bluuebunny/crossref_metadata_2025 huggingface dataset:
QUANTIFIED DEEP TENDON REFLEX DEVICE FOR RESPONSE AND LATENCY, THIRD GENERATION
Authors: LEMOYNE ROBERT , COROIAN CRISTIAN , MASTROIANNI TIMOTHY , GRUNDFEST WARREN
Published: December 2008

Deep tendon reflex is fundamental for a neurological examination. A hyperactive reflex response is correlated with spasticity, which can also be associated with the degree of damage to the supraspinal input, essentially assessing the severity of traumatic brain injury. Clinical evaluation of the myotatic stretch reflex is provided by the National Institute of Neurological Disorders and Stroke (NINDS) Myotatic Reflex Scale (0 to 4); however, the results of the NINDS Myotatic Reflex Scale vary in terms of interpretation and lack temporal data. Deep tendon reflex can assess the severity and degree of peripheral neuropathy. Subsequent to the neurological examination, suspect patients are often referred to a specialist for definitive electrodiagnostic testing. A study by Cocito found that 28% of the prescriptions for testing were considered to be inappropriate. Therefore, the solution is a fully quantified tendon reflex evaluation system. The input force of the reflex hammer is derived from a predetermined potential energy setting. Tandem wireless three-dimensional (3D) microelectromechanical systems (MEMS) accelerometers quantify the output and latency time of the reflex. The wireless 3D MEMS accelerometers are positioned to a standard anchor point near the ankle and reflex hammer swing arm. Reflex response is quantified by the maximum and minimum components of the acceleration profile. The temporal disparity between hammer strike and response defines the latency of the reflex loop. The quantified data collected from wireless 3D MEMS accelerometers are conveyed to a portable computer. Enclosed are the initial test and evaluation and the description of such a device, which quantitatively evaluates the reflex response and latency using wireless 3D MEMS accelerometers, while demonstrating precision for reproducibility.
PERISTALTIC TRANSPORT OF A PHYSIOLOGICAL FLUID IN AN ASYMMETRIC POROUS CHANNEL IN THE PRESENCE OF AN EXTERNAL MAGNETIC FIELD
Authors: MISRA J. C. , MAITI S. , SHIT G. C.
Published: December 2008

This paper deals with a theoretical investigation of the peristaltic transport of a physiological fluid in a porous asymmetric channel under the action of a magnetic field. The stream function, pressure gradient, and axial velocity are studied by using appropriate analytical and numerical techniques. Effects of different physical parameters such as permeability, phase difference, wave amplitude and magnetic parameter on the velocity, pumping characteristics, streamline pattern, and trapping are investigated with particular emphasis. The computational results are presented in graphical form. The results are found to be in perfect agreement with those of a previous study carried out for a nonporous channel in the absence of a magnetic field.
Crystallizing Membrane Proteins for Structure Determination: Use of Lipidic Mesophases
Authors: Caffrey Martin
Published: December 2008

The principal route to determine the structure and the function and interactions of membrane proteins is via macromolecular crystallography. For macromolecular crystallography to be successful, structure-quality crystals of the target protein must be forthcoming, and crystallogenesis represents a major challenge. Several techniques are employed to crystallize membrane proteins, and the bulk of these techniques make direct use of solubilized protein-surfactant complexes by the more traditional, so-called in surfo methods. An alternative in meso approach, which employs a bicontinuous lipidic mesophase, has emerged as a method with considerable promise in part because it involves reconstitution of the solubilized protein back into a stabilizing and organizing lipid bilayer reservoir as a prelude to crystallogenesis. A hypothesis for how the method works at the molecular level and experimental evidence in support of the proposal are reviewed here. The latest advances, successes, and challenges associated with the method are described.
Psychological Treatment of Anxiety: The Evolution of Behavior Therapy and Cognitive Behavior Therapy
Authors: Rachman S.
Published: December 2008

The development of evidence-based treatments for anxiety disorders is a major achievement of clinical psychology, and cognitive behavior therapy is the best-established and most widely used method. The first form of this therapy, behavior therapy, was a combination of Pavlovian and Behavioristic ideas and methods and was particularly successful in reducing fears. The infusion of cognitive ideas in the late 1970s generated the wider and more flexible cognitive behavior therapy that independent agencies in the United States and United Kingdom now recommend as the treatment of choice for most of the anxiety disorders. Remaining theoretical problems and clinical limitations need to be tackled.
Clathrate Hydrates in Nature
Authors: Hester Keith C. , Brewer Peter G.
Published: December 2008

Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Major unresolved questions remain about the role of hydrates in response to climate change today, and correlations between the hydrate reservoir of Earth and the stable isotopic evidence of massive hydrate dissociation in the geologic past. The examination of hydrates as a possible energy resource is proceeding apace for the subpermafrost accumulations in the Arctic, but serious questions remain about the viability of marine hydrates as an economic resource. New and energetic explorations by nations such as India and China are quickly uncovering large hydrate findings on their continental shelves.
Peroxisome Proliferator‐Activated Receptor Delta: A Conserved Director of Lipid Homeostasis through Regulation of the Oxidative Capacity of Muscle
Authors: de Lange Pieter , Lombardi Assunta , Silvestri Elena , Goglia Fernando , Lanni Antonia , Moreno Maria
Published: December 2008

