bluuebunny/crossref_metadata_2025 huggingface dataset:
Very high dielectric strength for dielectric elastomer actuators in liquid dielectric immersion
Authors: La Thanh-Giang , Lau Gih-Keong
Published: May 2013

This letter reported that a dielectric elastomer actuator (3M VHB), which is immersed in a liquid dielectric bath, is enhanced tremendously in dielectric strength up to 800 MV/m, as compared to 450 MV/m for the actuator operated in air. The bath consists of silicone oil (Dow Corning Fluid 200 50cSt), which is 6.5 times more thermally conductive than air, and it is found able to maintain the actuator at a stable temperature. As a result, the oil-immersed dielectric elastomer actuator is prevented from local thermal runaway, which causes loss of electrical insulation, and consequently avoids the damage by electromechanical instability.
Effect of Calcination Temperature on Catalytic Activity and Textual Property of Cu/HMOR Catalysts in Dimethyl Ether Carbonylation Reaction
Authors: Zhang Xue , Li Yu-ping , Qiu Song-bai , Wang Tie-jun , Ma Long-long , Zhang Qi , Ding Ming-yue
Published: May 2013

The effect of calcination temperature on the catalytic activity for the dimethyl ether (DME) carbonylation into methyl acetate (MA) was investigated over mordenite supported copper (Cu/HMOR) prepared by ion-exchange process. The results showed that the catalytic activity was obviously affected by the calcination temperature. The maximal DME conversion of 97.2% and the MA selectivity of 97.9% were obtained over the Cu/HMOR calcined at 430 °C under conditions of 210 °C, 1.5 MPa, and GSHV of 4883 h−1. The obtained Cu/HMOR catalysts were characterized by powder X-ray diffraction, N2 absorption, NH3 temperature program desorption, CO temperature program desorption, and Raman techniques. Proper calcination temperature was effective to promote copper ions migration and diffusion, and led the support HMOR to possess more acid activity sites, which exhibited the complete decomposing of copper nitrate, large surface area and optimum micropore structure, more amount of CO adsorption site and proper amount of weak acid centers.
Comparison of approaches for reporting forest fire-related biomass loss and greenhouse gas emissions in southern Europe
Authors: Chiriacò Maria Vincenza , Perugini Lucia , Cimini Dora , D'Amato Enrico , Valentini Riccardo , Bovio Giovanni , Corona Piermaria , Barbati Anna
Published: May 2013

Wildfires are the most common disturbances in Mediterranean forest ecosystems that cause significant emissions of greenhouse gases as a result of biomass burning. Despite this, there is reasonably high uncertainty regarding the actual fraction of burnt biomass and the related CO2 and non-CO2 gas emissions released during forest fires. The aim of this paper is to compare existing methodologies adopted in the National Greenhouse Gas Inventory reports of five of the most fire-affected countries of southern Europe (Italy, Spain, Greece, Portugal, France) with those proposed in the literature, to operationally estimate forest fire emissions, and to discuss current perspectives on reducing uncertainties in reporting activities for the Land Use, Land Use Change and Forestry sector under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. Five selected approaches have been experimentally applied for the estimation of burnt biomass in forest fire events that occurred in Italy in the period 2008–2010. Approaches based on nominal rates of biomass loss can lead to an overly conservative value or, conversely, to underestimation of the fraction of burnt biomass. Uncertainties can be greatly reduced by an operational method able to assess inter-annual and local variability of fire effects on fire-affected forest types.
Specialized stem cell niche enables repetitive renewal of alligator teeth
Authors: Wu Ping , Wu Xiaoshan , Jiang Ting-Xin , Elsey Ruth M. , Temple Bradley L. , Divers Stephen J. , Glenn Travis C. , Yuan Kuo , Chen Min-Huey , Widelitz Randall B. , Chuong Cheng-Ming
Published: May 2013

Reptiles and fish have robust regenerative powers for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose their ability for tooth renewal. Here, we study tooth renewal in a crocodilian model, the American alligator, which has well-organized teeth similar to mammals but can still undergo life-long renewal. Each alligator tooth is a complex family unit composed of the functional tooth, successional tooth, and dental lamina. Using multiple mitotic labeling, we map putative stem cells to the distal enlarged bulge of the dental lamina that contains quiescent odontogenic progenitors that can be activated during physiological exfoliation or artificial extraction. Tooth cycle initiation correlates with β-catenin activation and soluble frizzled-related protein 1 disappearance in the bulge. The dermal niche adjacent to the dermal lamina dynamically expresses neural cell adhesion molecule, tenascin-C, and other molecules. Furthermore, in development, asymmetric
β-catenin
localization leads to the formation of a heterochronous and complex tooth family unit configuration. Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals.
Huntington disease skeletal muscle is hyperexcitable owing to chloride and potassium channel dysfunction
Authors: Waters Christopher W. , Varuzhanyan Grigor , Talmadge Robert J. , Voss Andrew A.
Published: May 2013

