bluuebunny/crossref_metadata_2025 huggingface dataset:
“Dr. Soundbite”
Authors: Kruvand Marjorie
Published: March 2012

Bioethicists have been increasingly used as expert sources in science and medical stories involving ethical issues. This case study examines how and why one bioethicist, Dr. Arthur L. Caplan, has become so ubiquitous. Organizational news routines provide the theoretical framework for a newspaper content analysis and interviews. As part of journalists’ small roster of trusted experts, Caplan has been the de facto bioethics representative for two decades, helping shape media discourse on bioethical issues. Caplan understands news routines, provides pithy quotes, and supports public engagement. Critics worry, however, that news consumers may conflate Caplan’s opinions with “the” ethical position.
A Model of Knowledge Translation in Health
Authors: Colley Rachel C. , Brownrigg Michelle , Tremblay Mark S.
Published: March 2012

The health of Canadian children and youth has deteriorated in the past few decades and physical inactivity is a powerful contributor. Active Healthy Kids Canada (AHKC; www.activehealthykids.ca ) is a national not-for-profit organization with a mission to inspire the nation to engage all children and youth in physical activity by providing expertise and direction to policy makers and the public on how to increase and effectively allocate resources and attention toward physical activity for Canadian children and youth. Annually, for the past 7 years, the AHKC Report Card has consolidated and translated research knowledge to drive social action for policy change relating to physical activity among children and youth. Original published articles and key surveillance data from national and regional surveys are reviewed. A group of content experts from across Canada meet semiannually to review the evidence and assign letter grades. The AHKC Report Card has played a key role in informing discussions that have led to action on physical inactivity in Canada. Further evidence of the Report Card’s influence is in the replication of the model in several other jurisdictions, including Saskatchewan and Ontario, Canada; Louisiana, United States; South Africa; Mexico; and Kenya.
Hepatic uptake and deacylation of the LPS in bloodborne LPS-lipoprotein complexes
Authors: Shao Baomei , Munford Robert S , Kitchens Richard , Varley Alan W
Published: March 2012

Much evidence indicates that bacterial LPS (endotoxin) is removed from the bloodstream mainly by the liver, yet the hepatic uptake mechanisms remain uncertain and controversial. In plasma, LPS can be either ‘free’ (as aggregates, bacterial membrane fragments or loosely bound to albumin, CD14, or other proteins) or ‘bound’ (complexed with lipoproteins). Whereas most free LPS is taken up by Kupffer cells (KCs), lipoprotein-bound LPS has seemed to be cleared principally by hepatocytes. Here, we compared the liver’s ability to take up and deacylate free LPS aggregates and the LPS in preformed LPS-high density lipoprotein (HDL) complexes. In mice examined from 1 h to 7 d after a small amount of fluorescent (FITC-)LPS was injected into a lateral tail vein, we found FITC-LPS almost entirely within, or adjacent to, KCs. As expected, FITC-LPS complexed with HDL (FITC-LPS-HDL) disappeared more slowly from the circulation and a smaller fraction of the injected dose of FITC-LPS was found in the liver. Unexpectedly, the FITC-LPS injected as FITC-LPS-HDL complexes was also found within sinusoids, adjacent to, or within, KCs. In other experiments, we found that both free and HDL-bound radiolabeled LPS underwent enzymatic deacylation by acyloxyacyl hydrolase (AOAH), the LPS-inactivating enzyme that is principally produced within the liver by KCs. Our observations suggest that KCs and AOAH play important roles in clearing and catabolizing both free LPS and the LPS in circulating LPS-HDL complexes.
Pain in Older Adults: Epidemiology, Impact and Barriers to Management
Authors: Schofield Pat
Published: March 2012

• There will be increased numbers of older adults in society in the next few decades. • Older adults are more likely to have pain problems and other co-morbidities. • Generally pain is poorly managed in older adults and this becomes worse when cognitive impairment exists. • The impact of chronic pain on older adults will be greater than that of their younger counterparts in terms of social isolation. • Attitudes and barriers exist in both the older adults themselves and their younger counterparts.
Non-Obstetric Pain in Pregnancy
Authors: Lalkhen Abdul , Grady Kate
Published: March 2012

• The hormonal and mechanical changes which result from pregnancy have the capacity to exacerbate existing chronic pain conditions as well as produce pain unique to this physiological and anatomical state. • Pain in pregnancy is very common and can impact negatively on maternal satisfaction with the pregnancy. • Management of pain requires a multidisciplinary, biopsychosocial approach. The possible presence of co-existing pathology and obstetric conditions must be borne in mind when assessing pain in pregnancy. • Treatment of pain in pregnancy should focus on non-pharmacological interventions in the first instance with due consideration of the risk of medications to the mother, fetus and the course of the pregnancy.
Insomnia Co-Occurring with Chronic Pain: Clinical Features, Interaction, Assessments and Possible Interventions
Authors: Hester Joan , Tang Nicole K. Y.
Published: March 2012

