bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Shocks and Democratization in Africa
Authors: Barron Manuel , Miguel Edward , Satyanath Shanker
Published: November 2013

The literature on the determinants of democratization has long been dominated by a view that claimed a central role for economic development (‘modernization’). Acemogluet al. (2008, 2009) have recently challenged the robustness of empirical support for the modernization hypothesis. As an alternative, they claim that democratization is likely to occur in moments of economic crisis. Brückner and Ciccone (2011) appear to offer strong support for this latter view, and claim that lagged adverse GDP shocks generated by poor rainfall generate ‘windows of opportunity’ for democratization in contemporary Sub-Saharan Africa. The current article presents evidence that Brückner and Ciccone's provocative finding does not survive several sensible robustness checks, calling into question whether their claim in fact offers new insights into the process of democratization.
THE ISRAELI QUEUE WITH INFINITE NUMBER OF GROUPS
Authors: Perel Nir , Yechiali Uri
Published: November 2013

The so called “Israeli Queue” is a single server polling system with batch service of an unlimited size, where the next queue to be visited is the one in which the first customer in line has been waiting for the longest time. The case with finite number of queues (groups) was introduced by Boxma, Van der Wal and Yechiali [3]. In this paper we extend the model to the case with a (possibly) infinite number of queues. We analyze the M/M/1, M/M/c, and M/M/1/N—type queues, as well as a priority model with (at most) M high-priority classes and a single lower priority class. In all models we present an extensive probabilistic analysis and calculate key performance measures.
PERMUTATIONAL METHODS FOR PERFORMANCE ANALYSIS OF STOCHASTIC FLOW NETWORKS
Authors: Gertsbakh Ilya , Rubinstein Reuven , Shpungin Yoseph , Vaisman Radislav
Published: November 2013

In this paper we show how the permutation Monte Carlo method, originally developed for reliability networks, can be successfully adapted for stochastic flow networks, and in particular for estimation of the probability that the maximal flow in such a network is above some fixed level, called thethreshold. A stochastic flow network is defined as one, where the edges are subject to random failures. A failed edge is assumed to be erased (broken) and, thus, not able to deliver any flow. We consider two models; one where the edges fail with the same failure probability and another where they fail with different failure probabilities. For each model we construct a different algorithm for estimation of the desired probability; in the former case it is based on the well known notion of the D-spectrum and in the later one—on the permutational Monte Carlo. We discuss the convergence properties of our estimators and present supportive numerical results.
The Aegean Islands (Prehistoric to Roman)
Authors: Archibald Zosia
Published: November 2013

Strabo, who visited the island of Gyaros in 31 BC, described it as a village (kōmion, κώμιον Strabo 10.5.3) inhabited by fishermen. This comes as no surprise to anyone familiar with the Aegean islands today. Modern photographic promotions give local fish specialities, and the modest, traditionally whitewashed homes of the fishermen responsible for fresh catches, plenty of colourful emphasis. Not all the fish on offer in the islands are locally caught today, and many visitors arrive by air, rather than by boat, following one of the principal maritime itineraries (which do not, as it happens, normally include Gyaros).

More surprising, perhaps, is the fact that Strabo refers to Gyaros at all. This little island, no more than 17km2 and thus never big enough to provide much of a land-based way of life, even for a small community, lies midway, as the crow flies, between Kea to the west, Kythnos to the southwest and Syros to the south, and is flanked to the northeast by the long chain of islands which in effect extend the mountains of Euboea southeastwards into the heart of the Aegean — Andros, Tenos and Mykonos (map of the Cyclades). The geographer was simply articulating a memorable anecdote, according to which the Gyarians sent their own ambassador to Octavian in the hope of getting a reduction of the 150 dr tribute that had been laid on the inhabitants' reluctant shoulders. The Gyarians were not quite as inconspicuous as they wanted to appear in the eyes of Octavian, or as miserable as they looked to Strabo.
Pragmatic ethics and the will to believe in cosmopolitanism
Authors: Bray Daniel
Published: November 2013

Recent conflicts and crises in international relations have tested the ethical commitments of many cosmopolitans. However, this article argues that cosmopolitanism can be morally compelling and practically useful if it is conceived pragmatically as a set of ideals that guide interactions concerning cross-border problems. It argues that a will to believe in cosmopolitanism can be rationally justified by historical achievements and present tendencies in social conditions. Cosmopolitan beliefs are warranted, first, by demonstrating the empirical relevance of cosmopolitan ethics as a ‘living option’ in a new era of interaction and interdependence. Second, a pragmatic reorientation of cosmopolitan theory is conducted to widen the basis for identifying cosmopolitan action and permit a reconstruction of its ideals appropriate to today's pluralistic world. Finally, cosmopolitan ideals of equality, critical intelligence, and intercultural dialogue are developed as guides to addressing cross-border problems, drawing on the issue of climate change to illustrate how they become operative. A pragmatic faith in these ideals is thus justified by empirical hypotheses concerning the historical tendencies and latent potentialities of human experience, rather than metaphysical premises attached to a supernatural force or universal Reason.
Retracted Article: Intracellular fluorescent thermometry and photothermal-triggered drug release developed from gold nanoclusters and doxorubicin dual-loaded liposomes
Authors: Gui Rijun , Wan Ajun , Liu Xifeng , Jin Hui
Published: November 2013

