bluuebunny/crossref_metadata_2025 huggingface dataset:
Unilateral internal carotid arterial occlusion: special considerations.
Authors: Andersen C A , Rich N M , Collins G J , McDonald P T , Boone S C
Published: June 2011

Cases of patients with unilateral internal carotid arterial occlusion and contralateral internal carotid arterial stenosis are reviewed. Forty-two percent presented with a fixed neurological deficit. The deficit was referable to the side of occlusion in 92% and to the side of stenosis in 8%. Eleven percent had a neurological complication following carotid endarterectomy on the side of the stenotic lesion. The neurological complication was referable to the side of stenosis in 67% and to the side of occlusion in 33%. Patients have been followed for an average of 19 months and have not developed any additional TIA's or strokes in the followup period. There may be a role for an extracranial-intracranial bypass (ECIC) on the occluded side prior to an endarterectomy on the stenotic side if a poor collateral situation exists. An ECIC should be done in patients who remain symptomatic following carotid endarterectomy on the stenotic side. These data do not support doing ECIC in asymptomatic patients with unilateral carotid arterial occlusion.
Correlation between the location of hematoma and its clinical symptoms in the lateral type of hypertensive intracerebral hemorrhage. Observations on Pantopaque radiography of the hematoma cavity in cases of early surgical treatment.
Authors: Koba T , Yokoyama T , Kaneko M
Published: June 2011

The authors studied the Pantopaque radiograms of a hematoma cavity in 46 patients following early surgical treatment for the lateral type of hypertensive intracerebral hematoma. All patients were operated on within 7 hours after the apoplectic attack and most of them had a localized hematoma. It was concluded that they could be classified in three subtypes from the location of hematoma in the antero-posterior direction. Each subtype had particular clinical symptoms and prognosis.
Intracranial hemorrhage and infarction in anticoagulated patients with prosthetic heart valves.
Authors: Lieberman A , Hass W K , Pinto R , Isom W O , Kupersmith M , Bear G , Chase R
Published: June 2011

In 1 year 6 patients with prosthetic heart valves (PHVs) treated with anticoagulants suffered intracranial hemorrhage. In 4, hemorrhage occurred into the site of a recent non-hemorrhagic infarction. In the others, both of whom had endocarditis, hemorrhages probably occurred as the result of rupture of a mycotic aneurysm. Five patients were treated with warfarin, 1 with heparin. In all patients the level of anticoagulant activity was greater than 1.5 times control. Five patients were in atrial fibrillation; 1 was hypertensive. The diagnosis of intracranial hemorrhage was made and its location and extent accurately determined by computed tomography (CT). Three patients underwent surgery and 2 are alive with only minor neurological deficits. Among the 3 patients who did not undergo surgery 2 died and 1 is alive with a moderate neurological deficit. The management of PHV patients with use of anticoagulants is discussed in terms of the mechanisms involved in intracranial bleeding. Emphasis is placed on prevention of emboli, discontinuation of anticoagulants once non-hemorrhagic infarction has occurred and the primacy of CT scan in diagnosis when hemorrhage is suspected. The special problems of anticoagulation in the presence of endocarditis are also discussed.
Sympathetic nervous system activity in patients with subarachnoid hemorrhage.
Authors: Benedict C R , Loach A B
Published: June 2011

In patients with subarachnoid hemorrhage there were increased concentrations of plasma epinephrine and norepinephrine when compared with those concentrations in a group of patients admitted to hospital with other illness. Reassessment after a variable period showed that in patients whose eventual clinical result was poor the plasma epinephrine and norepinephrine concentrations increased further while in those with a good result those concentrations showed a decline. No such changes were evident in plasma dopamine-beta-hydroxylase activities which were within normal range. In a sub-group of patients who had neurosurgery after admission for clipping an aneurysm, the post-operative changes of plasma epinephrine and norepinephrine concentrations were related to the clinical condition of the patients.
Delayed pentobarbital therapy of acute focal cerebral ischemia.
Authors: Black K L , Weidler D J , Jallad N S , Sodeman T M , Abrams G D
Published: June 2011

The efficacy of pentobarbital in the delayed treatment of acute cerebral ischemia was investigated in cats. Cerebral ischemia was produced by left middle cerebral artery (LMCA) ligation. Ten cats received 50 mg/kg of pentobarbital prior to ligation; a second group of 10 cats received the same dose of pentobarbital 2 hrs after ligation, and the control group of 7 cats received no pentobarbital. Brains were removed after spontaneous or induced death and the volume infarction was determined histologically. It was found that the volume of brain infarction in the group receiving pentobarbital 2 hrs after ligation was significantly less than that of the control group, which received no pentobarbital; but the volume of infarction in the former group was significantly greater than that found in the experimental group, which received pentobarbital prior to ligation. However, the mortality after LMCA ligation was higher in the 2 experimental groups, which received pentobarbital therapy, than in the control group, which did not receive pentobarbital. An hypothesis was advanced, which speculated that secondary adrenal insufficiency and altered cardiovascular function accounted for the increased mortality after pentobarbital treatment of patients with ischemic stroke.
Clinical and arteriographic comparison of amaurosis fugax with hemispheric transient ischemic attacks.
Authors: Eisenberg R L , Mani R L
Published: June 2011

