bilingual deaf children
Authors: ORMEL ELLEN , HERMANS DAAN , KNOORS HARRY , VERHOEVEN LUDO
Published: September 2011

In recent years, multiple studies have shown that the languages of a bilingual interact during processing. We investigated sign activation as deaf children read words. In a word–picture verification task, we manipulated the underlying sign equivalents. We presented children with word–picture pairs for which the sign translation equivalents varied with respect to sign phonology overlap (i.e., handshape, movement, hand-palm orientation, and location) and sign iconicity (i.e., transparent depiction of meaning or not). For the deaf children, non-matching word–picture pairs with sign translation equivalents that had highly similar elements (i.e., strong sign phonological relations) showed relatively longer response latencies and more errors than non-matching word–picture pairs without sign phonological relations (inhibitory effects). In contrast, matching word–picture pairs with strongly iconic sign translation equivalents showed relatively shorter response latencies and fewer errors than pairs with weakly iconic translation equivalents (facilitatory effects). No such activation effects were found in the word–picture verification task for the hearing children. The results provide evidence for interactive cross-language processing in deaf children.
The Politics of Economic Crises: The Panic of 1873, the End of Reconstruction, and the Realignment of American Politics
Authors: Barreyre Nicolas
Published: September 2011

On September 18, 1873, the announcement of Jay Cooke and Company's bankruptcy sent Wall Street to a panic, and the country to a long, harsh depression. Americans interpreted this economic crisis in the light of the acrimonious financial debates born of the Civil War—the money question chief among them. The consequences transformed American politics. Ideologically ill-equipped to devise cohesive economic policies, political parties split dangerously along sectional lines (between the Northeast and the Midwest). Particularly divided over President U.S. Grant's veto of the 1874 Inflation Bill, the Republican Party decisively lost the 1874 congressional elections. As a Democratic majority in the House spelled the doom of Reconstruction, the ongoing divisions of both parties on economic issues triggered a political realignment. The dramatic 1876 elections epitomized a new political landscape that would last for twenty years: high instability in power at the national level and what has been described as the “politics of inertia.” Therefore, by closely following the ramifications of the 1873 panic, this article proposes an explanation of how an economic crisis transformed into a pivotalpoliticalevent.
Fabrication and Evaluation of a MEMS Piezoelectric Bimorph Generator for Vibration Energy Harvesting
Authors: Lee B. S. , Lin S. C. , Wu W. J.
Published: September 2011

We present the development of a MEMS piezoelectric bimorph generator, a cantilever type bimorph which was formed by laminating two PZT piezoelectric layers. Our bimorph generator can scavenge mechanical energy from ambient vibrations and transform it into useful electrical energy. Two poling configurations of the PZT piezoelectric layers of our bimorph MEMS generator were fabricated and tested. A tip proof mass used for adjusting the resonance frequency was also demonstrated. Experimental results confirm that our device possessed a maximum open-circuit output voltage of 1.91VP-P and a 3.42VP-P for a parallel polarization device and a serial polarization device, respectively with a 2g externally applied vibration. At an optimal resistive load, the maximum output power was 1.548μ–W and 1.778μ–W for a parallel polarization device and a serial polarization device, respectively.
John Commons's organizational theory of institutions: a discussion
Authors: CHAVANCE BERNARD
Published: September 2011

The paper discusses John R. Commons's original theory of institutions, where the latter are defined as going concerns and their working rules, or collective action restraining and expanding individual action. Such organizational approach of institutions makes important contributions to institutional economics in general, through its notion of a hierarchy of collective action, its threefold typology of transactions, and its holindividualist stance. Commons's genuine advances are counterbalanced by theoretical limits, which illustrate the unfinished character of his attempt to make a contribution to a ‘rounded-out theory of Political economy’, e.g. the ambiguous place of markets in his theory, the state understood as a model for other going concerns and, distinctly, the restricted definition of institutions as organizations. In some important respects, his theory complements or goes further than other currents of institutional economics; its weak points are sometimes the reverse side of his very contributions.
Mode matching technique-based modeling of coaxial and circular waveguide discontinuities for material characterization purposes
Authors: Decrossas Emmanuel , EL Sabbagh Mahmoud A. , Hanna Victor Fouad , El-Ghazaly Samir M.
Published: September 2011