• Insomnia is a major source of distress to people with chronic pain; many of whom presenting for treatment want tangible help with sleep. • Compared to chronic pain patients who do not have trouble sleeping, those who do, report more severe pain, longer pain duration, greater levels of anxiety, depression and health anxiety, and worse impairment in physical and psychosocial functioning. • Sleep disturbance experienced by patients with chronic pain can be characterised by longer sleep onset, more frequent and longer awakenings after sleep onset, shorter total sleep time, lower sleep efficiency and poorer sleep quality. Such pattern of disturbance is analogous to that of primary insomnia. • The relationship between pain and sleep is likely to be bi-directional, although exactly how the two problems interact is little understood. • The offer of sleep advice and the use of pharmacotherapy for pain-related insomnia have their respective limitations. Psychological and behavioural treatments demonstrated to be effective for both primary and comorbid insomnia may be a viable treatment alternative.
Maturation-related histone modifications in the PU.1 promoter regulate Th9-cell development
Authors: Ramming Andreas , Druzd David , Leipe Jan , Schulze-Koops Hendrik , Skapenko Alla
Published: March 2012

Epigenetic histone modifications are thought to underlie the rapid memory immune response to recall antigen that develops after vaccination. However, histone-modification patterns in genes encoding transcription factors regulating cytokine production have not been investigated in either memory and naive T cells or as the immune system matures to understand the differences in cytokine response patterns. In the present study, we analyzed histone modifications in promoter regions of T-bet, GATA-3, PU.1, IRF4, and RORC in neonatal naive T cells and in adult naive and memory CD4 T cells, and found a unique and dynamic histone-modification pattern in the PU.1 promoter that was related to age and the naive/memory status of a T cell. Naive T cells required more intense stimulation to switch the chromatin pattern in the PU.1 promoter from a repressive to permissive state, and therefore to produce IL-9 than did memory T cells. Inhibition of repressive histone methylation by the specific inhibitor 3-deazaneplanocin induced Th9-specific PU.1 expression, even in conditions that would normally yield only Th0 cytokines. Conversely, prevention of histone acetylation by the histone acetyltransferase inhibitor curcumin diminished PU.1 expression after IL-9–inducing stimulation. Our findings identify age- and differentiation-status–related epigenetic modifications of PU.1 as a unique regulator of Th9 memory acquisition and Th9 immunity.
Cervical cancer screening by visual inspection in Côte d'Ivoire, operational and clinical aspects according to HIV status
Authors: Horo Apollinaire , Jaquet Antoine , Ekouevi Didier K , Toure Badian , Coffie Patrick A , Effi Benjamin , Messou Eugene , Minga Albert , Moh Raoul , Kone Mamourou , Dabis François , Sasco Annie J ,   The IeDEA West Africa collaboration
Published: March 2012

Background

Cervical cancer screening is not yet standard of care of women attending HIV care clinics in Africa and presents operational challenges that need to be addressed.

Methods

A cervical cancer screening program based on visual inspection methods was conducted in clinics providing antiretroviral treatment (ART) in Abidjan, Côte d'Ivoire. An itinerant team of midwives was in charge of proposing cervical cancer screening to all HIV-positive women enrolled in ART clinics as well as to HIV-negative women who were attending the Abidjan national blood donor clinic. Positively screened women were systematically referred to a colposcopic examination. A phone-based tracking procedure was implemented to reach positively screened women who did not attend the medical consultation. The association between HIV status and cervical cancer screening outcomes was estimated using a multivariate logistic model.

Results

The frequency of positive visual inspection was 9.0% (95% CI 8.0-10.0) in the 2,998 HIV-positive women and 3.9% (95% CI 2.7-5.1) in the 1,047 HIV-negative ones (p < 10-4). In multivariate analysis, HIV infection was associated with a higher risk of positive visual inspection [OR = 2.28 (95% CI 1.61-3.23)] as well as more extensive lesions involving the endocervical canal [OR = 2.42 (95% CI 1.15-5.08)]. The use of a phone-based tracking procedure enabled a significant reduction of women not attending medical consultation after initial positive screening from 36.5% to 19.8% (p < 10-4).

Conclusion

The higher frequency of positive visual inspection among HIV-positive women supports the need to extend cervical cancer screening program to all HIV clinics in West Africa. Women loss to follow-up after being positively screened is a major concern in cervical screening programs but yet, partly amenable to a phone tracking procedure.
Phosphorylated tau/amyloid beta 1-42 ratio in ventricular cerebrospinal fluid reflects outcome in idiopathic normal pressure hydrocephalus
Authors: Patel Sunil , Lee Edward B , Xie Sharon X , Law Anica , Jackson Eric M , Arnold Steven E , Clark Christopher M , Shaw Leslie M , Grady M Sean , Trojanowski John Q , Hamilton Roy H
Published: March 2012

Background

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible cause of dementia and gait disturbance that is typically treated by operative placement of a ventriculoperitoneal shunt. The outcome from shunting is variable, and some evidence suggests that the presence of comorbid Alzheimer's disease (AD) may impact shunt outcome. Evidence also suggests that AD biomarkers in cerebrospinal fluid (CSF) may predict the presence of AD. The aim of this study was to investigate the relationship between the phosphorylated tau/amyloid beta 1-42 (ptau/Aβ1-42) ratio in ventricular CSF and shunt outcome in patients with iNPH.

Methods

We conducted a prospective trial with a cohort of 39 patients with suspected iNPH. Patients were clinically and psychometrically assessed prior to and approximately 4 months after ventriculoperitoneal shunting. Lumbar and ventricular CSF obtained intraoperatively, and tissue from intraoperative cortical biopsies were analyzed for AD biomarkers. Outcome measures included performance on clinical symptom scales, supplementary gait measures, and standard psychometric tests. We investigated relationships between the ptau/Aβ1-42 ratio in ventricular CSF and cortical AD pathology, initial clinical features, shunt outcome, and lumbar CSF ptau/Aβ1-42 ratios in the patients in our cohort.

