bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trading Partners, Traded Products and Firm Performances of China’s Exporter‐Importers: Does Processing Trade Make a Difference?
Authors: Wang Zheng , Yu Zhihong 
Published: December 2012

AbstractIn this study, we explore a newly available unique data set that links China’s international trade transactions to its manufacturing firms’ census data and establish a number of interesting stylised facts linking firms’ key economic performances to their exporting‐importing behaviours. One novelty of our analysis is that we distinguish between ordinary trade and processing trade; the latter involves importing inputs and materials to be assembled and re‐exported to the overseas market. Several novel patterns emerge. First, we discover significant heterogeneitywithintwo‐way traders – in terms of size, productivity and factor intensity – depending on their engagement in processing exports/imports. Whilst the existing literature typically finds that two‐way traders are larger and more productive than one‐way traders, we show that pure processing two‐way traders are actually the least productive and exhibit the lowestcapita/skill intensity compared to one‐way traders. Second, consistent with the market hierarchy hypothesis, larger and more productive firms trade with a larger number of trade partners that are on average ‘less popular’ as characterised by longer distances and smaller market size. Remarkably, this pattern is highly symmetric between exports and imports, as well as between ordinary and processing trade. Third, firms with greater capital and skill intensities source more complex inputs from countries with higher incomeper capita, and this pattern holds only for ordinary imports but not for processing imports. While some of our findings confirm existing stylised facts reported for other countries, some patterns we discover are new to the literature and remain to be reconciled with the heterogeneous firm trade theory.
SC‐GRAPPA: Self‐constraint noniterative GRAPPA reconstruction with closed‐form solution
Authors: Ding Yu , Xue Hui , Ahmad Rizwan , Ting Samuel T. , Simonetti Orlando P. 
Published: December 2012

Purpose:Parallel MRI (pMRI) reconstruction techniques are commonly used to reduce scan time by undersampling the k‐space data. GRAPPA, a k‐space based pMRI technique, is widely used clinically because of its robustness. In GRAPPA, the missing k‐space data are estimated by solving a set of linear equations; however, this set of equations does not take advantage of the correlations within the missing k‐space data. All k‐space data in a neighborhood acquired from a phased‐array coil are correlated. The correlation can be estimated easily as a self‐constraint condition, and formulated as an extra set of linear equations to improve the performance of GRAPPA. The authors propose a modified k‐space based pMRI technique called self‐constraint GRAPPA (SC‐GRAPPA) which combines the linear equations of GRAPPA with these extra equations to solve for the missing k‐space data. Since SC‐GRAPPA utilizes a least‐squares solution of the linear equations, it has a closed‐form solution that does not require an iterative solver.Methods:The SC‐GRAPPA equation was derived by incorporating GRAPPA as a prior estimate. SC‐GRAPPA was tested in a uniform phantom and two normal volunteers. MR real‐time cardiac cine images with acceleration rate 5 and 6 were reconstructed using GRAPPA and SC‐GRAPPA.Results:SC‐GRAPPA showed a significantly lower artifact level, and a greater than 10% overall signal‐to‐noise ratio (SNR) gain over GRAPPA, with more significant SNR gain observed in low‐SNR regions of the images.Conclusions:SC‐GRAPPA offers improved pMRI reconstruction, and is expected to benefit clinical imaging applications in the future.
Mefloquine Exposure Induces Cell Cycle Delay and Reveals Stage-Specific Expression of the
pfmdr1
Gene
Authors: Bohórquez Elaine B. , Juliano Jonathan J. , Kim Hyung-Suk , Meshnick Steven R. 
Published: December 2012