Huntington disease is a progressive and fatal genetic disorder with debilitating motor and cognitive defects. Chorea, rigidity, dystonia, and muscle weakness are characteristic motor defects of the disease that are commonly attributed to central neurodegeneration. However, no previous study has examined the membrane properties that control contraction in Huntington disease muscle. We show primary defects in ex vivo adult skeletal muscle from the R6/2 transgenic mouse model of Huntington disease. Action potentials in diseased fibers are more easily triggered and prolonged than in fibers from WT littermates. Furthermore, some action potentials in the diseased fibers self-trigger. These defects occur because of decreases in the resting chloride and potassium conductances. Consistent with this, the expression of the muscle chloride channel, ClC-1, in Huntington disease muscle was compromised by improper splicing and a corresponding reduction in totalClcn1(gene for ClC-1) mRNA. Additionally, the totalKcnj2(gene for the Kir2.1 potassium channel) mRNA was reduced in disease muscle. The resulting muscle hyperexcitability causes involuntary and prolonged contractions that may contribute to the chorea, rigidity, and dystonia that characterize Huntington disease.
Significance of activity peaks in fruit flies,
Drosophila melanogaster
, under seminatural conditions
Authors: De Joydeep , Varma Vishwanath , Saha Soham , Sheeba Vasu , Sharma Vijay Kumar
Published: May 2013

Studies on circadian entrainment have traditionally been performed under controlled laboratory conditions. Although these studies have served the purpose of providing a broad framework for our understanding of regulation of rhythmic behaviors under cyclic conditions, they do not reveal how organisms keep time in nature. Although a few recent studies have attempted to address this, it is not yet clear which environmental factors regulate rhythmic behaviors in nature and how. Here, we report the results of our studies aimed at examining (
i
) whether and how changes in natural light affect activity/rest rhythm and (
ii
) what the functional significance of this rhythmic behavior might be. We found that wild-type strains of fruit flies,
Drosophila melanogaster
, display morning (M), afternoon (A), and evening (E) peaks of activity under seminatural conditions (SN), whereas under constant darkness in otherwise SN, they exhibited M and E peaks, and under constant light in SN, only the E peak occurred. Unlike the A peak, which requires exposure to bright light in the afternoon, light information is dispensable for the M and E peaks. Visual examination of behaviors suggests that the M peak is associated with courtship-related locomotor activity and the A peak is due to an artifact of the experimental protocol and largely circadian clock independent.
182
Hf–
182
W age dating of a
26
Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System
Authors: Holst Jesper C. , Olsen Mia B. , Paton Chad , Nagashima Kazuhide , Schiller Martin , Wielandt Daniel , Larsen Kirsten K. , Connelly James N. , Jørgensen Jes K. , Krot Alexander N. , Nordlund Åke , Bizzarro Martin
Published: May 2013

Refractory inclusions [calcium–aluminum-rich inclusions, (CAIs)] represent the oldest Solar System solids and provide information regarding the formation of the Sun and its protoplanetary disk. CAIs contain evidence of now extinct short-lived radioisotopes (e.g.,
26
Al,
41
Ca, and
182
Hf) synthesized in one or multiple stars and added to the protosolar molecular cloud before or during its collapse. Understanding how and when short-lived radioisotopes were added to the Solar System is necessary to assess their validity as chronometers and constrain the birthplace of the Sun. Whereas most CAIs formed with the canonical abundance of
26
Al corresponding to
26
Al/
27
Al of ∼5 × 10
−5
, rare CAIs with fractionation and unidentified nuclear isotope effects (FUN CAIs) record nucleosynthetic isotopic heterogeneity and
26
Al/
27
Al of <5 × 10
−6
, possibly reflecting their formation before canonical CAIs. Thus, FUN CAIs may provide a unique window into the earliest Solar System, including the origin of short-lived radioisotopes. However, their chronology is unknown. Using the
182
Hf–
182
W chronometer, we show that a FUN CAI recording a condensation origin from a solar gas formed coevally with canonical CAIs, but with
26
Al/
27
Al of ∼3 × 10
−6
. The decoupling between
182
Hf and
26
Al requires distinct stellar origins: steady-state galactic stellar nucleosynthesis for
182
Hf and late-stage contamination of the protosolar molecular cloud by a massive star(s) for
26
Al. Admixing of stellar-derived
26
Al to the protoplanetary disk occurred during the epoch of CAI formation and, therefore, the
26
Al–
26
Mg systematics of CAIs cannot be used to define their formation interval. In contrast, our results support
182
Hf homogeneity and chronological significance of the
182
Hf–
182
W clock.
Systematic identification of conserved bacterial c-di-AMP receptor proteins
Authors: Corrigan Rebecca M. , Campeotto Ivan , Jeganathan Tharshika , Roelofs Kevin G. , Lee Vincent T. , Gründling Angelika
Published: May 2013

Nucleotide signaling molecules are important messengers in key pathways that allow cellular responses to changing environments. Canonical secondary signaling molecules act through specific receptor proteins by direct binding to alter their activity. Cyclic diadenosine monophosphate (c-di-AMP) is an essential signaling molecule in bacteria that has only recently been discovered. Here we report on the identification of four
Staphylococcus aureus
c-di-AMP receptor proteins that are also widely distributed among other bacteria. Using an affinity pull-down assay we identified the potassium transporter-gating component KtrA as a c-di-AMP receptor protein, and it was further shown that this protein, together with c-di-AMP, enables
S. aureus
to grow in low potassium conditions. We defined the c-di-AMP binding activity within KtrA to the RCK_C (
r
egulator of
c
onductance of
K
+
) domain. This domain is also found in a second
S. aureus
protein, a predicted cation/proton antiporter, CpaA, which as we show here also directly binds c-di-AMP. Because RCK_C domains are found in proteinaceous channels, transporters, and antiporters from all kingdoms of life, these findings have broad implications for the regulation of different pathways through nucleotide-dependent signaling. Using a genome-wide nucleotide protein interaction screen we further identified the histidine kinase protein KdpD that in many bacteria is also involved in the regulation of potassium transport and a
P
II-like
s
ignal
t
ransduction protein, which we renamed PstA, as c-di-AMP binding proteins. With the identification of these widely distributed c-di-AMP receptor proteins we link the c-di-AMP signaling network to a central metabolic process in bacteria.
Biodegradable synthetic high-density lipoprotein nanoparticles for atherosclerosis
Authors: Marrache Sean , Dhar Shanta
Published: May 2013