Results

We found that high ptau/Aβ1-42 ratios in ventricular CSF correlated with the presence of cortical AD pathology. At baseline, iNPH patients with ratio values most suggestive of AD presented with better gait performance but poorer cognitive performance. Patients with high ptau/Aβ1-42 ratios also showed a less robust response to shunting on both gait and cognitive measures. Finally, in a subset of 18 patients who also underwent lumbar puncture, ventricular CSF ratios were significantly correlated with lumbar CSF ratios.

Conclusions

Levels of AD biomarkers in CSF correlate with the presence of cortical AD pathology and predict aspects of clinical presentation in iNPH. Moreover, preliminary evidence suggests that CSF biomarkers of AD may prove useful for stratifying shunt prognosis in patients being evaluated and treated for this condition.
Fluorescence anisotropy of diphenylhexatriene and its cationic Trimethylamino derivative in liquid dipalmitoylphosphatidylcholine liposomes: opposing responses to isoflurane
Authors: Nelson Steven C , Neeley Steven K , Melonakos Eric D , Bell John D , Busath David D
Published: March 2012

Background

The mechanism of action of volatile general anesthetics has not yet been resolved. In order to identify the effects of isoflurane on the membrane, we measured the steady-state anisotropy of two fluorescent probes that reside at different depths. Incorporation of anesthetic was confirmed by shifting of the main phase transition temperature.

Results

In liquid crystalline dipalmitoylphosphatidylcholine liposomes, isoflurane (7-25 mM in the bath) increases trimethylammonium-diphenylhexatriene fluorescence anisotropy by ~0.02 units and decreases diphenylhexatriene anisotropy by the same amount.

Conclusions

The anisotropy data suggest that isoflurane decreases non-axial dye mobility in the headgroup region, while increasing it in the tail region. We propose that these results reflect changes in the lateral pressure profile of the membrane.
Antioxidant-induced INrf2 (Keap1) tyrosine 85 phosphorylation controls the nuclear export and degradation of the INrf2–Cul3–Rbx1 complex to allow normal Nrf2 activation and repression
Authors: Kaspar James W. , Niture Suryakant K. , Jaiswal Anil K.
Published: March 2012

INrf2 (Keap1) serves as a negative regulator of the cytoprotective transcription factor Nrf2. At basal levels, INrf2 functions as a substrate adaptor to sequester Nrf2 into the Cul3–Rbx1 E3 ligase complex for ubiquitylation and proteasomal degradation. In response to antioxidants, Nrf2 is released from the INrf2–Cul3–Rbx1 complex and translocates into the nucleus, where it activates ARE-mediated cytoprotective gene expression. The present studies demonstrate that INrf2, Cul3 and Rbx1 export out of the nucleus and are degraded during the early or pre-induction response to antioxidants. Mutation of Tyr85 in INrf2 stymied the nuclear export of INrf2, suggesting that tyrosine phosphorylation controls the pre-induction nuclear export and degradation in response to antioxidants. The nuclear export of Cul3–Rbx1 were also blocked when INrf2Tyr85 was mutated, suggesting that INrf2–Cul3–Rbx1 undergo nuclear export as a complex. INrf2 siRNA also inhibited the nuclear export of Cul3–Rbx1, confirming that Cul3–Rbx1 requires INrf2 for nuclear export. Newly synthesized INrf2–Cul3–Rbx1 is imported back into the nucleus during the post-induction period to ubiquitylate and degrade Nrf2. Mutation of INrf2Tyr85 had no effect on activation of Nrf2 but led to nuclear accumulation of Nrf2 during the post-induction period owing to reduced export and degradation of Nrf2. Our results also showed that nuclear export and degradation followed by the new synthesis of INrf2–Cul3–Rbx1 controls the cellular abundance of the proteins during different phases of antioxidant responses. In conclusion, the early or pre-induction nuclear export of INrf2 in response to antioxidants is controlled by tyrosine phosphorylation, whereas the nuclear export of Cul3 and Rbx1 is controlled by INrf2, allowing normal activation or repression of Nrf2.
Li Distribution and Mode of Occurrences in Li-Bearing Coal Seam # 6 from the Guanbanwusu Mine, Inner Mongolia, Northern China
Authors: Sun Yuzhuang , Zhao Cunliang , Li Yanheng , Wang Jinxi , Liu Shiming
Published: March 2012

Thirty-six coal bench samples from Coal Seam 6 and 13 parting samples from 5 parting layers were taken from the Guanbanwusu Coal Mine, Jungar Coalfield, Inner Mongolia, and the samples were analysed by optical microscopy, A scanning electron microscope in conjunction with an energy-dispersive X-ray spectrometer (SEM-EDX) analysis, X-ray powder diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometric (XRF) techniques. The results indicate that the average Li content are 264 ppm in coal and 1320 ppm or 0.28% Li2O in coal ash, indicating a Li ore deposit in coal. XRD analysis indicates that the minerals are kaolinite, boehmite, chlorite-group mineral, quartz, calcite, pyrite, siderite and amorphous clay material. The absorbed Li phases by kaolinite, boehmite and chlorite could be the most likely host model. Li could also be migrated into the peat by isomorphic impurity in chlorite. However, this migration form should not be the main form because chlorite contents are relative low. The total Li reserves reach to 24288 tons, that is, 52045 ton Li2O in this mine. The Yinshan Oldland chould be the most possible source of Li of the coal. The bauxite of the Benxi formation could be another source of Li of the coal in the NE Jungar Coalfield. The bauxite in the NE Jungar Coalfield was originally derived from the Yinshan Oldland.
Combustion Efficiency and Performance of RSO Biodiesel as Alternative Fuel in a Single Cylinder CI Engine
Authors: Thaiyasuit P. , Pianthong K. , Milton B.
Published: March 2012