ABSTRACT

Drug-resistant
Plasmodium falciparum
malaria is a major public health problem. An elevated
pfmdr1
gene copy number (CN) is known to decrease parasite sensitivity to the commonly used antimalarial mefloquine (MFQ). To understand the relationship between
pfmdr1
CN and mefloquine resistance, we evaluated
pfmdr1
transcript levels in three
P. falciparum
strains with different CNs in the presence and absence of MFQ. Parasite strains with multiple
pfmdr1
gene copies exhibited higher relative transcript levels than single-copy parasites, and MFQ induced
pfmdr1
expression above the levels without treatment in all three strains evaluated. Concomitant morphology analyses of the sampled cultures revealed that MFQ treatment of synchronized ring-stage parasites induced a delay in parasite maturation through the intraerythrocytic cycle.
pfmdr1
expression peaks in the ring stage, and MFQ could be causing increased transcription by delaying parasite maturation. However, pretreatment with mefloquine did not affect the artemisinin
in vitro
half-maximal inhibitory concentration (IC
50
). These results suggest that MFQ-induced increases in
pfmdr1
expression are the direct result of the maturation delay at the ring stage but that this change in expression does not affect the antimalarial activity of artemisinin.
Chemical Genomic Screening of a Saccharomyces cerevisiae Genomewide Mutant Collection Reveals Genes Required for Defense against Four Antimicrobial Peptides Derived from Proteins Found in Human Saliva
Authors: Lis Maciej , Bhatt Sanjay , Schoenly Nathan E. , Lee Anna Y. , Nislow Corey , Bobek Libuse A. 
Published: December 2012

ABSTRACT

To compare the effects of four antimicrobial peptides (MUC7 12-mer, histatin 12-mer, cathelicidin KR20, and a peptide containing lactoferricin amino acids 1 to 11) on the yeast
Saccharomyces cerevisiae
, we employed a genomewide fitness screen of combined collections of mutants with homozygous deletions of nonessential genes and heterozygous deletions of essential genes. When an arbitrary fitness score cutoffs of 1 (indicating a fitness defect, or hypersensitivity) and −1 (indicating a fitness gain, or resistance) was used, 425 of the 5,902 mutants tested exhibited altered fitness when treated with at least one peptide. Functional analysis of the 425 strains revealed enrichment among the identified deletions in gene groups associated with the Gene Ontology (GO) terms “ribosomal subunit,” “ribosome biogenesis,” “protein glycosylation,” “vacuolar transport,” “Golgi vesicle transport,” “negative regulation of transcription,” and others. Fitness profiles of all four tested peptides were highly similar, particularly among mutant strains exhibiting the greatest fitness defects. The latter group included deletions in several genes involved in induction of the RIM101 signaling pathway, including several components of the ESCRT sorting machinery. The RIM101 signaling regulates response of yeasts to alkaline and neutral pH and high salts, and our data indicate that this pathway also plays a prominent role in regulating protective measures against all four tested peptides. In summary, the results of the chemical genomic screens of
S. cerevisiae
mutant collection suggest that the four antimicrobial peptides, despite their differences in structure and physical properties, share many interactions with
S. cerevisiae
cells and consequently a high degree of similarity between their modes of action.
Phase Diagrams Map the Properties of Antiviral Agents Directed against Hepatitis B Virus Core Assembly
Authors: Li Lichun , Chirapu Srinivas Reddy , Finn M. G. , Zlotnick Adam 
Published: December 2012

ABSTRACT
Assembly effectors are small molecules that induce inappropriate virus capsid assembly to antiviral effect. To identify attributes of hepatitis B virus (HBV) assembly effectors, assembly reaction products (normal capsid, noncapsid polymer, intermediates, and free dimeric core protein) were quantified in the presence of three experimental effectors: HAP12, HAP13, and AT-130. Effectors bound stoichiometrically to capsid protein polymers, but not free protein. Thermodynamic and kinetic effects, not aberrant assembly, correlate with maximal antiviral activity.
Multilaboratory Approach to Preclinical Evaluation of Vaccine Immunogens for Placental Malaria
Authors: Fried Michal , Avril Marion , Chaturvedi Richa , Fernandez Pablo , Lograsso Joseph , Narum David , Nielsen Morten A. , Oleinikov Andrew V. , Resende Mafalda , Salanti Ali , Saveria Tracy , Williamson Kathryn , Dicko Alassane , Scherf Artur , Smith Joseph D. , Theander Thor G. , Duffy Patrick E. 
Published: December 2012