The peroxisome proliferator‐activated receptors (PPARs), which are ligand‐inducible transcription factors expressed in a variety of tissues, have been shown to perform key roles in lipid homeostasis. In physiological situations such as fasting and physical exercise, one PPAR subtype, PPARδ, triggers a transcriptional program in skeletal muscle leading to a switch in fuel usage from glucose/fatty acids to solely fatty acids, thereby drastically increasing its oxidative capacity. The metabolic action of PPARδ has also been verified in humans. In addition, it has become clear that the action of PPARδ is not restricted to skeletal muscle. Indeed, PPARδ has been shown to play a crucial role in whole‐body lipid homeostasis as well as in insulin sensitivity, and it is active not only in skeletal muscle (as an activator of fat burning) but also in the liver (where it can activate glycolysis/lipogenesis, with the produced fat being oxidized in muscle) and in the adipose tissue (by incrementing lipolysis). The main aim of this review is to highlight the central role for activated PPARδ in the reversal of any tendency toward the development of insulin resistance.
CFD Analysis of a Slug Mixing Experiment Conducted on a VVER‐1000 Model
Authors: Moretti F. , Melideo D. , Del Nevo A. , D′Auria F. , Höhne T. , Lisenkov E.
Published: December 2008

A commercial CFD code was applied, for validation purposes, to the simulation of a slug mixing experiment carried out at OKB “Gidropress” scaled facility in the framework of EC TACIS project R2.02/02: “Development of safety analysis capabilities for VVER‐1000 transients involving spatial variations of coolant properties (temperature or boron concentration) at core inlet.” Such experimental model reproduces a VVER‐1000 nuclear reactor and is aimed at investigating the in‐vessel mixing phenomena. The addressed experiment involves the start‐up of one of the four reactor coolant pumps (the other three remaining idle), and the presence of a tracer slug on the starting loop, which is thus transported to the reactor pressure vessel where it mixes with the clear water. Such conditions may occur in a boron dilution scenario, hence the relevance of the addressed phenomena for nuclear reactor safety. Both a pretest and a posttest CFD simulations of the mentioned experiment were performed, which differ in the definition of the boundary conditions (based either on nominal quantities or on measured quantities, resp.). The numerical results are qualitatively and quantitatively analyzed and compared against the measured data in terms of space and time tracer distribution at the core inlet. The improvement of the results due to the optimization of the boundary conditions is evidenced, and a quantification of the simulation accuracy is proposed.
Vitronectin Concentrations Predict Risk in Patients Undergoing Coronary Stenting
Authors: Derer Wolfgang , Barnathan Elliot S. , Safak Erdal , Agarwal Prasheen , Heidecke Harald , Möckel Martin , Gross Michael , Oezcelik Cemil , Dietz Rainer , Dechend Ralf
Published: December 2008

Background—

Vitronectin is a multifunctional protein with a multiple binding domain that interacts with a variety of plasma and cell proteins. Vitronectin binds multiple ligands, including the soluble vitronectin receptor. Abciximab binds equally well to soluble vitronectin receptor and glycoprotein IIb/IIIa, because both share the β
3
subunit. We tested whether vitronectin concentrations correlate with adverse outcomes in acute coronary syndrome patients.

Methods and Results—

Baseline serum samples (n=233) from a randomized, placebo-controlled trial of abciximab plus stenting (Evaluation of Platelet IIb/IIIa Inhibitor for Stenting EPISTENT) were retrospectively analyzed. We stratified vitronectin concentrations into the 3 lower quartiles (n=178; <49.7 μg/mL) versus the fourth upper quartile (n=55; ≥49.7 μg/mL). The end point was a major adverse cardiovascular event defined as death, myocardial infarction or urgent revascularization at 30 days and 6 months. A higher proportion of patients with baseline vitronectin ≥49.7 μg/mL had major adverse cardiovascular event than patients with baseline vitronectin <49.7 μg/mL at 30 days (18.2% versus 5.6%;
P
=0.01) and 6 months (20.0% versus 6.2%;
P
=0.006). When baseline variables not predictive of major adverse cardiovascular event (eg, troponin positive, history of congestive heart failure, diabetes, history of hypertension, smoking status) were excluded from the multivariate model, only baseline vitronectin ≥49.7 μg/mL (at 30 days: OR, 3.23; 95% CI, 1.23, 8.49; at 6 months: OR, 3.36; 95% CI, 1.33, 8.52) and history of myocardial infarction (at 30 days: OR, 5.02; 95% CI, 1.41, 17.9; at 6 months: OR, 3.99; 95% CI, 1.28, 12.43) remained. No interaction occurred between abciximab and vitronectin.

