bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy saving through a simple load control mechanism
Authors: Ramírez Tanausú , Pajuelo Alex , Santana Oliverio J. , Valero Mateo
Published: December 2007

To alleviate the memory wall problem, current architectural trends suggest implementing large instruction windows able to maintain a high number of in-flight instructions. However, the benefits achieved by these recent proposals may be limited because more instructions are executed down the wrong path of a mispredicted branch. The larger number of misspeculated instructions involves increasing the energy consumed compared to traditional designs with smaller instruction windows. Our analysis shows that, for some SPEC2000 integer benchmarks, up to 2, 5X wrong-path load instructions are executed when the instruction window of a 4-way superscalar processor is increased from 256 to 1024 entries.

This paper describes a simple speculative control technique to prevent wrong-path load instructions from being executed. Our technique extends the functionality of the load-store queue to block those load instructions that depend on a hard-to-predict conditional branch until it is resolved. If the branch is actually mispredicted, unnecessary cache misses can be avoided, saving energy down the wrong path. Furthermore, instructions that depend on a blocked load are not issued because their source values are not available, which also saves dynamic energy. Our results show that the proposed mechanism reduces, on average, up to 26% misspeculated load instructions and 18% wrong-path instructions without any performance loss.
Improving power efficiency of D-NUCA caches
Authors: Bardine A. , Foglia P. , Gabrielli G. , Prete C. A. , Stenström P.
Published: December 2007

D-NUCA caches are cache memories that, thanks to banked organization, broadcast search and promotion/demotion mechanism, are able to tolerate the increasing wire delay effects introduced by technology scaling. As a consequence, they will outperform conventional caches (UCA, Uniform Cache Architectures) in future generation cores.

Due to the promotion/demotion mechanism, we have found that, in a D-NUCA cache, the distribution of hits on the ways varies across applications as well as across different execution phases within a single application. In this paper, we show how such a behavior can be utilized to improve D-NUCA power efficiency as well as to decrease its access latencies. In particular, we propose a new D-NUCA structure, called Way Adaptable D-NUCA cache, in which the number of active (i.e. powered-on) ways is dynamically adapted to the need of the running application. Our initial evaluation shows that a consistent reduction of both the average number of active ways (42% in average) and the number of bank access requests (29% in average) is achieved, without significantly affecting the IPC.
Color in Complex Scenes
Authors: Shevell Steven K. , Kingdom Frederick A. A.
Published: December 2007

The appearance of an object or surface depends strongly on the light from other objects and surfaces in view. This review focuses on color in complex scenes, which have regions of different colors in view simultaneously and/or successively, as in natural viewing. Two fundamental properties distinguish the chromatic representation evoked by a complex scene from the representation for an isolated patch of light. First, in complex scenes, the color of an object is not fully determined by the light from that object reaching the eye. Second, the chromatic representation of a complex scene contributes not only to hue, saturation, and brightness, but also to other percepts such as shape, texture, and object segmentation. These two properties are cornerstones of this review, which examines color perception with context that varies over space or time, including color constancy, and chromatic contributions to such percepts as orientation, contour, depth, and motion.
Putting the Altruism Back into Altruism: The Evolution of Empathy
Authors: de Waal Frans B.M.
Published: December 2007

Evolutionary theory postulates that altruistic behavior evolved for the return-benefits it bears the performer. For return-benefits to play a motivational role, however, they need to be experienced by the organism. Motivational analyses should restrict themselves, therefore, to the altruistic impulse and its knowable consequences. Empathy is an ideal candidate mechanism to underlie so-called directed altruism, i.e., altruism in response to anothers's pain, need, or distress. Evidence is accumulating that this mechanism is phylogenetically ancient, probably as old as mammals and birds. Perception of the emotional state of another automatically activates shared representations causing a matching emotional state in the observer. With increasing cognition, state-matching evolved into more complex forms, including concern for the other and perspective-taking. Empathy-induced altruism derives its strength from the emotional stake it offers the self in the other's welfare. The dynamics of the empathy mechanism agree with predictions from kin selection and reciprocal altruism theory.
A Purely Electronic Method to Measure Transfection Efficiency in a Single-Cell Electroporation Biochip
Authors: Cellere Giorgio , Bandiera Leonardo , Borgo Mauro , De Toni Alessandro , Santoni Lisbet , Paccagnella Alessandro , Lorenzelli Leandro
Published: December 2007

