bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Requirements for T Cell Recognition of N-Myristoylated Peptides Derived from the Simian Immunodeficiency Virus Nef Protein
Authors: Morita Daisuke , Yamamoto Yukie , Suzuki Juri , Mori Naoki , Igarashi Tatsuhiko , Sugita Masahiko
Published: October 2012

We have recently isolated a rhesus macaque cytotoxic T cell line, 2N5.1, that specifically recognizes an N-myristoylated 5-mer peptide (C
14
-Gly-Gly-Ala-Ile-Ser [C14nef5]) derived from the simian immunodeficiency virus (SIV) Nef protein. Such C14nef5-specific T cells expand in the circulation of SIV-infected monkeys, underscoring the capacity of T cells to recognize viral lipopeptides; however, the molecular basis for the lipopeptide antigen presentation remains to be elucidated. Here, functional studies indicated that the putative antigen-presenting molecule for 2N5.1 was likely to have two separate antigen-binding sites, one for interaction with a C
14
-saturated acyl chain and the other for anchorage of the C-terminal serine residue. Mutants with alanine substitutions for the second glycine residue and the fourth isoleucine residue were not recognized by 2N5.1 but interfered with the presentation of C14nef5 to 2N5.1, indicating that these structural analogues retained the ability to interact with the antigen-presenting molecules. In contrast to the highly specific recognition of C14nef5 by 2N5.1, an additional cytotoxic T cell line, SN45, established independently from a C14nef5-stimulated T cell culture, showed superb reactivity to both C14nef5 and an N-myristoylated Nef 4-mer peptide, and therefore, the C-terminal serine residue was dispensable for the recognition of lipopeptides by the SN45 T cells. Furthermore, the mutants with alanine substitutions were indeed recognized by the SN45 T cells. Given that N-myristoylation of the Nef protein occurs in the conserved motifs and is critical for viral pathogenesis, these observations predict that the lipopeptide-specific T cell response is difficult for viruses to avoid by simply introducing amino acid mutations.
Genomic Characterization of Japanese Macaque Rhadinovirus, a Novel Herpesvirus Isolated from a Nonhuman Primate with a Spontaneous Inflammatory Demyelinating Disease
Authors: Estep Ryan D. , Hansen Scott G. , Rogers Kelsey S. , Axthelm Michael K. , Wong Scott W.
Published: October 2012

Japanese macaque rhadinovirus (JMRV) is a novel gamma-2 herpesvirus that was isolated from a Japanese macaque (JM) with an inflammatory demyelinating encephalomyelitis referred to as Japanese macaque encephalomyelitis, a disease that possesses clinical and histopathological features resembling multiple sclerosis in humans. Genomic DNA sequence analysis reveals that JMRV is a gammaherpesvirus closely related to rhesus macaque rhadinovirus (RRV) and human herpesvirus 8. We describe here the complete nucleotide sequence and structure of the JMRV genome, as well as the sequence of two plaque isolates of this virus. Analysis of the JMRV genome not only demonstrates that this virus shares a number of genes with RRV that may be involved in pathogenesis but also indicates the presence of unique JMRV genes that could potentially contribute to disease development. The knowledge of the genomic sequence of JMRV, and the ability to easily propagate the virus
in vitro
, make JMRV infection of JM an attractive model for examining the potential role of an infectious viral agent in the development of demyelinating encephalomyelitis disease
in vivo
.
Deep RNA Sequencing Reveals Complex Transcriptional Landscape of a Bat Adenovirus
Authors: Wu Lijun , Zhou Peng , Ge Xingyi , Wang Lin-Fa , Baker Michelle L. , Shi Zhengli
Published: October 2012

Bat adenoviruses are a group of recently identified adenoviruses (AdVs) which are highly prevalent in bats yet share low similarity to known AdVs from other species. In this study, deep RNA sequencing was used to analyze the transcriptome at five time points following the infection of a bat AdV in a kidney cell line derived from a myotis bat species. Evidence of AdV replication was observed with the proportion of viral RNAs ranging from 0.01% at 6 h to 1.3% at 18 h. Further analysis of viral temporal gene expression revealed three replication stages, the early-stage genes encoding mainly host interaction proteins, the intermediate-stage genes for the DNA replication and assembly proteins, and the late-stage genes for most structural proteins. Several bat AdV genes were expressed at stages that differed from those of their counterpart genes previously reported for human AdV type 2. In addition, single-base resolution splice sites of several genes and promoter regions of all 30 viral genes were fully determined. Simultaneously, the temporal cellular gene expression profiles were identified. The most overrepresented functional categories of the differentially expressed genes were related to cellular immune response, transcription, translation, and DNA replication and repair. Taken together, the deep RNA sequencing provided a global, transcriptional profile of the novel bat AdV and the virus-host interactions which will be useful for the understanding and investigation of AdV replication, pathogenesis, and specific virus-bat interactions in future research.
ADP Ribosylation Factor 1 Plays an Essential Role in the Replication of a Plant RNA Virus
Authors: Hyodo Kiwamu , Mine Akira , Taniguchi Takako , Kaido Masanori , Mise Kazuyuki , Taniguchi Hisaaki , Okuno Tetsuro
Published: October 2012