ABSTRACT

Pregnancy malaria is caused by
Plasmodium falciparum
-infected erythrocytes that adhere to the placental receptor chondroitin sulfate A (CSA) and sequester in the placenta; women become resistant to pregnancy malaria as they acquire antiadhesion antibodies that target surface proteins of placental parasites. VAR2CSA, a member of the
P. falciparum
EMP1 variant surface antigen family, is the leading candidate for a pregnancy malaria vaccine. Because VAR2CSA is a high-molecular-weight protein, a vaccine based on the full-length protein may not be feasible. An alternative approach has been to develop a vaccine targeting individual Duffy binding-like (DBL) domains. In this study, a consortium of laboratories under the Pregnancy Malaria Initiative compared the functional activity of antiadhesion antibodies elicited by different VAR2CSA domains and variants produced in prokaryotic and eukaryotic expression systems. Antisera were initially tested against laboratory lines of maternal parasites, and the most promising reagents were evaluated in the field against fresh placental parasite samples. Recombinant proteins expressed in
Escherichia coli
elicited antibody levels similar to those expressed in eukaryotic systems, as did the two allelic forms of the DBL4 and DBL5 domains. The procedures developed for this head-to-head comparison will be useful for future evaluation and down-selection of malaria vaccine immunogens.
A comparison of enrichment and direct-plating methods for isolation of Listeria monocytogenes from surface water
Authors: Lyautey Emilie , Hartmann Alain , Lapen David R. , Topp Edward 
Published: December 2012

Listeria monocytogenes is a facultative intracellular pathogen distributed in the environment. Reference isolation methods include an enrichment step. We compared 2 protocols: one based on enrichment and the other on direct plating, with respect to the efficiency of isolation of L. monocytogenes from surface water samples. From March to May 2006, 126 surface water samples were collected biweekly from 24 discrete sampling sites located in the South Nation River basin (Ontario). Presumptive Listeria spp. were isolated using the 2 methods, and L. monocytogenes isolates were confirmed based on colony morphology and amplification of 3 pathogenicity genes: iap, inlA, and hlyA. Listeria monocytogenes was detected in 31 water samples using the enrichment approach and in 27 using the direct-plating approach, with only 13 samples positive using both approaches. No correlation was observed between the ability of the enrichment procedure to fail in the detection of the pathogenic bacterium and the abundance of several indicator bacteria. The proportion of samples carrying isolates from serovar groups 1/2a, 3a; 1/2b, 3b, 7; 4b, 4d, 4e; and Listeria spp. was significantly different between the 2 approaches. This data indicate that a direct-plating approach would be suitable for the detection of L. monocytogenes in water samples, but that enrichment and direct-plating protocols both have specific biases.
A new set of reference genes for RT-qPCR assays in the yeast Dekkera bruxellensis
Authors: de Barros Pita Will , Leite Fernanda Cristina Bezerra , de Souza Liberal Anna Theresa , Pereira Luciana Filgueira , Carazzolle Marcelo Falsarella , Pereira Gonçalo Amarante , de Morais Marcos Antonio 
Published: December 2012

The yeast Dekkera bruxellensis has been recently regarded as an important microorganism for bioethanol production owing to its ability to convert glucose, sucrose, and cellobiose to ethanol. The aim of this work was to validate a new set of reference genes for gene expression analysis by quantitative real-time PCR in D. bruxellensis and compare the influence of the method of choice for quantification of mRNA levels with the reliability of our data. Three candidate reference genes, DbEFA1, DbEFB1, and DbYNA1, were used in a quantitative analysis of 4 genes of interest, DbYNR1, DbTPS1, DbADH7, and DbUBA4, based on an approach for calculating the normalization factors by means of the geNorm applet. Each reference gene was also individually used for a [Formula: see text] (comparative Cq method) calculation of the relative expression of genes of interest. Our results showed that the 3 reference genes provided enough stability and were complementary to the normalization factors method in different culture conditions. This work was able to confirm the usefulness of a previously reported reference gene, EFA1/TEF1, and increased the set of possible reference genes in D. bruxellensis to 4. Moreover, this can improve the reliability of the analysis of the regulation of gene expression in the industrial yeast D. bruxellensis.
Effect of starvation, body size, and temperature on the onset of metamorphosis in Japanese eel (Anguilla japonica)
Authors: Okamura Akihiro , Yamada Yoshiaki , Mikawa Naomi , Horie Noriyuki , Tsukamoto Katsumi 
Published: December 2012