Gold nanoclusters and doxorubicin dual-loaded liposomes were prepared and developed toward intracellular fluorescence thermometry and photothermal-triggered drug release.
In situ growth of Au nanocrystals on graphene oxide sheets
Authors: Qin Yong , Li Juan , Kong Yong , Li Xiazhang , Tao Yongxin , Li Shan , Wang Yuan
Published: November 2013

The morphology of Au nanocrystals decorated on graphene oxide can be tailored by the degree of oxidation on the graphene oxide surface.
Formation of a pseudo-β-hairpin motif utilizing the Ant–Pro reverse turn: consequences of stereochemical reordering
Authors: Nair Roshna V. , Kotmale Amol S. , Dhokale Snehal A. , Gawade Rupesh L. , Puranik Vedavadi G. , Rajamohanan Pattuparambil R. , Sanjayan Gangadhar J.
Published: November 2013

Herein, we report a special case of pseudo-β-hairpin formation by tetrapeptide sequences featuring a two-residue Ant–Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region.
The interaction of helical tip and root vortices in a wind turbine wake
Authors: Sherry Michael , Nemes András , Lo Jacono David , Blackburn Hugh M. , Sheridan John
Published: November 2013

Analysis of the helical vortices measured behind a model wind turbine in a water channel are reported. Phase-locked measurements using planar particle image velocimetry are taken behind a Glauert rotor to investigate the evolution and breakdown of the helical vortex structures. Existing linear stability theory predicts helical vortex filaments to be susceptible to three unstable modes. The current work presents tip and root vortex evolution in the wake for varying tip speed ratio and shows a breaking of the helical symmetry and merging of the vortices due to mutual inductance between the vortical filaments. The merging of the vortices is shown to be steady with rotor phase, however, small-scale non-periodic meander of the vortex positions is also observed. The generation of the helical wake is demonstrated to be closely coupled with the blade aerodynamics, strongly influencing the vortex properties which are shown to agree with theoretical predictions of the circulation shed into the wake by the blades. The mutual inductance of the helices is shown to occur at the same non-dimensional wake distance.
General active space commutator-based coupled cluster theory of general excitation rank for electronically excited states: Implementation and application to ScH
Authors: Hubert Mickaël , Olsen Jeppe , Loras Jessica , Fleig Timo
Published: November 2013

We present a new implementation of general excitation rank coupled cluster theory for electronically excited states based on the single-reference multi-reference formalism. The method may include active-space selected and/or general higher excitations by means of the general active space concept. It may employ molecular integrals over the four-component Lévy-Leblond Hamiltonian or the relativistic spin-orbit-free four-component Hamiltonian of Dyall. In an initial application to ground- and excited states of the scandium monohydride molecule we report spectroscopic constants using basis sets of up to quadruple-zeta quality and up to full iterative triple excitations in the cluster operators. Effects due to spin-orbit interaction are evaluated using two-component multi-reference configuration interaction for assessing the accuracy of the coupled cluster results.
Onset of vertical threading dislocations in Si1−xGex/Si (001) at a critical Ge concentration
Authors: Isa Fabio , Marzegalli Anna , Taboada Alfonso G. , Falub Claudiu V. , Isella Giovanni , Montalenti Francesco , von Känel Hans , Miglio Leo
Published: November 2013

We show that the Ge concentration in Si1−xGex alloys grown under strong out-of-equilibrium conditions determines the character of the population of threading dislocations (TDs). Above a critical value x ∼ 0.25 vertical TDs dominate over the common slanted ones. This is demonstrated by exploiting a statistically relevant analysis of TD orientation in micrometer-sized Si1−xGex crystals, deposited on deeply patterned Si(001) substrates. Experiments involving an abrupt change of composition in the middle of the crystals clarify the role of misfit-strain versus chemical composition in favoring the vertical orientation of TDs. A scheme invoking vacancy-mediated climb mechanism is proposed to rationalize the observed behavior.
Perfect narrow-band absorber based on a monolayer of metallodielectric microspheres
Authors: Dyachenko P. N. , Petrov A. Yu. , Eich M.
Published: November 2013

We have studied how two-dimensional arrays of metallodielectric core-shell microspheres on a metal substrate can efficiently absorb infrared electromagnetic radiation in a narrow wavelength range under normal incidence. Our simulations indicate that perfect absorption efficiencies can be achieved for resonance wavelengths. The influence of core-shell microspheres geometry and lattice geometry is studied on absorption properties. For wavelength from 1.2 μm to 2.6 μm, an optimal combination of sphere and core radius was obtained to provide perfect absorption which can be wavelength adjusted.
Slanted annular aperture arrays as enhanced-transmission metamaterials: Excitation of the plasmonic transverse electromagnetic guided mode
Authors: Ndao Abdoulaye , Belkhir Abderrahmane , Salut Roland , Baida Fadi I.
Published: November 2013

