bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of blanketing Es layer (Esb) over the equatorial region during the peculiar minimum of solar cycle 24
Authors: Yadav V. , Kakad B. , Nayak C. K. , Surve G. , Emperumel K.
Published: May 2014

Abstract. A thin and highly dense sporadic E layer, which can occasionally block the upper ionospheric layers, is called blanketing sporadic E (Esb). We present the statistical seasonal local time occurrence pattern of Esb at equatorial station Tirunelveli (8.7° N, 77.8° E, dip latitude 0.7° N) during the extended minimum of solar cycle 24 (2007–2009). In spite of nearly the same average solar activity during both 2007 and 2009, considerable differences are noticed in the seasonal occurrence of Esb during this period. The percentage of Esb occurrence is found to be the highest during the summer solstice (≥ 50%) for both 2007 and 2009, which is in general accordance with the earlier studies. The occurrences of Esb during the vernal equinox (~ 33%) and January–February (~ 28%) are substantial in 2009 as compared to those during the same seasons in 2007. We find that, during winter (January–February), ~ 75% of Esb occurred during or just after the period of sudden stratospheric warming (SSW). We suggest that enhanced Esb occurrence during winter (January–February) and the vernal equinox of 2009 could be associated with SSW-driven changes in the E region ambient conditions. Furthermore, the close association of Esb with counter equatorial electrojet (CEEJ) suggested by earlier studies is re-examined carefully using the scenario of Esb occurrence on non-CEEJ days. Such an exercise is crucial as we are unaware whether the physical mechanisms driving Esb and CEEJ are linked or not. We find that, of all the seasons, the association of Esb and CEEJ is strongest during winter (November–December).
Heavy rainfall episodes over Liguria in autumn 2011: numerical forecasting experiments
Authors: Buzzi A. , Davolio S. , Malguzzi P. , Drofa O. , Mastrangelo D.
Published: May 2014

Abstract. The Liguria coastal region in Italy was affected by two heavy rainfall episodes and subsequent severe flooding that occurred at the end of October and the beginning of November 2011. In both cases, the very large accumulated precipitation maxima were associated with intense and quasi-stationary convective systems that developed near the coast, both related to orographic lift and similar low-level mesoscale flow patterns over the Ligurian Sea, giving rise to pronounced convergence lines. This study aims at analysing the main dynamical processes responsible for the onset, lifecycle, intensity and localisation/propagation of the precipitating systems, using the ISAC convection-permitting model MOLOCH applied at different spatial resolutions and comparing model output fields with available observations. The ability of the model in quantitative precipitation forecasting (QPF) is tested with respect to initial conditions and model horizontal resolution. Although precipitation maxima remain underestimated in the model experiments, it is shown that errors in QPF in both amount and position tend to decrease with increasing grid resolution. It is shown that model accuracy in forecasting rainfall amounts and localisation of the precipitating systems critically depends on the ability to represent the cold air outflow from the Po Valley to the Ligurian Sea, which determines the position and intensity of the mesoscale convergence lines over the sea. Such convergence lines controls, together with the lifting produced by the Apennines chain surrounding the coast, the onset of the severe convection.
Brief communication: Light-absorbing impurities can reduce the density of melting snow
Authors: Meinander O. , Kontu A. , Virkkula A. , Arola A. , Backman L. , Dagsson-Waldhauserová P. , Järvinen O. , Manninen T. , Svensson J. , de Leeuw G. , Leppäranta M.
Published: May 2014

Abstract. Climatic effects of black carbon (BC) deposition on snow have been proposed to result from reduced snow albedo and increased melt due to light-absorbing particles. In this study, we hypothesize that BC may decrease the liquid-water retention capacity of melting snow, and present our first data, where both the snow density and elemental carbon content were measured. In our experiments, artificially added light-absorbing impurities decreased the density of seasonally melting natural snow. No relationship was found in case of natural non-melting snow. We also suggest three possible processes that might lead to lower snow density.
Production costs of the organic Clementine crop in the region of Valencia (Spain)
Authors: Peris Moll E.M. , Juliá Igual J.F.
Published: May 2014

The aim of this paper was to analyse the feasibility of the organic Clementine crop in the Spanish autonomous region of Valencia. With this purpose, the production costs schemes comparing the two crop modalities extended in the region (citrus grown with flow irrigation, and citrus grown with drip irrigation systems), have been developed. The cultivar Clemenules was chosen in order to carry out the study. Considering the present market tendencies, organic Clementines should represent a higher value crop for producers, mainly for two reasons: on one hand, consumer preferences for easy-peelers; on the other hand, the possibility of obtaining price premiums for their harvests.
Genetic parameter estimates for birth and weaning weights, pre-weaning daily weight gain and three type traits for Charolais beef cattle in Spain
Authors: El-Saied U.M. , De la Fuente L.F. , Rodríguez R. , San Primitivo F.
Published: May 2014

