bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing 1D MM of Axisymmetric Transient Quenched Chromium Steel to Determine LHP
Authors: Elmaryami Abdlmanam S. A. , Omar Badrul
Published: March 2012

The modelling of an axisymmetric industrial quenched chromium steel bar AISI-SAE 8650H based on finite element method has been produced to investigate the impact of process history on metallurgical and material properties. Mathematical modelling of 1-dimensional line (radius) element axisymmetric model has been adopted to predict temperature history and consequently the hardness of the quenched steel bar at any point (node). The lowest hardness point (LHP) is determined. In this paper hardness in specimen points was calculated by the conversion of calculated characteristic cooling time for phase transformation t8/5 to hardness. The model can be employed as a guideline to design cooling approach to achieve desired microstructure and mechanical properties such as hardness. The developed mathematical model is converted to a computer program. This program can be used independently or incorporated into a temperature history calculator to continuously calculate and display temperature history of the industrial quenched steel bar and thereby calculate LHP. The developed program from the mathematical model has been verified and validated by comparing its hardness results with commercial finite element software results.
Hypoxic-Ischemic Injury in the Developing Brain: The Role of Reactive Oxygen Species Originating in Mitochondria
Authors: Ten Vadim S. , Starkov Anatoly
Published: March 2012

Mitochondrial dysfunction is the most fundamental mechanism of cell damage in cerebral hypoxia-ischemia and reperfusion. Mitochondrial respiratory chain (MRC) is increasingly recognized as a source for reactive oxygen species (ROS) in the postischemic tissue. Potentially, ROS originating in MRC can contribute to the reperfusion-driven oxidative stress, promoting mitochondrial membrane permeabilization. The loss of mitochondrial membranes integrity during reperfusion is considered as the major mechanism of secondary energy failure. This paper focuses on current data that support a pathogenic role of ROS originating from mitochondrial respiratory chain in the promotion of secondary energy failure and proposes potential therapeutic strategy against reperfusion-driven oxidative stress following hypoxia-ischemia-reperfusion injury of the developing brain.
Refined Qingkailing Protects MCAO Mice from Endoplasmic Reticulum Stress-Induced Apoptosis with a Broad Time Window
Authors: Cheng Fafeng , Zhong Xianggen , Lu Yi , Wang Xueqian , Song Wenting , Guo Shaoying , Wang Xiaotong , Liu Dantong , Wang Qingguo
Published: March 2012

In the current study, we are investigating effect of refined QKL on ischemia-reperfusion-induced brain injury in mice.Methods.Mice were employed to induce ischemia-reperfusion injury of brain by middle cerebral artery occlusion (MCAO). RQKL solution was administered with different doses (0, 1.5, 3, and 6 mL/kg body weight) at the same time of onset of ischemia, and with the dose of 1.5 mL/kg at different time points (0, 1.5, 3, 6, and 9 h after MCAO). Neurological function and brain infarction were examined and cell apoptosis and ROS at prefrontal cortex were evaluated 24 h after MCAO, and western blot and intracellular calcium were also researched, respectively.Results.RQKL of all doses can improve neurological function and decrease brain infarction, and it performed significant effect in 0, 1.5, 3, and 6 h groups. Moreover, RQKL was able to reduce apoptotic process by reduction of caspase-3 expression, or restraint of eIF2a phosphorylation and caspase-12 activation. It was also able to reduce ROS and modulate intracellular calcium in the brain.Conclusion.RQKL can prevent ischemic-induced brain injury with a time window of 6 h, and its mechanism might be related to suppress ER stress-mediated apoptotic signaling.
Iterative Learning Control for Remote Control Systems with Communication Delay and Data Dropout
Authors: Liu Chunping , Xu Jianxin , Wu Jun
Published: March 2012

Iterative learning control (ILC) is applied to remote control systems in which communication channels from the plant to the controller are subject to random data dropout and communication delay. Through analysis, it is shown that ILC can achieve asymptotical convergence along the iteration axis, as far as the probabilities of the data dropout and communication delay are known a priori. Owing to the essence of feedforward‐based control ILC can perform trajectory‐tracking tasks while both the data‐dropout and the one‐step delay phenomena are taken into consideration. Theoretical analysis and simulations validate the effectiveness of the ILC algorithm for network‐based control tasks.
Altered Hemodynamics Associated with Pathogenesis of the Vertebral Artery Dissecting Aneurysms
Authors: Kurata Akira , Suzuki Sachio , Iwamoto Kazuhisa , Nakahara Kuniaki , Abe Katsutoshi , Inukai Madoka , Niki June , Sasaki Makoto , Fujii Kiyotaka , Konno Shingo , Kan Shinichi , Fukasaku Kazuaki
Published: March 2012