Eukaryotic positive-strand RNA viruses replicate using the membrane-bound replicase complexes, which contain multiple viral and host components. Virus infection induces the remodeling of intracellular membranes. Virus-induced membrane structures are thought to increase the local concentration of the components that are required for replication and provide a scaffold for tethering the replicase complexes. However, the mechanisms underlying virus-induced membrane remodeling are poorly understood. RNA replication of red clover necrotic mosaic virus (RCNMV), a positive-strand RNA plant virus, is associated with the endoplasmic reticulum (ER) membranes, and ER morphology is perturbed in RCNMV-infected cells. Here, we identified ADP ribosylation factor 1 (Arf1) in the affinity-purified RCNMV RNA-dependent RNA polymerase fraction. Arf1 is a highly conserved, ubiquitous, small GTPase that is implicated in the formation of the coat protein complex I (COPI) vesicles on Golgi membranes. Usingin vitropulldown and bimolecular fluorescence complementation analyses, we showed that Arf1 interacted with the viral p27 replication protein within the virus-induced large punctate structures of the ER membrane. We found that inhibition of the nucleotide exchange activity of Arf1 using the inhibitor brefeldin A (BFA) disrupted the assembly of the viral replicase complex and p27-mediated ER remodeling. We also showed that BFA treatment and the expression of dominant negative Arf1 mutants compromised RCNMV RNA replication in protoplasts. Interestingly, the expression of a dominant negative mutant of Sar1, a key regulator of the biogenesis of COPII vesicles at ER exit sites, also compromised RCNMV RNA replication. These results suggest that the replication of RCNMV depends on the host membrane traffic machinery.
THE VELDKAMP SPACE OF THE SMALLEST SLIM DENSE NEAR HEXAGON
Authors: GREEN R. M. , SANIGA METOD
Published: October 2012

We give a detailed description of the Veldkamp space of the smallest slim dense near hexagon. This space is isomorphic to PG(7,2) and its 28- 1 = 255 Veldkamp points (that is, geometric hyperplanes of the near hexagon) fall into five distinct classes, each of which is uniquely characterized by the number of points/lines as well as by a sequence of the cardinalities of points of given orders and/or that of (grid-)quads of given types. For each type we also give its weight, stabilizer group within the full automorphism group of the near hexagon and the total number of copies. The totality of (255 choose 2)/3 = 10,795 Veldkamp lines split into 41 different types. We give a complete classification of them in terms of the properties of their cores (i.e. subconfigurations of points and lines common to all the three hyperplanes comprising a given Veldkamp line) and the types of the hyperplanes they are composed of. These findings may lend themselves into important physical applications, especially in view of recent emergence of a variety of closely related finite geometrical concepts linking quantum information with black holes.
NONCOMMUTATIVE MIXMASTER COSMOLOGIES
Authors: ESTRADA CHRISTOPHER , MARCOLLI MATILDE
Published: October 2012

In this paper we investigate a variant of the classical mixmaster universe model of anisotropic cosmology, where the spatial sections are noncommutative 3-tori. We consider ways in which the discrete dynamical system describing the mixmaster dynamics can be extended to act on the noncommutative torus moduli, and how the resulting dynamics differs from the classical one, for example, in the appearance of exotic smooth structures. We discuss properties of the spectral action, focussing on how the slow-roll inflation potential determined by the spectral action affects the mixmaster dynamics. We relate the model to other recent results on spectral action computation and we identify other physical contexts in which this model may be relevant.
CARTAN SPACES AND NATURAL FOLIATIONS ON THE COTANGENT BUNDLE
Authors: ATTARCHI H. , REZAII M. M.
Published: October 2012

In this paper, the natural foliations in cotangent bundle T*M of Cartan space (M, K) is studied. It is shown that geometry of these foliations are closely related to the geometry of the Cartan space (M, K) itself. This approach is used to obtain new characterizations of Cartan spaces with negative constant curvature.
Large molecule protein feeding during the suckling period is required for the development of pancreatic digestive functions in rats
Authors: Kinouchi Toshi , Koyama Satomi , Harada Etsumori , Yajima Takaji
Published: October 2012

We examined if large molecule protein feeding during the suckling period is prerequisite for the proper development of pancreatic digestive functions. Most amino acids in breast milk exist as the constituent of large proteins and not as oligopeptides or free amino acids. Accumulating evidence indicates the nutritional importance of large protein feeding for suckling infants; however, evidence on the physiological significance remains small. We thus artificially reared rat pups on a standard rat formula with milk protein or a formula with milk protein hydrolysate from 7 to 21 days of age, and thereafter, fed a standard solid diet until 42 days of age. Pancreas weight and the stock of pancreatic digestive enzymes in the hydrolysate-fed rats were significantly lower than those in the protein-fed rats during and also after the suckling period. Plasma insulin, a stimulator of amylase synthesis, was also significantly low in the hydrolysate-fed rats compared with the protein-fed rats. At 28 days of age, we evaluated the pancreatic secretory ability in response to dietary protein and cholecystokinin (CCK) by means of pancreatic duct cannulation. Pancreatic secretion stimulated by dietary protein in the hydrolysate-fed rats was significantly weaker than that in the protein-fed rats. No significant difference was observed in the increasing rate of pancreatic enzyme secretion in response to CCK between the two groups. These results suggest that the presence of large proteins in breast milk is significant for the development of pancreatic digestive functions and the outcomes could remain even later on in life.
Role of protein kinase C-α in hypertonicity-stimulated urea permeability in mouse inner medullary collecting ducts
Authors: Wang Yanhua , Klein Janet D. , Froehlich Otto , Sands Jeff M.
Published: October 2012