Many fundamental researches in molecular biology deal with molecules which need to be inserted into the plasmatic membrane of living (cultured) cells. Working with single cells represents an important improvement for some of these studies, since it allows experiments where the behavior of a modified cell in a non modified context can be studied. This result can be achieved with a Multi Electrode Array which can locally break down the cell membrane, allowing molecules to enter the cell and acting as a multi-site, single-cell, electroporation biochip. Electrochemical impedance spectroscopy (EIS) measurements, coupled with an accurate electrical model of the biochip and cell interface, are used to detect the presence of a cell above the biochip microelectrode. This allows fully automatic single cell electroporation.
Effect of Oxide Film Containing Fluorine Ion on Enhancing the Initial Osseointegration of Titanium-Based Alloy
Authors: Shih Yung H. , Tsai Ming H. , Ou Keng-Liang L.
Published: December 2007

The effects of nano-γ-TiH phase on formation of nanoporous titanium oxide by anodization with HF pretreatment have been investigated by optical microscopy, x-ray photoelectron spectroscopy, thin film x-ray diffractometry, scanning electron microscopy, transmission electron microscopy and secondary ion mass spectroscopy. Furthermore, nanostructural titanium oxide was formed after anodization under various current densities. The γ-TiH is formed by HF pretreatments before anodization. The nano-γ-TiH phase is directly dissolved after anodization. Furthermore, the nanoporous Ti formed by dissolution of nano-titanium hydrides was changed to nanoporous TiO2. The nano-γ-TiH phase plays an important role in forming nanoporous TiO2. The anodization with HF pretreatment not only produces titanium hydride layer, but also results in formation of nanostructural titanium oxide. The bioactive nanoporous titanium oxide film presented in the prese nt study is believed to result in enhancing cell differentiation, thereby providing stable fixation to bone and rapid osseointegration.
Novel Hybrid Abrasive Particles for Oxide CMP Applications
Authors: Mudhivarthi Subrahmanya R. , Coutinho Cecil , Kumar Ashok , Gupta Vinay
Published: December 2007

In the present research, novel abrasive particles are investigated in order to carry out CMP at relatively low down force (low mechanical stress) yet achieve desirable removal rates and superior post CMP surface quality (reduced scratches). Hybrid abrasives are developed where the composition of the polymeric particles formed via colloidal precipitation is modified with inorganic segments to reduce surface damage during CMP. The composition is controlled by changing the time for condensation and hydrolysis of the inorganic oxide. Characterization of these particles is performed by FTIR spectroscopy, dynamic light scattering, and electron microscopy (TEM/SEM). Tribological characteristics during polishing employing these novel particles are studied on a bench-top CMP tester. Surface roughness and defectivity are estimated using Atomic Force Microscopy (AFM).
Analysis of Pre- and Post-Conditioned Polyurethane CMP Pad Surfaces as a Function of Conditioning Temperature
Authors: Prasad Abaneshwar , Xiang Hongqi , Wang Jianhua , Remsen Edward E.
Published: December 2007

The investigation of water diffusion in polyurethane CMP pads via hydrogen-deuterium (H-D) exchange, measured by attenuated total reflectance/FT-IR (ATR/FT-IR), is reported. Significant differences in the kinetics of H-D exchange for a thermoplastic polyurethane (TPU) pad and a conventional cross- linked polyurethane (PU) pad were found. These differences were attributed to the intrinsic chemical and physical differences between the polymeric materials constituting the pads that were characterized by liquid chromatography/mass spectrometry (LCMS) and 1H NMR spectroscopy. Extraction kinetics for low molecular weight compounds in the pads are reported. H-D exchange kinetics for both TPU and PU pads show a strong dependence on temperature and were unique to the specific pad type. Pad conditioning also influenced the kinetics. These findings suggest a re-organization of chain segments at or near the surface during pad conditioning. Additiona l studies are proposed to characterize the nature of the molecular changes modulating water diffusion in the pads.
Composite Polymer Core - Silica Shell Abrasive Particles During Oxide CMP: A Defectivity Study
Authors: Armini Silvia , Whelan Caroline M. , Maex Karen
Published: December 2007