In this paper, it is proposed to use a cylindrical cell for the characterization of dielectric material. The extraction of complex permittivity is based on inverse gradient approach where the full-wave simulation results are mapped to experimental data to extract the complex permittivity. As the operational frequency of radio frequency (RF)/microwave devices is increased, it becomes difficult to accurately model waveguide transitions using traditional methods based on meshing such as finite-element method (FEM) where mesh size is determined according to the wavelength. Moreover, these techniques usually require extensive computational resources. Mode matching technique (MMT) is the full-wave tool implemented in this current work. It is used to compute the generalized scattering matrices (GSMs) of the different discontinuities of test setup. These GSMs model precisely discontinuities as they include the effects of all higher-order modes propagating and evanescent. Simulation and experimental results are included to validate the proposed approach for the rigorous modeling of those discontinuities and hence the extraction of complex permittivity.
Prediction of the diurnal warming of sea surface temperature using an atmosphere‐ocean mixed layer coupled model
Authors: Noh Yign , Lee Eunjeong , Kim Dong‐Hoon , Hong Song‐You , Kim Mee‐Ja , Ou Mi‐Lim
Published: September 2011

An atmosphere‐ocean mixed layer coupled model is developed to predict the diurnal variability of sea surface temperature (SST). For this purpose, a new mixed layer model is developed, which is able to reproduce realistic temperature profiles under the various atmospheric conditions, ranging from the formation of a diurnal thermocline under strong wind to the appearance of strong near surface stratification under weak wind. The predicted diurnal warming of SST (ΔSST) from the model is compared with satellite and buoy data in various aspects, including scatterplots, time series, and probability density functions of ΔSST, in order to examine the predictability. The model performance is also compared with other model results. In addition the diurnal variation of temperature profiles below the sea surface, whose information is not available from satellite data, is investigated based on model output.
Improved modeling of sea level patterns by incorporating self‐attraction and loading
Authors: Kuhlmann J. , Dobslaw H. , Thomas M.
Published: September 2011

We implement the effects of gravitational self‐attraction and loading (SAL) into a global baroclinic ocean circulation model and investigate effects on sea level patterns, ocean circulation, and density distributions. We compute SAL modifications as an additional force on the water masses at every time step by decomposing the field of ocean bottom pressure anomalies into spherical harmonic functions and then applying Love numbers to account for the elastic properties of the solid Earth. Considering SAL in the postprocessing turns out to be insufficient, especially in coastal waters and on subweekly time scales, where SAL modifies local sea level by around 0.6–0.8 cm on average; in the open ocean, changes mostly remain around 0.3 cm. Modifications of water velocities as well as of heat and salt distributions are modeled, yet they are small. Simple parameterizations of SAL effects currently used in a number of ocean circulation models suffer from the process's inhomogeneity in space and time. These parameterizations improve the modeled sea level patterns but fail to reproduce SAL impacts on circulation and density distributions. We therefore suggest to explicitly consider the full SAL effect in ocean circulation models, especially when investigating sea level variations faster than around 4 days.
Chondroitin 4-O-sulfotransferase-2 regulates the number of chondroitin sulfate chains initiated by chondroitin N-acetylgalactosaminyltransferase-1
Authors: Izumikawa Tomomi , Koike Toshiyasu , Kitagawa Hiroshi
Published: September 2011

Recently, it has been shown that a deficiency in ChGn-1 (chondroitin N-acetylgalactosaminyltransferase-1) reduced the numbers of CS (chondroitin sulfate) chains, leading to skeletal dysplasias in mice. Although these results indicate that ChGn-1 regulates the number of CS chains, the mechanism mediating this regulation is not clear. ChGn-1 is thought to initiate CS biosynthesis by transferring the first GalNAc (N-acetylgalactosamine) to the tetrasaccharide in the protein linkage region of CS. However, in vitro chondroitin polymerization does not occur on the non-reducing terminal GalNAc-linkage pentasaccharide structure. In the present study we show that several different heteromeric enzyme complexes composed of different combinations of four chondroitin synthase family members synthesized more CS chains when a GalNAc-linkage pentasaccharide structure with a non-reducing terminal 4-O-sulfation was the CS acceptor. In addition, C4ST-2 (chondroitin 4-O-sulfotransferase-2) efficiently transferred sulfate from 3′-phosphoadenosine 5′-phosphosulfate to position 4 of non-reducing terminal GalNAc-linkage residues, and the number of CS chains was regulated by the expression levels of C4ST-2 and of ChGn-1. Taken together, the results of the present study indicate that C4ST-2 plays a key role in regulating levels of CS synthesized via ChGn-1.
Targeting tumour cells at the entrance
Authors: Bröer Stefan
Published: September 2011

Metabolism in tumour cells is adapted to the demands of a growing cell. The Warburg effect and increased use of glutamine are two well-known adaptations of tumour metabolism. Both require transporters to allow uptake of substrates and efflux of products. Differentiated cells are less reliant on these pathways and as a result are less vulnerable to drugs that curtail nutrient uptake. Thus drugs that reduce nutrient uptake are promising candidates for tumour therapy. Detailed understanding of tumour cell biology will allow the generation of new chemotherapeutic drugs with limited side effects. In this issue of the Biochemical Journal, Romero Rosales et al. have identified the mechanism by which the sphingolipid analogue FTY720 inhibits tumour growth.
Prototype cantilevers for quantitative lateral force microscopy
Authors: Reitsma Mark G. , Gates Richard S. , Friedman Lawrence H. , Cook Robert F.
Published: September 2011