Conclusions—

Our findings indicate that vitronectin may be an independent predictor of adverse cardiovascular outcomes following acute stenting.
Evaluation of Noninvasive Methods to Assess Wave Reflection and Pulse Transit Time From the Pressure Waveform Alone
Authors: Kips Jan G. , Rietzschel Ernst R. , De Buyzere Marc L. , Westerhof Berend E. , Gillebert Thierry C. , Van Bortel Luc M. , Segers Patrick
Published: December 2008

Accurate quantification of pressure wave reflection requires separation of pressure in forward and backward components to calculate the reflection magnitude as the ratio of the amplitudes backward and forward pressure. To do so, measurement of aortic flow in addition to the pressure wave is mandatory, a limitation that can be overcome by replacing the unknown flow wave by an (uncalibrated) triangular estimate. Another extended application of this principle is the derivation of aortic pulse transit time from a single pulse recording. We verified these approximation techniques for reflection magnitude and transit time using carotid pressure and aortic flow waveforms measured noninvasively in the Asklepios Study (>2500 participants; 35 to 55 years of age). A triangular flow approximation using timing information from the measured aortic flow waveform yielded moderate agreement between reference and estimated reflection magnitude (
R
2
=0.55). Approximating the flow by a more physiological waveform significantly improved these results (
R
2
=0.74). Aortic transit time was assessed using pressure and measured or approximated flow waveforms, and results were compared with carotid-femoral transit times measured by Doppler ultrasound. Agreement between estimated and reference transit times was moderate (
R
2
<0.29). Both for reflection magnitude and transit time, agreement between reference and approximated values further decreased when the approximated flow waveform was obtained using timing information from the pressure waveform. We conclude that, in our Asklepios population, results from pressure-based approximative methods to derive reflection magnitude or aortic pulse transit time differ substantially from the values obtained when using both measured pressure and flow information.
Bradykinin Protects Against Oxidative Stress–Induced Endothelial Cell Senescence
Authors: Oeseburg Hisko , Iusuf Dilek , van der Harst Pim , van Gilst Wiek H. , Henning Robert H. , Roks Anton J.M.
Published: December 2008

Premature aging (senescence) of endothelial cells might play an important role in the development and progression of hypertension and atherosclerosis. We hypothesized that bradykinin, a hormone that mediates vasoprotective effects of angiotensin-converting enzyme inhibitors, protects endothelial cells from oxidative stress–induced senescence. Bradykinin treatment (0.001 to 1 nmol/L) dose-dependently decreased senescence induced by 25 μmol/L of H
2
O
2
in cultured bovine aortic endothelial cells, as witnessed by a complete inhibition of increased senescent cell numbers and a 34% reduction of the levels of the senescence-associated cell cycle protein p21. Because H
2
O
2
induces senescence through superoxide-induced DNA damage, single-cell DNA damage was measured by comet assay. Bradykinin reduced DNA damage to control levels. The protective effect of bradykinin also resulted in a significant increase in the migration of H
2
O
2
-treated bovine aorta endothelial cells in an in vitro endothelial injury model, or “scratch” assay. The protective effect of bradykinin was abolished by the bradykinin B2 receptor antagonist HOE-140 and the NO production inhibitor
N
ω
-methyl-
l
-arginine acetate salt. Therefore, we conclude that bradykinin protects endothelial cells from superoxide-induced senescence through bradykinin B2 receptor– and NO-mediated inhibition of DNA damage.
Urinary Angiotensinogen as a Novel Biomarker of the Intrarenal Renin-Angiotensin System Status in Hypertensive Patients
Authors: Kobori Hiroyuki , Alper A. Brent , Shenava Rajesh , Katsurada Akemi , Saito Toshie , Ohashi Naro , Urushihara Maki , Miyata Kayoko , Satou Ryousuke , Hamm L. Lee , Navar L. Gabriel
Published: December 2008

We reported previously that urinary angiotensinogen (UAGT) levels provide a specific index of the intrarenal renin-angiotensin system (RAS) status in angiotensin II–dependent hypertensive rats. To study this system in humans, we recently developed a human angiotensinogen ELISA. To test the hypothesis that UAGT is increased in hypertensive patients, we recruited 110 adults. Four subjects with estimated glomerular filtration levels <30 mL/min per 1.73 m
2
were excluded because previous studies have already shown that UAGT is highly correlated with estimated glomerular filtration in this stage of chronic kidney disease. Consequently, 106 paired samples of urine and plasma were analyzed from 70 hypertensive patients (39 treated with RAS blockers [angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers; systolic blood pressure: 139±3 mm Hg] and 31 not treated with RAS blockers [systolic blood pressure: 151±4 mm Hg]) and 36 normotensive subjects (systolic blood pressure: 122±2 mm Hg). UAGT, normalized by urinary concentrations of creatinine, were not correlated with race, gender, age, height, body weight, body mass index, fractional excretion of sodium, plasma angiotensinogen levels, or estimated glomerular filtration. However, UAGT/urinary concentration of creatinine was significantly positively correlated with systolic blood pressure, diastolic blood pressure, urinary albumin:creatinine ratio (
r
=0.5994), and urinary protein:creatinine ratio (
r
=0.4597). UAGT/urinary concentration of creatinine was significantly greater in hypertensive patients not treated with RAS blockers (25.00±4.96 μg/g) compared with normotensive subjects (13.70±2.33 μg/g). Importantly, patients treated with RAS blockers exhibited a marked attenuation of this augmentation (13.26±2.60 μg/g). These data indicate that UAGT is increased in hypertensive patients, and treatment with RAS blockers suppresses UAGT, suggesting that the efficacy of RAS blockade to reduce the intrarenal RAS activity can be assessed by measurements of UAGT.
Children affected by earthquakes and their immediate emotional needs
Authors: Doostgharin Taghi
Published: December 2008

English

The article explores the way in which Iranian children were affected by grief after being uprooted and having experienced the loss of family members, their homes and communities. Lack of access to information about what had happened to their immediate family members and uncertainty concerning the future were the most important expressed worries.