Genetic parameters were estimated using REML in a multiple-trait animal model including genetic direct and maternal effects for birth and weaning weights, pre-weaning daily weight gain and three linearly scored traits (muscularity, skeletal size and general appearance) in 3,428 Charolais calves. The three complex type traits were scored at weaning on a nine-point scale. Fixed effects considered were herd-year-season of birth, sex of the calf and parity number of the dam. The fixed effect of weaning season and the linear covariate of age at weaning were considered for all variables except for birth weight. All fixed effects contributed significantly (P < 0.001) to variations in all traits except for the effect of weaning season which was not significant for the general appearance score. The percentage of variance explained by the model averaged 50.74% for the considered traits. Average birth and weaning weights and pre-weaning daily weight gain were 42.95, 278.21 and 1.11 kg, respectively, while muscularity, skeletal size and general appearance scores averaged 5.33, 5.19 and 5.36, respectively. Direct heritability estimates were 0.36, 0.36, 0.22, 0.50, 0.52 and 0.52 for the six traits, respectively. The corresponding maternal heritabilities were 0.37, 0.32, 0.18, 0.18, 0.15 and 0.13, respectively. Direct genetic correlations among these traits varied from low and negative (0.11) between birth and weaning weights to extremely high and positive (0.95) between muscularity and skeletal size scores. Type traits can be effectively used to improve the efficiency of beef production for Charolais calves in Spain.
Short communication. Can highly pathogenic avian influenza (HPAI) reach the Iberian Peninsula from Asia by means of migratory birds?
Authors: Muñoz M.J. , Sánchez-Vizcaíno J.M. , Peris S.
Published: May 2014

This work discusses the possibilities of direct and indirect contact across Central Asia, between migratory bird populations from the Iberian Peninsula, Southwestern Eurasian and Eastern Asian countries. This fact should be considered when preparing surveillance studies for highly pathogenic avian influenza viruses. Records were checked from birds ringed or recovered between 1980 and 2002 in the Iberian Peninsula, an important wintering area for waterfowl in the European Union. This study only addresses migrations covering more than 5000 km and exclusively to or from Asia. A total of seven species have developed migratory routes between Europe and the Caspian Sea/Central Asia in the following proportions to the total of birds recovered: Podiceps nigricollis (17%), Anas penelope (11.1%), A. clypeata (2.17%), A. platyrhynchos (1.86%), Pluvialis squatarola (33.33%), Calidris ferruginea (1.36%) and Sterna sandvicensis (0.67%). These recovery rates suggest the possibility of interchange - at the Central Asia and Caspian breeding groundsbetween the populations originating in Europe and those from Southeast Asia. Over the following seasons, through direct migration, misorientation or, as frequently observed in certain duck species, through a phenomenon of abmigration, some birds with a priori Asian wintering quarters could conceivably escort their "European" brethren to this continent and thus contribute to the propagation of avian flu to so far virus-free areas.
Short communication. Resistance to Phytophthora infestans in populations of wild potato species in the Sorata microcentre of genetic diversity, La Paz, Bolivia
Authors: Coca Morante M. , Montealegre Villanueva N.
Published: May 2014

Endemic wild potato species can be found in the Sorata microcentre of potato genetic diversity (Bolivia). This area, which lies at some 2640 m above sea level, is also a region of intensive phurejas potato cultivation. Pressure from the fungus Phytophthora infestans is high. In vitro experiments were performed to assess the resistance of the following potatoes to P. infestans: i) populations of the wild species Solanum acaule (S. acl), S. circaeifolium (S. crc-LA, S. crc-LB and S. crc-CO) and S. achacachense (S. ach), maintained at the Belén Research Station ex situ bank, ii) the reference species S. capsicibaccatum (S. cap), S. berthaultii (S. ber), S. toralapanum (S. tor) and S. sparsipilum (S. spl), and iii) susceptible cultivated varieties of S. phureja (S. phu) and S. tuberosum subsp. andigena (S. adg). The populations of S. acl, S. crc-LA, S. crc-LB and S. crc-CO showed high levels of resistance to P. infestans, while S. ach was very susceptible, in fact even more so than S. phu. S. tor was very resistant, while S. cap, S. ber and S. spl showed susceptibility similar to that of S. phu. The susceptible control S. adg showed the expected response to P. infestans, while that of S. phu was in agreement with its non-specific resistance to this pathogen.
Short communication. First report in Cuba of bovine coronavirus detection in a winter dysentery outbreak
Authors: Barrera Valle M. , Rodríguez Batista E. , Betancourt Martell A. , Frías Lepuroux M. T. , Brandão P.
Published: May 2014

Bovine coronavirus (BCoV) infection causes epidemics of acute diarrhea in calves and winter dysentery (WD) in adult cattle. The disease in adult cattle can cause a decrease in milk production resulting in serious economic losses. In Cuba, BCoV infections have not been previously reported. During 2004, many outbreaks of enteric disease have occurred in adult cattle from thirteen dairy farms in the central and western part of the island. The clinical features of the outbreaks resembled those of WD, such as decrease in milk production and, 24 hours later, diarrhea, sometimes bloody, that lasted until the animals recovered in about 7-15 days. Laboratory confirmation of BCoV infection was provided by hemagglutination test (HAT) in 24 samples from four dairy farms from three provinces; RT-PCR assays confirmed the presence of BCoV in three of these samples. Cell culture isolation in secondary calf kidney cells was obtained from four pools of fecal diarrheic samples from each dairy farm. It was remarkable that the disease was also observed during summer. Studies of molecular characterization of the viral strain are in progress.
Conservation Agriculture in Zambia: Effects on Selected Soil Properties and Biological Nitrogen Fixation in Soya Beans (Glycine max (L.) Merr)
Authors: Muchabi Jane , Lungu Obed I. , Mweetwa Alice M.
Published: May 2014