Atherosclerosis remains one of the most common causes of death in the United States and throughout the world because of the lack of early detection. Macrophage apoptosis is a major contributor to the instability of atherosclerotic lesions. Development of an apoptosis targeted high-density lipoprotein (HDL)-mimicking nanoparticle (NP) to carry contrast agents for early detection of vulnerable plaques and the initiation of preventative therapies that exploit the vascular protective effects of HDL can be attractive for atherosclerosis. Here, we report the construction of a synthetic, biodegradable HDL-NP platform for detection of vulnerable plaques by targeting the collapse of mitochondrial membrane potential that occurs during apoptosis. This HDL mimic contains a core of biodegradable poly(lactic-
co
-glycolic acid), cholesteryl oleate, and a phospholipid bilayer coat that is decorated with triphenylphosphonium (TPP) cations for detection of mitochondrial membrane potential collapse. The lipid layer provides the surface for adsorption of apolipoprotein (apo) A-I mimetic 4F peptide, and the core contains diagnostically active quantum dots (QDs) for optical imaging. In vitro uptake, detection of apoptosis, and cholesterol binding studies indicated promising detection ability and therapeutic potential of TPP-HDL-apoA-I-QD NPs. In vitro studies indicated the potential of these NPs in reverse cholesterol transport. In vivo biodistribution and pharmacokinetics indicated favorable tissue distribution, controlled pharmacokinetic parameters, and significant triglyceride reduction for i.v.-injected TPP-HDL-apoA-I-QD NPs in rats. These HDL NPs demonstrate excellent biocompatibility, stability, nontoxic, and nonimmunogenic properties, which prove to be promising for future translation in early plaque diagnosis and might find applications to prevent vulnerable plaque progression.
Ribonucleolytic resection is required for repair of strand displaced nonhomologous end-joining intermediates
Authors: Bartlett Edward J. , Brissett Nigel C. , Doherty Aidan J.
Published: May 2013

Significance

Nonhomologous end joining (NHEJ) is a major DNA-break repair pathway in eukaryotes and prokaryotes but is assumed to be absent in archaea. This study establishes that a functionally homologous pathway is present in archaea. We have reconstituted archaeal NHEJ repair in vitro, demonstrating that it is closely related to the bacterial apparatus and preferentially repairs breaks using RNA intermediates. We identify a role for a functionally unascribed nuclease in preventing the accumulation of genotoxic repair intermediates produced by strand displacement. This study has important implications for our understanding of the mechanisms of DNA-break repair by NHEJ and the evolution of end-joining pathways.
The Approximate Number System is not Predictive for Symbolic Number Processing in Kindergarteners
Authors: Sasanguie Delphine , Defever Emmy , Maertens Bieke , Reynvoet Bert
Published: May 2013

The relation between the approximate number system (ANS) and symbolic number processing skills remains unclear. Some theories assume that children acquire the numerical meaning of symbols by mapping them onto the preexisting ANS. Others suggest that in addition to the ANS, children also develop a separate, exact representational system for symbolic number processing. In the current study, we contribute to this debate by investigating whether the nonsymbolic number processing of kindergarteners is predictive for symbolic number processing. Results revealed no association between the accuracy of the kindergarteners on a nonsymbolic number comparison task and their performance on the symbolic comparison task six months later, suggesting that there are two distinct representational systems for the ANS and numerical symbols.
Prevalence of Colonization and Infection with Methicillin-ResistantStaphylococcus aureusand Vancomycin-ResistantEnterococcusand ofClostridium difficileInfection in Canadian Hospitals
Authors: Simor Andrew E. , Williams Victoria , McGeer Allison , Raboud Janet , Larios Oscar , Weiss Karl , Hirji Zahir , Laing Felicia , Moore Christine , Gravel Denise ,   Community and Hospital Infection Control Association–Canada
Published: May 2013

Objective.

To determine the prevalence of methicillin-resistantStaphylococcus aureus(MRSA), vancomycin-resistant enterococci (VRE), andClostridium difficileinfection (CDI) in Canadian hospitals.

Design.

National point prevalence survey in November 2010.

Setting.

Canadian acute care hospitals with at least 50 beds.

Patients.

Adult inpatients colonized or infected with MRSA or VRE or with CDI.

Methods.

The prevalence (per 100 inpatients) of MRSA, VRE, and CDI was determined. Associations between prevalence and institutional characteristics and infection control policies were evaluated.

Results.