Eighty-seven patients with either amaurosis fugax (40 patients) or hemispheric transient ischemic attacks (47 patients) were studied to determine whether the two symptom groups could be differentiated clinically and arteriographically. Clinical data assessed were age of patient, incidence of cardiac disease, and presence of claudication, hypertension, diabetes, and carotid bruits. Contrary to a prior report, our results indicate no significant difference between the 2 patient groups based on clinical and arteriographic findings.
Relationship between primitive reflexes in stroke patients and rehabilitation outcome.
Authors: Botvin J G , Keith R A , Johnston M V
Published: June 2011

The reappearance of developmental reflexes in the aged has been found to be associated with severe, diffuse cerebral damage. This study examined the relationship between the presence of such reflexes in stroke patients and the outcome of rehabilitation. Tests for the presence of snout, suck, jaw-jerk and palmomental reflexes were tested in 106 consecutive stroke patients admitted for rehabilitation treatment. A mental status test was also included in the usual medical admission examination. Functional status ratings for self-care and mobility at discharge, and the setting to which the patient was discharged, were used as outcome criteria. All of the reflex signs were negatively related to a favorable outcome, but the correlations were not high enough for predictive value. The mental status measures were more highly related to rehabilitation outcome than were the presence of developmental reflexes.
Cerebral hemorrhage from a mycotic aneurysm developing during appropriate antibiotic therapy.
Authors: Schold C , Earnest M P
Published: June 2011

A patient with bacterial endocarditis had headaches, cerebrospinal fluid pleocytosis and normal cerebral angiograms. Fifteen days later, while on appropriate antibiotic therapy, he developed an intracerebral hematoma due to a mycotic aneurysm. Mycotic aneurysm is an infrequent but serious complication of bacterial endocarditis. An aneurysm should be considered whenever a patient with bacterial endocarditis has neurologic symptoms even when the patient is receiving antibiotics.
Xenon-133 inhalation method for regional cerebral blood flow measurements: normal values and test-retest results.
Authors: McHenry L C , Merory J , Bass E , Stump D A , Williams R , Witcofski R , Howard G , Toole J F
Published: June 2011

The purpose of this investigation is to determine the normal values for regional cerebral blood flow (rCBF) as determined by the xenon inhalation method of Obrist. Normal values for all rCBF parameters were measured in 15 healthy individuals. Our data are compared with the normal data obtained by other investigators. In addition, test-retest rCBF measurements were performed to determine the reproducibility of the method. Our results show that the method is highly reproducible when carried out in serial studies over a short period of time.
Intravenous glycerol in cerebral infarction: a controlled 4-month trial.
Authors: Fawer R , Justafré J C , Berger J P , Schelling J L
Published: June 2011

A double-blind, randomized trial was performed with 51 patients suffering from focal ischemic lesions in the territory of the middle cerebral artery. Intravenous infusions of 10% glycerol in 0.9% NaCl--5% glucose solutions were administered twice daily for 6 days to 26 patients, and the same amount of NaCl--glucose solutions to 25 controls. Glycerol did not reduce mortality (9 deaths in each group). The functional recovery was assessed by repeated neurological examinations during the 4 month trial. Glycerol significantly improved global performances and motor and sensory functions in patients with moderate disability, but its effect on global performances was transient. The patients with severe disability were not improved at all.
Holter monitoring in patients with transient focal cerebral ischemia.
Authors: Fisher M
Published: June 2011

The value of continuous long-term ECG monitoring in patients with transient generalized neurological symptoms is well established, but its value in transient focal neurological deficits is less clear. A patient is reported who had significant dysrhythmias and transient focal cerebral symptoms which did not clear after cardiac pacing. Nineteen other patients were monitored as part of their evaluation for transient focal cerebral symptoms and were found to have essentially no cerebrally significant dysrhythmias. This report suggests cardiac dysrhythmias rarely cause such symptoms.
Trends in mortality from cerebrovascular diseases in the United States, 1960 to 1975.
Authors: Soltero I , Liu K , Cooper R , Stamler J , Garside D
Published: June 2011

A long-term decline in death rates from cerebrovascular diseases in the United States accelerated in 1969, with a further increase in the rate of decline after 1972. This break in the pattern of the mortality curve for stroke was observed in all 4 major sex-color groups, and affected all age groups in which a significant number of stroke deaths occur. The decline for non-whites was relatively and absolutely greater than for the comparable white sex. If the 1960 rates had persisted in 1975, 87,600 more lives would have been lost to cerebrovascular diseases. Although there are no data documenting a declining prevalence of hypertension in the population, detection, treatment and control of hypertension have improved markedly over recent years. A concomitant decrease in the severity of epidemic respiratory infection may have contributed to the improvement in recorded death rates from stroke. Mortality from all major cardiovascular diseases has demonstrated a parallel downward trend. Continued emphasis on public health efforts to detect and treat hypertension and other known cardiovascular risk factors can be expected to result in further improvement in cardiovascular mortality.
Effects of reduced regional or body temperatures on responses of pial arterioles.
Authors: Rosenblum W I , Segreti A C
Published: June 2011