We assessed the effects of starvation, body size, and water temperature on the onset of metamorphosis in leptocephali of Japanese eel ( Anguilla japonica Temminck and Schlegel, 1846) as determined by the morphological criteria of proportion, preanal length, and body depth to total length. Leptocephali of mean total length 55.6 mm that had been reared in captivity for 241 days from hatching were divided into unfed (n = 28) and fed (n = 30) groups in triplicate and reared for an additional 2 weeks. The mean percentage of larvae starting metamorphosis within 2 weeks was significantly higher in the unfed than in the fed groups (70% vs. 28.6%), suggesting that food deprivation acted as a cue for metamorphosis. The critical size for metamorphosis was a total length of 50–55 mm; smaller larvae did not start metamorphosis even in the absence of food, whereas larvae reaching that critical size were induced to undergo metamorphosis by starvation. The start of metamorphosis under unfed conditions was independent of diel-varying water temperature (day 23 °C; night 21–29 °C), suggesting a high plasticity in response to a wide range of environmental temperatures. These findings suggest methods for the efficient production of glass eels, as well as new insights into the mechanism of eel metamorphosis.
Assessment of the mode of action of polyhexamethylene biguanide against Listeria innocua by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis
Authors: Chadeau Elise , Dumas Emilie , Adt Isabelle , Degraeve Pascal , Noël Claude , Girodet Christophe , Oulahal Nadia 
Published: December 2012

Polyhexamethylene biguanide (PHMB) is a cationic biocide. The antibacterial mode of action of PHMB (at concentrations not exceeding its minimal inhibitory concentration) upon Listeria innocua LRGIA 01 was investigated by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis. Fourier transformed infrared spectra of bacteria treated with or without PHMB presented some differences in the lipids region: the CH2/CH3 (2924 cm–1/2960 cm–1) band areas ratio significantly increased in the presence of PHMB. Since this ratio generally reflects membrane phospholipids and membrane microenvironment of the cells, these results suggest that PHMB molecules interact with membrane phospholipids and, thus, affect membrane fluidity and conformation. To assess the hypothesis of PHMB interaction with L. innocua membrane phospholipids and to clarify the PHMB mode of action, we performed fluorescence anisotropy experiments. Two probes, 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative 1-[4-(trimethyl-amino)-phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH), were used. DPH and TMA-DPH incorporate inside and at the surface of the cytoplasmic membrane, respectively. When PHMB was added, an increase of TMA-DPH fluorescence anisotropy was observed, but no changes of DPH fluorescence anisotropy occurred. These results are consistent with the hypothesis that PHMB molecules perturb L. innocua LRGIA 01 cytoplasmic membrane by interacting with the first layer of the membrane lipid bilayer.
Effects of arsenic trioxide (As2O3) on airway remodeling in a murine model of bronchial asthma
Authors: Xu Zi-ping , Huo Jian-min , Sang Yu-lan , Kang Jian , Li Xue 
Published: December 2012

We investigated the effects of arsenic trioxide (As2O3) as a possible approach for preventing airway remodeling in a murine model of bronchial asthma induced by ovalbumin (OVA) challenge. Forty Balb/c mice were randomly assigned to 1 of 4 groups (10 mice/group) as follows: controls (challenged with sterile saline inhalation only); OVA-challenged, no treatment; OVA-challenged, treated with dexamethasone; and OVA-challenged, treated with As2O3. All mice were sensitized by intraperitoneal injection with 10% OVA at 2 weeks prior to saline or OVA inhalation challenge. Challenges were for 8 weeks. After OVA challenge, typical asthma-like morphology changes in the bronchi and lung tissues were observed by hematoxylin–eosin staining and pulmonary function indices were reduced compared with controls. Changes in pulmonary indices and lung tissues were similar in the dexamethasone and As2O3 groups and were in between those of the untreated and control groups. Compared with the untreated group, transforming growth factor β1, vascular endothelial growth factor, and matrix metalloproteinase-9 protein levels and mRNA expression were decreased in lung tissues of the dexamethasone and As2O3 groups. Our results suggest that steroids and As2O3 can inhibit airway remodeling in chronic asthma by mechanisms related to inhibiting the expression of the 3 aforementioned mediators.
Chiral recognition of doxazosin enantiomers in 3 targets for therapy as well as adverse drug reactions in animal experiments
Authors: Zhao Ding , Duan Li-Hua , Wang Feng-Yu , Wang Miao , Lu Hai-Gang , Wu Zhi-Gang , Wang Xue , Ren Lei-Ming 
Published: December 2012