French

Cette étude examine la façon dont les enfants iraniens ont immédiatement été affectés par la douleur après s’être vus déracinés et avoir vécu la perte des membres de leur famille, de leur maison, de leur communauté. Les deux principales détresses exprimées sont le manque d’information concernant le sort des membres de leur proche famille et l’incertitude quant à leur avenir.

Spanish

El artículo explora la manera en que los niños iraníes fueron afectados, en forma inmediata, por pena después de haber sido desarraigados y de haber experimentado la pérdida de miembros familiares, sus hogares y comunidades. La carencia de acceso a información sobre lo que ocurrió a los miembros de sus familias inmediatas y la incertidumbre sobre el futuro, fueron las preocupaciones más importantes expresadas.
Decolonizing the pedagogy and practice of international social work
Authors: Razack Narda
Published: December 2008

English

This article examines the complexities inherent in a diverse classroom when teaching international issues by exploring decolonizing pedagogy, which includes theories and understandings from postcolonial studies, spatial and criti cal race theory. Student stories are included, to engage in a discourse on pedagogy and provide theoretical constructs to examine and critique the reactions to these stories.

French

Cet article examine les complexités inhérentes à une classe multiculturelle lors de l’enseignement des questions internationales en explorant la pédagogie de la décolonisation, qui comprend des théories et des apports conceptuels venant des études postcoloniales ainsi que de la théorie critique de la race. Y inclus sont des histoires d’étudiants afin d’engager une discussion sur la pédagogie et de proposer des constructions théoriques pour examiner et critiquer les réactions à ces histoires.

Spanish

Este ensayo examina las complejidades inherentes a enseñar asuntos internacionales a un salón de clase diverso mediante la exploración de una pedagogía descolonizante que incluye teorías y entendimientos provenientes de estudios postcoloniales y teorías de raza críticas y espaciales. Yo incluyo teorías de estudiantes para comprometernos en un discurso de pedagogía y proveer construcciones teóricas para examinar y criticar las reacciones a estas historias.
The Meaning of Neighborhood in the Modern City
Authors: Boger Gretchen
Published: December 2008

From 1910 to 1917, the city of Baltimore engaged in the first American effort to separate black and white neighborhoods by law. Often interpreted as a component of early twentieth-century reform agendas, residential segregation actually had a different genealogy than elite progressive reform. Professional reformers and Baltimore elites presaged a trend in later residential segregation battles by allowing less affluent whites with vested interests in a neighborhood to wage the frontline attacks. At the heart of the struggle was the relationship of class and geography in the spatially unstable modern city. Middle-class whites and blacks both hoped to inscribe status onto Baltimore's residential landscape to secure their social positions and their access to municipal services. They found instead that the single-purpose neighborhoods of the modern city could abruptly change character in a way that the mixed space of preindustrial cities had not, threatening their careful investment in select urban spaces.
Sex and Equality in Republican China
Authors: Tran Lisa
Published: December 2008

Centered on the controversy that erupted over a proposal to include men in the adultery law in the 1935 revised criminal code, this article demonstrates the role of public opinion in legal reform and reveals a new public urgency in the Republic to regulate male sexuality. The debate over the adultery law pitted women's groups, which invoked the Guomindang-endorsed discourse of equality between men and women to oppose retention of the late imperial law that punished only wives for adultery, against lawmakers, who sought to protect a man's relationship with his concubine—now considered adulterous— from the law. As the debate expanded, commentators expressed increasing concern over the threat posed by male adultery to family, society, and nation. In the end, the activism of women's groups and public consensus on the need to regulate male sexuality combined to pressure lawmakers to include men in the adultery law.
Caloric Restriction and Aging: Studies in Mice and Monkeys
Authors: Anderson Rozalyn M. , Shanmuganayagam Dhanansayan , Weindruch Richard
Published: December 2008

It is widely accepted that caloric restriction (CR) without malnutrition delays the onset of aging and extends lifespan in diverse animal models including yeast, worms, flies, and laboratory rodents. The mechanism underlying this phenomenon is still unknown. We have hypothesized that a reprogramming of energy metabolism is a key event in the mechanism of CR (Anderson and Weindruch 2007). Data will be presented from studies of mice on CR, the results of which lend support to this hypothesis. Effects of long-term CR (but not short-term CR) on gene expression in white adipose tissue (WAT) are overt. In mice and monkeys, a chronic 30% reduction in energy intake yields a decrease in adiposity of approximately 70%. In mouse epididymal WAT, long-term CR causes overt shifts in the gene expression profile: CR increases the expression of genes involved in energy metabolism (Higami et al. 2004), and it down-regulates the expression of more than 50 pro-inflammatory genes (Higami et al. 2006). Whether aging retardation occurs in primates on CR is unknown. We have been investigating this issue in rhesus monkeys subjected to CR since 1989 and will discuss the current status of this project. A new finding from this project is that CR reduces the rate of age-associated muscle loss (sarcopenia) in monkeys (Colman et al. 2008).
Relational identities of always-single Japanese women
Authors: Maeda Eriko
Published: December 2008