Prototype cantilevers are presented that enable quantitative surface force measurements using contact-mode atomic force microscopy (AFM). The “hammerhead” cantilevers facilitate precise optical lever system calibrations for cantilever flexure and torsion, enabling quantifiable adhesion measurements and friction measurements by lateral force microscopy (LFM). Critically, a single hammerhead cantilever of known flexural stiffness and probe length dimension can be used to perform both a system calibration as well as surface force measurements in situ, which greatly increases force measurement precision and accuracy. During LFM calibration mode, a hammerhead cantilever allows an optical lever “torque sensitivity” to be generated for the quantification of LFM friction forces. Precise calibrations were performed on two different AFM instruments, in which torque sensitivity values were specified with sub-percent relative uncertainty. To examine the potential for accurate lateral force measurements using the prototype cantilevers, finite element analysis predicted measurement errors of a few percent or less, which could be reduced via refinement of calibration methodology or cantilever design. The cantilevers are compatible with commercial AFM instrumentation and can be used for other AFM techniques such as contact imaging and dynamic mode measurements
Enhanced reflection from arrays of silicon based inverted nanocones
Authors: Butt Haider , Dai Qing , Rajasekharan Ranjith , Wilkinson Timothy D. , Amaratunga Gehan A. J.
Published: September 2011

We report enhanced reflection displayed by arrays of silicon based inverted nanocones. Theoretical studies suggest that such arrays display enhanced reflection and photonic band gaps within the optical and near infrared regions. Measured results show three to four fold enhancement in reflection and agree well with calculations. Such arrays can be used to enhance infrared reflection in photovoltaic devices which mostly contribute towards heating.
Electric field thermopower modulation analysis of an interfacial conducting layer formed between Y2O3 and rutile TiO2
Authors: Mizuno Taku , Nagao Yuki , Yoshikawa Akira , Koumoto Kunihito , Kato Takeharu , Ikuhara Yuichi , Ohta Hiromichi
Published: September 2011

Electric field modulation analysis of thermopower (S)–carrier concentration (n) relation of a bilayer laminate structure composed of a 1.5-nm-thick conducting layer, probably TinO2n–1 (n = 2, 3, …) Magnéli phase, and rutile TiO2, was performed. The results clearly showed that both the rutile TiO2 and the thin interfacial layer contribute to carrier transport: the rutile TiO2 bulk region (mobility μ ∼ 0.03 cm2 V−1 s−1) and the 1.5-nm-thick interfacial layer (μ ∼ 0.3 cm2 V−1 s−1). The effective thickness of the interfacial layer, which was obtained from the S-n relation, was below ∼3 nm, which agrees well with that of the TEM observation (∼1.5 nm), clearly showing that electric field modulation measurement of S-n relation can effectively clarify the carrier transport properties of a bilayer laminate structure.
Characterization of channel strain evolution upon the silicidation of recessed source/drain Si1−xGex structures
Authors: Kim S.-W. , Yoo J.-H. , Koo S.-M. , Ko D.-H. , Lee H.-J.
Published: September 2011

This letter reports on Ni germanosilicide formation on recessed Si0.82Ge0.18 source/drain structures and its effects on channel strain. A combination of transmission electron microscopy techniques, including nanobeam diffraction, shed some light on a previously unrecognized factor in the channel strain evolution during silicidation: a Ge accumulation layer produced at the bottom of the germanosilicide layer. The formation of such a Ge rich layer added an additional compressive strain to the channel strain upon moderate silicidation, while the contribution of thermal strain arising from the cooling cycle became dominant in an excessively silicided sample, which turned the channel strain into a tensile value.
Nucleation barriers in tetrahedral liquids spanning glassy and crystallizing regimes
Authors: Saika-Voivod Ivan , Romano Flavio , Sciortino Francesco
Published: September 2011

Crystallization and vitrification of tetrahedral liquids are important both from a fundamental and a technological point of view. Here, we study via extensive umbrella sampling Monte Carlo computer simulations the nucleation barriers for a simple model for tetrahedral patchy particles in the regime where open tetrahedral crystal structures (namely, cubic and hexagonal diamond and their stacking hybrids) are thermodynamically stable. We show that by changing the angular bond width, it is possible to move from a glass-forming model to a readily crystallizing model. From the shape of the barrier we infer the role of surface tension in the formation of the crystalline clusters. Studying the trends of the nucleation barriers with the temperature and the patch width, we are able to identify an optimal value of the patch size that leads to easy nucleation. Finally, we find that the nucleation barrier is the same, within our numerical precision, for both diamond crystals and for their stacking forms.
Generating macroscopic chaos in a network of globally coupled phase oscillators
Authors: So Paul , Barreto Ernest
Published: September 2011