One hundred seventy-six hospitals (65% of those eligible) participated. The median (range) prevalence rates for MRSA and VRE colonization or infection and CDI were 4.2% (0%–22.1%), 0.5% (0%–13.1%), and 0.9% (0%–8.6%), respectively. Median MRSA and VRE infection rates were low (0.3% and 0%, respectively). MRSA, VRE, and CDI were thought to have been healthcare associated in 79%, 96%, and 84% of cases, respectively. In multivariable analysis, routine use of a private room for colonized/infected patients was associated with lower median MRSA infection rate (prevalence ratio [PR], 0.44 [95% confidence interval (CI), 0.22–0.88]) and VRE prevalence (PR, 0.26 [95% CI, 0.12–0.57]). Lower VRE rates were also associated with enhanced environmental cleaning (PR, 0.52 [95% CI, 0.36–0.75]). Higher bed occupancy rates were associated with higher rates of CDI (PR, 1.02 [95% CI, 1.01–1.03]).

Conclusions.

These data provide the first national prevalence estimates for MRSA, VRE, and CDI in Canadian hospitals. Certain infection prevention and control policies were found to be associated with prevalence and deserve further investigation.
Estimating Party Positions across Countries and Time—A Dynamic Latent Variable Model for Manifesto Data
Authors: König Thomas , Marbach Moritz , Osnabrügge Moritz
Published: May 2013

This article presents a new method for estimating positions of political parties across country- and time-specific contexts by introducing a latent variable model for manifesto data. We estimate latent positions and exploit bridge observations to make the scales comparable. We also incorporate expert survey data as prior information in the estimation process to avoid ex post facto interpretation of the latent space. To illustrate the empirical contribution of our method, we estimate the left-right positions of 388 parties competing in 238 elections across twenty-five countries and over sixty years. Compared to the puzzling volatility of existing estimates, we find that parties more modestly change their left-right positions over time. We also show that estimates without country- and time-specific bias parameters risk serious, systematic bias in about two-thirds of our data. This suggests that researchers should carefully consider the comparability of party positions across countries and/or time.
First Report of Blackleg Caused by Leptosphaeria maculans on Canola in Idaho
Authors: Agostini A. , Johnson D. A. , Hulbert S. , Demoz B. , Fernando W. G. D. , Paulitz T.
Published: May 2013

Canola (Brassica napus L.) is produced in the dryland agriculture areas of eastern Washington State and northern Idaho, often in rotation with cereal cropping systems. Canola is also used as a rotation crop in irrigated circles in the Columbia Basin of Washington and southern Idaho, where potato is the main cash crop. In 2011, 7,700 ha of canola were harvested in Idaho and 4,200 ha in Washington. One of the major diseases of canola around the world is blackleg, caused by Leptosphaeria maculans (aggressive) and L. biglobosa (non-aggressive). Both Washington and Idaho have been considered blackleg-free, and production of canola in Idaho is subject to government regulations. Canola seed originating from outside of Washington and Idaho should have a phytosanitary certificate. This disease is widespread in Canada and the U.S. Northern Plains, Midwest, and South, and is the major disease of canola in these areas. In August 2011, a sample from a canola field in Bonners Ferry, Idaho, was brought for diagnosis to Washington State University. The canola stems showed the typical gray to dark grey lesions with black pycnidia. The pycnidia and conidia were examined microscopically, and found to be similar to descriptions of Phoma lingam, the anamorph of L. maculans (2). Samples were sent to the University of Manitoba for confirmation with PCR. The pathogen was cultured out of stems on V8 juice agar amended with streptomycin and 22 single pynidiospore isolates were made from the cultures. DNA was extracted from the cultures using methods described in Fernando et al. (1) and a multiplex PCR was performed with species-specific primers for L. maculans and L. biglobosa. The reaction should produce a 330-bp amplicon for L. maculans and a 440-bp amplicon for L. biglobosa. Based on this, all 22 isolates were identified as L. maculans. The susceptible cultivar Westar was inoculated with the isolates, by wound inoculating 7-day-old cotyledons with a concentration of 107 spores/ml. Plants were kept in a moist chamber at 23°C. After 14 days, plants were rated for disease with a 0 to 9 scale, where 0 = no infection and 9 = tissue collapse and appearance of pycnidiospores. Isolates with rating ≥5 are considered virulent. All isolates produced a rating of 7 to 9, indicating a high level of virulence. The source of the seed used in the infested fields is not known at this time. This disease is seedborne, and may pose a threat to the two major vegetable and oilseed brassica seed production areas of Washington: the Skagit River valley of western Washington and the Columbia Basin area of central Washington. In addition, the susceptibility of Pacific Northwest varieties of canola and other brassica oilseeds is largely unknown.

References: (1) W. G. D. Fernando et al. Plant Dis. 90:1337, 2006. (2) S. Roger Rimmer et al. Compendium of Brassica Diseases, APS Press, 2007.
Validation of the Modified Vesikari Score in Children With Gastroenteritis in 5 US Emergency Departments
Authors: Schnadower David , Tarr Phillip I. , Gorelick Marc H. , O'Connell Karen , Roskind Cindy G. , Powell Elizabeth C. , Rao Jayashree , Bhatt Seema , Freedman Stephen B.
Published: May 2013

Objectives:

The burden of acute gastroenteritis (AGE) in US children is substantial. Research into outpatient treatment strategies has been hampered by the lack of easily used and validated gastroenteritis severity scales relevant to the populations studied. We sought to evaluate, in a US cohort, the reliability, construct validity, and generalizability of a gastroenteritis severity scale previously derived in a Canadian population, the modified Vesikari score (MVS).