In this study, the combustion efficiency and performance of an engine using biodiesel produced from rubber seed oil (RSO) was compared with petroleum diesel. The tests were performed at full load over a range of engine speeds in a single cylinder, direct injection diesel engine. The experimental results show that the RSO biodiesel resulted in better combustion than with the petroleum diesel at low to medium engine speeds (1300–1900 rpm). In this range, the combustion efficiency and the brake fuel conversion efficiency of the RSO biodiesel were found to be 1.03% and 7.33% higher respectively than those of petroleum diesel. In addition, a slightly lower brake specific CO2 emission level was achieved, this being because of the higher H/C ratio of the RSO biodiesel. A major improvement in the brake specific CO emission of the RSO biodiesel was found, these being 55% lower than those of the petroleum diesel. However, the brake specific NOx emission was 39.5% higher. Both the brake torque and brake power of the RSO biodiesel were 4.91% lower than those of the petroleum diesel while an increase of around 6.84% fuel consumption was required at the same power output all these being due to its lower heating value. Above 1900 rpm in these tests, the combustion efficiency trend reversed with the RSO biodiesel giving a lower value than the petroleum diesel. In this higher speed range, the performance (i.e. brake fuel conversion efficiency, brake power, and brake torque) fell below that of the petroleum diesel with the brake specific fuel consumptions and the brake specific CO emissions being higher.
Storage and Seepage Unit: A New Approach to Evaluating Reservoir Anisotropy of Low-Permeability Sandstones
Authors: Zeng Lianbo , Tang Xiaomei , Gong Lei , Liu Hongtao
Published: March 2012

According to geological characteristics of storage and seepage in the low-permeability sandstone reservoirs, the storage and seepage unit is put forward to evaluate reservoir anisotropy of low-permeability sandstones in the paper. The storage and seepage unit is a special rock combination unit formed by sedimentation, diagenesis and tectogenesis. Then, starting with synthetical analysis of sedimentation, diagenesis and tectonic movement and based on plotting out storage unit of matrix pore and seepage unit of fracture, the storage and seepage unit can be obtained using the method of clustering analysis. Due to the differences of geological characteristics, fracture, micro-pore texture, micro-seepage mechanism and fluid interaction between fractures and pores, the enrichment rule for hydrocarbon and seepage rule for fluid are obviously different in the dissimilar types of the storage and seepage unit. The storage and seepage unit is the basic unit for development of the low-permeability sandstone reservoirs. It has important roles on compartmentalizing reservoir, predicting reservoir distribution and capability and guiding prediction of residual oil distribution.
Molecular Simulation of Hydrogen Physisorption and Chemisorption in Nanoporous Carbon Structures
Authors: Kumar K. Vasanth , Salih Alaaeldin , Lu Linghong , Müller Erich A. , Rodríguez-Reinoso Francisco
Published: March 2012

The effect of pore morphology on the hydrogen-storage capacity of carbon materials at room temperature (298 K) has been studied using Grand Canonical Monte Carlo (GCMC) molecular simulation. Prototypical pore geometries such as slit pores and nanotubes were considered along with carbon foams and a random disordered carbon structure. Both physisorption and chemisorption models were considered in order to take into account the most favourable adsorption scenarios. Fluid–fluid and fluid–solid interactions were assumed to follow a Lennard-Jones-type potential.

It was seen that physisorption alone cannot account for the adsorption of more than a few weight percentages, regardless of the pore morphology. Under physisorption conditions, the simulation results show that carbons with a slit-shaped pore geometry are more efficient than other geometries at storing hydrogen, particularly at pore distances which allow the formation of fluid layers commensurate with the pore geometry. Slit pores appear to store a maximum of 1.77 wt% hydrogen by physisorption as opposed to carbon foams (1.48 wt%), carbons with a random structure (1.04 wt%) and carbon nanotubes (0.31 wt%). Simulation with hypothetical chemisorption models where the solid–fluid interaction is artificially enhanced showed that the storage capacity is higher in pore geometries with a larger accessible volume. Strong chemisorption gave loadings of up to 17 g/ℓ (1.5 wt%), 91 g/ℓ (13.8 wt%), 57.33 g/ℓ (9.6 wt%) and 42.94 g/ℓ (8.29 wt%) in nanotubes, foams, random structures and slit pores, respectively. Desorption is a problem in this scenario, as only ca. 1–3 wt% hydrogen can be delivered from these structures. Ultimately, the comparison of the different fluid–solid potentials revealed that if solid–fluid interactions could be enhanced beyond the classical dispersion, the more open structures could be ideal candidates for hydrogen-storage materials.
Copper-Modified Activated Carbons as Adsorbents of NO under Ambient Conditions
Authors: Levasseur Benoit , Gonzalez-Lopez Eugene , Bandosz Teresa J.
Published: March 2012