We consider an infinite network of globally coupled phase oscillators in which the natural frequencies of the oscillators are drawn from a symmetric bimodal distribution. We demonstrate that macroscopic chaos can occur in this system when the coupling strength varies periodically in time. We identify period-doubling cascades to chaos, attractor crises, and horseshoe dynamics for the macroscopic mean field. Based on recent work that clarified the bifurcation structure of the static bimodal Kuramoto system, we qualitatively describe the mechanism for the generation of such complicated behavior in the time varying case.
Crystal structure evolution and local symmetry of perovskite solid solution Ba[(Fe1/2Nb1/2)1−xTix]O3 investigated by Raman spectra
Authors: Zhang Wei , Wang Zhuo , Chen Xiang Ming
Published: September 2011

The local crystal structure and phonon modes of Ba[(Fe1/2Nb1/2)1−xTix]O3 solid solutions (x = 0, 0.2, 0.4, 0.6, 0.8, 0.85, 0.9, 0.95) were investigated by Raman spectroscopy in the range of 100–1000 cm− 1 at room temperature. Typical tetragonal structure with C4v symmetry was determined for Ba[(Fe1/2Nb1/2)0.05Ti0.95]O3, which was in accordance with the X-ray diffraction (XRD) result. Similar Raman spectra with broader peaks were observed for x decreasing from 0.95 to 0.80, indicating weakening of the Ti4 +  displacement. New features in low-, medium- and high-wavenumber regions were observed in Raman spectra of Ba[(Fe1/2Nb1/2)1−xTix]O3 system with x ≤ 0.6, which could be attributed to the heterogeneous distribution of multiple B-site ions. Most interestingly, two-mode-like behavior was observed in the high-wavenumber region in Raman spectra of Ba(Fe1/2Nb1/2)O3 and Ba[(Fe1/2Nb1/2)0.8Ti0.2]O3, which was probably caused by very local chemically heterogeneous zones of NbO6 and FeO6. As the existence of the local Nb rich region, slight distortion of octahedron could be expected due to the second-order Jahn-Teller (SOJT) effect of Nb5 +  ion. The local composition fluctuation could play an important role in the unique relaxor-like dielectric characteristics of Ba(Fe1/2Nb1/2)O3.
The destruction of Landau levels in graphene nanoribbons by magnetic modulation
Authors: Wu Jhao-Ying , Chen Szu-Chao , Lin Ming-Fa
Published: September 2011

The destruction of Landau levels of one-dimensional graphene nanoribbons in a modulated magnetic field is investigated by the Peierls tight-binding model. The partial flat subbands are transformed into oscillating parabolic subbands, and the dispersion is very sensitive to the modulation period and the field phase. The density of states, which reflects the main features of the energy bands, reveals peak spectra that are controllable through adjusting parameters of the modulated magnetic field. These spectra promise possible applications in electronic devices.
A synchronized emissive probe for time-resolved plasma potential measurements of pulsed discharges
Authors: Sanders Jason M. , Rauch Albert , Mendelsberg Rueben J. , Anders André
Published: September 2011

A pulsed emissive probe technique is presented for measuring the plasma potential of pulsed plasma discharges. The technique provides time-resolved data and features minimal disturbance of the plasma achieved by alternating probe heating with the generation of plasma. Time resolution of about 20 ns is demonstrated for high power impulse magnetron sputtering (HIPIMS) plasma of niobium in argon. Spatial resolution of about 1 mm is achieved by using a miniature tungsten filament mounted on a precision translational stage. Repeated measurements for the same discharge conditions show that the standard deviation of the measurements is about 1–2 V, corresponding to 4%–8% of the maximum plasma potential relative to ground. The principle is demonstrated for measurements at a distance of 30 mm from the target, for different radial positions, at an argon pressure of 0.3 Pa, a cathode voltage of −420 V, and a discharge current of about 60 A in the steady-state phase of the HIPIMS pulse.
Generation kinetics of color centers in irradiated poly(4-methyl-1-pentene)
Authors: Peng J. S. , Chou K. F. , Li C. L. , Lee Sanboh
Published: September 2011

The transient absorbance of poly(4-methyl-1-pentene) (PMP) irradiated with gamma rays at elevated temperatures has been investigated. The absorbance in the ultraviolet and visible range increases with gamma ray dose. A bathochromic shift in transmission spectra emerges significantly upon irradiation. A first-order generation model is proposed to analyze the kinetics of color centers during annealing. The activation energy of the color center increases with increasing gamma ray dose. The equilibrium behavior of color centers in PMP is similar to that of vacancies in metals, and the formation energy of color centers in PMP decreases with increasing gamma ray dose. However, annealable color centers are not observed in this study.
In-plane and tunneling pressure sensors based on graphene/hexagonal boron nitride heterostructures
Authors: Xu Yang , Guo Zhendong , Chen Huabin , Yuan You , Lou Jiechao , Lin Xiao , Gao Haiyuan , Chen Hongsheng , Yu Bin
Published: September 2011