We have investigated the effects of a reduced regional or a reduced body temperature, on pial arteriolar response to a variety of vasoactive stimuli. This has been done by studying the effects of these stimuli on groups of mice with different body temperatures, or with different temperatures of the artificial cerebrospinal fluid (CSF) irrigating the pial surface. Responses in mice with body temperatures of 30 degrees or 22 degrees C showed little or no difference from responses in mice with body temperatures of 37 degrees. This was so whether the surface irrigant was maintained at 37 degrees or at 23 degrees. On the other hand, significant reductions in pial vascular responses were observed when mice with "CSF" temperatures of 22 degrees were compared with those having "CSF" temperatures of 37 degrees. The data suggest that regional cooling is more effective than cooling the body in reducing the response of pial arterioles. The data also indicate that marked reductions in body temperature would have to occur before a detectable effect on pial vascular responses is produced, at least in mice anesthetized with urethane.
Indomethacin prevents impaired perfusion of the dogs's brain after global ischemia.
Authors: Furlow T W , Hallenbeck J M
Published: June 2011

Compression ischemia of the central nervous system (CNS) in heparinized dogs caused areas of diminished cerebral blood flow measured by 14C-antipyrine autoradiography. Intravenous infusion of indomethacin (1.5 or 4.0 mg/kg) approximately 1 hour before ischemia eliminated the circulatory defects. Prophylactic inhibition of prostaglandin synthetase may promote postischemic perfusion of the CNS by preventing vasoconstriction and by anti-hemostatic effects on blood.
Computerized axial tomography in brain death.
Authors: Rangel R A
Published: June 2011

Two patients with the diagnosis of brain death were evaluated with computerized axial tomography (CAT). After intravenous infusion of 30% Conray there was no visualization of the intracranial vasculature (circle of Willis). The second patient also had an isoelectric EEG. A third patient with an intracerebral lesion similar to the other cases but without diagnosis of brain death, showed good visualization of the circle of Willis. Therefore, contrast-enhanced CAT scans can be used as another diagnostic aid to confirm brain death.
Exposure to Uremic Serum Induces a Procalcific Phenotype in Human Mesenchymal Stem Cells
Authors: Kramann Rafael , Couson Simone K. , Neuss Sabine , Kunter Uta , Bovi Manfred , Bornemann Jörg , Knüchel Ruth , Jahnen-Dechent Willi , Floege Jürgen , Schneider Rebekka K.
Published: June 2011

Objective—

Medial artery calcification in patients with chronic kidney disease proceeds through intramembranous ossification resulting from osteoblast-induced calcification of the collagen extracellular matrix. The current study is based on the hypothesis that mesenchymal stem cells (MSC) constitute critical cells for procalcific extracellular matrix remodeling in patients with chronic kidney disease.

Methods and Results—

Human MSC were cultured in media supplemented with pooled sera from either healthy or uremic patients (20%). Exposure to uremic serum enhanced the proliferation of MSC (cell counting, BrdU incorporation) whereas apoptosis and necrosis were not affected (annexin V and 7-amino-actinomycin staining). Uremic serum–exposed MSC recapitulated osteogenesis by matrix calcification and expression of bone-related genes (bone morphogenetic protein [BMP]-2 receptor, alkaline phosphatase, osteopontin, and Runx2) in 35 days. The uremic serum–induced osteogenesis was completely blocked by a BMP-2/4 neutralizing antibody or the natural antagonist NOGGIN. Calcification and matrix remodeling were further analyzed in a collagen-embedded osteogenesis model recapitulating the vascular collagen I/III environment. The uremic serum–induced calcification was shown to occur along collagen fibers as shown by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and von Kossa staining and was accompanied by extensive matrix remodeling.

Conclusion—

Uremic serum induced in a BMP-2/4-dependent manner an osteoblast-like phenotype in MSC accompanied by matrix remodeling and calcification.
An Automated, Objective, Multiple-Satellite-Platform Tropical Cyclone Surface Wind Analysis
Authors: Knaff John A. , DeMaria Mark , Molenar Debra A. , Sampson Charles R. , Seybold Matthew G.
Published: June 2011

A method to estimate objectively the surface wind fields associated with tropical cyclones using only data from multiple satellite platforms and satellite-based wind retrieval techniques is described. The analyses are computed on a polar grid using a variational data-fitting method that allows for the application of variable data weights to input data. The combination of gross quality control and the weighted variational analysis also produces wind estimates that have generally smaller errors than do the raw input data. The resulting surface winds compare well to the NOAA Hurricane Research Division H*Wind aircraft reconnaissance–based surface wind analyses, and operationally important wind radii estimated from these wind fields are shown to be generally more accurate than those based on climatological data. Most important, the analysis system produces global tropical cyclone surface wind analyses and related products every 6 h—without aircraft reconnaissance data. Also, the analysis and products are available in time for consideration by forecasters at the Joint Typhoon Warning Center, the Central Pacific Hurricane Center, and the National Hurricane Center in preparing their forecasts and advisories. This Multiplatform Tropical Cyclone Surface Wind Analysis (MTCSWA) product is slated to become an operationally supported product at the National Environmental Satellite Data and Information Service (NESDIS). The input data, analysis method, products, and verification statistics associated with the MTCSWA are discussed within.
Simple Multicloud Models for the Diurnal Cycle of Tropical Precipitation. Part I: Formulation and the Case of the Tropical Oceans
Authors: Frenkel Yevgeniy , Khouider Boualem , Majda Andrew J.
Published: June 2011