Activated carbon was impregnated with a copper salt and the surface of the resulting material then reduced either with hydrazine hydrate or by heat treatment under nitrogen at 925 °C. The adsorption of NO was carried out under dynamic conditions at ambient temperature on the samples obtained. To derive the mechanism of adsorption, the initial material and that exposed to NO were characterized using nitrogen adsorption, thermal analysis and potentiometric titration. The introduction of copper and reduction treatment had very positive effects on the amounts of NO retained on the surface. It is suggested that both copper particles and oxygen-containing groups on the carbon surface contribute to the reactive adsorption. Two different mechanisms are proposed to describe NO adsorption depending on the oxidation state of the copper particles. In the absence of reducing treatment, it is believed that NO is oxidized to NO2 by copper oxide particles. This NO2 either reacts with the carbon surface to oxidize it and generate oxygen-containing functional groups or reacts with reduced copper particles. Equally, after surface reduction, the metallic copper could activate oxygen which would then participate in the oxidation of NO into NO2. This NO2 would either chemisorb onto copper in the form of the nitrate or react with the surface oxygen functional groups.
An Overview of Mechanisms and Patterns with Origami
Authors: Dureisseix David
Published: March 2012

Origami (paperfolding) has greatly progressed since its first usage for design of cult objects in Japan, and entertainment in Europe and the USA. It has now entered into artistic areas using many other materials than paper, and has been used as an inspiration for scientific and engineering realizations. This article is intended to illustrate several aspects of origami that are relevant to engineering structures, namely: geometry, pattern generation, strength of material, and mechanisms. It does not provide an exhaustive list of applications nor an in-depth chronology of development of origami patterns, but exemplifies the relationships of origami to other disciplines, with selected examples.
Utilizing Reanalysis and Synthesis Datasets in Wind Resource Characterization for Large-Scale Wind Integration
Authors: Henson William L.W. , McGowan Jon G. , Manwell James F.
Published: March 2012

As wind plants become a more substantial portion of the generation resource, the ability of and manner in which this new fleet of generation supports meeting the power system load in a given area must be quantified in order to ensure security of supply. This paper describes the manner in which a reanalysis dataset—the National Aeronautics and Space Administration (NASA) Modern Era Retrospective-Analysis for Research and Applications (MERRA) dataset—was utilized in conjunction with the National Renewable Energy Laboratory (NREL) Eastern Wind Integration Dataset in order to perform an estimation of the interannual variability in wind power production as related to the capacity value of the investigated potential wind plants. Also described in the paper is a comparison of the MERRA data with publicly available wind data collected by the University of Massachusetts Wind Energy Center (UMass WEC).
Large-Scale Parallel Simulation of High-Dimensional American Option Pricing
Authors: Hong-Xu Chang , Zhong-Hua Lu , Xue-Bin Chi
Published: March 2012

High-dimensional American option pricing is computationally challenging in both theory and practice. We use stochastic mesh method combined with performance enhancement policy of bias reduction to solve this practical problem in classic Black-Scholes framework. We effectively parallelize this algorithm through splitting the generated mesh by row among processors, use MPI for efficient implementation, and perform large-scale numerical experiments on heterogeneous supercomputer DeepComp7000. Numerical results of parallel simulation demonstrate that parallel simulation has good scalability in different parallel environments of DeepComp7000; large-scale parallel simulation can obtain much better speedup. The convergent performance is also empirically demonstrated. The estimated option value converges with the increase of mesh size; when using smaller mesh size, the stochastic mesh method with bias reduction can underestimate the true American option value.
Parallel Randomized Quasi-Monte Carlo Simulation for Asian Basket Option Pricing
Authors: Hu Yong-Hong , Chen Da-Qian
Published: March 2012

High-dimensional derivatives pricing, such as Asian basket options, poses great computational challenges in practice. In this paper, parallel Randomized Quasi-Monte Carlo (RQMC) simulation method is investigated to tackle this kind of intractable problems. By using the intrinsic nature of “embarrassingly parallel”, parallel RQMC algorithm for Asian basket option pricing is effectively implemented using MPI. Numerical experiments are performed on supercomputer DeepComp6800 and the parallel performance is then analyzed. Our parallel algorithm has exerted perfect performance and good scalability. Parallel computing has greatly improved the computational efficiency of derivatives pricing.
On a Modified Diffusion Model for Noise Removal
Authors: Liu X. Y. , Lai C.-H. , Pericleous K. A. , Wang M. Q.
Published: March 2012

The anisotropic diffusion model plays an important role on image denoising and some other applications, such as image enhancement, image inpainting. In this paper, drawbacks of the anisotropic diffusion model and the fourth-order PDE model are discussed and examined. In order to compensate these drawbacks, two modified diffusion models are proposed and numerical results show that the modified models produce better results by checking against the PSNR and two other metrics.
Numerical Analysis and Comparative Study of the Cross-Sectional Capacity of Structural Steel Members in Fire
Authors: Knobloch Markus , Somaini Diego , Pauli Jacqueline , Fontana Mario
Published: March 2012

The cross-sectional capacity of steel sections subjected to fire is strongly affected by the decreasing stiffness during heating and the nonlinear stress-strain relationship of steel at elevated temperatures. This paper analyses the cross-sectional capacity of common steel sections subjected to combined axial compression and biaxial bending moments at both ambient and elevated temperatures considering section yielding and local buckling effects. The results of a parametric study using the finite element approach are presented as temperature-dependent normalized N-M interaction curves and are compared to results using elastic and plastic interaction formulae. A comparative study shows that European fire design models may lead to conservative results for semi-compact and slender cross sections (class 3 and 4 sections) due to the partial plastic capacity of these sections. However, for steel members predominately subjected to axial compression the design models may lead to unconservative results due to local buckling deflections that occur even for plastic and compact sections (class 1 and 2).
On Blast Pressure Analysis Due to a Partially Confined Explosion: II. Numerical Studies
Authors: Feldgun V.R. , Karinski Y.S. , Edri I. , Tsemakh D. , Yankelevsky D.Z.
Published: March 2012