An in-plane pressure sensor (IPPS) consisting of graphene sandwiched by hexagonal boron nitride (h-BN) and a tunneling pressure sensor (TPS) consisting of h-BN sandwiched by graphene are demonstrated. The responses as function of external pressure are modeled. The current varies by 3 orders of magnitude as pressure increases from 0 to 5 nN/nm2. The IPPS current is negatively correlated to pressure, whereas TPS current exhibits positive correlation to pressure. The IPPS design is insensitive to the number of wrapping h-BN layers, indicating precise process control is unnecessary. The result paves a viable avenue towards realizing of atomic scale pressure sensors.
Ultra-low thermal conductivity of ellipsoidal TiO2 nanoparticle films
Authors: Hopkins Patrick E. , Mittal Manish , Phinney Leslie M. , Grillet Anne M. , Furst Eric M.
Published: September 2011

We report on the thermal conductivity of a series of convectively assembled, anisotropic titania (TiO2) nanoparticle films. The TiO2 films are fabricated by flow coating a suspension of ellipsoidal colloidal nanoparticles, resulting in structured films with tailored orientational order. The thermal conductivities depend on nanoparticle orientation and can be less than amorphous TiO2 films due to inter-nanoparticle boundary scattering. This nanoparticle ordering presents a unique method for manipulating the thermal conductivity of nanocomposites.
Polar-fluoropolymer blends with tailored nanostructures for high energy density low loss capacitor applications
Authors: Wu Shan , Lin Minren , Lu S. G. , Zhu Lei , Zhang Q. M.
Published: September 2011

A polar-fluoropolymer blend consisting of a high energy density poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)) and a low dielectric loss poly(ethylene-chlorotrifluoroethylene) (ECTFE) was developed. Both the blend and crosslinked blend films exhibit a dielectric constant of 7 and low loss (∼1%), as expected from the classical composite theory. Moreover, introducing crosslinking in the blends can lead to a marked reduction of losses in blend films at high fields while maintaining a high energy density. At 250 MV/m, a loss of 3% can be achieved in the crosslinked blend compared with 7% loss in pure blend, which is already much below that of neat P(VDF-CTFE) (∼35%).
Single-walled carbon nanotubes and nanocrystalline graphene reduce beam-induced movements in high-resolution electron cryo-microscopy of ice-embedded biological samples
Authors: Rhinow Daniel , Weber Nils-Eike , Turchanin Andrey , Gölzhäuser Armin , Kühlbrandt Werner
Published: September 2011

For single particle electron cryo-microscopy (cryoEM), contrast loss due to beam-induced charging and specimen movement is a serious problem, as the thin films of vitreous ice spanning the holes of a holey carbon film are particularly susceptible to beam-induced movement. We demonstrate that the problem is at least partially solved by carbon nanotechnology. Doping ice-embedded samples with single-walled carbon nanotubes (SWNT) in aqueous suspension or adding nanocrystalline graphene supports, obtained by thermal conversion of cross-linked self-assembled biphenyl precursors, significantly reduces contrast loss in high-resolution cryoEM due to the excellent electrical and mechanical properties of SWNTs and graphene.
Surface morphology and physical properties of partially melt textured Mn doped Bi-2223
Authors: Verma Indu , Kumar R. , Rawat R. , Ganesan V. , Das B.
Published: September 2011

The samples of Bi2Sr2Ca2Cu3-xMnxO10+δ (x = 0.0 to 0.30) were prepared by the standard solid-state reaction method. The phase identification characteristics of synthesized (HTSC) materials were explored through powder X-ray diffractometer reveals that all the samples crystallize in orthorhombic structure with lattice parameters a = 5.4053 Å, b = 5.4110 Å and c = 37.0642 Å up to Mn concentration of x = 0.30. The critical temperature (Tc) measured by standard four probe method has been found to depress from 108 K to 70 K as Mn content (x) increases from 0.00 to 0.30. The effects of sintering temperature on the surface morphology of Bi2Sr2Ca2Cu3-xMnxO10+δ have also been investigated. The surface morphology investigated through scanning electron microscope and atomic force microscopy (SEM & AFM) results that voids are decreasing but grains size increases as the Mn concentration increases besides, nanosphere like structures on the surface of the Mn doped Bi2Sr2Ca2Cu3-xMnxO10+δ (Bi-2223) samples.
Ubiquitin ligase Nedd4 promotes α-synuclein degradation by the endosomal–lysosomal pathway
Authors: Tofaris George K. , Kim Hyoung Tae , Hourez Raphael , Jung Jin-Woo , Kim Kwang Pyo , Goldberg Alfred L.
Published: September 2011