We present here the fabrication and the optical characterization of slanted annular aperture arrays engraved into silver film. An experimental enhanced transmission based on the excitation of the cutoff-less plasmonic guided mode of the nano-waveguides (the transmission electron microscopy mode) is demonstrated and agrees well with the theoretical predicted results. By the way, even if it is less efficient (70% → 20%), an enhanced transmission can occur at larger wavelength value (720 nm–930 nm) compared to conventional annular aperture arrays structure by correctly setting the metal thickness.
Large temperature span and giant refrigerant capacity in elastocaloric Cu-Zn-Al shape memory alloys
Authors: Mañosa Lluís , Jarque-Farnos Segio , Vives Eduard , Planes Antoni
Published: November 2013

We report on the elastocaloric effect in a Cu-Zn-Al shape memory alloy. We show that both the isothermal entropy and adiabatic temperature changes are large and reproducible upon field cycling over a very broad temperature span of ∼130 K. The combination of large entropy and such a broad temperature span results in an outstanding refrigerant capacity of ∼2300 J/kg.
Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions
Authors: Durand O. , Soulard L.
Published: November 2013

Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 108 atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle.
Generation of Sr2Ca(n-1)CunOy phases (n = 5-7) by high pressure synthesis
Authors: Aoba Tomoya , Kato Takahito , Suzuki Tsuneo , Nakayama Tadachika , Suematsu Hisayuki , Niihara Koichi
Published: November 2013

We prepared Sr2Ca(n-1)CunOy (n = 3-7) phases using a high-pressure apparatus. In the Sr-Ca-Cu-O system, the n = 5-7 members of a homologous series, Sr2Ca(n-1)CunOy, were prepared as mixed phases for the first time. The c-axis length increases linearly with increasing n; c = 6.46(n-1) + 14.3 Å. Half of this slope gives reasonable value of 3.2 Å as the thickness of a Ca and CuO2 plane. It is likely that a 0(Sr)2(n-1)n phase is formed from a 0(Sr)2(n-2)(n-1) phase to intercalate CaCuO2 into its infinite layer because the number of CuO2 planes increases with increasing sintering temperature and synthetic time. Too high temperature and too long synthesis time result in the formation of the infinite layer phase.
Exposure of MC4R to agonist in the endoplasmic reticulum stabilizes an active conformation of the receptor that does not desensitize
Authors: Granell Susana , Molden Brent M. , Baldini Giulia
Published: November 2013

Significance

Melanocortin-4 receptor (MC4R) is a cell-surface hormone receptor in the brain that is central to the control of appetite. Upstream pathways sensing energy balance in the organism lead to the secretion of α-melanocyte–stimulating hormone (α-MSH), which stimulates MC4R activity and leads to decreased appetite. Previously, it was found that MC4R becomes resistant to treatment with extracellular agonists by a mechanism that may involve desensitization of the receptor, arguing against their usefulness in treating obesity. In this study, we show that exposing MC4R to α-MSH in the endoplasmic reticulum leads to constant signaling of MC4R without desensitization. Our results indicate that the cellular localization where agonist binding initially takes place affects the conformation and the desensitization properties of MC4R, suggesting a target for therapy.
Rho GTPases orient directional sensing in chemotaxis
Authors: Wang Yu , Senoo Hiroshi , Sesaki Hiromi , Iijima Miho
Published: November 2013

Significance

During chemotaxis, cells recognize an extracellular chemical gradient and produce amplified intracellular responses independently of the actin cytoskeleton. This process is called directional sensing and observed as the activation of Ras GTPase and the production of phosphatidylinositol (3,4,5)-triphosphate (PIP3) toward higher concentrations of chemoattractants. How directional sensing is controlled is largely unknown. In our current study, we demonstrate that a Rho GTPase (RacE) and a Rho guanine nucleotide exchange factor (GxcT) are required for the orientation of directional sensing independently of feedback from the actin cytoskeleton and cell polarity in
Dictyostelium
, and reveal a previously unknown role for Rho GTPases in intracellular signaling upstream of Ras activation and PIP3 production.
Nanoparticle conjugation of CpG enhances adjuvancy for cellular immunity and memory recall at low dose
Authors: de Titta Alexandre , Ballester Marie , Julier Ziad , Nembrini Chiara , Jeanbart Laura , van der Vlies André J. , Swartz Melody A. , Hubbell Jeffrey A.
Published: November 2013

Significance

High adjuvant doses are generally required to induce strong CD8
+
T-cell immunity with subunit vaccines. Here we codeliver an antigen and an adjuvant coupled on separate ultrasmall polymeric nanoparticles. Because both payloads are attached to similarly sized nanoparticles, and as size is the principle determinant of nanoparticle drainage, this enhanced the dual uptake of antigen and adjuvant by cross-presenting dendritic cells resident in the draining lymph nodes. This cotargeting induced potent effector CD8
+
T cells and a more powerful memory recall of these cytotoxic T cells compared with nanoparticle-conjugated antigen with free adjuvant. As such, nanoparticle conjugation enhanced the immunogenicity of adjuvants while maintaining a low dose, and thus limiting toxicity, affecting the design of future subunit vaccine formulations.
Lamellipodin and the Scar/WAVE complex cooperate to promote cell migration in vivo
Authors: Law Ah-Lai , Vehlow Anne , Kotini Maria , Dodgson Lauren , Soong Daniel , Theveneau Eric , Bodo Cristian , Taylor Eleanor , Navarro Christel , Perera Upamali , Michael Magdalene , Dunn Graham A. , Bennett Daimark , Mayor Roberto , Krause Matthias
Published: November 2013