Conservation agriculture has been promoted in Zambia as a strategy to mitigate some of the negative effects arising from conventional tillage practices. Conservation agriculture offers several potential benefits on soil properties. However, these benefits and impacts vary across agro ecological regions and management practices. This study investigated changes, over time, associated with the practice of conservation agriculture in selected soil chemical, physical and biological properties, including an assessment of the effects on soil respiration, nodulation and biological nitrogen fixation in soya beans (Glycine max (L.) Merr). Six paired soil samples were collected from conservation agriculture and conventional tillage fields. Fields under conservation agriculture were 4, 7 and 16 years old while those under conventional tillage had been cultivated for over 18 years. Changes in soil properties due to conservation agriculture practice were determined using published laboratory procedures and compared using the paired t-test at 95% confidence level. The results indicated significantly higher soil pH, soil organic carbon, nodulation and biological nitrogen fixation under conservation agriculture than conventional tillage after seven years of practice. The study also showed significantly higher total porosity, soil microbial biomass, soil respiration and lower soil bulk density after sixteen years of practice. Based on these results, the practice of conservation agriculture has potential to improve crop productivity by improving the different aspects of soil fertility, the length of time before this is realized notwithstanding. Further studies that compare several conservation agriculture systems are recommended in other agro-ecological zones of the country to validate these findings.
On the ionospheric and thermospheric response of solar flare events of 19 January 2005: An investigation using radio and optical techniques
Authors: Sumod S. G. , Pant Tarun Kumar , Vineeth C. , Hossain M. M.
Published: May 2014

This study presents optical signatures of thermospheric OI 630.0 nm dayglow variability over a geomagnetic dip equatorial station Trivandrum (8.5°N, 77°E, 0.5° dip latitude), India, in response to solar flares of different ranks that occurred on 19 January 2005. It is found that over equator, the response of thermospheric dayglow to solar flares can be either prompt or delayed depending upon rank of the flare and dominant neutral/electrodynamical processes prevailing in the emission altitudes. This is strikingly in contrast to the earlier results, where prompt response of equatorial OI 630.0 nm dayglow to solar flares has been noticed. In addition, the flare‐induced changes at the E and F regions of the equatorial ionosphere are studied using high‐cadence measurements of the equatorial electrojet (EEJ) and total electron content (TEC) obtained from the ground‐based magnetometers and GPS receivers, respectively. The Hall/Pedersen conductivity measurements as inferred using the magnetometers over the EEJ station and an off‐EEJ station showed concomitant changes during these flares. Although, the GPS‐measured TEC showed prompt enhancement associated with these flares, the evolution of the equatorial ionization anomaly, as seen in the TEC did not show any flare‐induced changes. The plausible mechanisms explaining these observations are adduced in context of the present understanding of the equatorial electrodynamics and its imprint on these dayglow features.
Seismic structure changes beneath Redoubt Volcano during the 2009 eruption inferred from local earthquake tomography
Authors: Kasatkina Ekaterina , Koulakov Ivan , West Michael , Izbekov Pavel
Published: May 2014

We present seismic velocity models of the area beneath Redoubt Volcano (Alaska) corresponding to two time periods, before and after the strong eruption that occurred in March 2009. The calculations were based on tomographic inversion of P and S arrival time data recorded by 19 stations using the local earthquake tomography code LOTOS. We performed thorough analysis of the results based on synthetic tests in each of the time periods that allow real‐time variations in structure to be distinguished from artifacts caused by changes in the observation system configurations. In the resulting images corresponding to the period before the eruption, the summit area is characterized by higher values of both P and S velocities and moderate values of the Vp/Vs ratio. This may correspond to the rigid igneous rocks composing the body of the volcano that lack significant liquid content. In the second episode corresponding to the time of the eruption, the P velocity remained high, whereas the S velocity became very low. The anticorrelation of P and S anomalies in the summit area produced a Vp/Vs ratio as high as 2.2, which is seen down to 2–3 km depth. This indicates presence of mobile phase at shallow depth beneath the volcano, which can be either in the form of partial melt or fluid‐saturated rocks.
Seaglider observations of equatorial Indian Ocean Rossby waves associated with the Madden‐Julian Oscillation
Authors: Webber Benjamin G. M. , Matthews Adrian J. , Heywood Karen J. , Kaiser Jan , Schmidtko Sunke
Published: May 2014

During the CINDY–DYNAMO field campaign of September 2011–January 2012, a Seaglider was deployed at 80°E and completed 10 north‐south sections between 3 and 4°S, measuring temperature, salinity, dissolved oxygen concentration, and chlorophyll fluorescence. These high‐resolution subsurface observations provide insight into equatorial ocean Rossby wave activity forced by three Madden‐Julian Oscillation (MJO) events during this time period. These Rossby waves generate variability in temperature O(1°C), salinity O(0.2 g kg−1), density O(0.2 kg m−3), and oxygen concentration O(10 μmol kg−1), associated with 10 m vertical displacements of the thermocline. The variability extends down to 1000 m, the greatest depth of the Seaglider observations, highlighting the importance of surface forcing for the deep equatorial ocean. The temperature variability observed by the Seaglider is greater than that simulated in the ECCO‐JPL reanalysis, especially at depth. There is also marked variability in chlorophyll fluorescence at the surface and at the depth of the chlorophyll maximum. Upwelling from Rossby waves and local wind stress curl leads to an enhanced shoaling of the chlorophyll maximum by 10–25 m in response to the increased availability of nutrients and light. This influence of the MJO on primary production via equatorial ocean Rossby waves has not previously been recognized.
Ionospheric total electron contents (TECs) as indicators of solar EUV changes during the last two solar minima
Authors: Didkovsky Leonid , Wieman Seth
Published: May 2014