The etiology of the vertebral dissecting aneurysms is largely unknown, and they frequently occurs in relatively healthy young men.Objectives and Methods. A series of 57 consecutive cases defined by angiography were evaluated with regard to deviation in the course of the affected and contralateral vertebral arteries. Division was into 3 types: Type I without any deviation, Type II with mild-to-moderate deviation but not over the midline; and Type III with marked deviation over to the contralateral side beyond the midline.Results. The most frequent type of VA running was Type III for the affected and Type I nonaffected side, with this being found in all 17 patients except one. All of the Type III dissections occurred just proximal to a tortuous portion, while in cases with Type-I- and Type-II-affected sides, the majority (33 of 39) occurred near the union of the vertebral artery. In 10 of 57, a non-dominant side was affected, all except one being of Type I or II. With 12 recent patients assessed angiographically in detail for hemodynamics, eleven patients showed contrast material retrograde inflowing into the pseudolumen from the distal portion of the dissection site. Turbulent blood flow was recognized in all of these patients with retrograde inflow.Conclusions. Turbulent blood flow is one etiology of vertebral artery dissection aneurysms, with the sites in the majority of the cases being just proximal to a tortuous portion or union of vessels. In cases with dissection proximal to the tortuous course of the vertebral artery, retrograde inflow will occur more frequently than antegrade, which should be taken into account in designing therapeutic strategies.
Existence and Uniqueness for Stochastic Age‐Dependent Population with Fractional Brownian Motion
Authors: Qimin Zhang , xining Li
Published: March 2012

A model for a class of age‐dependent population dynamic system of fractional version with Hurst parameter h ∈ (1/2, 1] is established. We prove the existence and uniqueness of a mild solution under some regularity and boundedness conditions on the coefficients. The proofs of our results combine techniques of fractional Brownian motion calculus. Ideas of the finite‐dimensional approximation by the Galerkin method are used.
A Study of Prognosis, Outcome, and Changing Tendency of Hospitalized AMI Patients in Beijing Third-Grade A-Level Traditional Chinese Medicine Hospitals from 1999 to 2008
Authors: Shang Ju-Ju , Shi Hui , Zhou Qi , Gao Wei , Liu Hong-xu
Published: March 2012

Objectives. To survey and analyse the prognosis, outcome, and changing tendency of the Acute Myocardial Infarction (AMI) patients in Beijing third-grade A-level Traditional Chinese Medicine (TCM) hospitals.Methods. We collected the clinical datum of hospitalized AMI patients in Beijing 6 TCM hospitals from January 1999 to December 2008 and then analysed the clinical datum.Results. (1) The mean age of patients had showed a slowly rising tendency during this ten years. The patients who had previous history of cerebrovascular diseasea and multiple comorbidities had increased year by year. (2) The rate of reperfusion therapy, revascularization and standardized using of drug, and usage of TCM of AMI patients presented a significant increasing tendency in these hospitals. (3) The proportion of AMI patients combined with cardiac arrhythmia and heart failure had decreased significantly. (4) The AMI mortality presented a decreasing tendency in 10 years.Conclusions. The AMI patients in Beijing TCM hospitals had their own unique clinical features, and it can improve their prognosis by combined therapy of Western Medicine and Traditional Chinese Medicine.
Solitary‐Solution Formulation for Differential‐Difference Equations Using an Ancient Chinese Algorithm
Authors: He Ji-Huan , Elagan S. K. , Wu Guo-Cheng
Published: March 2012

This paper applies an ancient Chinese algorithm to differential‐difference equations, and a solitary‐solution formulation is obtained. The discrete mKdV lattice equation is used as an example to elucidate the solution procedure.
Comparison Study of Two Different Sun-Tracking Methods in Optical Efficiency of Heliostat Field
Authors: Chong K.-K. , Tan M. H.
Published: March 2012

There are two sun-tracking methods widely used for the heliostat, which are conventional Azimuth-Elevation and revolutionary Spinning-Elevation methods. Following the previous study to compare the range of motion, a comparison study in optical efficiency of heliostat field for the two methods is further explored in this paper. A special algorithm using ray-tracing technique has also been developed to simulate the optical efficiency of heliostat field for both sun-tracking methods in different latitudes. With the new algorithm, comprehensive analysis to compare the optical efficiency of individual heliostat and the overall heliostat field for the two sun-tracking methods has been carried out.
Design and Methods for a Pilot Study of a Phone-Delivered, Mindfulness-Based Intervention in Patients with Implantable Cardioverter Defibrillators
Authors: Salmoirago-Blotcher Elena , Carmody James , Yeh Gloria , Crawford Sybil , Rosenthal Lawrence , Ockene Ira
Published: March 2012

Background. Meditation practices are associated with a reduction in adrenergic activity that may benefit patients with severe cardiac arrhythmias. This paper describes the design and methods of a pilot study testing the feasibility of a phone-delivered mindfulness-based intervention (MBI) for treatment of anxiety in patients with implantable cardioverter defibrillators (ICDs).Design and Methods. Consecutive, clinically stable outpatients (n=52) will be screened for study eligibility within a month of an ICD-related procedure or ICD shock and will be randomly assigned to MBI or to usual care. MBI patients will receive eight weekly individual phone sessions based on two mindfulness practices (awareness of breath and body scan) plus home practice with a CD for 20 minutes daily. Patients assigned to usual care will be offered the standard care planned by the hospital. Assessments will occur at baseline and at the completion of the intervention (between 9 and 12 weeks after randomization). The primary study outcome is feasibility; secondary outcomes include anxiety, mindfulness, and number of administered shocks during the intervention period.Conclusions. If proven feasible and effective, phone-delivered mindfulness-based interventions could improve psychological distress in ICD outpatients with serious cardiovascular conditions.
Dithiolethiones Inhibit NF-κB Activity via Covalent Modification in Human Estrogen Receptor–Negative Breast Cancer
Authors: Switzer Christopher H. , Cheng Robert Y.-S. , Ridnour Lisa A. , Murray Margaret C. , Tazzari Valerio , Sparatore Anna , Del Soldato Piero , Hines Harry B. , Glynn Sharon A. , Ambs Stefan , Wink David A.
Published: March 2012