Cell migration is essential for development, but its deregulation causes metastasis. The Scar/WAVE complex is absolutely required for lamellipodia and is a key effector in cell migration, but its regulation in vivo is enigmatic. Lamellipodin (Lpd) controls lamellipodium formation through an unknown mechanism. Here, we report that Lpd directly binds active Rac, which regulates a direct interaction between Lpd and the Scar/WAVE complex via Abi. Consequently, Lpd controls lamellipodium size, cell migration speed, and persistence via Scar/WAVE in vitro. Moreover, Lpd knockout mice display defective pigmentation because fewer migrating neural crest-derived melanoblasts reach their target during development. Consistently, Lpd regulates mesenchymal neural crest cell migration cell autonomously in Xenopus laevis via the Scar/WAVE complex. Further, Lpd’s Drosophila melanogaster orthologue Pico binds Scar, and both regulate collective epithelial border cell migration. Pico also controls directed cell protrusions of border cell clusters in a Scar-dependent manner. Taken together, Lpd is an essential, evolutionary conserved regulator of the Scar/WAVE complex during cell migration in vivo.
IL-9–mediated survival of type 2 innate lymphoid cells promotes damage control in helminth-induced lung inflammation
Authors: Turner Jan-Eric , Morrison Peter J. , Wilhelm Christoph , Wilson Mark , Ahlfors Helena , Renauld Jean-Christophe , Panzer Ulf , Helmby Helena , Stockinger Brigitta
Published: November 2013

IL-9 fate reporter mice established type 2 innate lymphoid cells (ILC2s) as major producers of this cytokine in vivo. Here we focus on the role of IL-9 and ILC2s during the lung stage of infection with Nippostrongylus brasiliensis, which results in substantial tissue damage. IL-9 receptor (IL-9R)–deficient mice displayed reduced numbers of ILC2s in the lung after infection, resulting in impaired IL-5, IL-13, and amphiregulin levels, despite undiminished numbers of Th2 cells. As a consequence, the restoration of tissue integrity and lung function was strongly impaired in the absence of IL-9 signaling. ILC2s, in contrast to Th2 cells, expressed high levels of the IL-9R, and IL-9 signaling was crucial for the survival of activated ILC2s in vitro. Furthermore, ILC2s in the lungs of infected mice required the IL-9R to up-regulate the antiapoptotic protein BCL-3 in vivo. This highlights a unique role for IL-9 as an autocrine amplifier of ILC2 function, promoting tissue repair in the recovery phase after helminth-induced lung inflammation.
Early Postnatal Calcium and Phosphorus Metabolism in Preterm Infants
Authors: Christmann Viola , de Grauw Anne M. , Visser Reina , Matthijsse René P. , van Goudoever Johannes B. , van Heijst Arno F.J.
Published: November 2013

Objectives:

Bone mineralisation in preterm infants is related to the supply of calcium (Ca) and phosphorus (P). We increased the amount of minerals in parenteral nutrition (PN) for preterm infants and evaluated postnatal Ca and P metabolism in relation to mineral and vitamin D (vitD) intake.

Methods:

Preterm infants, included on their first day of life, received standard PN, providing a maximum Ca/P intake of 3/1.92 mmol · kg−1 · day−1 on day 3. Ca/P content of formula was 2.5/1.6 mmol/dL, and fortified human milk was 2.4/1.95 mmol/dL. PN supplied 80 IU · kg−1 · day−1 vitD. Formula and fortified human milk contained 200 IU/dL of vitD. During a 5‐week period, serum concentrations and urinary excretion of Ca/P were registered and related to the intake of minerals and vitD.

Results:

During 12 months, 79 infants (mean gestational age 29.8 ± 2.2 weeks, mean birth weight 1248 ± 371 g) were included. The recommended intake for minerals was achieved by day 5 and for vitD by 4 weeks. Infants developed hypercalcaemia, hypercalciuria, and hypophosphataemia during the first postnatal week, leading to the additional P supplementation in 49 infants. The renal tubular reabsorption of P was >95% until day 9 but decreased <70% after the second week. Alkaline phosphatase was normal at birth, increased to a maximum of 450 IU/L by day 14, and remained above the normal range for the remaining period.

Conclusions:

Parenteral intake of P appeared to be too low, leading to mineral imbalances in the early postnatal period, and vitD intake was also below recommendations.
Structures of native, substrate-bound and inhibited forms ofMycobacterium tuberculosisimidazoleglycerol-phosphate dehydratase
Authors: Ahangar Mohammad Syed , Vyas Rajan , Nasir Nazia , Biswal Bichitra K.
Published: November 2013