Methods:

We conducted a prospective, cohort, clinical observational study of children 3 to 48 months of age with acute gastroenteritis presenting to 5 US emergency departments. A baseline MVS score was determined in the emergency department, and telephone follow‐up 14 days after presentation was used to assign the follow‐up MVS. We determined reliability using inter‐item correlations; construct validity via principal component factor analysis; cross‐sectional construct validity via correlations with the presence of dehydration, hospitalization, and day care and parental work absenteeism; and generalizability via score distribution among sites.

Results:

Two hundred eighteen of 274 patients (80%) were successfully contacted for follow‐up. Cronbach α was 0.63, indicating expectedly low internal reliability because of the multidimensional properties of the MVS. Factor analysis supported the appropriateness of retaining all variables in the score. Disease severity correlated with dehydration (P < 0.001), hospitalization (P < 0.001), and subsequent day care (P = 0.01) and work (P < 0.001) absenteeism. The MVS was normally distributed, and scores did not differ among sites.

Conclusions:

The MVS effectively measures global severity of disease and performs similarly in varying populations within the US health care system. Its characteristics support its use in multisite outpatient clinical trials.
Alopecia areata possibly induced by autoimmune reaction in a patient with human T‐cell lymphotropic virus‐1‐associated myelopathy
Authors: Ito Taisuke , Shimada Shinichiro , Mori Tatsuyoshi , Tokura Yoshiki
Published: May 2013

A 38‐year‐old female patient suffered from alopecia areata totalis followed by human T‐cell lymphotropic virus‐1‐associated myelopathy (HAM). These two diseases have recently been considered to be related to cell‐mediated autoimmune reactions. Immunohistochemistry revealed accumulation of CXCR3+ CD8+ T cells around hair bulbs in alopecic lesions. Furthermore, flow cytometric analysis showed the elevated frequency of CD8+ human leukocyte antigen DR+‐activated T cells at the initial time and declined at the hair regrowth phase with HAM. CD4+ CD25+ adult T‐cell leukemia/lymphoma cells were elevated at hair loss phase and decreased after improvement of hair loss. These results suggest that autoreactive and cytotoxic CD8+ T cells induce not only alopecia areata but also HAM in ATL patients. This case highlights that the autoimmune reactions may play an important role in the pathogenesis of alopecia areata and HAM.
Evaluation of the double‐disk synergy test for New Delhi metallo‐β‐lactamase‐1 and other metallo‐β‐lactamase producing gram‐negative bacteria by using metal‐ethylenediaminetetraacetic acid complexes
Authors: Fujisaki Momoko , Sadamoto Shinya , Hishinuma Akira
Published: May 2013

New Delhi metallo‐β‐lactamase‐1 (NDM‐1), one of the metallo‐β‐lactamases (MBLs), has been identified from clinical isolates worldwide. Rapid detection of NDM‐1 producers is necessary to prevent their dissemination. Seven types of EDTA complexes were evaluated as MBL inhibitors in double‐disk synergy tests (DDSTs), resulting in detection of the first isolate of NDM‐1‐producing Escherichia coli (NDM‐1 Dok01) in Japan. NDM‐1 Dok01 was detected when EDTA magnesium disodium salt tetrahydrate (Mg‐EDTA), EDTA calcium disodium salt dihydrate, EDTA cobalt disodium salt tetrahydrate and EDTA copper disodium salt tetrahydrate were used as MBL inhibitors. The sensitivity and specificity of DDSTs using Mg‐EDTA for 75 MBL producers and 25 non‐MBL producers were 96.0% and 100%, respectively. These findings indicate that the DDST method using Mg‐EDTA can detect MBL‐producing strains, including NDM‐1 producers.
An alternative receptor to poly I:C on cell surfaces for interferon induction
Authors: Yoshida Itsuro , Azuma Masanobu
Published: May 2013

Not‐self or denatured nucleic acids are recognized by pattern recognition receptors localized mainly in endosomes and cytoplasm, such as Toll‐like receptor (TLR) 3, TLR7, TLR9, retinoic acid‐inducible gene‐I, DNA‐dependent activator of IFN‐regulatory factors and other receptors. The binding of polyriboinosinic:polyribocytidylic acid (poly I:C), a synthetic dsRNA that robustly induces type I interferon, to a putative cell‐surface receptor on a rabbit kidney cell line, RK13, has been analyzed by the authors and RK13 cells found to capture poly I:C in a specific fashion with sufficient affinity. These findings suggest that an alternative receptor to poly I:C participates in the induction of type 1 interferon, which localizes on cell surfaces. Although the nature of this molecule has not yet been identified, accumulating evidence has led the present authors to speculate that there are undefined classes of RNA‐recognition molecules on cell surfaces and that these are unlikely to be categorized as previously reported dsRNA receptors. Although many years have passed since this possibility was first reported by the present authors, it remains attractive. In this article, previously reported cell‐surface dsRNA receptors are reviewed in comparison with other receptors reported to date that are firmly involved in the innate immune‐sensing of nucleic acids.
Allee effects in ants
Authors: Luque Gloria M. , Giraud Tatiana , Courchamp Franck
Published: May 2013

Allee effects occur when the aggregation of individuals result in mutually beneficial intraspecific interactions whereby individual fitness, or per capita growth rate, increases with the number of individuals. Allee effects are common in social species due to their cooperative behaviours, such as breeding, feeding or defence. Allee effects have important implications for many aspects of basic and applied ecology. Over the past decades, the study of Allee effects has influenced population dynamics, community ecology, endangered species management and invasion biology.