α-Synuclein is an abundant brain protein that binds to lipid membranes and is involved in the recycling of presynaptic vesicles. In Parkinson disease, α-synuclein accumulates in intraneuronal inclusions often containing ubiquitin chains. Here we show that the ubiquitin ligase Nedd4, which functions in the endosomal–lysosomal pathway, robustly ubiquitinates α-synuclein, unlike ligases previously implicated in its degradation. Purified Nedd4 recognizes the carboxyl terminus of α-synuclein (residues 120–133) and attaches K63-linked ubiquitin chains. In human cells, Nedd4 overexpression enhances α-synuclein ubiquitination and clearance by a lysosomal process requiring components of the endosomal-sorting complex required for transport. Conversely, Nedd4 down-regulation increases α-synuclein content. In yeast, disruption of the Nedd4 ortholog Rsp5p decreases α-synuclein degradation and enhances inclusion formation and α-synuclein toxicity. In human brains, Nedd4 is present in pigmented neurons and is expressed especially strongly in neurons containing Lewy bodies. Thus, ubiquitination by Nedd4 targets α-synuclein to the endosomal–lysosomal pathway and, by reducing α-synuclein content, may help protect against the pathogenesis of Parkinson disease and other α-synucleinopathies.
Influence of Electrode Type and Location upon Bioelectrical Impedance Analysis Measurements of Brook Trout
Authors: Hafs Andrew W. , Hartman Kyle J.
Published: September 2011

In recent years, bioelectrical impedance analysis (BIA) has started to develop into a low‐cost tool that can provide accurate estimates of fish condition. Past researchers have had success predicting mass‐based proximate condition components, but attempts to predict percent‐based components have not been as successful, suggesting that methodological improvements are needed. The percent dry weight (%DW) of a fish is a desirable value because energy density and body composition estimates can be obtained from it using previously developed or easily developable equations. The primary objective of this study was to determine the locations at which electrodes should be placed to provide the best estimates of %DW for brook trout Salvelinus fontinalis ranging from 140 to 330 mm (total length). A second objective was to determine the effect that electrode type has on the ability to predict %DW. Models developed using two electrode locations performed better than those with only one location. One set of measurements should be made by placing the electrodes along the dorsal midline (DML) of the fish. A second set should be made by placing one electrode on the dorsal midline directly in front of the dorsal fin and another on the ventral midline directly below the first electrode (DTVpre). On average, models developed using these locations explained 13.2% more of the variation in%DW than models developed using the same locations as previous researchers. Validation of the BIA models demonstrated that both subdermal needle (root mean square error [RMSE] = 1.34, R2 = 0.82) and less‐invasive external rod electrodes (RMSE = 1.37, R2 = 0.79) provided accurate estimates of %DW using the DML and DTVpre locations. More research is needed to determine whether these patterns hold true for smaller fish and species with distinctly different morphologies, bone structures, or scale types.
A wide repertoire of miRNA binding sites: prediction and functional implications
Authors: Elefant Naama , Altuvia Yael , Margalit Hanah
Published: September 2011

Motivation: Over the past decade, deciphering the roles of microRNAs (miRNAs) has relied heavily upon the identification of their targets. Most of the targets that were computationally and experimentally characterized were evolutionarily conserved ‘seed’ targets, containing a perfect 6–8 nt match between the miRNA 5′-region and the messenger RNA (mRNA). Gradually, it has become evident that other types of miRNA binding can confer target regulation, but their characterization has been lagging behind.

Results: Here, we complement the putative evolutionarily-conserved seed-containing targets by a wide repertoire of putative targets exhibiting a variety of miRNA binding patterns, predicted by our algorithm RepTar. These include non-conserved sites, ‘seed’ binding sites with G:U-wobbles within the seed, ‘3′ compensatory’ sites and ‘centered’ sites. Apart from the centered sites, we demonstrate the functionality of these sites and characterize the target profile of a miRNA by the types of binding sites predicted in its target 3′ UTRs. We find that different miRNAs have individual target profiles, with some more inclined to seed binding and others more inclined to binding through 3′ compensatory sites. This diversity in targeting patterns is also evident within several miRNA families (defined by common seed sequences), leading to divergence in the target sets of members of the same family. The prediction of non-conventional miRNA targets is also beneficial in the search for targets of the non-conserved viral miRNAs. Analyzing the cellular targets of viral miRNAs, we show that viral miRNAs use various binding patterns to exploit cellular miRNA binding sites and suggest roles for these targets in virus–host interactions.