Imidazoleglycerol-phosphate dehydratase (IGPD; HisB), which catalyses the conversion of imidazoleglycerol-phosphate (IGP) to imidazoleacetol-phosphate in the histidine biosynthesis pathway, is absent in mammals. This feature makes it an attractive target for herbicide discovery. Here, the crystal structure ofMycobacterium tuberculosis(Mtb) IGPD is reported together with the first crystal structures of substrate-bound and inhibited (by 3-amino-1,2,4-triazole; ATZ) forms of IGPD from any organism. The overall tertiary structure ofMtbIGPD, a four-helix-bundle sandwiched between two four-stranded mixed β-sheets, resembles the three-dimensional structures of IPGD from other organisms; however,MtbIGPD possesses a unique structural feature: the insertion of a one-turn 310-helix followed by a loop ten residues in length. The functional form of IGPD is 24-meric, exhibiting 432 point-group symmetry. The structure of the IGPD–IGP complex revealed that the imidazole ring of the IGP is firmly anchored between the two Mn atoms, that the rest of the substrate interacts through hydrogen bonds mainly with residues Glu21, Arg99, Glu180, Arg121 and Lys184 which protrude from three separate protomers and that the 24-mer assembly contains 24 catalytic centres. Both the structural and the kinetic data demonstrate that the inhibitor 3-amino-1,2,4-triazole inhibits IGPD competitively.
Split green fluorescent protein as a modular binding partner for protein crystallization
Authors: Nguyen Hau B. , Hung Li-Wei , Yeates Todd O. , Terwilliger Thomas C. , Waldo Geoffrey S.
Published: November 2013

A modular strategy for protein crystallization using split green fluorescent protein (GFP) as a crystallization partner is demonstrated. Insertion of a hairpin containing GFP β-strands 10 and 11 into a surface loop of a target protein provides two chain crossings between the target and the reconstituted GFP compared with the single connection afforded by terminal GFP fusions. This strategy was tested by inserting this hairpin into a loop of another fluorescent protein, sfCherry. The crystal structure of the sfCherry-GFP(10–11) hairpin in complex with GFP(1–9) was determined at a resolution of 2.6 Å. Analysis of the complex shows that the reconstituted GFP is attached to the target protein (sfCherry) in a structurally ordered way. This work opens the way to rapidly creating crystallization variants by reconstituting a target protein bearing the GFP(10–11) hairpin with a variety of GFP(1–9) mutants engineered for favorable crystallization.
Soil aggregate stratification of nematodes and ammonia oxidizers affects nitrification in an acid soil
Authors: Jiang Yuji , Jin Chen , Sun Bo
Published: November 2013

Nitrification plays a central role in global nitrogen cycle, which is affected by interaction between soil microfauna and microorganisms. The impact of synchronized changes in nematodes and ammonia oxidizers within aggregate fractions on nitrification was investigated in an acid soil under 10‐year manure application. Nematodes, ammonia oxidizers and potential nitrification activity (PNA) were examined in three soil aggregate fractions under four fertilization regimes. Pyrosequencing data revealed that the dominant bacterial amoA operational taxonomic units (OTUs) were related to Nitrosospira species, while archaeal OTUs were affiliated with Nitrososphaera and Nitrosotalea species. PNA was more strongly correlated with ammonia‐oxidizing bacteria (AOB) abundance than ammonia‐oxidizing archaea (AOA) abundance, although AOA were dominant in the acid soil. Plant parasites had a negative effect on AOB abundance; however, bacterivores stimulated AOB abundance and contributed more to PNA than plant parasites. Aggregate fractions exerted significant impacts on AOA abundance and AOB community composition. Total carbon content strongly affected the abundance and composition of AOA community, while soil pH primarily affected that of AOB community. Soil variables explained 62.7% and 58.1% variations, and nematode variables explained 11.7% and 19.5% variations in the AOA and AOB community composition respectively.
Identifying 2 Prenylflavanones as Potential Hepatotoxic Compounds in the Ethanol Extract of Sophora flavescens
Authors: Yu Qianqian , Cheng Nengneng , Ni Xiaojun
Published: November 2013

Zhixue capsule is a prescription for hemorrhoid commonly used in traditional Chinese medicine. This drug was recalled by the State Food and Drug Administration in 2008 because of severe adverse hepatic reactions. Zhixue capsule is composed of ethanol extracts of Cortex Dictamni (ECD) and Sophora flavescens (ESF). In our preliminary study, we observed the hepatotoxic effects of ESF on rat primary hepatocytes. However, ECD did not exhibit hepatotoxicity at the same concentration range. In this study, ESF was evaluated for its potential hepatotoxic effects on rats. Bioassay‐guided isolation was used to identify the material basis for hepatotoxicity. Treatment with 1.25 g/kg and 2.5 g/kg ESF significantly elevated the alanine aminotransferase and aspartate aminotransferase levels in the serum. The changes in the levels of transaminases were supported by the remarkable fatty degeneration of liver histopathology. Further investigations using bioassay‐guided isolation and analysis indicated that prenylated flavanones accounted for the positive hepatotoxic results. Two isolated compounds were identified, kurarinone and sophoraflavanone G, using nuclear magnetic resonance and mass spectrometry techniques. These compounds have potent toxic effects on primary rat hepatocytes (with IC50 values of 29.9 μM and 16.5 μM) and human HL‐7702 liver cells (with IC50 values of 48.2 μM and 40.3 μM), respectively. Consequently, the hepatotoxic constituents of S. flavescens were determined to be prenylated flavanones, kurarinone, and sophoraflavanone G.
Microbiota in the stomach: New insights
Authors: Wu Wen Ming , Yang Yun Sheng , Peng Li Hua
Published: November 2013