Increasing numbers of Japanese women remain single after the traditionally “marked” marriageable age of twenty-something. Interpersonal relationships are very important and influential for Japanese women remaining single. I interviewed thirty always-single Japanese women in Japan to examine their interpersonal relationships. Content-analysis of the interview data revealed three themes that relate to the women's interpersonal relationships: family dependency and responsibility, social support, and relationship issues that prevent marriage. These themes suggest that single women's role as a daughter and/or family member, romantic experiences, and relationships with other women influence their identity construction. Women's accounts, moreover, presented various interrelated relationship issues, suggesting the importance of understanding the history and continuity of relationships.
Sexual minority stress and changes in relationship quality in same-sex couples
Authors: Mohr Jonathan J. , Daly Christopher A.
Published: December 2008

Same-sex romantic partners face the challenge of developing a positive relationship while managing stressors associated with being members of a stigmatized minority group. This study examined links between two potential sources of minority stress (internalized homonegativity and sexual orientation self-concealment) and change in predictors of relationship commitment (constraints, attractions, and satisfaction) in lesbian, gay, and bisexual (LGB) individuals. Fifty-one LGB college students who were in a same-sex dating relationship with the same person throughout the study completed surveys at two time points six weeks apart. Initial levels of internalized homonegativity were associated with decreases in relationship attractions and satisfaction but not constraints. Initial self-concealment levels, however, were unrelated to changes in any of the relationship variables.
The Dynamic Character of Political Party Evaluations
Authors: Brasher Holly
Published: December 2008

Over the past 50 years, the American public has consistently been asked to compare the two major parties' ability to handle a variety of issues. The meaning of their answers is an under-studied phenomenon. In this article, I explore changes in comparative party evaluations over time and the source of those changes in attitudes towards the parties. Previous research is based on the assumption that the parties have enduring associations with particular issues and credibility in dealing with those issues. I argue instead that this phenomenon is dynamic and that the association of parties with issues varies in important ways over time. I test a model of dynamic change that emphasizes communication campaigns and institutional platforms. I use an ARIMA model and data on comparative party evaluations for seven issues from the 1950s to the present.
Recombinant Poetics, Urban Flânerie, and Experimentation in the Database Narrative Bleeding Through: Layers of Los Angeles 1920—1986
Authors: Bénézet Delphine
Published: December 2008

Bleeding Through: Layers of Los Angeles 1920—1986, is a DVD-ROM produced under the auspices of the Labyrinth Project at the University of Southern California, and directed by the scholar/artist Norman Klein. Drawing on hundreds of photographs, newspaper clippings and films from the archives of USC, and the Los Angeles Public Library, among other sources, this DVD offers us the chance to reconsider our understanding and vision of Southern California. This database narrative proposes a multi-perspectived and critically informed exploration of Los Angeles, which to this day remains surprisingly unexamined. This article analyses this unconventional project and examines its objectives. Klein's experimental flânerie invites us to a renewed urban experience that relies on a set of distinctive formal characteristics. I will therefore discuss this project's exploration of mediatic combinations, and its resistance to narrative closure, in order to demonstrate that Klein tries to reinvent the way to engage with art and to write history.
Videogame as Media Practice
Authors: Roig Antoni , San Cornelio Gemma , Ardèvol Elisenda , Alsina Pau , Pagès Ruth
Published: December 2008

Our aim in this article is to explore videogames as new media practices, not in isolation but as part of broader media transformations related to the development of current digital technologies. Videogames are the product of a hybridization process between audiovisual media forms and game cultures, rapidly gaining popularity among kids and the elderly population. The experience of audiovisual consumption and aesthetic pleasure is enhanced by interactive and game amusement components not found in previous audiovisual genres such as cinema or TV. In fact, videogames situate `play' at the core of the audiovisual experience, introducing innovative changes in audiovisual production and reception patterns. Our proposal is that videogames introduce a new relationship between subject and representation that goes far beyond the `spectatorship' position, pointing to a playful relationship with images that may be useful for understanding new forms of media practices. Videogames, thus, as a new media practice, can be seen as an exponent of greater change not only regarding how media are produced and consumed, but also in the way leisure is organized and in the role of play in our everyday life.
Video Programming for Individuals With Dementia: Assessing Cognitive Congruence
Authors: Heller Robert B. , Dobbs Bonnie M. , Strain Laurel A.
Published: December 2008

The effect of cognitively congruent video programming on attentional engagement, as measured by the average look duration and the proportion of the video viewed, was examined among long-term care facility residents with Alzheimer's disease. Over a 2-week period, 24 residents viewed 4 cognitively congruent videos and 1 control video (ie, a recorded episode of a local news program) at least once. Level of attentional engagement was significantly higher for cognitively congruent video programs compared to the News. Neither history of television viewing nor cognitive status was related to engagement. The results suggest that video programs with less cognitive complexity may be more engaging for individuals with Alzheimer's disease.
Strain measurement of forming process using digital imaging
Authors: Deng H. , Wiskel J. B. , Ben-Zvi A. , Rieder M. D. , Henein H.
Published: December 2008

An understanding of local strain behaviour during a metal forming operation can be important but maybe difficult to measure. A non-invasive digital imaging procedure has been developed to quantify local strain behaviour in metal forming. From digital images obtained during the forming process, discrete spatial data of the object profile was acquired. B-spline curve fitting was then applied to obtain a continuous profile. The deformation strains were calculated from the curvature of the continuous profile. The procedure was applied to an electric resistance welded pipe forming process. Strain gauge data was used to validate the proposed procedure.
Mechanism of reaction of molten NiTi with EBM graphite crucible
Authors: Sadrnezhaad S. K. , Ahmadi E. , Malekzadeh M.
Published: December 2008