The kidney's ability to concentrate urine is vitally important to our quality of life. In the hypertonic environment of the kidney, urea transporters must be regulated to optimize function. We previously showed that hypertonicity increases urea permeability and that the protein kinase C (PKC) blockers chelerythrine and rottlerin decreased hypertonicity-stimulated urea permeability in rat inner medullary collecting ducts (IMCDs). Because PKCα knockout (PKCα−/−) mice have a urine-concentrating defect, we tested the effect of hypertonicity on urea permeability in isolated perfused mouse IMCDs. Increasing the osmolality of perfusate and bath from 290 to 690 mosmol/kgH2O did not change urea permeability in PKCα−/−mice but significantly increased urea permeability in wild-type mice. To determine whether the response to protein kinase A was also missing in IMCDs of PKCα−/−mice, tubules were treated with vasopressin and subsequently with the PKC stimulator phorbol dibutyrate (PDBu). Vasopressin stimulated urea permeability in PKCα−/−mice. Like vasopressin, forskolin stimulated urea permeability in PKCα−/−mice. We previously showed that, in rats, vasopressin and PDBu have additive stimulatory effects on urea permeability. In contrast, in PKCα−/−mice, PDBu did not further increase vasopressin-stimulated urea permeability. Western blot analysis showed that expression of the UT-A1 urea transporter in IMCDs was increased in response to vasopressin in wild-type mice as well as PKCα−/−mice. Hypertonicity increased UT-A1 phosphorylation in wild-type mice but not in PKCα−/−mice. We conclude that PKCα mediates hypertonicity-stimulated urea transport but is not necessary for vasopressin stimulation of urea permeability in mouse IMCDs.
The Activation of MAPK in Melanoma Cells Resistant to BRAF Inhibition Promotes PD-L1 Expression That Is Reversible by MEK and PI3K Inhibition
Authors: Jiang Xiaofeng , Zhou Jun , Giobbie-Hurder Anita , Wargo Jennifer , Hodi F. Stephen
Published: October 2012

Purpose: Selective BRAF inhibition (BRAFi) provides a paradigm shift for melanoma treatment. The duration of benefit is typically limited before resistance develops. Interest remains in combining targeted and immune therapies to overcome resistance and improve durability of clinical benefit. One mechanism of evading immune destruction is programmed death-1-ligand 1 (PD-L1) expression by tumors that results in potent antitumor immune suppression.

Experimental Design: BRAFi-resistant melanoma cells were examined for changes in PD-L1 expression by immunoblot and flow cytometry. Signaling pathways involved in altering PD-L1 expression were examined. Strategies to maximize the effect of the BRAFi therapy were studied including MEKi, MEKi combinations, and additional pathways including phosphoinositide-3 kinase (PI3K).

Results: Melanoma cells resistant to BRAFi exhibit increased MAPK signaling and promotion of PD-L1 expression. PD-L1 expression is transcriptionally modulated by c-Jun and augmented by STAT3. MEK inhibition (MEKi) regains downregulation of MAPK signaling and suppresses the production of PD-L1. MEKi in melanoma cells shows dual therapeutic effects with simultaneous suppression of PD-L1 expression and induction of apoptosis. By combining MEKi with BRAFi, an additive effect on the inhibition of PD-L1 expression results.

Conclusions: We report a novel mechanism that suppresses preexisting immune responses in patients with melanoma receiving BRAFi therapy. BRAFi resistance leads to increased expression of PD-L1 in melanoma cells, mediated by c-Jun and STAT3. MEKi may be feasible to counteract BRAFi resistance of MAPK reactivation and also for the additive effect of PD-L1 suppression. Potential therapeutic benefits of combining targeted inhibitors and immune modulation to improve patient outcomes should be investigated. Clin Cancer Res; 19(3); 598–609. ©2012 AACR.
Some Video Abstraction Techniques for Displaying Body Movement in Analysis and Performance
Authors: Jensenius Alexander Refsum
Published: October 2012

This paper presents an overview of techniques for creating visual displays of human body movement based on video recordings. First a review of early movement and video visualization techniques is given. Then follows an overview of techniques that the author has developed and used in the study of music-related body movements: motion history images, motion average images, motion history keyframe images and motiongrams. Finally, examples are given of how such visualization techniques have been used in empirical music research, in medical research and for creative applications.
Early Visions of Interactivity: The In(put)s and Out(put)s of Real-Time Computing
Authors: Utterson Andrew
Published: October 2012

Analyzing technical and other texts of the late 1960s and early 1970s, this paper explores the early discourses of interactivity—including writings by Charles Csuri, J.C.R. Licklider, Michael Noll, Ivan Sutherland and other notable figures—via the intersecting fields of computing and the arts, with a particular emphasis on the dynamic (in this instance, a disjuncture) between visionary ideas and the technical preconditions necessary for their realization.
Surface Irradiances Consistent with CERES-Derived Top-of-Atmosphere Shortwave and Longwave Irradiances
Authors: Kato Seiji , Loeb Norman G. , Rose Fred G. , Doelling David R. , Rutan David A. , Caldwell Thomas E. , Yu Lisan , Weller Robert A.
Published: October 2012