The variation of tropical precipitation due to the diurnal cycle of solar heating is examined here in the context of two simple models for tropical convection. The models utilize three cloud types—congestus, deep, and stratiform—that are believed to characterize organized tropical convection and are based on the two first baroclinic modes of vertical structure plus a boundary layer mode. The two models differ mainly in the way they treat the boundary layer dynamics. The first one is purely thermodynamical and is reduced to a single equation for the equivalent potential temperature θe connecting the boundary layer to the upper troposphere through downdrafts and to the surface through evaporation while the second uses full bulk boundary layer (FBBL) dynamics with a careful separation between sensible and latent heat fluxes and parameterization of nonprecipitating shallow cumulus. It turns out that in the case of the precipitation over the ocean where the Bowen ratio is small, both models yield a qualitatively similar solution, characterized by an overnight initiation and early morning peak in precipitation consistent with observations. The modeled diurnal cycle of precipitation over the ocean is divided into four cyclic phases: 1) a CAPE (re)generation phase characterized by the enhancement of the boundary layer θe and moisture fluxes during midday and early afternoon that is followed by 2) a (re)moistening phase dominated by congestus heating during the late afternoon and moistening from downdrafts (due to detrainment of shallow cumulus, specifically in the FBBL model) and radiative cooling that lasts until midnight. 3) Deep convection is initiated around midnight when the midtroposphere is sufficiently moist and cool and (re)establishes the precipitation level near its radiative convective equilibrium (1 K day−1) and then 4) peaks with sunrise at 0600 LST to yield a precipitation maximum of roughly 2 K day−1 at around 0900 LST that dries the troposphere and consumes CAPE and closes the cycle.
Comparison of Raman Lidar Observations of Water Vapor with COSMO-DE Forecasts during COPS 2007
Authors: Herold Christian , Althausen Dietrich , Müller Detlef , Tesche Matthias , Seifert Patric , Engelmann Ronny , Flamant Cyrille , Bhawar Rohini , Di Girolamo Paolo
Published: June 2011

Water vapor measurements with the multiwavelength Raman lidar Backscatter Extinction Lidar-Ratio Temperature Humidity Profiling Apparatus (BERTHA) were performed during the Convective and Orographically-induced Precipitation Study (COPS) in the Black Forest, Germany, from June to August 2007. For quality assurance, profiles of the water vapor mixing ratio measured with BERTHA are compared to simultaneous measurements of a radiosonde and an airborne differential absorption lidar (DIAL) on 31 July 2007. The differences from the radiosonde observations are found to be on average 1.5% and 2.5% in the residual layer and in the free troposphere, respectively. During the two overflights at 1937 and 2018 UTC, the differences from the DIAL results are −2.2% and −3.7% in the residual layer and 2.1% and −2.6% in the free troposphere. After this performance check, short-range forecasts from the German Meteorological Service’s (Deutscher Wetterdienst, DWD) version of the Consortium for Small-Scale Modeling (COSMO-DE) model are compared to the BERTHA measurements for two case studies. Generally, it is found that water vapor mixing ratios from short-range forecasts are on average 7.9% drier than the values measured in the residual layer. In the free troposphere, modeled values are 9.7% drier than the measurements.
Immigration and disability: Ableismin the policies of the Canadian state
Authors: El-Lahib Yahya , Wehbi Samantha
Published: June 2011

In this article, we discuss how the current immigration selection policy in Canada impacts people with disabilities. Using anti-oppressive and anti-colonial theoretical frameworks we analyze a recent example and demonstrate how the selection process to determine immigration eligibility disadvantages people with disabilities. Implications for social work are discussed.
The assessment of the performance of balconies using computational fluid dynamics
Authors: Ai ZT , Mak CM , Niu JL , Li ZR
Published: June 2011

This article presents a numerical study of ventilation performance of balconies using computational fluid dynamics. The pressure coefficients distributed on the opposite walls of a five-storey building model, both with and without balconies, were studied under variation of the wind direction, balcony dimensions and building height. The effect of balconies on the capacity for wind-induced natural ventilation is discussed. The numerical results show good agreement with the experiments of Chand et al. They also indicate that a balcony enhances the cross-ventilation of intermediate floors but weakens that of the ground and top floors, by significantly changing the pressure distribution on the windward wall. Finally, the ventilation performance of a balcony is not greatly affected by variations in its size but is slightly weakened as the height of the building increases.