Despite the fact that cooperation is the basis of their social structure, Allee effects have received little attention among eusocial insects. Extreme cooperation is common, and reproductive specialization of individuals occurs due to division of labour. These life‐history traits suggest that the potential contribution of each caste to reproduction and survival may be differential and nonadditive.

We studied Allee effects in the invasive Argentine ant (Linepithema humile). In this species, many queens and workers are present in colonies, which allowed us to explore the differential effects of castes on the presence of Allee effects. In the laboratory, we measured brood production and individual survival in experimental colonies that differed in the initial numbers of queens and workers.

Our results highlight the differential effect of queens and workers on survival and productivity. We found three positive density‐dependent relationships indicative of component Allee effects at the colony level: both workers and queens had a positive effect on the productivity of the other caste, and queens had a positive effect on worker survivorship.

Our experimental results suggest a potential positive feedback between worker and queen abundance, which may have contributed to the evolution of large colony sizes. Our study provides the first evidence of Allee effects in eusocial insects and highlights the need to consider castes separately in population dynamics. Division of labour and differential reproductive rates are factors that should be integrated into the study of Allee effects.
An improved cell separation technique for marine subsurface sediments: applications for high‐throughput analysis using flow cytometry and cell sorting
Authors: Morono Yuki , Terada Takeshi , Kallmeyer Jens , Inagaki Fumio
Published: May 2013

Development of an improved technique for separating microbial cells from marine sediments and standardization of a high‐throughput and discriminative cell enumeration method were conducted. We separated microbial cells from various types of marine sediment and then recovered the cells using multilayer density gradients of sodium polytungstate and/or Nycodenz, resulting in a notably higher percent recovery of cells than previous methods. The efficiency of cell extraction generally depends on the sediment depth; using the new technique we developed, more than 80% of the total cells were recovered from shallow sediment samples (down to 100 meters in depth), whereas ∼ 50% of cells were recovered from deep samples (100–365 m in depth). The separated cells could be rapidly enumerated using flow cytometry (FCM). The data were in good agreement with those obtained from manual microscopic direct counts over the range 104–108 cells cm−3. We also demonstrated that sedimentary microbial cells can be efficiently collected using a cell sorter. The combined use of our new cell separation and FCM/cell sorting techniques facilitates high‐throughput and precise enumeration of microbial cells in sediments and is amenable to various types of single‐cell analyses, thereby enhancing our understanding of microbial life in the largely uncharacterized deep subseafloor biosphere.
Political Parties' Perceptions and Uses of Anti-Semitic Conspiracy Theories in Turkey
Authors: Nefes Türkay Salim
Published: May 2013

Despite its ever-present and at times escalating significance, conspiracy theory is an under-researched topic in the social sciences. This paper analyses the political influence of conspiracy theories by drawing on semi-structured interviews with the representatives of four major political parties from the Turkish parliament about widespread anti-Semitic conspiracy theories regarding Dönmes (converts). The findings indicate that right-wing political parties problematize the secret character of the Dönme community and use the conspiracy theories to express their own ontological insecurities emerging from the Sèvres syndrome. Left-wing and liberal parties conversely dissociate themselves from the conspiratorial rhetoric. The research concludes that the political parties reject or accept the conspiracy theories rationally and in alignment with their own ontological insecurities; by doing so, they pragmatically confirm their individual ideological perspective.
On Elimination in Contests: A Perspective on Output Maximization
Authors: Jiao Qian
Published: May 2013

This paper investigates the desirability of adding a preliminary elimination stage for output maximization in a winner‐take‐all contest framework in which the contestant who achieves the highest (random) output wins. We find that, generally, the desirability of an elimination stage does not monotonically depend on the productivity of the effort; adding a preliminary stage can improve output for both concave and convex production functions. This result contrasts sharply with current insight from effort maximization, which argues that adding a preliminary stage can increase effort supply only if the production function is concave.
Exit and Voice: A Game‐theoretic Analysis of Customer Complaint Management
Authors: Liang Pinghan
Published: May 2013

The present study develops a multi‐agent communication model involving participation decisions to address customer complaint behaviour and the corresponding management policy. Privately informed customers choose among complaining, which is costly, keeping silent and exiting. A firm determines complaint barriers and decides whether to undertake corrective action. It is shown that customers truthfully complain only under a moderate complaint barrier. The observed low complaint/dissatisfaction ratio and costly complaints arise as one equilibrium outcome. Customers' expectations, the precision of signals and the temptation of outside options are identified as the determinants of complaint management policy. Firms are likely to set socially‐excessive complaint barriers.
Decentralization is Dead, Long Live Decentralization! Capital City Reform and Political Rights in Kampala, Uganda
Authors: Gore Christopher D. , Muwanga Nansozi K.
Published: May 2013