The NF-κB transcription factor family influences breast cancer outcomes by regulating genes involved in tumor progression, angiogenesis, and metastasis. Dithiolethiones, a class of naturally occurring compounds with cancer chemoprevention effects that have become clinically available, have been found to inhibit NF-κB activity. However, the mechanism of this inhibition has not been identified, and the influence of dithiolethines on NF-κB pathway in breast cancer cells has not been examined. Here, we investigated the chemical and biochemical effects of dithiolethione on NF-κB and downstream effector molecules in estrogen receptor–negative breast cancer cells and murine tumor xenografts. The dithiolethiones ACS-1 and ACS-2 inhibited NF-κB transcriptional activity. Interestingly, this inhibition was not due to H2S release or protein phosphatase 2A activation, which are key properties of dithiolethiones, but occurred via a covalent reaction with the NF-κB p50 and p65 subunits to inhibit DNA binding. Dithiolethione-mediated inhibition of NF-κB–regulated genes resulted in the inhibition of interleukin (IL)-6, IL-8, urokinase-type plasminogen activator, and VEGF production. ACS-1 also inhibited matrix metalloproteinase-9 activity, cellular migration, and invasion, and ACS-2 reduced tumor burden and resulted in increased tumor host interactions. Together, our findings suggest that dithiolethiones show potential clinical use for estrogen negative breast cancer as a chemotherapeutic or adjuvant therapy. Cancer Res; 72(9); 2394–404. ©2012 AACR.
Beyond the Blues: Towards a Cross-Cultural Phenomenology of Depressed Mood
Authors: Postert Christian , Dannlowski Udo , Müller Jörg M. , Konrad Carsten
Published: March 2012

Background: There is a great cultural variety in the social phenomenology of depressed mood. The aim of this qualitative study was to compare English and Laotian Hmong semantic and pragmatic differences in depressed mood and to assess their relevance for cross-cultural psychiatric research and practice. Sampling and Method: The first author conducted long-term ethnographic fieldwork from 2000 to 2002 among the Hmong in Laos. Methods included participant observation, interviews and focus group interviews in the Hmong language. The semantic and pragmatic context of Hmong depressed mood tu siab, literally translated as ‘broken liver’, is compared to that of ‘sadness’ in Western contexts. Results: Hmong ‘broken liver’ and English ‘sadness’ are deeply shaped by culture-specific premises concerning notions of social interaction, morality, interiority, socialisation, and cosmology. Conclusions: Critical attention has to be paid when assessing depressed mood cross-culturally. A social phenomenology combining qualitative and quantitative methods should be developed to analyse important semantic and pragmatic differences of depressed mood across cultural contexts.
Cerebellar Cognitive Affective Syndrome and Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay: A Report of Two Male Sibs
Authors: Verhoeven Willem M.A. , Egger Jos I.M. , Ahmed Amir I.M. , Kremer Berry P.H. , Vermeer Sascha , van de Warrenburg Bart P.C.
Published: March 2012

Background: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare neurodegenerative disorder caused by mutations in the SACS gene (13q12) encoding the protein sacsin. It is characterized by early-onset cerebellar ataxia, lower limb spasticity, sensorimotor axonal polyneuropathy, and atrophy of the superior cerebellar vermis. Cerebellar disorders in general may be accompanied by the cerebellar cognitive affective syndrome (CCAS) which presents with disturbances of executive functioning, spatial cognition, linguistic capacities, and affect. Sampling and Methods: Two middle-aged brothers with ARSACS, one of whom was referred for behavioral disinhibition, are described. A detailed neuropsychiatric and neuropsychological assessment was performed. Results: Apart from motor symptoms, motivational deficits along with cognitive and behavioral dysfunctions were present; these were much more pronounced in the older sib. Conclusions: These observations add to the literature which suggests that the cerebellum, apart from its significance for motor behavior, plays a functional role in human cognition and affect. The nonmotor symptoms of ARSACS are discussed in terms of the CCAS.
Endoscopic Minimally Invasive Neurosurgery: Emerging Techniques and Expanding Role through an Extensive Review of the Literature and Our Own Experience – Part I: Intraendoscopic Neurosurgery
Authors: Di Xiao , Sui Alan , Hakim Rodolfo , Wang Maode , Warnke Jan Peter
Published: March 2012