Practical application: This study provides information and guidance in how best to incorporate the use of a balcony in building development at the design stage.
Electoral authoritarianism and backlash: Hardening Malaysia, oscillating Thailand
Authors: Case William
Published: June 2011

Where new democracies threaten the interests of capital owning and military elites, O’Donnell and Schmitter (1986) argued that they may readily be reversed. This paper, in carrying out a paired comparison of authoritarian reversals in contemporary Malaysia and Thailand, extends this thesis in several ways. It extends the logic of threats to elite-level interests and reversals to electoral authoritarian regimes, the posture in which much of the third wave has reached equilibrium. It examines more deeply the societal grounding and institutional bases that support elite-level statuses. It locates the threats to elite-level interests along dimensions identified in a new literature on democratic quality. It characterizes elite-level relations as cohesive or fractious, enabling us to chart the different modes of reversal that take place, as well as the durability of the authoritarianism that follows.
Dispossession and changes in class relations in Japan since 1980
Authors: Bernier Bernard
Published: June 2011

Postwar Japan was marked by the definition of a new rather stable hegemony that linked families closely to the education system and to the economy. The main objective of the dominant class was economic growth, and in order to achieve such an objective, they put into place measures to distribute income. As a consequence, there appeared an ideology of Japan as a giant middle-class society. This hegemony was weakened by the prosperity of the 1980s, but even more by the serious economic difficulties of 1990— 2003 and 2008—10. The last period saw many types of dispossession that resulted in changes in class relations, including a dislocation of the so-called middle class.
Less methodology more epistemology please: The body, metaphysics and ‘certainty’
Authors: Al-Mohammad Hayder
Published: June 2011

One of the distinguishing features of anthropology is its reliance on the ethnographic method of sustained, long-term fieldwork in a given ‘field’ or set of ‘fields’. This reliance on practical engagement, along with the rise in the popularity of practice theory, and embodiment as a paradigm of not only the acquisition and performance of knowledge but also as a founded mode of being-in-the-world, has resulted in discursive and epistemic deadlocks or limitations being translated into practical or methodological deadlocks. In this article I want to highlight the theoretical oversights of reliance on practicality as a means of dealing with issues which in essence are epistemic and categorial but which are translated as methodological problems. After exemplifying these categorial misnomers I want to propose that what we as anthropologists encounter in many cases as insufficiencies in our understanding of certain topics cannot be overcome with more sophisticated and nuanced methods, rather we gain more by acknowledging such insufficiencies as constituting the type of knowledge we are trying to gain.
Electrospinning of polyvinyl alcohol/gelatin nanofiber composites and cross-linking for bone tissue engineering application
Authors: Linh Nguyen Thuy Ba , Lee Byong-Taek
Published: June 2011

A three-dimensional polymer composite system consisting of polyvinyl alcohol/gelatin (PVA/GE) was fabricated via the electrospinning method and physically cross linked by methanol treatment. The effects of cross-linking between PVA/GE blend on physical, mechanical, and biological properties were investigated. After treating with methanol, PVA/GE mats become dense, hard, and aggregative with increased resistance to water dissolution. Osteoblasts like MG-63 cells were seeded on the surfaces of the cross linked PVA/GE mats and were found to attach firmly by expressing philopodial extensions. In addition, MTT assay and Western Blot analysis confirmed that the cells readily proliferated on the cross linked PVA/GE scaffolds. The osteoblast cell–matrix interaction demonstrated that the active biocompatibility of the mats was facilitated by using GE and cross-linking. In conclusion, our results suggest that cross-linked PVA/GE scaffolds hold promise for tissue engineering applications, especially in the field of artificial bone implant.
Development of a pre-vascularized 3D scaffold-hydrogel composite graft using an arterio-venous loop for tissue engineering applications
Authors: Rath Subha N , Arkudas Andreas , Lam Christopher XF , Olkowski Radoslaw , Polykandroitis Elias , Chróścicka Anna , Beier Justus P , Horch Raymund E , Hutmacher Dietmar W , Kneser Ulrich
Published: June 2011

Hyaluronic acid (HA) and fibrin glue (FG) are effective hydrogels for tissue engineering applications as they support tissue in-growth, retain growth factors, and release them slowly with time. The scaffolds, in combination with a hydrogel, effectuate a successful graft. However, the survival of a graft entirely depends upon a functional vascular supply. Therefore, hydrogels must support the in-growing vasculature. To study and compare the vascular patterns, HA and FG hydrogel-containing PLDLLA-TCP-PCL scaffolds were implanted in the groin of male Lewis rats and supplied with a micro-surgically prepared arterio-venous (A-V) loop. The rats were perfused with a vascular contrast media after 4 and 8 weeks and sacrificed for further analysis. The specimens were scanned with micro-CT to find the vascular growth patterns. Corrosion casting of blood vessels followed by SEM demonstrated a high vascular density near the parent blood vessels. Histologically, HA and FG implanted animal groups showed significant angiogenetic activity, especially within the pores of the scaffold. However, formation of new blood vessels was more conspicuously observed at 4 weeks in FG than HA implants. Furthermore, by 8 weeks, the number and pattern of blood vessels were comparable between them. At this time, HA was still present indicating its slow degradation. The finding was confirmed by histomorphometric analysis. This experimental study demonstrates that HA containing composite scaffold systems permit stabile in-growth of blood vessels due to sustained degradation over 8 weeks. HA is a potential matrix for a tissue engineered composite graft.
Numerical and scalability analysis of an unstructured Cartesian flow solver
Authors: Yau Y H , Badarudin A , Rubini P A
Published: June 2011