During the extended solar minimum from 2007 to 2009 anomalously low densities were observed in the Earth's thermosphere. Solar activity for the minimum of Solar Cycles 23 and 24 was lower than for Solar Cycles 22 and 23. However, a comparison of global daily averaged Total Electron Content (TEC) for these two solar minima does not show any significant difference. Why these significant changes between the 2008 and 1996 minima were observed in the He II EUV absolute irradiance and not in the global TEC for which EUV irradiance is one of the primary drivers is not well understood and may be interpreted as an effect of EUV instrument degradation. In this study, we analyze TEC data from 1995 to 2013 from the Center for Orbit Determination in Europe (CODE) database and compare global daily averaged TEC signal with TEC sectorial spherical harmonics which reflect a narrower temporal and spatial integration of the TEC in the Earth's ionosphere. Our analyses of both TEC data and errors show significant decreases of sectorial TECs for the 2008 and 2009 minimum compared to the minimum of 1996. We also compare the most recent version of Solar and Heliospheric Observatory/Solar EUV Monitor (SOHO/SEM) He II absolute EUV irradiance with the measurements from the Solar Dynamics Observatory/Extreme Ultraviolet Variability Experiment channels. This comparison shows that the EUV He II irradiance was about 12 ± 4% lower for the minimum of 2008 and 2009 compared to the minimum of 1996 when a low‐pass filter with a 365 day window was used.
Highly Uniform, Electroforming‐Free, and Self‐Rectifying Resistive Memory in the Pt/Ta2O5/HfO2‐x/TiN Structure
Authors: Yoon Jung Ho , Song Seul Ji , Yoo Il‐Hyuk , Seok Jun Yeong , Yoon Kyung Jean , Kwon Dae Eun , Park Tae Hyung , Hwang Cheol Seong
Published: May 2014

The development of a resistance switching (RS) memory cell that contains rectification functionality in itself, highly reproducible RS performance, and electroforming‐free characteristics is an impending task for the development of resistance switching random access memory. In this work, a two‐layered dielectric structure consisting of HfO2 and Ta2O5 layers, which are in contact with the TiN and Pt electrode, is presented for achieving these tasks simultaneously in one sample configuration. The HfO2 layer works as the resistance switching layer by trapping or detrapping of electronic carriers, whereas the Ta2O5 layer remains intact during the whole switching cycle, which provides the rectification. With the optimized structure and operation conditions for the given materials, excellent RS uniformity, electroforming‐free, and self‐rectifying functionality could be simultaneously achieved from the Pt/Ta2O5/HfO2/TiN structure.
Bio‐Inspired Preparation of Fibrin‐Boned Bionanocomposites of Biomacromolecules and Nanomaterials for Biosensing
Authors: Han Fangfang , Qi Xin , Li Lingyan , Bu Lijuan , Fu Yingchun , Xie Qingji , Guo Manli , Li Yanbin , Ying Yibin , Yao Shouzhuo
Published: May 2014

Learning from nature is one of the most promising ways to develop advanced functional materials. Here, inspired by blood coagulation, novel fibrin‐boned bionanocomposites are reported as efficient immobilization matrices of biomacromolecules and nanomaterials for biosensing. Glucose oxidase (GOx), Au nanoparticles (AuNPs), and Fe3O4 magnetic nanoparticles (MNPs) are adopted as the model biomacromolecules and nanomaterials. By integrating the thrombin‐triggered coagulation of fibrin with advanced surficial modification techniques, four kinds of immobilization strategies are developed and evaluated. Digital imaging, UV‐vis spectroscopy, scanning/transmission electron microscopy, electrochemical methods, and N2 adsorption‐desorption isotherms are used to investigate the formation, immobilization efficiency, and performance of various bionanocomposites. The fibrin‐boned networks show inherent biocompatibility, excellent adsorbability, porosity, and functionalization ability, endowing the bionanocomposites with high efficiencies in capturing AuNPs, MNPs and GOx (99%, 98%, and 57% captured under the given conditions, respectively), as well as significant mass‐transfer and biocatalysis efficiencies. Therefore, the fibrin‐boned bionanocomposites show great potential for biosensing, for example, a fibrin‐AuNPs‐GOx‐glutaraldehyde bionanocomposites modified Au electrode is highly sensitive to glucose (145 μA cm−2 mM−1) allowing for a limit of detection down to 25 nM, being much superior to those of the reported analogues. The presented experimental platform/strategy may find wide applications in the development of other bio/nano‐materials/devices.
Efficient Directed Energy Transfer through Size‐Gradient Nanocrystal Layers into Silicon Substrates
Authors: De Benedetti William J. I. , Nimmo Michael T. , Rupich Sara M. , Caillard Louis M. , Gartstein Yuri N. , Chabal Yves J. , Malko Anton V.
Published: May 2014

Spectroscopic evidence of directed excitonic energy transfer (ET) is presented through size‐gradient CdSe/ZnS nanocrystal quantum dot (NQD) layers into an underlying Si substrate. NQD monolayers are chemically grafted on hydrogen‐terminated Si surfaces via a self‐assembled monolayer of amine modified carboxy‐alkyl chains. Subsequent NQD monolayers are linked with short alkyldiamines. The linking approach enables accurate positioning and enhanced passivation of the layers. Two different sizes of NQDs (energy donors emitting at 545 nm, and energy acceptors emitting at 585 nm) are used in comparing different monolayer and bilayer samples grafted on SiO2 and oxide‐free Si surfaces via time‐resolved photoluminescence measurements. The overall efficiency of ET from the top‐layer donor NQDs into Si is estimated to approach ≈90% through a combination of different energy relaxation pathways. These include sequential ET through the intermediate acceptor layer realized mainly via the non‐radiative mechanism and direct ET into the Si substrate realized by means of the radiative coupling. The experimental observations are quantitatively rationalized by the theoretical modeling without introducing any extraneous energy scavenging processes. This indicates that the linker‐assisted fabrication enables the construction of defect‐free, bandgap‐gradient multilayer NQD/Si hybrid structures suitable for thin‐film photovoltaic applications.
Self‐Healing Reduced Graphene Oxide Films by Supersonic Kinetic Spraying
Authors: Kim Do‐Yeon , Sinha‐Ray Suman , Park Jung‐Jae , Lee Jong‐Gun , Cha You‐Hong , Bae Sang‐Hoon , Ahn Jong‐Hyun , Jung Yong Chae , Kim Soo Min , Yarin Alexander L. , Yoon Sam S.
Published: May 2014