Chemical Mechanical Planarization (CMP) is a triboelectrochemical process dominated by mechanical and chemical-assisted wear. The choice of the abrasive is of fundamental importance. Oxide CMP results using two different 350 nm polymer-core / 30 nm colloidal silica-shell composite abrasive particles are compared with oxide CMP performances of 30 nm and 90 nm colloidal silica abrasives in terms of removal rate and surface finishing. The composites are achieved by either creating chemical bonds by silane coupling agents or tuning the pH in order to form electrostatic attractive interactions between core and shell. Oxide CMP is considered as an easy test vehicle for defectivity characterization and comparison between different abrasives providing the same oxide thickness removed. Due to the higher complexity of the composite abrasive with respect to the simple silica particle- wafer system, we combine different surface analysis techniques with m ethods of defect quantification and enhancement. Fewer and shallower scratches are detected for the composites with respect to colloidal silica.
JAM-A is both essential and inhibitory to development of hepatic polarity in WIF-B cells
Authors: Braiterman Lelita T. , Heffernan Sean , Nyasae Lydia , Johns David , See Alfred P. , Yutzy Rebeca , McNickle Allison , Herman Mira , Sharma Arun , Naik Ulhas P. , Hubbard Ann L.
Published: December 2007

Junctional adhesion molecule (JAM) is involved in tight junction (TJ) formation in epithelial cells. Three JAMs (A, B, and C) are expressed in rat hepatocytes, but only rat JAM-A is present in polarized WIF-B cells, a rat-human hepatic line. We used knockdown (KD) and overexpression in WIF-B cells to determine the role of JAM-A in the development of hepatic polarity. Expression of rat JAM-A short hairpin RNA resulted in ∼50% KD of JAM-A and substantial loss of hepatic polarity, as measured by the absence of apical cysts formed by adjacent cells and sealed by TJ belts. When inhibitory RNA-resistant human JAM-A (huWT) was expressed in KD cells, hepatic polarity was restored. In contrast, expression of JAM-A that either lacked its PDZ-binding motif (huΔC-term) or harbored a point mutation (T273A) did not complement, indicating that multiple sites within JAM-A's cytoplasmic tail are required for the development of hepatic polarity. Overexpression of huWT in normal WIF-B cells unexpectedly blocked WIF-B maturation to the hepatic phenotype, as did expression of three huJAM-A constructs with single point mutations in putative phosphorylation sites. In contrast, huΔC-term was without effect, and the T273A mutant only partially blocked maturation. Our results show that JAM-A is essential for the development of polarity in cultured hepatic cells via its possible phosphorylation and recruitment of relevant PDZ proteins and that hepatic polarity is achieved within a narrow range of JAM-A expression levels. Importantly, formation/maintenance of TJs and the apical domain in hepatic cells are linked, unlike simple epithelia.
Chronic inflation of ferret lungs with CPAP reduces airway smooth muscle contractility in vivo and in vitro
Authors: Xue Z. , Zhang L. , Liu Y. , Gunst S. J. , Tepper R. S.
Published: December 2007

The mechanical stress imposed on the lungs during breathing is an important modulator of airway responsiveness in vivo. Our recent study demonstrated that continuous positive airway pressure applied to the lungs of nonanesthetized, tracheotomized rabbits for 4 days decreased lower respiratory system responsiveness to challenge with ACh (Xue Z, Zhang L, Ramchandani R, Liu Y, Antony VB, Gunst SJ, Tepper RS. J. Appl Physiol 99: 677–682, 2005). In addition, airway segments excised from the lungs of these animals and studied in vitro exhibited reduced contractility. However, the mechanism for this reduction in contractility was not determined. The stress-induced decrease in airway responsiveness could have resulted from alterations in the excitation-contraction coupling mechanisms of the smooth muscle cells, or it might reflect changes in the structure and/or composition of the airway wall tissues. In the present study, we assessed the effect of prolonged chronic stress of the lungs in vivo on airway smooth muscle force generation, myosin light chain phosphorylation, and airway wall structure. To enhance the potential development of stress-induced structural changes, we applied mechanical stress for a prolonged period of time of 2–3 wk. Our results demonstrate a direct connection between the decreased airway responsiveness caused by chronic mechanical stress of the lungs in vivo and a persistent decrease in contractile protein activation in the airway smooth muscle isolated from those lungs. The chronic stress also caused an increase in airway size but no detectable changes in the composition of the airway wall.
Training-specific changes in cardiac structure and function: a prospective and longitudinal assessment of competitive athletes
Authors: Baggish Aaron L. , Wang Francis , Weiner Rory B. , Elinoff Jason M. , Tournoux Francois , Boland Arthur , Picard Michael H. , Hutter Adolph M. , Wood Malissa J.
Published: December 2007