This article describes a systematic approach in building a flow solver for large eddy simulation (LES). Finite volume discretizations of the filtered, incompressible, Navier–Stokes equations were explained. The theory progresses to the description of the step-by-step process (mainly in increasing functionality or capability) in developing a three-dimensional, unstructured Cartesian mesh, parallel code after evaluating numerical factors, and available options carried out earlier. This was followed by a presentation of results produced from the simulations of laminar flow, related to the validation of the source codes, which indicates that the flow solver is behaving satisfactorily.
The biomechanics of plate repair of periprosthetic femur fractures near the tip of a total hip implant: the effect of cable-screw position
Authors: Dubov A , Kim S Y R , Shah S , Schemitsch E H , Zdero R , Bougherara H
Published: June 2011

Optimal surgical positioning of cable-screw pairs in repairing periprosthetic femur fractures near the tip of a total hip implant still remains unclear. No studies in the literature to date have developed a fully three-dimensional finite element (FE) model that has been validated experimentally to assess these injury patterns. The aim of the present study was to evaluate the biomechanical performance of three different implant–bone constructs for the fixation of periprosthetic femoral shaft fractures following total hip arthroplasty. Experimentally, three bone–plate repair configurations were applied to the periprosthetic synthetic femur fractured with a 5 mm gap near the tip of a total hip implant. Constructs A, B, and C, respectively, had successively larger distances between the most proximal and the most distal cable-screw pairs used to affix the plate. Specimens were oriented in 15° adduction, subjected to 1000 N of axial force to simulate the single-legged stance phase of walking, and instrumented with strain gauges. Computationally, a linearly elastic and isotropic three-dimensional FE model was developed to mimic the experimental setup. Results showed excellent agreement between experimental versus FE analysis strains, yielding a Pearson linearity coefficient, R2, of 0.90 and a slope for the line of best data fit of 0.96. FE axial stiffnesses were 601 N/mm (Construct A), 849 N/mm (Construct B), and 1359 N/mm (Construct C). FE surface stress maps for cortical bone showed maximum von Mises values of 74 MPa (Construct A), 102 MPa (Construct B), and 57 MPa (Construct C). FE stress maps for the metallic components showed minimum von Mises values for Construct C, namely screw (716 MPa), cable (445 MPa), plate (548 MPa), and hip implant (154 MPa). In the case of good bone stock, as modelled by the present synthetic femur model, optimal fixation can be achieved with Construct C.
Pragmatism, politics and the politiography of civil wars
Authors: Mundy Jacob
Published: June 2011

While Håvard Strand’s rejoinder to ‘Deconstructing civil wars’ is a welcome invitation to dialogue, its criticisms are grounded in a fundamental misreading of my article. Here I will attempt to address the sources of confusion, which stem from poor execution on my part and some theoretical blinders on the part of the author of the rejoinder. This response will clarify my ethical and theoretical concerns with the way in which mass intra-territorial armed violence has been studied recently, and then reinforce my proposed warrant for a pragmatic ( read: political) turn in the civil war/new war debate. This intervention will conclude by suggesting that the present debate highlights the need for a third estate in political studies, one that operates between political science and political theory: politiography.
Self-Efficacy, Perceived Social Support, and Psychological Adjustment in International Undergraduate Students in a Public Higher Education Institution in Malaysia
Authors: Yusoff Yusliza Mohd.
Published: June 2011

The globalization of the economy and society has had its impact on Malaysian higher education institutions, particularly universities. The Malaysian Ministry of Higher Education aims at intensifying globalization through increasing the number of international students. However, many international students struggle with adjusting to a new culture. The role of self-efficacy and social support on international students’ adjustment is important because international students encounter many academic and cultural challenges when they come to Malaysia. Thus, the present study examined the relationship between self-efficacy, perceived social support, and psychological adjustment of international students in a Malaysian public university. A total of 185 international students from various countries and regions completed questionnaires about their self-efficacy, perceived social support, and psychological adjustment. The General Self-Efficacy Scale (Schwarzer & Jerusalem, 1995) was administered to assess the international students’ self-beliefs to cope with a variety of difficult demands in life. The Multidimensional Scale of Perceived Social Support (Zimet et al., 1988) was used to assess international students’ social support. Psychological adjustment was measured with the Satisfaction With Life Scale (Diener et al., 1985). As hypothesized, self-efficacy and only 1 dimension of perceived social support (support from friends and significant others) significantly related with psychological adjustment. Implications of the findings for better adjustment in university environment among international students and future research on international students; adjustment are discussed.
Report of Maltreatment as a Risk Factor for Injury Death
Authors: Putnam-Hornstein Emily
Published: June 2011