Ultra clean NiTi shape memory alloy was produced by electron beam melting of Ni rich vacuum inductionally melted butts together with pure Ti chunks in both condensed and electrographite crucibles. A hollow cathode discharge gun was used for heating up to 1623, 1653 and 1693 K and holding the charge materials under vacuum for 300, 600, 900 and 1200 s. Effects of temperature, time and compactness of the crucible on formation/disappearance of the hard compounds like Ni3Ti, Ti4Ni2O, Ti4Ni2C, Ti3Ni2OC and TiC were determined by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. A combination of the experimental results with the kinetic rate equations indicated that the reaction between NiTi and the crucible obeyed first order transfer kinetics with carbon intake activation energy of 225·8 kJ mol–1 for the NiTi shape memory alloy melt.
Gold-bismuth-telluride-sulphide assemblages at the Viceroy Mine, Harare-Bindura-Shamva greenstone belt, Zimbabwe
Authors: Oberthür T. , Weiser T. W.
Published: December 2008

Gold mineralization at the Viceroy Mine is hosted in extensional veins in steep shear zones that transect metabasalts of the Archaean Arcturus Formation. The gold mineralization is generally made up of banded or massive quartz carrying abundant coarse arsenopyrite. However, most striking is a distinct suite of Au-Bi-Te-S minerals, namely joseite-A (Bi4TeS2), joseite-B (Bi4Te2S), hedleyite (Bi7Te3), ikunolite (Bi4S3), ‘protojoseite’ (Bi3TeS), an unnamed mineral (Bi6Te2S), bismuthinite (Bi2S3), native Bi, native gold, maldonite (Au2Bi), and jonassonite (AuBi5S4). The majority of the Bi-Te-S phases is characterized by Bi/(Se+Te) ratios of >1. Accordingly, this assemblage formed at reduced conditions at relatively low fS2 and fTe2. Fluid-inclusion thermometry indicates depositional temperatures of the main stage of mineralization of up to 342°C, in the normal range of mesothermal, orogenic gold deposits worldwide. However, melting temperatures of Au-Bi-Te phases down to at least 235°C (assemblage (Au2Bi + Bi + Bi7Te3)) imply that the Au-Bi-Te phases have been present as liquids or melt droplets. Furthermore, the close association of native gold, native bismuth and other Bi-Te-S phases suggests that gold was scavenged from the hydrothermal fluids by Bi-Te-S liquids or melts. It is concluded that a liquid/melt-collecting mechanism was probably active at Viceroy Mine, where the distinct Au-Bi-Te-S assemblage either formed late as part of the main, arsenopyrite-dominated mineralization, or it represents a different mineralization event, related to rejuvenation of the shear system. In either case, some of the gold may have been extracted from pre-existing, gold-bearing arsenopyrite by Bi-Te-S melts, thus leading to an upgrade of the gold ores at Viceroy. The Au-Bi-Te-S assemblage represents an epithermal-style mineralization overprinted on an otherwise mesothermal (orogenic) gold mineralization.
High-throughput sequencing screen reveals novel, transforming RAS mutations in myeloid leukemia patients
Authors: Tyner Jeffrey W. , Erickson Heidi , Deininger Michael W. N. , Willis Stephanie G. , Eide Christopher A. , Levine Ross L. , Heinrich Michael C. , Gattermann Norbert , Gilliland D. Gary , Druker Brian J. , Loriaux Marc M.
Published: December 2008

Transforming mutations in NRAS and KRAS are thought to play a causative role in the development of numerous cancers, including myeloid malignancies. Although mutations at amino acids 12, 13, or 61 account for the majority of oncogenic Ras variants, we hypothesized that less frequent mutations at alternate residues may account for disease in some patients with cancer of unexplained genetic etiology. To search for additional, novel RAS mutations, we sequenced all coding exons in NRAS, KRAS, and HRAS in 329 acute myeloid leukemia (AML) patients, 32 chronic myelomonocytic leukemia (CMML) patients, and 96 healthy individuals. We detected 4 “noncanonical” point mutations in 7 patients: N-RasG60E, K-RasV14I, K-RasT74P, and K-RasA146T. All 4 Ras mutants exhibited oncogenic properties in comparison with wild-type Ras in biochemical and functional assays. The presence of transforming RAS mutations outside of positions 12, 13, and 61 reveals that alternate mechanisms of transformation by RAS may be overlooked in screens designed to detect only the most common RAS mutations. Our results suggest that RAS mutations may play a greater role in leukemogenesis than currently believed and indicate that high-throughput screening for mutant RAS alleles in cancer should include analysis of the entire RAS coding region.
New insights into the biology and origin of mature aggressive B-cell lymphomas by combined epigenomic, genomic, and transcriptional profiling
Authors: Martín-Subero José I. , Kreuz Markus , Bibikova Marina , Bentink Stefan , Ammerpohl Ole , Wickham-Garcia Eliza , Rosolowski Maciej , Richter Julia , Lopez-Serra Lidia , Ballestar Esteban , Berger Hilmar , Agirre Xabier , Bernd Heinz-Wolfram , Calvanese Vincenzo , Cogliatti Sergio B. , Drexler Hans G. , Fan Jian-Bing , Fraga Mario F. , Hansmann Martin L. , Hummel Michael , Klapper Wolfram , Korn Bernhard , Küppers Ralf , MacLeod Roderick A. F. , Möller Peter , Ott German , Pott Christiane , Prosper Felipe , Rosenwald Andreas , Schwaenen Carsten , Schübeler Dirk , Seifert Marc , Stürzenhofecker Benjamin , Weber Michael , Wessendorf Swen , Loeffler Markus , Trümper Lorenz , Stein Harald , Spang Rainer , Esteller Manel , Barker David , Hasenclever Dirk ,   for the Molecular Mechanisms in Malignant Lymphomas Network Project of the Deutsche Krebshilfe, Siebert Reiner
Published: December 2008