Background/Aims: Minimally invasive neurosurgery is a growing field, more so in recent decades. The modernization of tools, especially the endoscope, has allowed for critical improvements and crucial advancements in minimally invasive neurosurgery. The current classification scheme for endoscopic procedures needs to be updated to reflect these advancements. Methods: Although the field of neuroendoscopy is continually evolving, the terminologies utilized to describe endoscopic procedures reflect and favor its use as mostly an assisting device complementing the microscope. Even though the classification was adequate for its time, it has become inexact and therefore confusing. We therefore propose a new classification scheme that encompasses the growing independence of endoscopic minimally invasive neurosurgery (EMIN) as well as the changing landscape within EMIN procedures. Results: We have classified our EMIN procedures, since 2002, as either ‘intraendoscopic’ (IEN) or ‘extraendoscopic’ (XEN) in relation to the endoscope’s axis. Exemplary cases of IEN and a review of the literature are presented as well. Conclusion: Our proposed classification scheme for solely endoscopic procedures is presented. The role of the endoscope as an independent tool is clarified.
Endoscopic Minimally Invasive Neurosurgery: Emerging Techniques and Expanding Role through an Extensive Review of the Literature and Our Own Experience – Part II: Extraendoscopic Neurosurgery
Authors: Di Xiao , Sui Alan , Hakim Rodolfo , Wang Maode , Warnke Jan Peter
Published: March 2012

Background/Aims: The field of minimally invasive neurosurgery has grown dramatically especially in the last decades. This has been possible, in the most part, due to the advancements in technology especially in tools such as the endoscope. The contemporary classification scheme for endoscopic procedures needs to advance as well. Methods: The present classification scheme for neuroendoscopic procedures has become confusing because it mainly describes the use of the endoscope as an assisting device to the microscope. The authors propose an update to the current classification that reflects the independence of the endoscope as a tool in minimally invasive neurosurgery. Results: The proposed classification groups the procedures as ‘intraendoscopic’ neurosurgery or ‘extraendoscopic’ neurosurgery (XEN) in relation to the ‘axis’ of the endoscope. A review of the literature for the XEN group together with exemplary cases is presented. Conclusion: We presented our proposed classification for the endoscope-only surgical procedures. The XEN group is expanded in this article.
Health Status Assessment in Routine Clinical Practice: The Chronic Obstructive Pulmonary Disease Assessment Test Score in Outpatients
Authors: Kelly Julia L. , Bamsey Olivia , Smith Cayley , Lord Victoria M. , Shrikrishna Dinesh , Jones Paul W. , Polkey Michael I. , Hopkinson Nicholas S.
Published: March 2012

Background: The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is a simple, self-completion questionnaire developed to measure health status in patients with COPD, which is potentially suitable for routine clinical use. Objectives: The purpose of this study was to establish the determinants of the CAT score in routine clinical practice. Methods: Patients attending the clinic completed the CAT score before being seen. Clinical data, including, where available, plethysmographic lung volumes, transfer factor and arterial blood gas analysis, were recorded on a pro forma in the clinic. Results: In 224 patients (36% female), mean forced expiratory volume in 1 s (FEV1) was 40.1% (17.9) of predicted (%pred); CAT score was associated with exacerbation frequency [0–1/year 20.1 (7.6); 2–4/year 23.5 (7.8); >4/year 28.5 (7.3), p < 0.0001; 41/40/19% in each category] and with Medical Research Council (MRC) dyspnoea score (r2 = 0.26, p < 0.0001) rising approximately 4 points with each grade. FEV1 %pred had only a weak influence. Using stepwise regression, CAT score = 2.48 + 4.12 [MRC (1–5) dyspnoea score] + 0.08 (FEV1 %pred) + 1.06 (exacerbation rate/year)] (r2 = 0.36, p < 0.0001). The CAT score was higher in patients (n = 54) with daily sputum production [25.9 (7.5) vs. 22.2 (8.2); p = 0.004]. Detailed lung function (plethysmography and gas transfer) was available in 151 patients but had little influence on the CAT score. Conclusion: The CAT score is associated with clinically important variables in patients with COPD and enables health status measurement to be performed in routine clinical practice.
Differences in Plasma MMPs and TIMPs Protein Expression and Chemotherapy Response in Patients with Tobacco- or Wood-Smoke-Induced Lung Cancer
Authors: Gonzalez-Avila Georgina , Delgado Javier , Mendoza-Posada Daniel A. , Sommer Bettina , Ramos Carlos , Aquino-Galvez Arnoldo , Camacho Catalina
Published: March 2012

Background: One of the risk factors associated with lung cancer in never-smoker patients is wood smoke exposure (WS). However, information about its clinical and molecular characteristics remains scant. Objective: This was to analyze - in plasma from patients with tobacco- or wood-smoke-induced lung cancer - whether the enzymatic activity and concentration of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) differ, and to determine whether there was a correlation between these indicators of the metastatic potential and the first-line chemotherapy response. Methods: Patients were classified according to lung cancer associated with: the smoking of tobacco (T), WS and where no association with a known risk factor (N) could be established. The gelatinase activity of plasma MMP was analyzed by radiolabeled substrate degradation and zymography assay. Protein expression of MMPs and TIMPs was evaluated by Western blot densitometry analysis. Results: The 26.9% WS patients had a better response to therapy in comparison with the T group (OR = 4.9, 95% CI = 1.25-20.15; p = 0.019). The lowest gelatinase activity was observed in WS subjects, in comparison with T and N subjects (96.7 ± 15.9, 182.9 ± 31.5 and 163.3 ± 22.7 µg of degraded gelatin/mg of incubated plasma protein, respectively; p < 0.025); this enzymatic activity corresponded to MMP-2. The highest MMP-2, MMP-9, MT1-MMP and TIMP-1 plasma levels were observed in T subjects. Conclusion: Tobacco and wood smoke have different effects on MMP and TIMP synthesis and gelatinase activity, directly influencing lung cancer metastatic potential and chemotherapy response.
Cardiac Noradrenergic Denervation in a Patient with Multiple Symmetric Lipomatosis
Authors: Fonseca Válter R. , Freitas Carlos , Palmeira Mireille , Ferreira Carlos , Victorino Rui
Published: March 2012