Doxazosin used in benign prostatic hyperplasia has the side effects of causing hypotension and the risk of heart failure. The 3 targets of α1A-adrenoceptors (in the prostate), α1D-adrenoceptors (in the aorta), and an unknown mechanism (in the heart) are involved, respectively. We hypothesized that there is a chiral recognition of doxazosin enantiomers in the 3 targets. Using isolated rat aorta (α1D-adrenoceptors) and rabbit prostate (α1A-adrenoceptors), we examined pA2 and pKB values of doxazosin enantiomers. We observed chronotropic and inotropic effects of doxazosin enantiomers in isolated rat and rabbit heart tissues. (–)Doxazosin and (+)doxazosin produced a shift to the right of concentration–contraction curves for noradrenalin (aorta) and phenylephrine (prostate smooth muscle). The pA2 value of (–)doxazosin (8.625 ± 0.053) was smaller than (+)doxazosin (9.503 ± 0.051) in rat aorta, but their pKB values in rabbit prostate were the same. In rat and rabbit heart tissues, (+)doxazosin (3–30 µmol·L−1) significantly decreased atrial rate, and produced negative inotropic effects; however, (–)doxazosin did not affect the atrial rate, and produced positive inotropic effects in the atria. Thus, the chiral carbon atom of doxazosin does not affect its activity at the therapeutic target of α1A-adrenoceptors in the prostate, but significantly changes its blocking activity against α1D-adrenoceptors in the aorta, and produces opposite inotropic effects in the atria via an α1-adrenoceptor-independent mechanism.
Effect of dialkyl- [2-(1-oxa-3,4,9-triaza-fluoren-2-yl-methoxy)ethyl] amines on biogenic amines: new potential antidepressants
Authors: Venkatesham Akena , Rao J. Venkateshwar , Kumar K. Vijay , Sarangapani M. , Devarakonda Krishna 
Published: December 2012

A thorough survey of the literature has revealed that indole derivatives have shown various central nervous system activities. This study aims to evaluate the antidepressant activity of the newly synthesized dialkyl- [2-(1-oxa-3,4,9-triaza-fluoren-2-yl-methoxy)ethyl] amines and their effect on biogenic amines. In this study, the synthesized compounds were assessed by in-vivo antidepressant models, by forced swim test and tail suspension test in mice and effect of synthesized compounds on biogenic amines in brain in a chronic unpredictable stress model. The test compounds have demonstrated significant (P < 0.05) reduced immobility duration in mice when compared with the control group animals. The reduced immobility displayed by mice indicates potential antidepressant activity. In this study, chronic unpredictable stress led to decreased monoamine levels in the cortex and hippocampus regions of the brain. With chronic administration of the investigated compounds there is an increased in monoamines in the brain, in the chronic unpredictable stress model. Decreased levels of monoamines induced by the chronic unpredictable stress induced model of depression, were normalized by treatment with the test compounds, which indicates potential antidepressant activity.
Fay
Authors: Erlingsson Úlfar , Peinado Marcus , Peter Simon , Budiu Mihai , Mainar-Ruiz Gloria 
Published: December 2012

Fay is a flexible platform for the efficient collection, processing, and analysis of software execution traces. Fay provides dynamic tracing through use of runtime instrumentation and distributed aggregation within machines and across clusters. At the lowest level, Fay can be safely extended with new tracing primitives, including even untrusted, fully optimized machine code, and Fay can be applied to running user-mode or kernel-mode software without compromising system stability. At the highest level, Fay provides a unified, declarative means of specifying what events to trace, as well as the aggregation, processing, and analysis of those events.
We have implemented the Fay tracing platform for Windows and integrated it with two powerful, expressive systems for distributed programming. Our implementation is easy to use, can be applied to unmodified production systems, and provides primitives that allow the overhead of tracing to be greatly reduced, compared to previous dynamic tracing platforms. To show the generality of Fay tracing, we reimplement, in experiments, a range of tracing strategies and several custom mechanisms from existing tracing frameworks.
Fay shows that modern techniques for high-level querying and data-parallel processing of disagreggated data streams are well suited to comprehensive monitoring of software execution in distributed systems. Revisiting a lesson from the late 1960s [Deutsch and Grant 1971], Fay also demonstrates the efficiency and extensibility benefits of using safe, statically verified machine code as the basis for low-level execution tracing. Finally, Fay establishes that, by automatically deriving optimized query plans and code for safe extensions, the expressiveness and performance of high-level tracing queries can equal or even surpass that of specialized monitoring tools.