Availability: All RepTar's predictions are available for simple and advanced querying at http://reptar.ekmd.huji.ac.il

Contact:  hanahm@ekmd.huji.ac.il

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Dispersal of
Symbiodinium
by the stoplight parrotfish
Sparisoma viride
Authors: Castro-Sanguino Carolina , Sánchez Juan A.
Published: September 2011

Environmental reservoirs of zooxanthellae are essential for coral larvae settlement; understanding where they occur and how they are maintained is important for coral reef ecology. This study investigated the dispersal of
Symbiodinium
spp. by the stoplight parrotfish
Sparisoma viride
, which had high mean densities of viable and cultivable
Symbiodinium
(3207–8900 cells ml
−1
) in faeces. Clades A, B and G were detected using amplified chloroplast ribosomal sequences (cp23S-HVR), and corresponded with diet preferences of fish and the environmental
Symbiodinium
diversity of the region. Cells are constantly dispersed in the water column and deposited in the substrate at a local level (86 ± 17.8 m
2
), demonstrating that parrotfishes are vectors for short-distance dispersal of zooxanthellae. Such dispersal could constitute a key role in the maintenance of environmental
Symbiodinium
reservoirs.
Brain development and predation: plastic responses depend on evolutionary history
Authors: Gonda Abigél , Välimäki Kaisa , Herczeg Gábor , Merilä Juha
Published: September 2011

Although the brain is known to be a very plastic organ, the effects of common ecological interactions like predation or competition on brain development have remained largely unexplored. We reared nine-spined sticklebacks (
Pungitius pungitius
) from two coastal marine (predation-adapted) and two isolated pond (competition-adapted) populations in a factorial experiment, manipulating perceived predatory risk and food supply to see (i) if the treatments affected brain development and (ii) if there was population differentiation in the response to treatments. We detected differences in plasticity of the bulbus olfactorius (chemosensory centre) between habitats: marine fish were not plastic, whereas pond fish had larger bulbi olfactorii in the presence of perceived predation. Marine fish had larger bulbus olfactorius overall. Irrespective of population origin, the hypothalamus was smaller in the presence of perceived predatory risk. Our results demonstrate that perceived predation risk can influence brain development, and that the effect of an environmental factor on brain development may depend on the evolutionary history of a given population in respect to this environmental factor.
In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador
Authors: Eisenberg Joseph N. S. , Goldstick Jason , Cevallos William , Trueba Gabriel , Levy Karen , Scott James , Percha Bethany , Segovia Rosana , Ponce Karina , Hubbard Alan , Marrs Carl , Foxman Betsy , Smith David L. , Trostle James
Published: September 2011

The evolution of antibiotic resistance (AR) increases treatment cost and probability of failure, threatening human health worldwide. The relative importance of individual antibiotic use, environmental transmission and rates of introduction of resistant bacteria in explaining community AR patterns is poorly understood. Evaluating their relative importance requires studying a region where they vary. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to study how changes in the social and natural environment affect the epidemiology of resistantEscherichia coli. We conducted seven bi-annual 15 day surveys of AR between 2003 and 2008 in 21 villages. Resistance to both ampicillin and sulphamethoxazole was the most frequently observed profile, based on antibiogram tests of seven antibiotics from 2210 samples. The prevalence of enteric bacteria with this resistance pair in the less remote communities was 80 per cent higher than in more remote communities (OR = 1.8 [1.3, 2.3]). This pattern could not be explained with data on individual antibiotic use. We used a transmission model to help explain this observed discrepancy. The model analysis suggests that both transmission and the rate of introduction of resistant bacteria into communities may contribute to the observed regional scale AR patterns, and that village-level antibiotic use rate determines which of these two factors predominate. While usually conceived as a main effect on individual risk, antibiotic use rate is revealed in this analysis as an effect modifier with regard to community-level risk of resistance.
An X-ray and neutron reflectometry study of ‘PEG-like’ plasma polymer films
Authors: Menzies Donna J. , Nelson Andrew , Shen Hsin-Hui , McLean Keith M. , Forsythe John S. , Gengenbach Thomas , Fong Celesta , Muir Benjamin W.
Published: September 2011

Plasma-enhanced chemical vapour-deposited films of di(ethylene glycol) dimethyl ether were analysed by a combination of X-ray photoelectron spectroscopy, atomic force microscopy, quartz crystal microbalance with dissipation monitoring (QCM-D), X-ray and neutron reflectometry (NR). The combination of these techniques enabled a systematic study of the impact of plasma deposition conditions upon resulting film chemistry (empirical formula), mass densities, structure and water solvation, which has been correlated with the films' efficacy against protein fouling. All films were shown to contain substantially less hydrogen than the original monomer and absorb a vast amount of water, which correlated with their mass density profiles. A proportion of the plasma polymer hydrogen atoms were shown to be exchangeable, while QCM-D measurements were inaccurate in detecting associated water in lower power films that contained loosely bound material. The higher protein resistance of the films deposited at a low load power was attributed to its greater chemical and structural similarity to that of poly(ethylene glycol) graft surfaces. These studies demonstrate the utility of using X-ray and NR analysis techniques in furthering the understanding of the chemistry of these films and their interaction with water and proteins.
Using causal models to distinguish between neurogenesis-dependent and -independent effects on behaviour
Authors: Lazic Stanley E.
Published: September 2011