The estimate of surface irradiance on a global scale is possible through radiative transfer calculations using satellite-retrieved surface, cloud, and aerosol properties as input. Computed top-of-atmosphere (TOA) irradiances, however, do not necessarily agree with observation-based values, for example, from the Clouds and the Earth’s Radiant Energy System (CERES). This paper presents a method to determine surface irradiances using observational constraints of TOA irradiance from CERES. A Lagrange multiplier procedure is used to objectively adjust inputs based on their uncertainties such that the computed TOA irradiance is consistent with CERES-derived irradiance to within the uncertainty. These input adjustments are then used to determine surface irradiance adjustments. Observations by the Atmospheric Infrared Sounder (AIRS), Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat, and Moderate Resolution Imaging Spectroradiometer (MODIS) that are a part of the NASA A-Train constellation provide the uncertainty estimates. A comparison with surface observations from a number of sites shows that the bias [root-mean-square (RMS) difference] between computed and observed monthly mean irradiances calculated with 10 years of data is 4.7 (13.3) W m−2 for downward shortwave and −2.5 (7.1) W m−2 for downward longwave irradiances over ocean and −1.7 (7.8) W m−2 for downward shortwave and −1.0 (7.6) W m−2 for downward longwave irradiances over land. The bias and RMS error for the downward longwave and shortwave irradiances over ocean are decreased from those without constraint. Similarly, the bias and RMS error for downward longwave over land improves, although the constraint does not improve downward shortwave over land. This study demonstrates how synergetic use of multiple instruments (CERES, MODIS, CALIPSO, CloudSat, AIRS, and geostationary satellites) improves the accuracy of surface irradiance computations.
Climate Feedbacks in CCSM3 under Changing CO2 Forcing. Part II: Variation of Climate Feedbacks and Sensitivity with Forcing
Authors: Jonko Alexandra K. , Shell Karen M. , Sanderson Benjamin M. , Danabasoglu Gokhan
Published: October 2012

Are equilibrium climate sensitivity and the associated radiative feedbacks a constant property of the climate system, or do they change with forcing magnitude and base climate? Using the radiative kernel technique, feedbacks and climate sensitivity are evaluated in a fully coupled general circulation model (GCM) for three successive doublings of carbon dioxide starting from present-day concentrations. Climate sensitivity increases by 23% between the first and third CO2 doublings. Increases in the positive water vapor and cloud feedbacks are partially balanced by a decrease in the positive surface albedo feedback and an increase in the negative lapse rate feedback. Feedbacks can be decomposed into a radiative flux change and a climate variable response to temperature change. The changes in water vapor and Planck feedbacks are due largely to changes in the radiative response with climate state. Higher concentrations of greenhouse gases and higher temperatures lead to more absorption and emission of longwave radiation. Changes in cloud feedbacks are dominated by the climate response to temperature change, while the lapse rate and albedo feedbacks combine elements of both. Simulations with a slab ocean model (SOM) version of the GCM are used to verify whether an SOM-GCM accurately reproduces the behavior of the fully coupled model. Although feedbacks differ in magnitude between model configurations (with differences as large as those between CO2 doublings for some feedbacks), changes in feedbacks between CO2 doublings are consistent in sign and magnitude in the SOM-GCM and the fully coupled model.
Seasonal Prediction of Arctic Sea Ice Extent from a Coupled Dynamical Forecast System
Authors: Wang Wanqiu , Chen Mingyue , Kumar Arun
Published: October 2012

While fully coupled atmosphere–ocean models have been used to study the seasonal predictability of sea ice variations within the context of models’ own variability, their capability in predicting the observed sea ice at the seasonal time scales is not well assessed. In this study, sea ice predictions from the recently developed NCEP Climate Forecast System, version 2 (CFSv2), a fully coupled atmosphere–ocean model including an interactive dynamical sea ice component, are analyzed. The focus of the analysis is the performance of CFSv2 in reproducing observed Northern Hemisphere sea ice extent (SIE). The SIE climatology, long-term trend, interannual variability, and predictability are assessed. CFSv2 contains systematic biases that are dependent more on the forecast target month than the initial month, with a positive SIE bias for the forecast for January–September and a negative SIE bias for the forecast for October–December. A large source of seasonal prediction skill is from the long-term trend, which is underestimated in the CFSv2. Prediction skill of interannual SIE anomalies is found to be primarily within the first three target months and is largest in the summer and early fall. The performance of the prediction of sea ice interannual variations varies from year to year and is found to be related to initial sea ice thickness. Potential predictability based on the forecast ensemble, its dependence on model deficiencies, and implications of the results from this study for improvements in the seasonal sea ice prediction are discussed.
Tropical Cyclone Formation Guidance Using Pregenesis Dvorak Climatology. Part I: Operational Forecasting and Predictive Potential
Authors: Cossuth Joshua H. , Knabb Richard D. , Brown Daniel P. , Hart Robert E.
Published: October 2012