African cities are currently experiencing some of the highest population growth rates in the world. Accompanying this growth is constant and continuing pressure on national and local governments to develop political and institutional structures that respond to the multiple demands this demographic change provokes in relation to service delivery, economic development and social wellbeing. In response to these challenges, national governments are reviewing the political and administrative structures of their capital cities, sometimes recentralizing authority. This article examines the reforms to Kampala, capital city of Uganda. The article explains how the national government gradually created the legal conditions necessary to take over the capital city directly, and the political rhetoric and conflict that ensued. We argue that while Kampala had deep internal problems and fared poorly in service delivery, matters were exacerbated by the national government's historical indifference to the city. Moreover, past service delivery failures offered an easy rationale for recentralizing authority. We demonstrate that this recentralization was a well‐planned effort by the central government to regain political control of the capital city. This article illustrates how the national government's recentralization of authority in Kampala is a significant departure from its longstanding policy of democratic decentralization.
Racial/Ethnic Differences in Receipt of Timely Adjuvant Therapy for Older Women with Breast Cancer: Are Delays Influenced by the Hospitals Where Patients Obtain Surgical Care?
Authors: Freedman Rachel A. , He Yulei , Winer Eric P. , Keating Nancy L.
Published: May 2013

Objective

To examine whether hospitals where patients obtain care explain racial/ethnic differences in treatment delay.

Data Source

Surveillance, Epidemiology, and End Results data linked with Medicare claims.

Study Design

We examined delays in adjuvant chemotherapy or radiation for women diagnosed with stage I–III breast cancer during 1992–2007. We used multivariable logistic regression to assess the probability of delay by race/ethnicity and included hospital fixed effects to assess whether hospitals explained disparities.

Principal Findings

Among 54,592 women, black (11.9 percent) and Hispanic (9.9 percent) women had more delays than whites (7.8 percent, p < .0001). After adjustment, black (vs. white) women had higher odds of delay (odds ratio = 1.25, 95 percent confidence interval = 1.10–1.42), attenuated somewhat by including hospital fixed effects (OR = 1.17, 95 percent CI = 1.02–1.33).

Conclusions

Hospitals are the important contributors to racial disparities in treatment delay.
Trends in Racial Disparities for Injured Patients Admitted to Trauma Centers
Authors: Glance Laurent G. , Osler Turner M. , Mukamel Dana B. , Meredith J. Wayne , Li Yue , Qian Feng , Dick Andrew W.
Published: May 2013

Objective

To determine whether outcome disparities between black and white trauma patients have decreased over the last 10 years.

Data Source

Pennsylvania Trauma Outcome Study.

Study Design

We performed an observational cohort study on 191,887 patients admitted to 28 Level 1 and Level II trauma centers. The main outcomes of interest were (1) death, (2) death or major complication, and (3) failure‐to‐rescue. Hospitals were categorized according to the proportion of black patients. Multivariate regression models were used to estimate trends in racial disparities and to assess whether the source of racial disparities was within or between hospitals.

Principal Findings

Trauma patients admitted to hospitals with high concentrations of blacks (>20 percent) had a 45 percent higher odds of death (adj OR: 1.45, 95 percent CI: 1.09–1.92) and a 73 percent higher odds of death or major complication (adj OR: 1.73, 95 percent CI: 1.42–2.11) compared with patients admitted to hospitals treating low proportions of blacks. Blacks and whites admitted to the same hospitals had no difference in mortality (adj OR: 1.05, 95 percent CI: 0.87, 1.27) or death or major complications (adj OR: 1.01; 95 percent CI: 0.90, 1.13). The odds of overall mortality, and death or major complications have been reduced by 32 percent (adj OR: 0.68; 95 percent CI: 0.54–0.86) and 28 percent (adj OR: 0.72; 95 percent CI: 0.60–0.85) between 2000 and 2009, respectively. Racial disparities did not change over 10 years.

Conclusion

Despite the overall improvement in outcomes, the gap in quality of care between black and white trauma patients in Pennsylvania has not narrowed over the last 10 years. Racial disparities in trauma are due to the fact that black patients are more likely to be treated in lower quality hospitals compared with whites.
Patient‐controlled analgesia‐based pain control strategy for minimally‐invasive pectus excavatum repair
Authors: Bogert James N. , Potter Donald Dean , Moir Christopher R. , Haile Dawit , Wilder Robert T.
Published: May 2013

Aim

The minimally‐invasive Nuss procedure has become the preferred technique for pectus excavatum repair. This procedure is still associated with significant postoperative pain, and an optimal pain‐management strategy is yet to be determined. The purpose of this study was to compare the efficacy of patient‐controlled analgesia (PCA) to thoracic epidural analgesia (TEA).

Patients and Methods

We retrospectively reviewed 112 charts from a single paediatric centre. Patients were grouped according to pain‐management strategy: 90 patients received a PCA, and 22 patients received TEA. Outcomes included length of hospitalization and daily pain scores, operating room time and duration of Foley catheterization.

Results

Demographic data were similar between the two groups. The daily pain scores were not statistically different between the groups. Length of hospitalization was similar (PCA: 4.6 days, epidural: 4.3 days, P = 0.33). The PCA group required less operating room time (2:44 vs 2:58, P = 0.04) and shorter Foley catheter duration (2.1 days vs 2.5 days, P = 0.04).