There has been a substantial amount of research on the relationship between hippocampal neurogenesis and behaviour over the past 15 years, but the causal role that new neurons have on cognitive and affective behavioural tasks is still far from clear. This is partly due to the difficulty of manipulating levels of neurogenesis without inducing off-target effects, which might also influence behaviour. In addition, the analytical methods typically used do not directly test whether neurogenesis mediates the effect of an intervention on behaviour. Previous studies may have incorrectly attributed changes in behavioural performance to neurogenesis because the role of known (or unknown) neurogenesis-independent mechanisms was not formally taken into consideration during the analysis. Causal models can tease apart complex causal relationships and were used to demonstrate that the effect of exercise on pattern separation is via neurogenesis-independent mechanisms. Many studies in the neurogenesis literature would benefit from the use of statistical methods that can separate neurogenesis-dependent from neurogenesis-independent effects on behaviour.
Risky movement increases the rate of range expansion
Authors: Bartoń K. A. , Hovestadt T. , Phillips B. L. , Travis J. M. J.
Published: September 2011

The movement rules used by an individual determine both its survival and dispersal success. Here, we develop a simple model that links inter-patch movement behaviour with population dynamics in order to explore how individual dispersal behaviour influences not only its dispersal and survival, but also the population's rate of range expansion. Whereas dispersers are most likely to survive when they follow nearly straight lines and rapidly orient movement towards a non-natal patch, the most rapid rates of range expansion are obtained for trajectories in which individuals delay biasing their movement towards a non-natal patch. This result is robust to the spatial structure of the landscape. Importantly, in a set of evolutionary simulations, we also demonstrate that the movement strategy that evolves at an expanding front is much closer to that maximizing the rate of range expansion than that which maximizes the survival of dispersers. Our results suggest that if one of our conservation goals is the facilitation of range-shifting, then current indices of connectivity need to be complemented by the development and utilization of new indices providing a measure of the ease with which a species spreads across a landscape.
Heterozygosity–fitness correlations in the gilthead sea breamSparus auratausing microsatellite loci from unknown and gene‐rich genomic locations
Authors: Borrell Y. J. , Carleos C. E. , Sánchez J. A. , Vázquez E. , Gallego V. , Asturiano J. F. , Blanco G.
Published: September 2011

Heterozygosity–fitness correlations (HFC) were assessed for a sample of a gilthead sea breamSparus auratapopulation. Two hundred and seventy‐one fish were genotyped at 22 known and novel microsatellite loci, from which correlations between the multilocus heterozygosity index (IMLH) and various fitness traits (fork length, mass and specific growth rates) were calculated. Significant global HFCs were found in this sample (0·02 ≤r2≤ 0·08). In addition, all the significant correlations found in this work were negative, indicating that heterozygotes had lower fitness than their homozygote counterparts. Marker location could not explain the observed HFCs. Evidence of inbreeding, outbreeding or population and family structuring was not found in this work. The presence of undetected general effects that may lead to the appearance of HFCs, however, cannot be ruled out. These results seem to be best explained by the occurrence of local effects (due to linkage) or even by possible direct locus advantages.
Lack of association of vitamin D receptor gene 3′‐haplotypes with psoriasis in Croatian patients
Authors: RUCEVIC Ivana , STEFANIC Mario , TOKIC Stana , VUKSIC Melita , GLAVAS‐OBROVAC Ljubica , BARISIC‐DRUSKO Vladimira
Published: September 2011

Cis‐acting regulatory variants in biologically relevant pathways and target tissues are a common source of phenotypic variations and individual disease susceptibility. In the skin, vitamin D receptor (VDR) is a master regulator of epidermal barrier function, inflammation, stem cell proliferation and microbial defense; therefore, we tested whether VDR 3′‐regulatory haplotypes, a portion of which affect VDR transcriptional efficiency, allelic symmetry and mRNA turnover, were associated with psoriasis vulgaris. For this purpose, three VDR tag polymorphisms that capture most of the variability of the VDR 3′‐regulatory element (rs1544410, rs7975232 and rs731236) were genotyped by the polymerase chain reaction restriction fragment length polymorphism method in 180 Caucasian patients with chronic plaque psoriasis and 366 ethnically matched, healthy controls of the Croatian origin. We found no evidence of association for any of the selected polymorphisms. Similarly, none of the 3′‐VDR restriction haplotypes were associated with the risk for development of psoriasis in Croatian patients. These results show that neither VDR 3′‐restriction polymorphisms nor common 3′‐regulatory haplotypes contribute to psoriasis risk in the Croatian population.