While there are a variety of modes for tropical cyclone (TC) development, there have been relatively few efforts to systematically catalog both nondeveloping and developing cases. This paper introduces an operationally derived climatology of tropical disturbances that were analyzed using the Dvorak technique at the National Hurricane Center (NHC) and the Central Pacific Hurricane Center from 2001 to 2011. Using these Dvorak intensity estimates, the likelihood of genesis is calculated as a historical baseline for TC prediction. Despite the limited period of record, the climatology of Dvorak analyses of incipient tropical systems has a spatial distribution that compares well with previous climatologies. The North Atlantic basin shows substantial regional variability in Dvorak classification frequency. In contrast, tropical disturbances in the combined eastern and central North Pacific basins (which split at 125°W into an eastern region and a central region) have a single broad frequency maximum and limited meridional extent. When applied to forecasting, several important features are discovered. Dvorak fixes are sometimes unavailable for disturbances that develop into TCs, especially at longer lead times. However, when probabilities of genesis are calculated by a Dvorak current intensity (CI) number, the likelihood stratifies well by basin and intensity. Tropical disturbances that are analyzed as being stronger (a higher Dvorak CI number) achieve genesis more often. Further, all else being equal, genesis rates are highest in the eastern Pacific, followed by the Atlantic. Out-of-sample verification of predictive skill shows comparable results to that of the NHC, with potential to inform forecasts and provide the first disturbance-centric baseline for tropical cyclogenesis potential.
Experimental analysis of mold filling in vacuum assisted compression resin transfer molding
Authors: Chang Chih-Yuan
Published: October 2012

Vacuum-assisted compression resin transfer molding, a flexible resin transfer molding process, has been developed to reduce a cycling period in the present study. The vacuum-assisted compression resin transfer molding utilizes an extra elastic film placed between the upper mold and the mold cavity compared with resin transfer molding. Through the stretchable film, the state of the fabric stack is under control. During resin injection, a loose fiber stack is present and then resin is easily introduced into the cavity. Once enough amount of resin is injected, a compression pressure is applied on the film that compacts the preform and drives the resin through the preform. Prior to vacuum-assisted compression resin transfer molding experiment, a compression test is performed to understand the variation of the preform thickness at various loads. Through observing vacuum-assisted compression resin transfer molding experiments, some experimental shortcomings are inevitable including the edge effect and excess of injected resin. More resin leads to a longer injection and compression phase and more wastes. At all events, vacuum-assisted compression resin transfer molding is a feasible process and can be expected to fabricate a better part quality. It also reduces the mold filling time/injection pressure and cleaning mold time compared with resin transfer molding.
Preparation and characterization of graft copolymerized Cannabis indica L. fiber-reinforced unsaturated polyester matrix-based biocomposites
Authors: Singha Amar S , Rana Ashvinder K
Published: October 2012

In present manuscript, Cannabis indica L. fibers were graft copolymerized in air with acrylonitrile using redox initiator system in order to improve the mechanical properties of Cannabis indica L/unsaturated polyester composites. The various reaction parameters such as time, temperature, pH, concentration of initiator, nitric acid and monomer were optimized to get maximum graft yield. The kinetics of the graft copolymerization of acrylonitrile was also studied. The physical, chemical and thermal properties of grafted fibers have also been investigated. Further, both raw and grafted fibers in particle form with different loading (10, 20, 30 and 40%) were used as reinforcement to prepare unsaturated polyester matrix-based green polymer composites. Effects of particles loading on mechanical properties like tensile, compressive and flexural strength have been determined and were found to affect significantly by percent loading. A considerable increase in mechanical properties has been observed after reinforcing the neat resin with grafted particles. Further scanning electron microscopic, thermogravimetric analysis, differential scanning calorimetric and chemical resistance measurements were used as characterization techniques to evaluate different behavior of these polymer composites.
Comparative studies of mechanical and morphological properties of polylactic acid and polypropylene based natural fiber composites
Authors: Bajpai Pramendra Kumar , Singh Inderdeep , Madaan Jitendra
Published: October 2012

In this study, natural fiber reinforced polylactic acid composites have been developed by hot pressing through film-stacking procedure. The reinforcement materials used are nettle, Grewia optiva and sisal fibers in the plain weave form. For comparison purposes, polypropylene-based composites using the same fibers have also been developed. Mechanical properties (tensile, compressive, flexural, and impact properties) of all the developed composites have been evaluated through standard test procedures. It has been found that the polylactic acid based composites have superior mechanical properties and can be a potential substitute for traditional synthetic fiber composites in many application areas. Polylactic acid/sisal composite showed overall the best performance in terms of mechanical behavior. The morphological study of the fractured surface during mechanical testing has been done using scanning electron microscopy, which provides the mechanism of failure of composites during different types of mechanical loadings.
Improving out-of-plane behavior of aerated concrete walls with carbon fiber-reinforced polymer strips
Authors: Anil Özgür , Tatayoğlu Muhammed
Published: October 2012