Introduction: Multiple symmetric lipomatosis (MSL) is a rare disease of unknown etiology characterized by multiple subcutaneous lipomas with a symmetrical distribution. One interesting aspect about MSL is a high incidence of sudden cardiac death despite a low incidence of metabolic syndrome and coronary arterial disease. Autonomic nervous system dysfunction may probably explain this feature of MSL. Case Report: A 74-year-old man was admitted with acute heart failure and atrial fibrillation. He had a morphotype suggestive of MLS. A 123I-metaiodobenzylguanidine myocardial scintigraphy was conducted for evaluation of cardiac autonomic nervous integrity, since atrial fibrillation precluded the classical approach. The heart-to-mediastinum ratio was 1.68 (normal >2.2). Ischemia was not detected in myocardial perfusion scintigraphy. Conclusion: We present the first reported case of MSL autonomic neuropathy detected by 123I- metaiodobenzylguanidine scintigraphy and suggest that this approach could play a role in MSL stratification by risk of sudden cardiac death and in exploring MSL disease mechanisms.
Diagnosis and Rehabilitation of Visual Field Defects in Stroke Patients: A Retrospective Audit
Authors: Sand K.M. , Thomassen L. , Næss H. , Rødahl E. , Hoff J.M.
Published: March 2012

Objective: Visual field defects (VFD) after stroke can cause significant disability and reduction in quality of life. Adequate diagnosis of VFD and referral to visual rehabilitation are important to improve outcome. Our aim was to conduct a retrospective clinical audit to investigate how neurologists detect and follow up VFD in stroke patients in a university hospital in Norway. Methods: All patients registered in the Bergen NORSTROKE Registry from February 2006 to May 2009 with (1) occipital lobe infarctions and (2) non-occipital infarction and clinically detected VFD were included in the study. Their medical records were reviewed for referral to perimetry for examination of VFD and for referral to a visual rehabilitation program within the first year after brain injury. Results: Of 353 patients, 34 (9.6%) were referred to perimetry and 8 (2.3%) to visual rehabilitation. Patients referred to perimetry were younger (65.1 vs. 74.7 years, p < 0.001), had lower modified Rankin Scale scores (2.53 vs. 3.47, p = 0.003), and scored lower on the National Institutes of Health Stroke Scale upon admission (6.68 vs. 13.90, p < 0.001). Men were more often referred to perimetry than women (73.5 vs. 26.5%, p < 0.001), and those referred were younger (61.2 vs. 75.8 years, p = 0.03). Conclusions: Only few patients were referred to perimetry, and even fewer were offered visual rehabilitation. Age and gender were negative predictors for referral. Neurologists’ awareness of the significant disability related to VFD must be increased. Focused diagnostics on visual impairment and early referral to a visual rehabilitation program should be mandatory in stroke unit services.
Reduced coagulation at high altitude identified by thromboelastography
Authors: Martin Daniel , Pate Jim , Vercueil Andre , Doyle Patrick , Mythen Michael , Grocott Mike ,   for the Caudwell Xtreme Everest Research Group
Published: March 2012

The impact of hypoxaemia on blood coagulation remains unclear despite use of a variety of measures to address the issue. We report the first use of thromboelastography (TEG) at high altitude to describe the dynamics of clot formation in whole blood samples. Seventeen healthy volunteers ascended to 5,300 m following an identical ascent profile; TEG measurements at 4,250 m and 5,300 m were compared with those from sea level. Peripheral oxygen saturation (SpO2) and haematocrit were also measured. Ascent resulted in a decline in SpO2 from 97.8 (± 1.2) % at sea level to 86.9 (± 3.3) % at 4,250 m and 79.5 (± 5.8) % at 5,300 m (p<0.001); haematocrit rose from 43.7 (± 2.8) % at sea level, to 46.7 (± 3.9) % and 52.6 (± 3.2) % at 4,250 m and 5,300 m, respectively (p<0.01). TEG reaction (R)-time and kinetic (K)-time were both increased at 5,300 m compared to sea level, 8.95 (± 1.37) minutes (min) to 11.69 (± 2.91) min (p=0.016) and 2.40 (± 0.66) min to 4.99 (± 1.67) min (p<0.001), respectively. Additionally the alpha (α)- angle was decreased from 57.7 (± 8.2) to 51.6 (± 6.4) (p<0.001). There was no change in maximum amplitude (MA) on ascent to altitude. These changes are consistent with an overall pattern of slowed coagulation at high altitude.
Developing an Action Plan for Patient Radiation Safety in Adult Cardiovascular Medicine
Authors:   WRITING/STEERING COMMITTEE MEMBERS, Douglas Pamela S. , Carr J. Jeffery , Cerqueira Manuel D. , Cummings Jennifer E. , Gerber Thomas C. , Mukherjee Debabrata , Taylor Allen J.
Published: March 2012