This article presents a population-based study of early childhood injury mortality following a nonfatal allegation of maltreatment. Findings are based on a unique data set constructed by establishing child-level linkages between vital birth records, administrative child protective services records, and vital death records. These linked data reflect over 4.3 million children born in California between 1999 and 2006 and provide a longitudinal record of maltreatment allegations and death. Of interest was whether children reported for nonfatal maltreatment subsequently faced a heightened risk of unintentional and intentional injury mortality during the first 5 years of life. Findings indicate that after adjusting for risk factors at birth, children with a prior allegation of maltreatment died from intentional injuries at a rate that was 5.9 times greater than unreported children (95% CI [4.39, 7.81]) and died from unintentional injuries at twice the rate of unreported children (95% CI [1.71, 2.36]). A prior allegation to CPS proved to be the strongest independent risk factor for injury mortality before the age of five.
A viscoelastic thin rod model for large deformations: Numerical examples
Authors: Beyrouthy Joelle , Neff Patrizio
Published: June 2011

We present a Cosserat-based 3D–1D dimensional reduction for a viscoelastic finite strain model. The numerical resolution of the reduced coupled minimization/evolution problem is based on a splitting method. We start by approximating the minimization problem using the finite element method with P1 Lagrange elements. The solution of this problem is used in the time-incremental formulation of the evolution problem.
The determination of the pressure–viscosity coefficient of a lubricant through an accurate film thickness formula and accurate film thickness measurements. Part 2: high L values
Authors: van Leeuwen H
Published: June 2011

The pressure–viscosity coefficient of a traction fluid is determined by fitting calculation results on accurate film thickness measurements, obtained at different speeds, loads, and temperatures. Through experiments, covering a range of 5.6 <  M < 12 000, 2.1 <  L < 17.5, film thickness values are calculated using a numerical method and approximation formulas from 12 models. It is concluded that, to assess the pressure–viscosity coefficient of the fluid, the Chittenden et al. approximation formula applied to circular contacts is the best choice, having an inaccuracy in between (−15%, +11%). This expression has been used far outside the regime of the numerical data where it was based upon.
Numerical investigation of the use of machinery low-viscosity working fluids as lubricants in elastohydrodynamic lubricated point contacts
Authors: Habchi W , Vergne P , Eyheramendy D , Morales-Espejel G E
Published: June 2011

This study proposes a numerical investigation of the potential use of machinery working fluids as lubricants in contacts operating under an elastohydrodynamic regime. These fluids are usually of very low viscosity and pressure–viscosity dependence. This is why, unmixed with oil, they have been of little interest for the tribological community. Hence, their rheological properties are poorly known. In fact, these are restricted to a narrow range of conditions compared to the range of interest in EHL applications. This is why some measurements are carried out in order to determine both the viscosity and density of these uncommon lubricants. Besides, their viscosity being low, high-mean entrainment speeds are required for a sufficiently thick lubricant film to build up. This leads to an important thermal dissipation within the contact. Thermal effects are included in the analysis in order to make the estimation of film thicknesses and friction coefficients in these contacts as accurate as possible. Results are discussed in the light of the peculiar properties of machinery low-viscosity working fluids.
Squeeze processes in a narrow circular damper with highly compressible porous layer imbibed with liquids
Authors: Ilie M-B , Pascovici M D , Marian V G
Published: June 2011

Squeeze film dampers are widely used technical components for turbomachinery as a means to reduce the amplitude of rotor vibration owing to unbalance. This article proposes a different type of circular damper using highly compressible porous layers (HCPL) imbibed with Newtonian liquids. The elastic forces of the HCPL solid phase are negligible compared to the hydrodynamic forces generated within the porous layer. Such processes were named ex-poro-hydrodynamic (XPHD). The Kozeny–Carman equation was used to compute permeability in function of porosity/compacticity. Analytical and numerical solutions were performed for the impact process of the partial and full narrow circular dampers in XPHD conditions. The results were compared with the case of the classical squeeze film damper. The damping capacity of a HCPL imbibed with Newtonian liquid was found to be considerably greater than that of the Newtonian liquid layer.
Preload effects on the static performance of multi-lobe fixed profile journal bearings with micropolar fluids
Authors: Rahmatabadi A D , Rashidi Meybodi R , Nekoeimehr M
Published: June 2011

The performance of non-circular bearings, such as multi-lobe bearings is influenced by many bearing parameters such as the number of lobes, the preload factor, and the tilt angle. In this study, the effects of bearing preload factor on the static performance characteristics of micropolar lubricated two-, three-, and four-lobe bearings are investigated. For this purpose, modified Reynolds equation for micropolar fluids is solved by FEM, to find the fluid film pressure.Then, in turn, bearing performance characteristics, namely, load-carrying capacity, attitude angle, frictional force, friction coefficient, and side leakage flow are calculated. Results show that, in general, micropolarity of the lubricant improves the performance of the bearings; however, non-circularity parameter of the lobe of the bearings, preload, has a favourable effect on certain performance characteristics of the bearings, such as the attitude angle which decreases as non-circularity of the bearing increases. The results further show that the rate of influence of preload factor on the performance characteristics of different lobed bearings is not the same.
The importance of including both a child perspective and the child’s perspective within health care settings to provide truly child-centred care
Authors: Söderbäck Maja , Coyne Imelda , Harder Maria
Published: June 2011