The paper presents a second part of a study aiming at understanding some characteristics of an interior explosion within a room with limited venting. Internal explosions may occur as a result of an ammunition storage explosion, or a charge explosion within a room in a terrorist action or a warhead explosion following its penetration into a closed space. This paper follows an experimental study and validation of the problem and aims at an extended numerical investigation of several aspects of the problem. The analysis has been performed for a room with rigid walls having limited venting by using AUTODYN 12 commercial program implementing the Eulerian multi-material approach, and the results were compared with the experimental measurements. An effective simplified model with lumped parameters based on the Bernoulli equation has been developed for the quasi-stationary phase of the detonation products outflow from the room through the venting openings.
A Simplified Model for Explosion Venting Due to the Separation of a Heavy Protective Cover
Authors: Yankelevsky D.Z. , Kochetkov A.V. , Feldgun V.R. , Karinski Y.S.
Published: March 2012

The paper presents a study aiming at simulation and understanding of some characteristics of an interior explosion within a room with an opening, that is initially being closed by a heavy cover, and may open gradually due to the effect of the explosion products. An effective simplified model of explosion venting due to separation of the protective cover has been developed. The developed model with lumped parameters is based on the Bernoulli equation and describes the quasi-stationary phase of the vented interior explosion. The initial internal gas pressure induced by the very short non-stationary phase is predicted by the developed approximate analytical formula, based on the full energy conservation law. The formula yields very good agreement with experimental data and with numerical analysis results. The simulation of the unsteady outflow from a cylindrical high-pressure vessel upon a sudden separation of the cover has shown that the developed simplified model yields the integral characteristics of the outflow process (such as a maximum cover's velocity and displacement etc) with reasonable accuracy. The proposed approach is demonstrated by the simulation of gas outflow from a chamber upon a sudden separation of the cover or upon a rectangular shutter rotation about a fixed line hinge. The analysis has been performed using the developed simplified approach and through simulations with AUTODYN. A good correspondence between both methods has been obtained. The effect of gravity on the protective cover velocity and displacement has been also examined.
Ultrasound-guided percutaneous microwave ablation of benign thyroid nodules: experimental and clinical studies
Authors: Feng Bing , Liang Ping , Cheng Zhigang , Yu Xiaoling , Yu Jie , Han Zhiyu , Liu Fangyi
Published: March 2012

Purpose

To obtain the treatment parameters of internally cooled microwave antenna and to evaluate the feasibility of ultrasound-guided percutaneous microwave ablation (MWA) for benign thyroid nodules.

Materials and methods

MWAs were performed by microwave antenna (16G) in ex vivo porcine liver. The lesion diameters achieved in different groups (20, 25, and 30 W for 3, 5, 7, 10, and 12 min) were compared. The clinical study was approved by the ethics committee. Written informed consent was obtained from all patients. MWA was performed in 11 patients (male to female ratio=1:10; mean age, 50±7 years) with 11 benign thyroid nodules. Ultrasound scan, laboratory data, and clinical symptoms were evaluated before and 1 day and 1, 3, 6, 9, and 12 months after the procedure.

Results

In ex vivo study, the ablation lesion at 30 W 12 min tended to have appropriate scope and spherical shape. In clinical study, the follow-up periods ranged from 1 to 9 months. At the last follow-up, the largest diameter decreased from 2.9±1.0 (range, 1.6–4.1) to 1.9±0.7 (range, 0.4–3.0) cm (P<0.01), and the volume decreased from 5.30±4.88 (range, 0.89–14.81) to 2.40±2.06 (range, 0.02–6.35) ml (P<0.01). The volume reduction ratio was 45.99±29.90 (range, 10.56–98.15) %. The cosmetic grading score was reduced from 3.20±0.79 to 2.30±0.95 (P<0.05). One patient experienced temporary nerve palsy and was recovered within 2 months after treatment.

Conclusion

The internally cooled microwave antenna can yield ideal ablation lesions, and ultrasound-guided percutaneous MWA is a feasible technique for benign thyroid nodules.
Combined treatment with GH and anastrozole in a pubertal boy with Cushing's disease and postsurgical GH deficiency
Authors: Boronat Mauro , Marrero Dunia , López-Plasencia Yaiza , Nóvoa Yeray , García-Delgado Yaiza , Nóvoa Francisco J
Published: March 2012