Technological advances and increased utilization of medical testing and procedures have prompted greater attention to ensuring the patient safety of radiation use in the practice of adult cardiovascular medicine. In response, representatives from cardiovascular imaging societies, private payers, government and nongovernmental agencies, industry, medical physicists, and patient representatives met to develop goals and strategies toward this end; this report provides an overview of the discussions. This expert “think tank” reached consensus on several broad directions including: the need for broad collaboration across a large number of diverse stakeholders; clarification of the relationship between medical radiation and stochastic events; required education of ordering and providing physicians, and creation of a culture of safety; development of infrastructure to support robust dose assessment and longitudinal tracking; continued close attention to patient selection by balancing the benefit of cardiovascular testing and procedures against carefully minimized radiation exposures; collation, dissemination, and implementation of best practices; and robust education, not only across the healthcare community, but also to patients, the public, and media. Finally, because patient radiation safety in cardiovascular imaging is complex, any proposed actions need to be carefully vetted (and monitored) for possible unintended consequences.
Stroke in Children With Posterior Fossa Brain Malformations, Hemangiomas, Arterial Anomalies, Coarctation of the Aorta and Cardiac Defects, and Eye Abnormalities (PHACE) Syndrome
Authors: Siegel Dawn H. , Tefft Kimberly A. , Kelly Teresa , Johnson Craig , Metry Denise , Burrows Patricia , Pope Elena , Cordisco Maria , Holland Kristen E. , Maheshwari Mohit , Keith Phillip , Garzon Maria , Hess Christopher , Frieden Ilona J. , Fullerton Heather J. , Drolet Beth A.
Published: March 2012

Background and Purpose—

PHACE is an acronym for posterior fossa brain malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, and eye abnormalities. Several case reports of arterial ischemic stroke (AIS) in individuals with PHACE have been published, but risk factors for AIS in PHACE have not been clearly defined. The objective of this article is to review all cases of stroke in PHACE in children and describe clinical characteristics that may be associated with an increased risk of AIS.

Methods—

A literature and registry search was conducted to identify patients with PHACE who had experienced AIS. Data were analyzed to determine age of onset, presenting signs and symptoms, and clinical features among this cohort compared with PHACE without AIS.

Results—

Twenty-two individuals with PHACE and AIS were identified. Imaging of the arteries of the head and neck was reported in 20 of 22. Narrowing or nonvisualization of at least 1 great cerebral vessel was present in 19 of 20 and of those, 15 had ≥2 vessels involved. Aortic arch anomalies were reported in 13 of 22 individuals.

Conclusions—

Aplasia, hypoplasia, or occlusion of a major cerebral artery appears to be a significant risk factor for AIS in children with PHACE, especially when >1 vessel is involved or if there is coarctation of the aorta.
Simulated Density Currents beneath Embedded Stratified Layers
Authors: Seigel Robert B. , van den Heever Susan C.
Published: March 2012

The goal of this research is to investigate the impacts of a stably stratified layer embedded within a neutrally stratified environment on the behavior of density currents in an effort to extend the environmental regimes examined by Liu and Moncrieff. Such environments frequently support severe weather events. To accomplish this goal, nonhydrostatic numerical model experiments are performed in which the strength and height of the embedded stably stratified layer within a neutrally stratified environment are varied. The 1-km-deep stable layer base is varied between 1, 2, and 3 km AGL. Additionally, the strength of the stable layer is systematically varied between Brunt–Väisälä frequencies of 0.006, 0.012, and 0.018 s−1, following the methodology of Liu and Moncrieff. The model and grid setup are also similar to that of Liu and Moncrieff, utilizing the Arakawa C grid, leapfrog advection, a Robert–Asselin filter, and grid spacing of 100 and 50 m in the horizontal and vertical directions, respectively. Results show that the height of the density current decreases and the propagation speed increases with stronger and lower stable layers, provided that the stable layer is sufficiently thin so as to not act as a gravity wave ducting layer. As the strength of the stable layer increases and the height of this layer decreases, the horizontal pressure gradient driving the density current increases, resulting in faster propagation speeds. Such results have implications for cold pool propagation into more stable environments.
European Hot Summers Associated with a Reduction of Cloudiness
Authors: Tang Qiuhong , Leng Guoyong , Groisman Pavel Ya.
Published: March 2012