Bacteria are sparsely distributed in the stomach due to the gastric microbicidal barrier. Several innate defenses (low pH, migrating motor complex and the entero‐salivary circulation of nitrate) as well as external factors (diet, Helicobacter pylori infection, proton pump inhibitors, antibiotics and stomach diseases) have been shown to influence significantly the microbiota composition in the stomach. In recent years new culture‐independent technologies have allowed the investigation of the cross talk that occurs between hosts and stomach‐associated microflora, which helps us to understand the role of gastric bacterial flora in the gastrointestinal microbiological system, both in physiological and pathological conditions. Here, we reviewed the literatures related to this topic and set the stage for future developments of the field.
Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro‐aerobic conditions
Authors: Liu Jingjing , Sun Faqian , Wang Liang , Ju Xi , Wu Weixiang , Chen Yingxu
Published: November 2013

Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro‐aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real‐time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro‐aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD.
The environments of loess uplands to the north and east of the Carpathians during the penultimate interglacial (MOIS 7) in palaeopedological and palaeobotanical records
Authors: Łanczont M. , Madeyska T. , Komar M. , Bogucki A. B.
Published: November 2013

The stratigraphic rank of warming, distinguished in marine deposits as ‘marine oxygen isotope stage 7’ (MOIS 7) and recorded in terrestrial deposits as a palaeosol, has been discussed for a long time. The purpose of this paper is to describe the climate and environment of the time, determined from palaeopedological and palynological investigations of loess‐palaeosol sequences in the peri‐ and metha‐Carpathian zones, and to correlate these sequences with the Pleistocene stratigraphic units. The changes in chemical composition of the deposits were used to reconstruct the processes of chemical weathering and translocation of mobile elements during pedogenesis in three sections (Orzechowce, Galych and Velykyi Glybochok). The variability of the mean annual temperature and precipitation was estimated from the changes of elemental ratios resulting from chemical weathering and vegetation composition. From micromorphological analysis, the stages of palaeosol development and their transformation in cold periods were reconstructed. Pollen analysis carried out for the Velykyi Glyboczok, Maksymivka and Stari Kodaky sites, was used to reconstruct the vegetation cover and the temperature changes of the coldest and warmest months were calculated. The results indicate that the penultimate interglacial period, correlated with MOIS 7, comprised two warming periods separated by a profound cooling period. Warm periods were cooler than the last interglacial and more recent conditions. Vegetation was characterized by the co‐occurrence in changing proportions of patches of mixed forests and steppe vegetation. In the cold period, permafrost developed in places and cryogenic structures were formed. Regional differentiation of biotope environments, resulting from the increase in the continental nature of the climate towards the east, occurred during the whole interglacial period.
Encapsulated galanin‐producing cells attenuate focal epileptic seizures in the hippocampus
Authors: Nikitidou Litsa , Torp Malene , Fjord‐Larsen Lone , Kusk Philip , Wahlberg Lars U. , Kokaia Mérab
Published: November 2013

Purpose

Encapsulated cell biodelivery (ECB) is a relatively safe approach, since the devices can be removed in the event of adverse effects. The main objectives of the present study were to evaluate whether ECB could be a viable alternative of cell therapy for epilepsy. We therefore developed a human cell line producing galanin, a neuropeptide that has been shown to exert inhibitory effects on seizures, most likely acting via decreasing glutamate release from excitatory synapses. To explore whether ECB of genetically modified galanin‐producing human cell line could provide seizure‐suppressant effects, and test possible translational prospect for clinical application, we implanted ECB devices bilaterally into the hippocampus of rats subjected to rapid kindling, a model for recurrent temporal lobe seizures.

Methods

Two clones from a genetically modified human cell line secreting different levels of galanin were tested. Electroencephalography (EEG) recordings and stimulations were performed by electrodes implanted into the hippocampus at the same surgical session as ECB devices. One week after the surgery, rapid kindling stimulations were initiated.

Key Findings

Enzyme‐linked immunosorbent assay (ELISA) measurements prior to device implantation showed a release of galanin on average of 8.3 ng/mL/24 h per device for the low‐releasing clone and 12.6 ng/mL/24 h per device for the high‐releasing clone. High‐releasing galanin‐producing ECB devices moderately decreased stimulation‐induced focal afterdischarge duration, whereas low‐releasing ECB devices had no significant effect.

Significance

Our study shows that galanin‐releasing ECB devices moderately suppress focal stimulation‐induced recurrent seizures. Despite this moderate effect, the study provides conceptual proof that ECB could be a viable alternative approach to cell therapy in humans, with the advantage that the treatment could be terminated by removing these devices from the brain. Thereby, this strategy provides a higher level of safety for future therapeutic applications, in which genetically modified human cell lines that are optimized to produce and release antiepileptic compounds could be clinically evaluated for their seizure‐suppressant effects.