The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r‐GO) suspension. The r‐GO flakes are used as received, which are pre‐annealed and pre‐hydrazine‐treated, and do not undergo any post‐treatment. A part of the considerable kinetic energy of the r‐GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting “frozen elastic strains” heal the defects (topological defects, namely Stone‐Wales defect and C2 vacancies) in the r‐GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing.
SERS‐Fluorescence Joint Spectral Encoded Magnetic Nanoprobes for Multiplex Cancer Cell Separation
Authors: Wang Zhuyuan , Zong Shenfei , Chen Hui , Wang Chunlei , Xu Shuhong , Cui Yiping
Published: May 2014

A new kind of cancer cell separation method is demonstrated, using surface‐enhanced Raman scattering (SERS) and fluorescence dual‐encoded magnetic nanoprobes. The designed nanoprobes can realize SERS‐fluorescence joint spectral encoding (SFJSE) and greatly improve the multiplexing ability. The nanoprobes have four main components, that is, the magnetic core, SERS generator, fluorescent agent, and targeting antibody. These components are assembled with a multi‐layered structure to form the nanoprobes. Specifically, silica‐coated magnetic nanobeads (MBs) are used as the inner core. Au core‐Ag shell nanorods (Au@Ag NRs) are employed as the SERS generators and attached on the silica‐coated MBs. After burying these Au@Ag NRs with another silica layer, CdTe quantum dots (QDs), that is, the fluorescent agent, are anchored onto the silica layer. Finally, antibodies are covalently linked to CdTe QDs. SFJSE is fulfilled by using different Raman molecules and QDs with different emission wavelengths. By utilizing four human cancer cell lines and one normal cell line as the model cells, the nanoprobes can specifically and simultaneously separate target cancer cells from the normal ones. This SFJSE‐based method greatly facilitates the multiplex, rapid, and accurate cancer cell separation, and has a prosperous potential in high‐throughput analysis and cancer diagnosis.
Biphasic Ferrogels for Triggered Drug and Cell Delivery
Authors: Cezar Christine A. , Kennedy Stephen M. , Mehta Manav , Weaver James C. , Gu Luo , Vandenburgh Herman , Mooney David J.
Published: May 2014

Ferrogels are an attractive material for many biomedical applications due to their ability to deliver a wide variety of therapeutic drugs on‐demand. However, typical ferrogels have yet to be optimized for use in cell‐based therapies, as they possess limited ability to harbor and release viable cells. Previously, an active porous scaffold that exhibits large deformations and enhanced biological agent release under moderate magnetic fields has been demonstrated. Unfortunately, at small device sizes optimal for implantation (e.g., 2 mm thickness), these monophasic ferrogels no longer achieve significant deformation due to a reduced body force. A new biphasic ferrogel, containing an iron oxide gradient, capable of large deformations and triggered release even at small gel dimensions, is presented in this study. Biphasic ferrogels demonstrate increased porosity, enhanced mechanical properties, and potentially increased biocompatibility due to their reduced iron oxide content. With their ability to deliver drugs and cells on‐demand, it is expected that these ferrogels will have wide utility in the fields of tissue engineering and regenerative medicine.
Photon‐In/Photon‐Out Spectroscopic Techniques for Materials Analysis: Some Recent Developments
Authors: Sham Tsun‐Kong
Published: May 2014

Third‐generation synchrotron light source technology has greatly improved the capabilities for materials analysis using tunable X‐rays. Two such capabilities developed recently are reported herein – inverse partial fluorescence yield (IPFY) XANES (X‐ray absorption near edge structure) and 2D XANES – XEOL (X‐ray excited optical luminescence) in both the energy and time domain. These techniques take advantage of recent advances in soft X‐ray solid state detector, optical spectrometer with a CCD detector and optical streak camera on a soft X‐ray beamline as well as new data acquisition schemes. The studies of LiFePO4 materials for Li ion battery and solid solutions of GaN‐ZnO nanostructures for water splitting are used to illustrate these capabilities. The prospects of these and related synchrotron photon‐in photon‐out techniques are also noted.
Electron Collection as a Limit to Polymer:PCBM Solar Cell Efficiency: Effect of Blend Microstructure on Carrier Mobility and Device Performance in PTB7:PCBM
Authors: Foster Samuel , Deledalle Florent , Mitani Akiko , Kimura Toshio , Kim Ki‐Beom , Okachi Takayuki , Kirchartz Thomas , Oguma Jun , Miyake Kunihito , Durrant James R. , Doi Shuji , Nelson Jenny
Published: May 2014