The UN Convention on the Rights of the Child (1989) asserts the right of every child to self-determination, dignity, respect, non-interference, and the right to make informed decisions. The provision of quality care in health services tailored to children’s preferences means that health professionals have a responsibility to ensure children’s rights, and that the child is encouraged and enabled to make his or her view known on issues that affect them. This paper will help illuminate and differentiate between a child perspective and the child’s perspective in health care settings. The issues are supported with research which illustrates the different perspectives. Both perspectives are required to perceive and encounter children as equal human beings in child-centred health care settings.
Do you identify as a gamer? Gender, race, sexuality, and gamer identity
Authors: Shaw Adrienne
Published: June 2011

The demand for minority representation in video games often focuses on proving that members of marginalized groups are gamers. In turn, it is asserted that the gaming industry should focus on appealing to these players via targeted content. Being targeted as a gamer, however, does not a gamer make. Identity as a gamer intersects with other identities like gender, race, and sexuality. Negative connotations about gaming lead people to not identify as gamers, and even to not play video games. This article concludes, based on interview data, that those invested in diversity in video games must focus their attention on the construction of the medium, and not the construction of the audience as such. This shift in academic attention is necessary to develop arguments for representation in games that do not rely on marking groups as specific kinds of gaming markets via identifiers like gender, race, and sexuality.
Allometric Prediction of Energy Expenditure in Infants and Children
Authors: Blinman Thane , Cook Robin
Published: June 2011

Predicting energy needs in children is complicated by the wide range of patient sizes, confusing traditional estimation equations, nonobjective stress-activity factors, and so on. These complications promote errors in bedside estimates of nutritional needs by rendering the estimation methods functionally unavailable to bedside clinicians. Here, the authors develop a simple heuristic energy prediction equation that requires only body mass (not height, age, or sex) as input. Expert estimation of energy expenditure suggested a power-law relationship between mass and energy. A similar mass-energy expenditure relationship was derived from published pediatric echocardiographic data using a Monte Carlo model of energy expenditure based on oxygen delivery and consumption. A simplified form of the equation was compared with energy required for normal growth in a cohort of historical patients weighing 2 to 70 kg. All 3 methods demonstrate that variation in energy expenditure in children is dominated by mass and can be estimated by the following equation: Power(kcal/kg/d) = 200 × [Mass(kg)(−0.4)]. This relationship explains 85% of the variability in energy required to maintain expected growth over a broad range of surgical clinical contexts. A simplified power-law equation predicts real-world energy needs for growth in patients over a wide range of body sizes and clinical contexts, providing a more useful bedside tool than traditional estimators.
Not All Selves Feel the Same Uncertainty
Authors: Morrison Kimberly Rios , Johnson Camille S. , Wheeler S. Christian
Published: June 2011

Three experiments and a pilot study demonstrated that uncertainty about the self is uncomfortable (Pilot Study) and causes people to change their self-concepts in response to primes (Experiments 1–3), depending on both the nature of the uncertainty and how the self is defined. In Experiment 1, Asian Americans assimilated to a stereotype prime when made to feel uncertain about their collective selves, whereas European Americans assimilated to the prime when made to feel uncertain about their individual selves. Experiments 2 and 3 replicated the assimilation effect with a trait prime, and using individualism–collectivism instead of ethnicity as the moderator.
Shear behaviour of polyalkylmethacrylate solutions under thin film lubrication
Authors: Muraki M , Yamashina T
Published: June 2011

Film-forming properties and traction were determined for the oils containing polyalkylmethacrylates (PAMAs) under a temperature of 40 °C and a rolling speed between 0.001 and 1 m/s with the disc-on-roller tester. Oil film thickness measurements were made under a pure rolling condition and traction measurements were made under the slide/roll ratio of 50 per cent. All the copolymers were synthesized in the base oil by a random copolymerization method. Difference in oil film thickness between polymer solutions became significant under the rolling speed below 0.1 m/s. Among non-functionalized homopolymers, PAMAs with branched alkyl group were superior to those with linear alkyl group in film-forming performance. In functionalized PAMAs, film-forming performance was affected by the functional group as well as the coexisting alkyl group. High-mole-concentration of functional group produced a greater oil film thickness than the corresponding low-mole-concentration PAMAs. This tendency was more marked for high-molecular-weight PAMAs. Among all the polymer solutions, high-molecular-weight PAMA with methyl group as a main component showed the thickest oil film, followed by high-molecular-weight PAMA containing branched alkyl group and dimethylaminoethyl group. In the low speeds of the traction–speed curves, most PAMA solutions showed the effect of friction reduction, whose extent depended upon the type of alkyl group and functional group. It was inferred that the friction behaviour in the partial elastohydrodynamic lubrication (EHL) regime was considerably affected by the friction in the thin film lubrication based on the mutual interaction between polymer molecules.