A pronounced summer warming is observed in Europe since the 1980s that has been accompanied by an increase in the occurrence of heat waves. Water deficit that strongly reduces surface latent cooling is a widely accepted explanation for the causes of hot summers. The authors show that the variance of European summer temperature is partly explained by changes in summer cloudiness. Using observation-based products of climate variables, satellite-derived cloud cover, and radiation products, the authors show that, during the 1984–2007 period, Europe has become less cloudy (except northeastern Europe) and the regions east of Europe have become cloudier in summer daytime. In response, the summer temperatures increased in the areas of total cloud cover decrease and stalled or declined in the areas of cloud cover increase. Trends in the surface shortwave radiation are generally positive (negative) in the regions with summer warming (cooling or stalled warming), whereas the signs of trends in top-of-atmosphere (TOA) reflected shortwave radiation are reversed. The authors’ results suggest that total cloud cover is either the important local factor influencing the summer temperature changes in Europe or a major indicator of these changes.
Interannual Variations of Subsurface Spiciness in the Philippine Sea: Observations and Mechanism
Authors: Li Yuanlong , Wang Fan , Zhai Fangguo
Published: March 2012

The Philippine Sea (PS) is a key region connecting North Pacific subtropics to the equator via western boundary currents. Using available measurements from Argo profiling floats, satellite altimeters, and research surveys, the authors investigate the characteristics and mechanism of subsurface spiciness variability (represented by salinity changes between 23.5 and 24.5 σθ) in the PS. During the past decade, low-frequency salinity variability was dominated by interannual signals characterized by out-of-phase changes between the southern and northern PS with peak-to-peak amplitudes exceeding 0.1 psu. These salinity anomalies are mainly generated locally by anomalous cross-front geostrophic advections. In 2003, an anomalous cyclonic circulation developed in the PS, which transported greater (less) than normal high-salinity North Pacific Tropical Water to the northern (southern) PS and produced positive (negative) salinity anomalies there. In 2009, an anomalous anticyclone emerged, which produced negative (positive) salinity anomalies in the northern (southern) PS. These year-to-year variations are closely associated with ENSO cycle. During strong El Niño (La Niña) episodes, positive (negative) wind stress curl anomalies between 8° and 18°N evoke westward-propagating upwelling (downwelling) Rossby waves in the central Pacific and positive (negative) anomalous Ekman pumping in the western Pacific, resulting in the observed current and salinity changes in the PS. Further analysis suggests that these locally generated spiciness anomalies disperse quickly while propagating to the equatorial Pacific in the Mindanao Current (MC). In the meantime, anomalies advected from higher latitudes are nearly diminished upon reaching the PS. The western boundary of the North Pacific seems quite efficient in damping extratropical signals.
The Prosumption of Commemoration
Authors: Recuber Timothy
Published: March 2012

The Internet has created innumerable possibilities for the construction of memorials devoted to tragic or catastrophic events and the exercise of collective memory. Two recent American disasters, the September 11, 2001 attacks and Hurricane Katrina, have been widely commemorated and memorialized online. This article examines the nature of online disaster commemoration through an analysis of the messages and stories submitted to two digital archives devoted to these disasters: the September 11 Digital Archive and the Hurricane Digital Memory Bank. By viewing these online archives as sites of prosumption, inasmuch as the sites’ users both produce and consume its content, the article is able to tease out connections to other prosumer-oriented trends surrounding commemoration and collective memory in the physical landscape. These trends include the increasing popularity of spontaneous shrines and the growing acceptance of therapeutic monuments. These two forms of prosumption also manifest themselves online in the digital memory banks studied here, in that they allow a wide variety of different users to contribute to the commemoration of September 11 and Hurricane Katrina in ways that often seek to enact a kind of therapeutic self-help and emotional catharsis. However, an analysis of the messages and stories left at these archives also points to some of the political limitations of such therapeutic forms of prosumption.
Effects of Electronic Map Displays and Individual Differences in Ability on Navigation Performance
Authors: Rodes William , Gugerty Leo
Published: March 2012

Objective:

The aim of this study was to determine how strongly the performance of navigation tasks is affected by changing electronic map interfaces and by individual differences in spatial ability.

Background:

Electronic map interfaces have two common configurations, north up and track up. Research suggests that north-up maps benefit some navigational tasks and track-up maps benefit others. However, little research has investigated how map configuration affects the important navigation task of judging cardinal direction or how individual differences in spatial ability interact with map configuration in affecting navigation performance.

Method:

In an aerial reconnaissance task, 16 participants completed route-following, cardinal direction, and map reconstruction tasks. Participants also completed three spatial ability tests.

Results:

The track-up map led to better performance on the cardinal direction and route-following tasks. The north-up map led to better performance on the map reconstruction task. Effects of map configuration showed small to medium effect sizes. Spatial ability correlated positively with performance of each navigation task, showing medium to large effect sizes. For some tasks, a helpful map interface compensated for low ability. For other tasks, ability facilitated the performance of the helpful interface; optimal performance required a helpful interface and high ability.

Conclusion:

Achieving high performance at particular navigation subtasks requires two things: using the map configuration that optimizes subtask performance and having high spatial ability.

Application:

Some aspects of navigation performance can be improved primarily by using the optimal map configuration; other aspects require using the optimal configuration and having better spatial ability.
The effect of information on oversight: the European Parliament’s response to increasing information on comitology decision-making
Authors: Brandsma Gijs Jan
Published: March 2012

The European Parliament, like any parliament, needs information for scrutinizing executive decision-making. But how does it process this information in practice? This article focuses on the European Parliament’s increasing grip on ‘comitology’ decision-making: committees composed of national civil servants, producing executive measures that are adopted by the European Commission. Two types of changes are addressed: organizational changes and changes in working methods of EP staff. The analysis shows that the European Parliament has effectively built up a system of decentralized police-patrol oversight, but not following more information rights as such but rather as a result of its increasing political powers. The article concludes that information only affects the behaviour of the European Parliament in combination with very specific as opposed to quite general or diffuse political rights.