The poor photovoltaic performance of state‐of‐the‐art blends of poly[4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl] (PTB7) and [6,6]‐phenyl‐C61‐butyric acid (PCBM) at large active layer thicknesses is studied using space‐charge‐limited current mobility and photovoltaic device measurements. The poor performance is found to result from relatively low electron mobility. This is attributed to the low tendency of PTB7 to aggregate, which reduces the ability of the fullerene to form a connected network. Increasing the PCBM content 60–80 wt% increases electron mobility and accordingly improves performance for thicker devices, resulting in a fill factor (FF) close to 0.6 at 300 nm. The result confirms that by improving only the connectivity of the fullerene phase, efficient electron and hole collection is possible for 300 nm‐thick PTB7:PCBM devices. Furthermore, it is shown that solvent additive 1,8‐diiodooctane (DIO), used in the highest efficiency PTB7:PCBM devices, does not improve the thickness dependence and, accordingly, does not lead to an increase in either hole or electron mobility or in the carrier lifetime. A key challenge for researchers is therefore to develop new methods to ensure connectivity in the fullerene phase in blends without relying on either a large excess of fullerene or strong aggregation of the polymer.
Improved Bulk Materials with Thermoelectric Figure‐of‐Merit Greater than 1: Tl10–xSnxTe6 and Tl10–xPbxTe6
Authors: Guo Quansheng , Assoud Abdeljalil , Kleinke Holger
Published: May 2014

Noting the steadily worsening problem of depleted fossil fuel sources, alternate energy sources have become increasingly important; these include thermoelectrics, which may use waste heat to generate electricity. To be economically viable, the thermoelectric figure‐of‐merit, zT, which is related to the energy conversion efficiency, needs to be in excess of unity (zT > 1). Tl4SnTe3 and Tl4PbTe3 were reported to attain a thermoelectric figure‐of‐merit zT
max = 0.74 and 0.71, respectively, at 673 K. Here, the thermoelectric properties of both materials are presented as a function of x in Tl10–x
Sn
x
Te6 and Tl10–x
Pb
x
Te6, with x varying between 1.9 and 2.05, culminating in zT values in excess of 1.2. These materials are charge balanced when x = 2, according to (Tl+)8(Sn2+)2(Te2−)6 and (Tl+)8(Pb2+)2(Te2−)6 (or: (Tl+)4Pb2+(Te2−)3). Increasing x causes an increase in valence electrons, and thus a decrease in the dominating p‐type charge carriers. Larger x values occur with a smaller electrical conductivity and a larger Seebeck coefficient. In each case, the lattice thermal conductivity remains under 0.5 W m−1 K−1, resulting in several samples attaining the desired zT
max > 1. The highest values thus far are exhibited by Tl8.05Sn1.95Te6 with zT = 1.26 and Tl8.10Pb1.90Te6 with zT = 1.46 around 685 K.
Redox Targeting of Anatase TiO2 for Redox Flow Lithium‐Ion Batteries
Authors: Pan Feng , Yang Jing , Huang Qizhao , Wang Xingzhu , Huang Hui , Wang Qing
Published: May 2014

Anatase TiO2 is an extensively studied anode material for lithium‐ion batteries because of its superior capability of storing Li+ electrochemically. Here reversible lithium storage of TiO2 is achieved chemically using redox targeting reactions. In the presence of a pair of redox mediators, bis(pentamethylcyclopentadienyl)cobalt (CoCp*
2) and cobaltocene (CoCp2) in an electrolyte, TiO2 and its lithiated form Li
x
TiO2 can be reduced and oxidized by CoCp*
2 and CoCp2
+, respectively, which accompany Li+ insertion and extraction, albeit without attaching the TiO2 onto the electrode. The reversible chemical lithiation/delithiation and the involved phase transitions are unambiguously confirmed using density functional theory (DFT) calculations, UV‐vis spectroscopy, X‐ray photoelectron spectoscopy (XPS), and Raman spectroscopy. A redox flow lithium‐ion battery (RFLB) half‐cell is assembled and evaluated, which is a critical step towards the development of RFLB full cells.
An Aluminophosphate Molecular Sieve with 36 Crystallographically Distinct Tetrahedral Sites
Authors: Lee Jun Kyu , Turrina Alessandro , Zhu Liangkui , Seo Seungwan , Zhang Daliang , Cox Paul A. , Wright Paul A. , Qiu Shilun , Hong Suk Bong
Published: May 2014

The structure of the new medium‐pore aluminophosphate molecular sieve PST‐6 is determined by the combined use of rotation electron diffraction tomography, synchrotron X‐ray powder diffraction, and computer modeling. PST‐6 was prepared by calcination of another new aluminophosphate material with an unknown structure synthesized using diethylamine as a structure‐directing agent, which is thought to contain bridging hydroxy groups. PST‐6 has 36 crystallographically distinct tetrahedral sites in the asymmetric unit and is thus crystallographically the most complex zeolitic structure ever solved.
The Biosynthesis and Catabolism of the Maleic Anhydride Moiety of Stipitatonic Acid
Authors: al Fahad Ahmed , Abood Amira , Simpson Thomas J. , Cox Russell J.
Published: May 2014

A series of directed knockout experiments, combined with an in vitro assay of pathway components, has elucidated for the first time the chemical steps involved in the biosynthesis of the tropolone class of fungal maleic anhydrides. The pathway involves the stepwise oxidation of aldehyde and methyl carbon atoms to form a 1,2‐dicarboxylate. A hydrolase‐catalyzed interconversion of this and the corresponding maleic anhydride, followed by decarboxylation of the diacid leads to the pathway’s final product of stipitatic acid.
Interpnictogen Cations: Exploring New Vistas in Coordination Chemistry
Authors: Robertson Alasdair P. M. , Gray Paul A. , Burford Neil
Published: May 2014