Growth failure is a characteristic manifestation of pediatric Cushing's disease. Catch-up growth is usually incomplete after cure of the disease, and final height is often compromised. Possible mechanisms for this phenomenon include postoperative persistence of GH hyposecretion and absence of retardation of bone maturation in spite of GH deficiency. This report describes the outcome in the case of a boy with Cushing's disease for whom GH replacement therapy was combined with anastrozole, an aromatase inhibitor, in order to delay skeletal maturation and extend the available time for linear growth. The case of a 14 years 4-months-old pubertal male (Tanner stage III) with GH deficiency after successful surgical treatment of Cushing's disease is presented. His height was 147.2 cm (−2.34 SDS), and his midparental target height 171.2 cm (−0.95 SDS). Bone age was 13.5 years and predicted adult height 163.2 cm (−2.2 SDS). Combined treatment was administered for 2.5 years. GH was maintained up to age 18 years. Anastrozole induced a substantial deceleration of bone age. Near-final height at 18 years was 169.5 cm (−1.07 SDS). Puberty progressed normally. Compared with population reference data, bone mineral density before GH plus anastrozole treatment was −4.07 SDS in the lumbar spine and −1.85 SDS in the femoral neck. These measures increased to −1.95 and −0.89 SDSs respectively, at 18 years, when GH was discontinued. Combined treatment with GH and aromatase inhibitors could be a therapeutic alternative to improve the stature of pubertal boys with Cushing's disease and postsurgical GH deficiency.
Telomere-Targeted Retrotransposons in the Rice Blast Fungus Magnaporthe oryzae: Agents of Telomere Instability
Authors: Starnes John H , Thornbury David W , Novikova Olga S , Rehmeyer Cathryn J , Farman Mark L
Published: March 2012

The fungus Magnaporthe oryzae is a serious pathogen of rice and other grasses. Telomeric restriction fragments in Magnaporthe isolates that infect perennial ryegrass (prg) are hotspots for genomic rearrangement and undergo frequent, spontaneous alterations during fungal culture. The telomeres of rice-infecting isolates are very stable by comparison. Sequencing of chromosome ends from a number of prg-infecting isolates revealed two related non-LTR retrotransposons (M. oryzae  Telomeric Retrotransposons or MoTeRs) inserted in the telomere repeats. This contrasts with rice pathogen telomeres that are uninterrupted by other sequences. Genetic evidence indicates that the MoTeR elements are responsible for the observed instability. MoTeRs represent a new family of telomere-targeted transposons whose members are found exclusively in fungi.
Fatores de risco comportamentais acumulados para doenças cardiovasculares no sul do Brasil
Authors: Muniz Ludmila Correa , Schneider Bruna Celestino , Silva Inácio Crochemore Mohnsam da , Matijasevich Alicia , Santos Iná Silva
Published: March 2012

OBJETIVO: Estimar a prevalência e identificar fatores associados ao acúmulo de comportamentos de risco para doenças cardiovasculares entre adultos. MÉTODOS: Estudo transversal de base populacional com amostra representativa de 2.732 adultos de ambos os sexos de Pelotas, RS, em 2010. Os fatores de risco comportamentais investigados foram: tabagismo; inatividade física no lazer; consumo habitual de gordura aparente da carne; e consumo diário de embutidos, carne vermelha e leite integral. O desfecho do estudo foi o escore de aglomeração de fatores de risco comportamentais, variando de zero a três: nenhum fator de risco comportamental para doenças cardiovasculares ou exposição a 1, 2 ou > 3 fatores de risco comportamentais. Realizou-se regressão logística multinomial para avaliar o efeito ajustado das características individuais sobre o acúmulo de fatores de risco comportamentais, tendo como categoria de referência indivíduos sem qualquer dos fatores. RESULTADOS: A inatividade física foi o fator de risco mais prevalente (75,6%), seguido do consumo habitual de gordura aparente da carne (52,3%). Dois terços da população apresentaram dois ou mais fatores de risco comportamentais. A combinação de inatividade física e consumo habitual de gordura aparente da carne ocorreu em 17,5% da amostra; e inatividade física, consumo habitual de gordura aparente da carne e tabagismo, em 6,7%. Os odds ratios de acúmulo de dois ou mais fatores foram maiores entre homens e associaram-se inversamente com o indicador econômico nacional. CONCLUSÕES: O acúmulo de fatores de risco comportamentais para doenças cardiovasculares é elevado na população estudada. São necessárias intervenções públicas capazes de prevenir a ocorrência simultânea desses fatores.
O conceito de política posto à prova pela mundialização
Authors: Colliot-Thélène Catherine
Published: March 2012

Este artigo procura caracterizar o conceito moderno de política diante dos fenômenos que se designam pelo termo "globalização". Examina-se como o Estado moderno consolidou sua capacidade de dominação à medida em que se revelou capaz de estruturar simbolicamente uma identidade coletiva particular, expressa pela idéia de cidadania. Sustenta-se que a diversificação dos espaços de decisão e a transferência de competências econômicas, jurídicas e militares para instâncias supranacionais, regionais ou transnacionais, ao mesmo tempo em que questiona a soberania estatal, começa a redefinir de modo inédito o espaço da política, visto que as relações de poder, neste novo contexto, deixam de ser acompanhadas por processos de identificação coletiva, até agora assegurados pela capacidade de decisão do Estado.
Formas de influência das ONGs na política internacional contemporânea
Authors: Villa Rafael A. Duarte
Published: March 2012

Este artigo analisa a crescente importância que os atores não-estatais transnacionais vêm assumindo para a teoria das relações internacionais. Especificamente, o autor explora três aspectos: primeiro, a proposta da categoria de influência como meio político de atuação das ONGs transnacionais; segundo, a inserção destas em processos sociais globais - tais como desequilíbrios ecológicos, direitos humanos, consumo - e, finalmente, os métodos de criação de consenso em torno de problemas sociais de ordem planetária. Conclui-se que a atuação das ONGs atinge os planos interestatais, supranacionais e transnacionais.
A esquerda militante: entre o engajamento pastoral e os revides locais
Authors: Souza Nelson Rosário de
Published: March 2012