A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
Excessive use of nitrogen in Chinese agriculture results in high N2O/(N2O+N2) product ratio of denitrification, primarily due to acidification of the soils
Authors: Qu Zhi , Wang Jingguo , Almøy Trygve , Bakken Lars R
Published: November 2013

China is the world's largest producer and consumer of fertilizer N, and decades of overuse has caused nitrate leaching and possibly soil acidification. We hypothesized that this would enhance the soils' propensity to emit N2O from denitrification by reducing the expression of the enzyme N2O reductase. We investigated this by standardized oxic/anoxic incubations of soils from five long‐term fertilization experiments in different regions of China. After adjusting the nitrate concentration to 2 mM, we measured oxic respiration (R), potential denitrification (D), substrate‐induced denitrification, and the denitrification product stoichiometry (NO, N2O, N2). Soils with a history of high fertilizer N levels had high N2O/(N2O+N2) ratios, but only in those field experiments where soil pH had been lowered by N fertilization. By comparing all soils, we found a strong negative correlation between pH and the N2O/(N2O+N2) product ratio (r2 = 0.759, P < 0.001). In contrast, the potential denitrification (D) was found to be a linear function of oxic respiration (R), and the ratio D/R was largely unaffected by soil pH. The immediate effect of liming acidified soils was lowered N2O/(N2O+N2) ratios. The results provide evidence that soil pH has a marginal direct effect on potential denitrification, but that it is the master variable controlling the percentage of denitrified N emitted as N2O. It has been known for long that low pH may result in high N2O/(N2O+N2) product ratios of denitrification, but our documentation of a pervasive pH‐control of this ratio across soil types and management practices is new. The results are in good agreement with new understanding of how pH may interfere with the expression of N2O reductase. We argue that the management of soil pH should be high on the agenda for mitigating N2O emissions in the future, particularly for countries where ongoing intensification of plant production is likely to acidify the soils.
Oligo‐astheno‐teratozoospermia in mice lacking ORP4, a sterol‐binding protein in the OSBP‐related protein family
Authors: Udagawa Osamu , Ito Chizuru , Ogonuki Narumi , Sato Hiroyasu , Lee Shoken , Tripvanuntakul Pearlta , Ichi Ikuyo , Uchida Yasunori , Nishimura Taki , Murakami Makoto , Ogura Atsuo , Inoue Takao , Toshimori Kiyotaka , Arai Hiroyuki
Published: November 2013

Oligo‐astheno‐teratozoospermia (OAT), a condition that includes low sperm number, low sperm motility and abnormal sperm morphology, is the commonest cause of male infertility. Because genetic analysis is frequently impeded by the infertility phenotype, the genetic basis of many of OAT conditions has been hard to verify. Here, we show that deficiency of ORP4, a sterol‐binding protein in the oxysterol‐binding protein (OSBP)‐related protein family, causes male infertility due to severe OAT in mice. In ORP4‐deficient mice, spermatogonia proliferation and subsequent meiosis occurred normally, but the morphology of elongating and elongated spermatids was severely distorted, with round‐shaped head, curled back head or symplast. Spermatozoa derived from ORP4‐deficient mice had little or no motility and no fertilizing ability in vitro. In ORP4‐deficient testis, postmeiotic spermatids underwent extensive apoptosis, leading to a severely reduced number of spermatozoa. At the ultrastructural level, nascent acrosomes appeared to normally develop in round spermatids, but acrosomes were detached from the nucleus in elongating spermatids. These results suggest that ORP4 is essential for the postmeiotic differentiation of germ cells.
Immunohistochemical expression of homeoproteins Six1 and Pax3 in breast phyllodes tumours correlates with histological grade and clinical outcome
Authors: Tan Wai Jin , Thike Aye Aye , Bay Boon Huat , Tan Puay Hoon
Published: November 2013

Aims

Homeoproteins are transcription factors which critically regulate developmental processes. Deregulated expression of homeoproteins is observed in several malignancies, such as breast cancer and rhabdomyosarcoma, and contributes to malignant progression. We aimed to investigate the expression and prognostic importance of Six1 and Pax3 homeoproteins in phyllodes tumours – a group of uncommon biphasic tumours comprising both epithelial and stromal components.

Methods and results

A total of 272 cases diagnosed from January 2003 to December 2010 were included in this study – 189 (69.5%) benign, 60 (22.1%) borderline and 23 (8.4%) malignant tumours. Immunohistochemistry was performed on tissue microarray sections using antibodies against Six1 and Pax3. Staining H‐score was assessed in epithelium and stroma separately, and correlated with tumour grade, clinicopathological parameters and prognosis. Tumour grade was associated positively with stromal cytoplasmic expression (P < 0.001; P = 0.011) but correlated negatively with epithelial nuclear expression (P = 0.013; P = 0.007) of both Six1 and Pax3. High stromal cytoplasmic expression of Six1 was associated with metastasis (P = 0.044) and shorter time to recurrence (P = 0.056). Pax3 stromal cytoplasmic expression was associated with poorer overall survival (P = 0.033).

Conclusions

Six1 and Pax3 expression is correlated with tumour grade, unfavourable clinicopathological parameters and poorer clinical outcome, suggesting that both proteins may play a role in malignant progression.
Progression of liver fibrosis in HIV/hepatitis C virus‐coinfected individuals on antiretroviral therapy with early stages of liver fibrosis at baseline
Authors: Sanmartín R , Tor J , Sanvisens A , López JJ , Jou A , Muga R , Ojanguren I , Barluenga E , Videla S , Planas R , Clotet B , Tural C
Published: November 2013

Objectives

The aim of the study was to assess the progression of liver fibrosis in HIV/hepatitis C virus (HCV)‐coinfected patients with no or mild‐to‐moderate fibrosis (stages F0−F2).