Lymphomas are assumed to originate at different stages of lymphocyte development through chromosomal aberrations. Thus, different lymphomas resemble lymphocytes at distinct differentiation stages and show characteristic morphologic, genetic, and transcriptional features. Here, we have performed a microarray-based DNA methylation profiling of 83 mature aggressive B-cell non-Hodgkin lymphomas (maB-NHLs) characterized for their morphologic, genetic, and transcriptional features, including molecular Burkitt lymphomas and diffuse large B-cell lymphomas. Hierarchic clustering indicated that methylation patterns in maB-NHLs were not strictly associated with morphologic, genetic, or transcriptional features. By supervised analyses, we identified 56 genes de novo methylated in all lymphoma subtypes studied and 22 methylated in a lymphoma subtype–specific manner. Remarkably, the group of genes de novo methylated in all lymphoma subtypes was significantly enriched for polycomb targets in embryonic stem cells. De novo methylated genes in all maB-NHLs studied were expressed at low levels in lymphomas and normal hematopoietic tissues but not in nonhematopoietic tissues. These findings, especially the enrichment for polycomb targets in stem cells, indicate that maB-NHLs with different morphologic, genetic, and transcriptional background share a similar stem cell–like epigenetic pattern. This suggests that maB-NHLs originate from cells with stem cell features or that stemness was acquired during lymphomagenesis by epigenetic remodeling.
Fibrinogen variant BβD432A has normal polymerization but does not bind knob “B”
Authors: Bowley Sheryl R. , Lord Susan T.
Published: December 2008

Fibrinogen residue Bβ432Asp is part of hole “b” that interacts with knob “B,” whose sequence starts with Gly-His-Arg-Pro-amide (GHRP). Because previous studies showed BβD432A has normal polymerization, we hypothesized that Bβ432Asp is not critical for knob “B” binding and that new knob-hole interactions would compensate for the loss of this Asp residue. To test this hypothesis, we solved the crystal structure of fragment D from BβD432A. Surprisingly, the structure (rfD-BβD432A+GH) showed the peptide GHRP was not bound to hole “b.” We then re-evaluated the polymerization of this variant by examining clot turbidity, clot structure, and the rate of FXIIIa cross-linking. The turbidity and the rate of γ-γ dimer formation for BβD432A were indistinguishable compared with normal fibrinogen. Scanning electron microscopy showed no significant differences between the clots of BβD432A and normal, but the thrombin-derived clots had thicker fibers than clots obtained from batroxobin, suggesting that cleavage of FpB is more important than “B:b” interactions. We conclude that hole “b” and “B:b” knob-hole binding per se have no influence on fibrin polymerization.
Smad gene expression in pulmonary fibroblasts: indications for defective ECM repair in COPD
Authors: Zandvoort Andre , Postma Dirkje S , Jonker Marnix R , Noordhoek Jacobien A , Vos Johannes TWM , Timens Wim
Published: December 2008

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by defective extracellular matrix (ECM) turnover as a result of prolonged cigarette smoking. Fibroblasts have a central role in ECM turnover. The TGFβ induced Smad pathway provides intracellular signals to regulate ECM production. We address the following hypothesis: fibroblasts have abnormal expression of genes in the Smad pathway in COPD, resulting in abnormal proteoglycan modulation, the ground substance of ECM.

Methods

We compared gene expression of the Smad pathway at different time points after stimulation with TGFβ, TNF or cigarette smoke extract (CSE) in pulmonary fibroblasts of GOLD stage II and IV COPD patients, and controls.

Results

Without stimulation, all genes were similarly expressed in control and COPD fibroblasts. TGFβ stimulation: downregulation of Smad3 and upregulation of Smad7 occurred in COPD and control fibroblasts, indicating a negative feedback loop upon TGFβ stimulation. CSE hardly influenced gene expression of the TGFβ-Smad pathway in control fibroblasts, whereas it reduced Smad3 and enhanced Smad7 gene expression in COPD fibroblasts. Furthermore, decorin gene expression decreased by all stimulations in COPD but not in control fibroblasts.

Conclusion

Fibroblasts of COPD patients and controls differ in their regulation of the Smad pathway, the contrast being most pronounced under CSE exposure. This aberrant responsiveness of COPD fibroblasts to CSE might result in an impaired tissue repair capability and is likely important with regard to the question why only a subset of smokers demonstrates an excess ECM destruction under influence of cigarette smoking.
GeNESiS: gene network evolution simulation software
Authors: Kratz Anton , Tomita Masaru , Krishnan Arun
Published: December 2008

Background

There has been a lot of interest in recent years focusing on the modeling and simulation of Gene Regulatory Networks (GRNs). However, the evolutionary mechanisms that give rise to GRNs in the first place are still largely unknown. In an earlier work, we developed a framework to analyze the effect of objective functions, input types and starting populations on the evolution of GRNs with a specific emphasis on the robustness of evolved GRNs.