Conclusion

In our patient population, TEA for the Nuss procedure does not offer an advantage over PCA‐centred analgesia in terms of subjective daily pain scores or length of hospital stay. The potential risks of TEA need to be carefully considered in this patient population.
Development of Emergency Medicine in Europe
Authors: Totten Vicken , Bellou Abdelouahab
Published: May 2013

Emergency medicine (EM) is emerging worldwide. Its development as a recognized specialty is proceeding at difference rates in different countries. Europe is a region with complex political affiliations and is composed of countries both within and outside the European Union (EU). Europe is seeking greater standardization (harmonization) for mutually improved economic development. Medicine in general, and EM in particular, is no exception. In Europe, as in other regions, EM is struggling for acceptance as a valid field of specialization. The European Union of Medical Specialists requires that once two‐fifths of countries acknowledge a specialty, all EU countries must address the question. EM had achieved the needed majority by 2011. This article briefly describes the European road to specialty acceptance.
Improving Telephone Follow‐up for Patients Discharged from the Emergency Department: Results of a Randomized Controlled Trial
Authors: Menchine Michael , Oberfoell Stephanie , Schriger David , Walker Christopher , Riddell Jeff , Arora Sanjay
Published: May 2013

Objectives

Reliable telephone follow‐up offers physicians a timely method to notify patients of unexpected laboratory and imaging results, clarify discharge instructions, evaluate health status changes, and potentially boost patient satisfaction. This study sought to determine if verifying telephone numbers, obtaining best contact times, and informing patients that they will be contacted would increase the proportion of emergency department (ED) patients contacted at 48 to 72 hours postdischarge. Secondary outcomes included estimating successful postdischarge follow‐up across demographic categories.

Methods

This was a prospective, randomized controlled trial of adult patients in an inner‐city, public hospital ED. Patients were excluded for critical illness, no telephone number, non–English‐ or non–Spanish‐speaking, or anyone admitted as an inpatient. All subjects completed a demographic questionnaire. In the intervention arm, research assistants (RAs) verified the telephone number, obtained best contact times, and informed subjects that they would be called. In the control arm, telephone numbers were obtained from registration materials and were not verified, and subjects were not informed that postdischarge telephone calls were planned. RAs made four telephone attempts to contact each subject 48 to 72 hours after discharge.

Results

The intervention did not significantly improve postdischarge contact. Most subjects, 72.8% in the intervention group and 68.2% in the control group, were successfully contacted (difference = 4.6%, 95% confidence interval [CI] = –2.2% to 11.4%). On multivariate analysis, Hispanic ethnicity and owning a mobile phone were associated with increased odds of successful postdischarge follow‐up.

Conclusions

Verifying contact information, obtaining best contact times, and notifying patients of impending follow‐up calls did not substantially improve postdischarge telephone contact rates.
Crotaline Fab Antivenom Reverses Platelet Dysfunction Induced by Crotalus scutulatus Venom: An In Vitro Study
Authors: Carstairs Shaun D. , Kreshak Allyson A. , Tanen David A.
Published: May 2013

Background

Patients sustaining rattlesnake envenomation often develop thrombocytopenia, the etiology of which is not clear. Laboratory studies have demonstrated that venom from several species, including the Mojave rattlesnake (Crotalus scutulatus scutulatus), can inhibit platelet aggregation. In humans, administration of crotaline Fab antivenom has been shown to result in transient improvement of platelet levels; however, it is not known whether platelet aggregation also improves after antivenom administration.

Objectives

The objective was to determine the effect of C. scutulatus venom on platelet aggregation in vitro in the presence and absence of crotaline Fab antivenom.

Methods

Blood was obtained from four healthy male adult volunteers not currently using aspirin, nonsteroidal anti‐inflammatory drugs, or other platelet‐inhibiting agents. C. scutulatus venom from a single snake with known type B (hemorrhagic) activity was obtained from the National Natural Toxins Research Center. Measurement of platelet aggregation by an aggregometer was performed using five standard concentrations of epinephrine (a known platelet aggregator) on platelet‐rich plasma over time, and a mean area under the curve (AUC) was calculated. Five different sample groups were measured: 1) blood alone, 2) blood + C. scutulatus venom (0.3 mg/mL), 3) blood + crotaline Fab antivenom (100 mg/mL), 4) blood + venom + antivenom (100 mg/mL), and 5) blood + venom + antivenom (4 mg/mL). Standard errors of the mean (SEM) were calculated for each group, and paired t‐tests were used to measure differences between groups.

Results

Antivenom administration by itself (group 2) did not significantly affect platelet aggregation compared to baseline (103.8%, SEM ± 3.4%, p = 0.47). Administration of venom (group 3) decreased platelet aggregation (72.0%, SEM ± 8.5%, p < 0.05). Concentrated antivenom administration in the presence of venom (group 4) normalized platelet aggregation (101.4%, SEM ± 6.8%) and in the presence of diluted antivenom (group 5) significantly increased aggregation (133.9%, SEM ± 9.0%; p < 0.05 for both groups when compared to the venom‐only group). To further assess the effects of the venom and antivenom, each was run independently in platelet‐rich plasma without epinephrine; neither was found to significantly alter platelet aggregation in the absence of epinephrine.

Conclusions

Crotaline Fab antivenom improved platelet aggregation in an in vitro model of platelet dysfunction induced by venom from C. scutulatus. It is unclear at this time whether this improvement in platelet dysfunction translates into improved clinical outcomes in envenomated patients.