Pnictine derivatives can behave as both 2e− donors (Lewis bases) and 2e− acceptors (Lewis acids). As prototypical ligands in the coordination chemistry of transition metals, amines and phosphines also form complexes with p‐block Lewis acids, including a variety of pnictogen‐centered acceptors. The inherent Lewis acidity of pnictogen centers can be enhanced by the introduction of a cationic charge, and this feature has been exploited in recent years in the development of compounds resulting from coordinate Pn–Pn and Pn–Pn′ interactions. These compounds offer the unusual opportunity for homoatomic coordinate bonding and the development of complexes that possess a lone pair of electrons at the acceptor center. This Review presents new directions in the systematic extension of coordination chemistry from the transition series into the p‐block.
In Vitro Reconstitution of a Cellular Phase‐Transition Process that Involves the mRNA Decapping Machinery
Authors: Fromm Simon A. , Kamenz Julia , Nöldeke Erik R. , Neu Ancilla , Zocher Georg , Sprangers Remco
Published: May 2014

In eukaryotic cells, components of the 5′ to 3′ mRNA degradation machinery can undergo a rapid phase transition. The resulting cytoplasmic foci are referred to as processing bodies (P‐bodies). The molecular details of the self‐aggregation process are, however, largely undetermined. Herein, we use a bottom‐up approach that combines NMR spectroscopy, isothermal titration calorimetry, X‐ray crystallography, and fluorescence microscopy to probe if mRNA degradation factors can undergo phase transitions in vitro. We show that the Schizosaccharomyces pombe Dcp2 mRNA decapping enzyme, its prime activator Dcp1, and the scaffolding proteins Edc3 and Pdc1 are sufficient to reconstitute a phase‐separation process. Intermolecular interactions between the Edc3 LSm domain and at least 10 helical leucine‐rich motifs in Dcp2 and Pdc1 build the core of the interaction network. We show that blocking of these interactions interferes with the clustering behavior, both in vitro and in vivo.
Improving the cleanability of melamine‐formaldehyde‐based decorative laminates
Authors: Badila Monica , Kohlmayr Martin , Zikulnig‐Rusch Edith Martha , Dolezel‐Horwath Elisabeth , Kandelbauer Andreas
Published: May 2014

Decorative laminates based on melamine formaldehyde (MF) resin impregnated papers are used at great extent for surface finishing of engineered wood that is used for furniture, kitchen, and working surfaces, flooring and exterior cladding. In all these applications, optically flawless appearance is a major issue. The work described here is focused on enhancing the cleanability and antifingerprint properties of smooth, matt surface‐finished melamine‐coated particleboards for furniture fronts, without at the same time changing or deteriorating other important surface parameters such as hardness, roughness or gloss. In order to adjust the surface polarity of a low pressure melamine film, novel interface‐active macromolecular compounds were prepared and tested for their suitability as an antifingerprint additive. Two hydroxy‐functional surfactants (polydimethysiloxane, PDMS‐OH and perfluoroether, PF‐OH) were oxidized under mild conditions to the corresponding aldehydes (PDMS‐CHO and PF‐CHO) using a pyridinium chlorochromate catalyst. With the most promising oxidized polymeric additive, PDMS‐CHO, the contact angles against water,n‐hexadecane, and squalene increased from 79.8°, 26.3° and 31.4° for the pure MF surface to 108.5°, 54.8°, and 59.3°, respectively, for the modified MF surfaces. While for the laminated MF surface based on the oxidized fluoroether the gloss values were much higher than required, for the surfaces based on oxidized polydimethylsiloxane the technological values as well as the lower gloss values were in agreement with the requirements and showed much improved surface cleanability, as was also confirmed by colorimetric measurements. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 40964.
Fish species composition and host fish density in streams of the thick‐shelled river mussel (Unio crassus) – implications for conservation
Authors: Stoeckl Katharina , Taeubert Jens‐Eike , Geist Juergen
Published: May 2014

Recruitment and dispersal of freshwater mussels of the Unionoida is strongly linked to their host fishes on which the larvae develop into juvenile mussels. Host limitation has been suggested as one of the potential causes for the decline of the formerly widespread thick‐shelled river mussel (Unio crassus), although quantitative data analysing the importance of this factor are still missing.

In this study, the status of host fish populations was assessed in nine U. crassus streams within the Danube drainage system situated in southern Germany. In particular, links between recruitment patterns of U. crassus populations, fish species composition and quantitative data of host fish densities in functional and non‐functional streams were established.

Fish species composition and richness ranged between three and nine species with no difference in presence data between functional and non‐functional streams. Despite this high variability, functional U. crassus streams with high proportions of juvenile mussels had significantly higher (mean: 40 Ind. per 100 m2) densities of primary hosts (Phoxinus phoxinus, Squalius cephalus, Gasterosteus aculeatus) than non‐functional streams (mean: 8 Ind. per 100 m2). In contrast, no relationship was found between the numbers and densities of juvenile mussels and densities of poor hosts as well as of non‐hosts.

The results of this study indicate that the recruitment status of U. crassus strongly depends on the density of primary host fish species. Host limitation is likely to play a major role in a lack of juvenile recruitment and consequently in the decline of central European U. crassus populations. Therefore, future conservation for this endangered mussel species should more thoroughly incorporate management of host fish species and consider both the requirements of mussels and their hosts in habitat restoration.

Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of 5‐ and 8‐Deoxytetrodotoxin
Authors: Satake Yoshiki , Adachi Masaatsu , Tokoro Shouta , Yotsu‐Yamashita Mari , Isobe Minoru , Nishikawa Toshio
Published: May 2014

Tetrodotoxin, a toxic principle of puffer fish intoxication, is one of the most famous marine natural products owing to its complex structure and potent biological activity, which leads to fatal poisoning. Continuous synthetic studies on tetrodotoxin and its analogues to elucidate biologically interesting issues associated with tetrodotoxin have led to the development of versatile routes for a variety of tetrodotoxin derivatives. With the aim of investigating the structure–activity relationship of tetrodotoxin with voltage‐gated sodium channels, this study describes the first total syntheses of 5‐deoxytetrodotoxin, a natural analogue of tetrodotoxin, and 8‐deoxytetrodotoxin, an unnatural analogue, from a newly designed, versatile intermediate in an efficient manner. An estimation of the biological activities of these compounds reveals the importance of the hydroxy groups at the C‐5 and C‐8 positions on the inhibition of voltage‐gated sodium channels.
Synthesis of 1,4,7,10‐Tetra‐azacyclododecan‐1,4,7,10‐tetra‐azidoethylacetic Acid (DOTAZA) and Related “Clickable” DOTA Derivatives
Authors: Kriemen Ella , Ruf Erik , Behrens Ulrich , Maison Wolfgang
Published: May 2014

Herein, we report the synthesis of two enantiomeric DOTAZA esters and a related DOT3AZA ester. These compounds are tunable analogues of the well‐known chelator DOTA and can be easily functionalized through click chemistry of the side‐chain azide groups. Like DOTA, DOTAZA forms complexes with various di‐ and trivalent metals, as demonstrated in the synthesis and structural analysis of CuDOTAZA and the preparation of GdDOTAZA.
Enhanced short‐range forecasting of sub‐inversion cloudiness in complex terrain
Authors: Kann Alexander , Schellander‐Gorgas Theresa , Wittmann Christoph
Published: May 2014

Accurate spatial and temporal forecasts of fog and low cloud occurrence are still a challenging research topic due to the complexity of its physics. In the nowcasting range, observation‐based techniques are often superior to numerical weather prediction (NWP) models and provide useful guidelines for operational forecasters. This article proposes a low stratus nowcasting scheme which merges station measurements, satellite data, a nowcasting technique and NWP data at a very high horizontal resolution (1 km). Case studies and a comprehensive validation over Austria reveal that the proposed approach of parameterizing sub‐inversion cloudiness adds value especially in complex terrain and even for longer lead times due to the dynamic design of the method.
Brief report embryonic arterial and skeletal dysgenesis: Syracuse colloquium on congenital arterial and skeletal birth defects September 28 and 29, 2013
Authors: Hootnick David
Published: May 2014

Birth Defects Research (Part A) 100:789–791, 2014. © 2014 Wiley Periodicals, Inc.
Primary cilia in pancreatic development and disease
Authors: Lodh Sukanya , O'Hare Elizabeth A. , Zaghloul Norann A.
Published: May 2014

Primary cilia and their anchoring basal bodies are important regulators of a growing list of signaling pathways. Consequently, dysfunction in proteins associated with these structures results in perturbation of the development and function of a spectrum of tissue and cell types. Here, we review the role of cilia in mediating the development and function of the pancreas. We focus on ciliary regulation of major pathways involved in pancreatic development, including Shh, Wnt, TGF‐β, Notch, and fibroblast growth factor. We also discuss pancreatic phenotypes associated with ciliary dysfunction, including pancreatic cysts and defects in glucose homeostasis, and explore the potential role of cilia in such defects. Birth Defects Research (Part C) 102:139–158, 2014. © 2014 Wiley Periodicals, Inc.
Role of cilia in normal pancreas function and in diseased states
Authors: diIorio Philip , Rittenhouse Ann R. , Bortell Rita , Jurczyk Agata
Published: May 2014

Primary cilia play an essential role in modulating signaling cascades that shape cellular responses to environmental cues to maintain proper tissue development. Mutations in primary cilium proteins have been linked to several rare developmental disorders, collectively known as ciliopathies. Together with other disorders associated with dysfunctional cilia/centrosomes, affected individuals have increased risk of developing metabolic syndrome, neurologic disorders, and diabetes. In pancreatic tissues, cilia are found exclusively in islet and ductal cells where they play an essential role in pancreatic tissue organization. Their absence or disorganization leads to pancreatic duct abnormalities, acinar cell loss, polarity defects, and dysregulated insulin secretion. Cilia in pancreatic tissues are hubs for cellular signaling. Many signaling components, such as Hh, Notch, and Wnt, localize to pancreatic primary cilia and are necessary for proper development of pancreatic epithelium and β‐cell morphogenesis. Receptors for neuroendocrine hormones, such as Somatostatin Receptor 3, also localize to the cilium and may play a more direct role in controlling insulin secretion due to somatostatin's inhibitory function. Finally, unique calcium signaling, which is at the heart of β‐cell function, also occurs in primary cilia. Whereas voltage‐gated calcium channels trigger insulin secretion and serve a variety of homeostatic functions in β‐cells, transient receptor potential channels regulate calcium levels within the cilium that may serve as a feedback mechanism, regulating insulin secretion. This review article summarizes our current understanding of the role of primary cilia in normal pancreas function and in the diseased state. Birth Defects Research (Part C) 102:126–138, 2014. © 2014 Wiley Periodicals, Inc.