Results

In this work, we present a parallel software package, GeNESiS for the modeling and simulation of the evolution of gene regulatory networks (GRNs). The software models the process of gene regulation through a combination of finite-state and stochastic models. The evolution of GRNs is then simulated by means of a genetic algorithm with the network connections represented as binary strings. The software allows users to simulate the evolution under varying selective pressures and starting conditions. We believe that the software provides a way for researchers to understand the evolutionary behavior of populations of GRNs.

Conclusion

We believe that GeNESiS will serve as a useful tool for scientists interested in understanding the evolution of gene regulatory networks under a range of different conditions and selective pressures. Such modeling efforts can lead to a greater understanding of the network characteristics of GRNs.
Loss of Notch signalling induced by Dll4 causes arterial calibre reduction by increasing endothelial cell response to angiogenic stimuli
Authors: Benedito Rui , Trindade Alexandre , Hirashima Masanori , Henrique Domingos , da Costa Luis Lopes , Rossant Janet , Gill Parkash S , Duarte António
Published: December 2008

Background

In the vascular system, Notch receptors and ligands are expressed mainly on arteries, with Delta-like 4 (Dll4) being the only ligand known to be expressed early during the development of arterial endothelial cells and capillaries.Dll4null embryos die very early in development with severely reduced arterial calibre and lumen and loss of arterial cell identity.

Results

The current detailed analysis of these mutants shows that the arterial defect precedes the initiation of blood flow and that the arterialDll4-/-endothelial cells proliferate and migrate more actively.Dll4-/-mutants reveal a defective basement membrane around the forming aorta and increased endothelial cell migration from the dorsal aorta to peripheral regions, which constitute the main causes of arterial lumen reduction in these embryos. The increased proliferation and migration ofDll4-/-endothelial cells was found to coincide with increased expression of the receptors VEGFR-2 and Robo4 and with downregulation of the TGF-β accessory receptor Endoglin.

Conclusion

Together, these results strongly suggest that Notch signalling can increase arterial stability and calibre by decreasing the response of arterial endothelial cells to local gradients of pro-angiogenic factors like VEGF.
Global transcriptional profiling reveals Streptococcus agalactiae genes controlled by the MtaR transcription factor
Authors: Bryan Joshua D , Liles Roxanne , Cvek Urska , Trutschl Marjan , Shelver Daniel
Published: December 2008

Background

Streptococcus agalactiae (group B Streptococcus; GBS) is a significant bacterial pathogen of neonates and an emerging pathogen of adults. Though transcriptional regulators are abundantly encoded on the GBS genome, their role in GBS pathogenesis is poorly understood. The mtaR gene encodes a putative LysR-type transcriptional regulator that is critical for the full virulence of GBS. Previous studies have shown that an mtaR
- mutant transports methionine at reduced rates and grows poorly in normal human plasma not supplemented with methionine. The decreased virulence of the mtaR mutant was correlated with a methionine transport defect; however, no MtaR-regulated genes were identified.

Results

Microarray analysis of wild-type GBS and an mtaR mutant revealed differential expression of 12 genes, including 1 upregulated and 11 downregulated genes in the mtaR mutant. Among the downregulated genes, we identified a cluster of cotranscribed genes encoding a putative methionine transporter (metQ1NP) and peptidase (pdsM). The expression of four genes potentially involved in arginine transport (artPQ) and arginine biosynthesis (argGH) was downregulated and these genes localized to two transcriptional units. The virulence factor cspA, which encodes an extracellular protease, was downregulated. Additionally, the SAN_1255 locus, which putatively encodes a protein displaying similarity to plasminogen activators, was downregulated.

Conclusion

To our knowledge, this is the first study to describe the global influence of MtaR on GBS gene expression. This study implicates the metQ1NP genes as encoding the MtaR-regulated methionine transporter, which may provide a mechanistic explanation for the methionine-dependent growth defect of the mtaR mutant. In addition to modulating the expression of genes involved in metabolism and amino acid transport, inactivation of mtaR affected the expression of other GBS genes implicated in pathogenesis. These findings suggest the possibility that MtaR may play a multifaceted role in GBS pathogenesis by regulating the expression of numerous genes.
The Role of msa in Staphylococcus aureus Biofilm Formation
Authors: Sambanthamoorthy Karthik , Schwartz Antony , Nagarajan Vijayaraj , Elasri Mohamed O
Published: December 2008

Background

Staphylococcus aureus is an important pathogen that forms biofilms. The global regulator sarA is essential for biofilm formation. Since the modulator of sarA (msa) is required for full expression of sarA and regulates several virulence factors, we examined the capacity of the msa mutant to form biofilm.

Results

We found that mutation of msa results in reduced expression of sarA in biofilm and that the msa mutant formed a weak and unstable biofilm. The msa mutant is able to adhere to surfaces and begins to form biofilm but fails to mature indicating that the defect of the msa mutant biofilm is in the accumulation stage but not in primary adhesion.

Conclusion

The msa gene plays an important role in biofilm development which is likely due to its role in modulating the expression of sarA. This finding is significant because it identifies a new gene that plays a role in the development of biofilm.