Aerated concrete walls, mostly used in reinforced concrete structures, can be damaged under dynamic forces such as earthquake and can create danger for the life of the occupants. Many experimental studies have proved that infill walls have high strength against lateral forces acting in plane, but strength against same forces is quite low out-of-plane. Therefore, an experimental study is conducted for increasing out-of-plane strength of the aerated concrete walls and obtaining improvements at other behaviors. Out of the 11 specimens manufactured, one is considered as reference specimen, and the rest are strengthened with carbon fiber-reinforced polymer strips with different layouts. Test specimens are tested at four points by bending setup for simulating out-of-plane lateral force. The variables that are examined in this study are carbon fiber-reinforced polymer strip layout and carbon fiber-reinforced polymer anchorage usage. The performance of the proposed method of strengthening is determined by examining stiffness, ductility, energy dissipation capacity, and failure modes. ACI 440 Committee report is used for calculating the capacity of the specimens. This technique, strengthening aerated concrete walls by using carbon fiber-reinforced polymer strips, has enabled the improvement in strength by 12.5 times, ductility ratio 6.1 times and energy capacity 102.4 times.
Performance of near surface mounted glass fiber reinforced polymer bars in concrete
Authors: El-Gamal Sherif , Al-Salloum Yousef , Alsayed Saleh , Aqel Mohammad
Published: October 2012

Near surface mounted fiber reinforced polymer reinforcement has become very popular method in strengthening of reinforced concrete structures. The major problem that accompanied the near surface mounted technique is the bond between fiber-reinforced polymers and concrete that corresponds to the stress transfer from concrete into fiber-reinforced polymers. This article presents the test results of pullout tests of near surface mounted glass fiber reinforced polymer bars to investigate the effect of different parameters on the bond performance of this strengthening technique. The test parameters include: adhesive type, groove size, bonded length, environmental condition, and concrete strength. A total of 40 near surface mounted–fiber-reinforced polymer bars, installed in C-shaped concrete blocks, were constructed and tested to failure. Five types of cement and epoxy-based adhesives were used. Two groove sizes and three bonded lengths were also investigated. Normal and high strength concrete were also used. In addition, the effect of two harsh environmental conditions on the performance of the strengthening system was also investigated. The results are presented in terms of pullout loads, free end slip, and mode of failure.
Melatonin attenuates oxidative stress, liver damage and hepatocyte apoptosis after bile-duct ligation in rats
Authors: Aktas Cevat , Kanter Mehmet , Erboga Mustafa , Mete Rafet , Oran Mustafa
Published: October 2012

The goal of this study was to evaluate the possible protective effects of melatonin against cholestatic oxidative stress, liver damage and hepatocyte apoptosis in the common rats with bile duct ligation (BDL). A total of 24 male Wistar albino rats were divided into three groups: control, BDL and BDL + received melatonin; each group contains eight animals. Melatonin-treated BDL rats received daily melatonin 100 mg/kg/day via intraperitoneal injection. The application of BDL clearly increased the malondialdehyde (MDA) levels and decreased the superoxide dismutase (SOD) and glutathione (GSH) activities. Melatonin treatment significantly decreased the elevated tissue MDA levels and increased the reduced SOD and GSH enzyme levels in the tissues. The changes demonstrate that the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, mononuclear cells and neutrophil infiltration into the widened portal areas as observed in the BDL group. The data indicate that melatonin attenuates BDL-induced cholestatic liver injury, bile duct proliferation and fibrosis. The α-smooth muscle actin (α-SMA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in the BDL were observed to be reduced with the melatonin treatment. These results suggest that administration of melatonin is a potentially beneficial agent to reduce liver damage in BDL by decreasing oxidative stress.
Postfusion pullout strength comparison of a novel pedicle screw with classical pedicle screws on synthetic foams
Authors: Arslan Arslan K , Demir Teyfik , Örmeci Mehmet F , Camuşcu Necip , Türeyen Kudret
Published: October 2012

Pullout is a very common failure mode on the use of pedicle screws. Numerous studies were completed to increase the pullout strength of pedicle screws especially for osteoporotic bones. In this study, a previously designed pedicle screw type was tested before and after fusion condition. Synthetic polyurethane foams were used in all tests. Three different grades of foams were used in tests to simulate severely osteoporotic, osteoporotic, and healthy bones. Test blocks were produced and characterized in our clinical biomechanics laboratory. Foaming of polyurethane was accepted as fusion process (bone in growth). Pedicle screw including radial holes (new design) was tested both before and after the fusion. It also exhibited remarkably higher pullout strength after fusion than before fusion and most of other alternatives stated in the literature. In total, 70% higher pullout strength was achieved with new design after fusion. On the other hand, new design did not dominate other alternatives when comparison was carried out on severely osteoporotic and healthy bones. To the knowledge of the authors, this is the first study investigating the postfusion properties on synthetic foams.
Totally Anomalous Pulmonary Venous Connection Draining Through an Intrapulmonary Vertical Vein
Authors: Talwar Sachin , Rajashekar Palleti , Anderson Robert H. , Jagia Priya , Makhija Neeti , Choudhary Shiv Kumar , Airan Balram
Published: October 2012

We report a two-year-old patient with isomerism of the right atrial appendages, a functionally univentricular heart, and associated totally anomalous pulmonary venous connection. The unusual finding was an intrapulmonary course of the vertical vein. We discuss the anatomical findings, management, and outcome.
CXC chemokine ligand 12/Stromal cell-derived factor-1 regulates cell adhesion in human colon cancer cells by induction of intercellular adhesion molecule-1
Authors: Tung Shui-Yi , Chang Shun-Fu , Chou Ming-Hui , Huang Wen-Shih , Hsieh Yung-Yu , Shen Chien-Heng , Kuo Hsing-Chun , Chen Cheng-Nan
Published: October 2012

Background

The CXC chemokine ligand 12 (CXCL12)/stromal cell-derived factor-1 (SDF-1) and CXC receptor 4 (CXCR4) axis is involved in human colorectal cancer (CRC) carcinogenesis and can promote the progression of CRC. Interaction between CRC cells and endothelium is a key event in tumor progression. The aim of this study was to investigate the effect of SDF-1 on the adhesion of CRC cells.