O presente artigo procura analisar as ambigüidades do militantismo de esquerda e suas possibilidades de superação. Para tal propósito lançou-se um olhar sobre a procedência da prática militante moderna, sobre o debate marxista a respeito do militante revolucionário e também sobre os militantes dos chamados "novos movimentos sociais". A experiência militante mais recente combinada com uma certa recusa de intelectuais em se fazer "vanguarda" serviu de âncora para a crítica às práticas militantes pastorais e seu efeito totalizador.
Habilidades de codificacion y descodificacion de tablas y graficos estadisticos: un estudio comparativo en profesores y alumnos de pedagogia en enseñanza basica
Authors: Alveal Francisco Rodríguez , Rubilar Pedro Rodrigo Sandoval
Published: March 2012

El artículo presenta los resultados de la evaluación realizada a profesores de educación general básica en ejercicio y estudiantes en formación de la carrera de Pedagogía en Educación General Básica. Corresponde a una evaluación de tipo descriptiva y comparativa de corte transversal, a una población compuesta por 47 profesores en ejercicio y 44 alumnos en Formación Inicial Docente (FID) a quienes se les aplicó un instrumento debidamente validado por experto, con alfa de Cronbach α=0,75 y un índice de validez de contenido de 0,66. En el análisis de la información se utilizaron métodos descriptivos tales como promedio, desviaciones estándar y frecuencia porcentual. Los resultados evidencian que en general, los Profesores en ejercicio y alumnos en FID realizan procesos de descodificación por debajo de lo esperado y, según la clasificación de Curcio, se ubicarían en el nivel uno de los cuatros postulados, es decir presentan las habilidades básicas o iniciales asociadas a la descodificación y análisis de los datos.
Inclusão digital e capacidade funcional de idosos residentes em Florianópolis, Santa Catarina, Brasil (EpiFloripa 2009-2010)
Authors: Medeiros Felipe de Luca , Xavier André Junqueira , Schneider Ione Jayce Ceola , Ramos Luiz Roberto , Sigulem Daniel , d'Orsi Eleonora
Published: March 2012

OBJETIVO: Estudar a relação entre inclusão digital, na forma de troca de mensagens pela Internet, e capacidade funcional de idosos residentes em Florianópolis, Santa Catarina, Brasil. MÉTODOS: Utilizaram-se dados do EpiFloripa Idoso, um estudo transversal de base populacional com idosos (60+ anos) realizado entre 2009 e 2010. A capacidade funcional foi representada pela dificuldade ou incapacidade na realização de atividades básicas ou instrumentais da vida diária, e constituiu a variável dependente denominada dependência funcional. A variável independente principal foi a capacidade autorreferida de enviar e receber mensagens pela Internet usando um computador. Razões de prevalência (PR) e intervalos de confiança de 95% (IC95%) foram estimados em modelo multivariável por regressão de Poisson. RESULTADOS: A amostra compreendeu 1.656 idosos entre 60 e 102 anos com idade média de 70,39 anos (DP = 7,79). Os idosos que conseguiam enviar e receber mensagens pela Internet sem dificuldade apresentaram prevalência significativamente menor de dependência funcional moderada/grave (RP = 0,61; IC95%: 0,40 - 0,94) após ajuste para fatores demográficos, socioeconômicos, de saúde e comportamentais. CONCLUSÕES: A troca de mensagens pela Internet possui forte associação com independência funcional. Não é possível inferir a relação de causalidade dessa associação. Estudos alicerçam a hipótese de que a troca de mensagens pela Internet e a independência funcional tenham uma associação bidirecional, aditiva e sinérgica. Estudos longitudinais poderiam investigar os mecanismos envolvidos nessa associação, para fundamentar políticas de inclusão digital de idosos e para identificar qual o perfil de idosos que mais se beneficiaria com essa inclusão.
Mapping the niche space of soil microorganisms using taxonomy and traits
Authors: Lennon Jay T. , Aanderud Zachary T. , Lehmkuhl B. K. , Schoolmaster Donald R.
Published: March 2012

The biodiversity of microbial communities has important implications for the stability and functioning of ecosystem processes. Yet, very little is known about the environmental factors that define the microbial niche and how this influences the composition and activity of microbial communities. In this study, we derived niche parameters from physiological response curves that quantified microbial respiration for a diverse collection of soil bacteria and fungi along a soil moisture gradient. On average, soil microorganisms had relatively dry optima (0.3 MPa) and were capable of respiring under low water potentials (−2.0 MPa). Within their limits of activity, microorganisms exhibited a wide range of responses, suggesting that some taxa may be able to coexist by partitioning the moisture niche axis. For example, we identified dry‐adapted generalists that tolerated a broad range of water potentials, along with wet‐adapted specialists with metabolism restricted to less‐negative water potentials. These contrasting ecological strategies had a phylogenetic signal at a coarse taxonomic level (phylum), suggesting that the moisture niche of soil microorganisms is highly conserved. In addition, variation in microbial responses along the moisture gradient was linked to the distribution of several functional traits. In particular, strains that were capable of producing biofilms had drier moisture optima and wider niche breadths. However, biofilm production appeared to come at a cost that was reflected in a prolonged lag time prior to exponential growth, suggesting that there is a trade‐off associated with traits that allow microorganisms to contend with moisture stress. Together, we have identified functional groups of microorganisms that will help predict the structure and functioning of microbial communities under contrasting soil moisture regimes.