Points for practitioners

This article traces the effects of information on the functioning of the European Parliament as an accountability forum. It concludes that information only makes a difference when coupled with very specific as opposed to very general or diffuse political rights.
Procedural transparency in rural Romania: linking implementation with administrative capacity?
Authors: Dragoş Dacian C. , Neamtţu Bogdana , Cobârzan Bianca V.
Published: March 2012

The article discusses the concept of procedural administrative transparency and aims to investigate the extent to which the legal provisions of Law no. 52/2003 on transparency in decision-making are actually implemented by the local administrations from the rural communities in the Transylvania region, Romania. The main research questions are: Where are the weaknesses in the implementation of Law no. 52/2003 in the rural settings in Romania? Why do they occur? What could be changed to alleviate these weaknesses? Based on a mixed method approach – surveys followed by direct observation and informal interviews – we determined that the implementation of procedural transparency requirements is low and in many cases local public authorities comply only ‘for the record’ with the provisions of the law. The main challenge with regard to implementation is the existence of universal provisions for all local public authorities, irrespective of their administrative capacity, existing cultural and social characteristics of public participation and communication in rural communities as well as the relationship between central and local tiers of the government. In conclusion, the authors argue that the implementation level of these requirements could be enhanced by their inclusion in a general procedural administrative law.

Points for practitioners

Very often, countries from Eastern Europe adopt state-of-the-art legislation which is then difficult to implement due to factors such as limited administrative capacity at the local level coupled with differences between urban and rural areas, resistance to change within the bureaucratic machinery, passiveness on behalf of the citizens, etc. In 2003, Romania adopted the law on transparency in the decision-making process of public authorities in an attempt to create a more open, transparent, accountable, and predictable government. Since its adoption, studies conducted by NGOs have proved that the implementation level is relatively low. This research assesses how the legal provisions of Law no. 52/2003 are implemented in the rural areas of Transylvania, one of the most significant regions of the country from an economic and cultural standpoint. Based on their findings, the authors argue that implementation in rural areas could be enhanced provided that local authorities are given more discretion with regard to how to implement certain provisions (flexibility in the choice of policy tools); and more discretion should be complemented by increased sanctions for non-compliance and their enforcement. These two goals can be achieved by including the procedural transparency requirements in a general administrative procedure law/administrative code.
The relationship between transparent and participative government: A study of local governments in the United States
Authors: Welch Eric W.
Published: March 2012

The relationship between transparency and participation of government is not well articulated in the literature. Transparency provides stakeholders with knowledge about the processes, structures and products of government. Participation refers to the quantity, quality and diversity of input of stakeholders into government decision-making. Greater transparency and participation are often considered to operate side by side. However, in the Internet age the change in the magnitude of information disclosure may outweigh the change in the level of participative government. This article uses data from a 2010 national survey of five US local government agencies to test hypotheses about the relationship between transparency and participation and the factors that affect them. Findings show that participation is positively associated with transparency, but transparency does not lead to participation. In addition, organizations that are under stronger influence from external stakeholders report higher levels of participation but in some cases higher levels of external influence dampen transparency.

Points for practitioners

For practitioners, the article provides a framework for understanding the relationship between transparency and participation as two dimensions of open government. While in some departments these two dimensions are present at similar levels, in others they are not. For example, among five departments, police report the lowest overall participation and transparency levels, while parks and recreation and the mayor’s office report the highest transparency and participation levels, respectively. In addition, police departments report significantly higher transparency than participation, while the reverse is true for community development departments. The article provides public administrators with greater insight into causes of and relationships between transparency and participation.
Synthesis and characterization of polyhedral oligomeric silsesquioxane–siloxane-modified polyimide hybrid nanocomposites
Authors: Chandramohan A , Nagendiran S , Alagar M
Published: March 2012

Polyhedral oligomeric silsesquioxane (POSS)–siloxane-modified polyimide (PI) hybrid nanocomposites were prepared by the reaction of siloxane-modified polyamic acid (PAA) with octaaminophenylsilsesquioxane (OAPS). PAA was prepared by the reaction of 4,4-diaminodiphenylsulfone with pyromellitic dianhydride in N-methylpyrrolidone (NMP), followed by the reaction of PAA with bis(3-aminopropyl) polydimethylsiloxane to obtain siloxane-modified. The siloxane-modified PI was further blended with varying weight percentages of OAPS using NMP solution. The reactions occurred during the formation of hybrid nanocomposites were confirmed by Fourier transform infrared spectra. The siloxane-modified PI OAPS nanocomposites were characterized for their thermal properties using differential scanning calorimeter and by thermogravimetric analysis. Morphological studies of the nanocomposites indicate that the incorporation of siloxane moieties creates heterogeneous morphology. Data from thermal studies indicate that the incorporation of POSS appreciably enhanced the glass transition temperature, thermal stability, and char yield of hybrid nanocomposites compared to neat PI.