Methods

Human CRC DLD-1 cells were used to study the effect of SDF-1 on intercellular adhesion molecule-1 (ICAM-1) expression and cell adhesion to endothelium.

Results

SDF-1 treatment induced adhesion of DLD-1 cells to the endothelium and increased the expression level of the ICAM-1. Inhibition of ICAM-1 by small interfering RNA (siRNA) and neutralizing antibody inhibited SDF-1-induced cell adhesion. By using specific inhibitors and short hairpin RNA (shRNA), we demonstrated that the activation of ERK, JNK and p38 pathways is critical for SDF-1-induced ICAM-1 expression and cell adhesion. Promoter activity and transcription factor ELISA assays showed that SDF-1 increased Sp1-, C/EBP-β- and NF-κB-DNA binding activities in DLD-1 cells. Inhibition of Sp1, C/EBP-β and NF-κB activations by specific siRNA blocked the SDF-1-induced ICAM-1 promoter activity and expression. The effect of SDF-1 on cell adhesion was mediated by the CXCR4.

Conclusion

Our findings support the hypothesis that ICAM-1 up-regulation stimulated by SDF-1 may play an active role in CRC cell adhesion.
Malaria research challenges in low prevalence settings
Authors: Stresman Gillian , Kobayashi Tamaki , Kamanga Aniset , Thuma Philip E , Mharakurwa Sungano , Moss William J , Shiff Clive
Published: October 2012

The prevalence of malaria has reduced significantly in some areas over the past decade. These reductions have made local elimination possible and the research agenda has shifted to this new priority. However, there are critical issues that arise when studying malaria in low transmission settings, particularly identifying asymptomatic infections, accurate detection of individuals with microparasitaemic infections, and achieving a sufficient sample size to have an adequately powered study. These challenges could adversely impact the study of malaria elimination if they remain unanswered.
The utility of administrative data for neurotrauma surveillance and prevention in Ontario, Canada
Authors: Parsons Daria , Colantonio Angela , Mohan Michelle
Published: October 2012

Background

Surveillance of neurotrauma events is necessary to guide the development and evaluation of effective injury prevention initiatives. The aim of this paper is to review potential sources of existing population-based data to inform neurotrauma prevention in Canada, using sources available in Ontario as an example. Data sources, including administrative data holdings from Ontario’s publicly funded health care system and ongoing national surveys, were reviewed to determine the degree of relevance for neurotrauma surveillance, using standards outlined by the World Health Organization as a framework.

Results

Five key data sources were identified for neurotrauma surveillance. Five other sources were considered useful; cause of injury was not identifiable in 5 additional sources; and 4 sources were not relevant for surveillance purposes.

Conclusions

We provide information about which existing data sources are most relevant for neurotrauma surveillance and research, as well as examine the strengths and limitations of these sources. Administrative data can be used to facilitate surveillance of neurotrauma and are considered both useful and cost effective for the development and evaluation of injury prevention programs.
Prioritizing research for “One health - One world”
Authors: Zhou Xiao-Nong
Published: October 2012

Infectious diseases of poverty, a collective term coined for infections known to be particularly prevalent amongst poor populations, is increasingly used for neglected tropical diseases (NTDs) with special transmission routes, such as depending on vectors and/or intermediate hosts. The journal Infectious Diseases of Poverty (IDP) is launched to explore new avenues in research to better understand the relationship between infectious diseases and poverty, and to contribute to priority settings for plans to control them. Introducing the “One health - One world” concept, IDP will publish original and empirical work based on analyses of disease burdens, their distribution and research needs in this area. The new journal will not only bring out research articles but also scoping reviews and highlights of trans-disciplinary work undertaken to combat the infectious diseases of poverty, wherever in the world they exist.
Toll-like receptors expression and interferon-γ production by NK cells in human sepsis
Authors: Souza-Fonseca-Guimaraes Fernando , Parlato Marianna , Philippart François , Misset Benoît , Cavaillon Jean-Marc , Adib-Conquy Minou ,   the Captain study group
Published: October 2012

Introduction

During the course of infection, natural killer (NK) cells contribute to innate immunity by producing cytokines, particularly interferon-gamma (IFN-γ). In addition to their beneficial effects against infection, NK cells may play a detrimental role during systemic inflammation, causing lethality during sepsis. Little is known on the immune status of NK cells in patients with systemic inflammatory response syndrome (SIRS) or sepsis in terms of cell surface markers expression and IFN-γ production.

Methods

We investigated 27 sepsis patients and 11 patients with non-infectious SIRS. CD56bright and CD56dim NK cell subsets were identified by flow cytometry and Toll-like receptor (TLR)2, TLR4, TLR9, CX3CR1, CD16 and CD69 expression were analyzed, as well as ex vivo IFN-γ production by NK cells in whole blood samples.