Methods

Liver fibrosis was reassessed by transient elastometry (TE) between January 2009 and November 2011 in HIV/HCV‐coinfected patients with stage F0−F2 fibrosis in a liver biopsy performed between January 1997 and December 2007. Patients with liver stiffness at the end of follow‐up < 7.1 kPa were defined as nonprogressors, and those with values ≥ 9.5 kPa or who died from liver disease were defined as progressors. Cirrhosis was defined as a cut‐off of 14.6 kPa. The follow‐up period was the time between liver biopsy and TE. Cox regression models adjusted for age, gender and liver fibrosis stage at baseline were applied.

Results

The median follow‐up time was 7.8 years [interquartile range (IQR) 5.5–10 years]. The study population comprised 162 patients [115 (71%) nonprogressors and 47 (29%) progressors; 19 patients (11.7%) had cirrhosis]. The median time from the diagnosis of HCV infection to the end of follow‐up was 20 years (IQR 16.3–23.1 years). Three progressors died from liver disease (1.8%). The variables associated with a lower risk of progression were age ≤ 38 years (hazard ratio (HR) 0.32; 95% confidence interval (CI) 0.16–0.62; P = 0.001], having received interferon (HR 2.18; 95% CI 1.14–4.15; P = 0.017), being hepatitis B virus surface antigen (HBsAg) negative (HR 0.20; 95% CI 0.04–0.92; P = 0.039), and baseline F0−F1 (HR 0.43; 95% CI 0.28–0.86; P = 0.017).

Conclusions

A high proportion of patients with stage F0−F2 fibrosis progress to advanced liver fibrosis. Advanced liver fibrosis must be included in the list of diseases associated with aging. Our results support the recommendation to offer HCV antiviral therapy to HIV/HCV‐coinfected patients at early stages of liver fibrosis.
The regulation of cytotoxicity and cyclooxygenase‐2 expression by 2‐hydroxy‐ethyl methacrylate in human osteoblasts are related to intracellular glutathione levels
Authors: Ho Y.‐C. , Huang F.‐M. , Lee S.‐S. , Chang Y.‐C.
Published: November 2013

Aim

To investigate the effects of 2‐hydroxy‐ethyl methacrylate (HEMA) on cytotoxicity and cyclooxygenase‐2 (COX‐2) protein expression in human osteoblasts.

Methodology

Cytotoxicity was judged using an Alamar Blue reduction assay on human osteoblast cell line U2OS. Western blot was used to evaluate the expression of COX‐2 protein by HEMA. To determine whether glutathione (GSH) levels were important in cytotoxicity and COX‐2 expression of HEMA, cells were pre‐treated with the GSH precursor, 2‐oxothiazolidine‐4‐carboxylic acid (OTZ), to boost thiol levels, or buthionine sulfoximine (BSO) to deplete GSH. Paired Student's t‐tests were applied for the statistical analysis of the results.

Results

HEMA demonstrated a cytotoxic effect to U2OS cells in a dose‐dependent manner (P < 0.05). The 50% inhibition concentration of HEMA was approximately 3 mmol L−1. HEMA was found to induce COX‐2 protein expression in U2OS cells (P < 0.05). The addition of OTZ acted as a protective effect on HEMA‐induced cytotoxicity and COX‐2 expression (P < 0.05). In contrast, the addition of BSO enhanced HEMA‐induced cytotoxicity and COX‐2 expression (P < 0.05).

Conclusion

Taken together, the levels of HEMA that were tested inhibited cell growth on U2OS cells. HEMA has a significant potential for periapical toxicity. The activation of COX‐2 protein expression may be one of the mechanisms of HEMA‐induced periapical inflammation. These inhibitory effects were associated with intracellular GSH levels.
The Psychology of Corporate Social Responsibility and Humanitarian Work: A Person-Centric Perspective
Authors: Rupp Deborah E. , Skarlicki Daniel , Shao Ruodan
Published: November 2013

The field of industrial–organizational (I–O) psychology has and will continue to experience periods of growth and change. Our field has shifted and transformed along with society, through the industrial revolution, the human relations movement, the globalization of business, and the information age. And here we are, in 2013, at the cusp of what seems to be the beginning of a new stage in our development, this time evidenced by the marked attention that both the science and practice arms of I–O psychology are placing on issues of corporate social responsibility (CSR, Aguinis, 2011; Cruse, 2010; Scott et al. 2013)
What We Know and Don't: Eradicating Employment Discrimination 50 Years After the Civil Rights Act
Authors: Lindsey Alex , King Eden , McCausland Tracy , Jones Kristen , Dunleavy Eric
Published: November 2013

Although nearly 50 years have passed since the Civil Rights Act, employment discrimination persists. Thus, this focal article raises and addresses critical issues regarding a yet unanswered question: how can organizational researchers and practitioners contribute to the ultimate goal of eradicating employment discrimination? This article will push previous work a step forward by considering discrimination reduction tactics spanning the attraction, selection, inclusion, and retention phases of the employment cycle. Additionally, we expand our discussion of strategies to reduce discrimination beyond classically studied racial, ethnic, and gender differences. Our synthesis of this literature will inform organizational psychologists on how to address discrimination, but will also highlight the lack of evidence regarding important aspects of these strategies.