Results

We first showed that in NK cells from healthy controls, TLR2 and TLR4 expression is mainly intracellular, similarly to TLR9. Intracellular levels of TLR2 and TLR4, in both CD56bright and CD56dim NK cell subsets from sepsis patients, were increased compared to healthy subjects. In addition, the percentage of CD69+ cells was higher among NK cells of sepsis patients. No difference was observed for TLR9, CX3CR1, and CD16 expression. The ex vivo stimulation by TLR4 or TLR9 agonists, or whole bacteria in synergy with accessory cytokines (IL-15+IL-18), resulted in significant production of IFN-γ by NK cells of healthy controls. In contrast, for SIRS and sepsis patients this response was dramatically reduced.

Conclusions

This study reports for the first time an intracellular expression of TLR2 and TLR4 in human NK cells. Surface TLR4 expression allows discriminating sepsis and SIRS. Furthermore, during these pathologies, NK cells undergo an alteration of their immune status characterized by a profound reduction of their capacity to release IFN-γ.
Caregivers' appraisals of patients' involuntary hospital treatment: European multicentre study
Authors: Giacco Domenico , Fiorillo Andrea , Del Vecchio Valeria , Kallert Thomas , Onchev Georgi , Raboch Jiri , Mastrogianni Anastasia , Nawka Alexander , Hadrys Tomasz , Kjellin Lars , Luciano Mario , De Rosa Corrado , Maj Mario , Priebe Stefan
Published: October 2012

Background

Mental health policies emphasise that caregivers' views of involuntary psychiatric treatment should be taken into account. However, there is little evidence on how caregivers view such treatment.

Aims

To explore caregivers' satisfaction with the involuntary hospital treatment of patients and what factors are associated with caregivers' appraisals of treatment.

Method

A multicentre prospective study was carried out in eight European countries. Involuntarily admitted patients and their caregivers rated their appraisal of treatment using the Client Assessment of Treatment Scale 1 month after admission.

Results

A total of 336 patients and their caregivers participated. Caregivers' appraisals of treatment were positive (mean of 8.5 on a scale from 0 to 10) and moderately correlated with patients' views. More positive caregivers' views were associated with greater patients' symptom improvement.

Conclusions

Caregivers' appraisals of involuntary in-patient treatment are rather favourable. Their correlation with patients' symptom improvement may underline their relevance in clinical practice.
Deformation Limits for Structural Walls with Confined Boundaries
Authors: Kazaz İlker , Gülkan Polat , Yakut Ahmet
Published: October 2012

For accurate analytical assessment of performance and damage in reinforced concrete members, well-defined deformation limits at particular damage states are required. With advanced and computationally intensive finite element analyses, we establish deformation limits at yield and ultimate limit states for adequately confined rectangular reinforced concrete structural walls in terms of drift ratio, plastic rotation, and curvature. To investigate the deformation limits of structural walls, a parametric study on isolated cantilever wall models is performed. The primary variables of the parametric study are the shear-span-to-wall-length ratio, wall length, axial load ratio, normalized shear stress, the amount of horizontal web reinforcement, and the amount of longitudinal reinforcement at the confined boundary of structural wall models. Expressions and limit values are proposed for yield and ultimate deformation capacity of structural walls, based on the most influential parameters. The proposed equations are found to be promising when compared to results of experiments.
A Comparison of Ground Motion Prediction Equations for Arias Intensity and Cumulative Absolute Velocity Developed Using a Consistent Database and Functional Form
Authors: Campbell Kenneth W. , Bozorgnia Yousef
Published: October 2012

Arias intensity (AI) and cumulative absolute velocity (CAV) have been proposed as instrumental intensity measures that can incorporate the cumulative effects of ground motion duration and intensity on the response of structural and geotechnical systems. In this study, we have developed a ground motion prediction equation (GMPE) for the horizontal component of AI in order to compare its predictability to a similar GMPE for CAV. Both GMPEs were developed using the same strong motion database and functional form in order to eliminate any bias these factors might cause in the comparison. This comparison shows that AI exhibits significantly greater amplitude scaling and aleatory uncertainty than CAV. The smaller standard deviation and less sensitivity to amplitude suggests that CAV is more predictable than AI and should be considered as an alternative to AI in engineering and geotechnical applications where the latter intensity measure is traditionally used.
Backbone Model for Performance-Based Seismic Design of RC Walls for Low-Rise Housing
Authors: Carrillo Julian , Alcocer Sergio M.
Published: October 2012

The walls of modern low-rise economic housing in several Latin American countries are typically thin and have a low concrete strength, web steel ratios that are smaller than the minimum prescribed by current codes, and web shear reinforcement made of welded-wire mesh. In light of these particular wall characteristics, research was aimed at developing a performance-based backbone model capable of predicting the seismic behavior of reinforced concrete (RC) walls for one- and two-story housing. The selected tri-linear model is associated with three limit states: diagonal cracking, peak shear strength, and ultimate deformation capacity. The model was developed on the basis of the observed response of 39 quasi-static and shake table experiments. Iterative nonlinear regression analyses were performed for deriving the semi-empirical equations in this study. The paper also discusses the adequacy of some existing models to predict the seismic behavior of RC walls and the limitations of the proposed equations.