This prospective, longitudinal study examined the effects of participation in team-based exercise training on cardiac structure and function. Competitive endurance athletes (EA, n = 40) and strength athletes (SA, n = 24) were studied with echocardiography at baseline and after 90 days of team training. Left ventricular (LV) mass increased by 11% in EA (116 ± 18 vs. 130 ± 19 g/m2; P < 0.001) and by 12% in SA (115 ± 14 vs. 132 ± 11 g/m2; P < 0.001; P value for the compared Δ = NS). EA experienced LV dilation (end-diastolic volume: 66.6 ± 10.0 vs. 74.7 ± 9.8 ml/m2, Δ = 8.0 ± 4.2 ml/m2; P < 0.001), enhanced diastolic function (lateral E ′: 10.9 ± 0.8 vs. 12.4 ± 0.9 cm/s, P < 0.001), and biatrial enlargement, while SA experience LV hypertrophy (posterior wall: 4.5 ± 0.5 vs. 5.2 ± 0.5 mm/m2, P < 0.001) and diminished diastolic function (E′ basal lateral LV: 11.6 ± 1.3 vs. 10.2 ± 1.4 cm/s, P < 0.001). Further, EA experienced right ventricular (RV) dilation (end-diastolic area: 1,460 ± 220 vs. 1,650 ± 200 mm/m2, P < 0.001) coupled with enhanced systolic and diastolic function (E′ basal RV: 10.3 ± 1.5 vs. 11.4 ± 1.7 cm/s, P < 0.001), while SA had no change in RV parameters. We conclude that participation in 90 days of competitive athletics produces significant training-specific changes in cardiac structure and function. EA develop biventricular dilation with enhanced diastolic function, while SA develop isolated, concentric left ventricular hypertrophy with diminished diastolic relaxation.
A New Case of Human Atransferrinemia with a Previously Undescribed Mutation in the Transferrin Gene
Authors: Aslan Deniz , Crain Karen , Beutler Ernest
Published: December 2007

Hereditary atransferrinemia is a very rare disorder characterized by microcytic anemia and iron overload. It has been reported in only 10 patients in 8 families. The molecular basis of atransferrinemia has been determined in only 3 human cases. We now report a new patient with this rare disorder, who is the first known case in Turkey, the 11th patient reported in the published literature and only the 4th case of human atransferrinemia characterized on a molecular basis. DNA analysis of the serum transferrin gene in the patient revealed a previously undescribed mutation in exon 4, a G→A transition at cDNA 410(Cys137Tyr). A number of previously known polymorphisms and a previously undescribed mutation at IVS10(–23)C→T, presumably a polymorphism, were also documented.
Cerebral Hypoperfusion Increases Estrogen Receptor Abundance in the Ovine Fetal Brain and Pituitary
Authors: Wood Charles E.
Published: December 2007

Background/Aims: Estrogen is an important component of fetal neuroendocrine function in late-gestation fetal sheep; however, little is known about the regulation of estrogen receptor abundance in the brain and pituitary of fetuses. The present study was performed to test the hypotheses that estrogen receptor abundance in the fetal brain and pituitary are influenced by circulating estradiol concentrations and that they are acutely regulated after cerebral hypoperfusion. Methods: We studied 16 time-dated fetal sheep (124–128 days gestation) that were chronically catheterized and instrumented at least 5 days before study. Four groups (n = 4 each) were studied in which fetuses received estradiol (0.25 mg/day, producing physiological increases in fetal plasma estradiol concentrations) or placebo implants, and in which fetuses received a 10-min period of brachiocephalic occlusion (BCO) or sham-BCO. One hour after BCO or sham-BCO, fetuses were euthanized and tissues rapidly removed for analysis of estrogen receptors (ER)-α and -β at the mRNA and protein levels. Results: Both BCO and estradiol treatment were effective in changing ER expression, although the effects were region-specific. BCO dramatically increased ER-α in the pituitary and both ER-α and ER-β in the brainstem, while decreasing ER-α expression in the hypothalamus. Estradiol treatment decreased ER-α expression in the hypothalamus, whereas it increased ER-α expression in the brainstem, cerebral cortex and hippocampus. Conclusions: We conclude that the expression of ER-α and ER-β in the brain and pituitary of fetal sheep are influenced by circulating estrogen concentrations and acutely regulated in response to cerebral hypoperfusion.
Regulation of Vasculogenesis by Platelet-Mediated Recruitment of Bone Marrow–Derived Cells
Authors: Rafii Daniel C. , Psaila Bethan , Butler Jason , Jin David K. , Lyden David
Published: December 2007

Bone marrow–derived cells contribute to physiological and pathological vascular remodeling throughout ontogenesis and adult life. During tissue regeneration and tumor growth, the release of cytokines and chemokines mediates the recruitment of hematopoietic and endothelial progenitor cells that contribute to the assembly of neovessels. Current evidence implies that platelets contribute structurally and instructively to vascular remodeling. Platelets adhere almost immediately to exposed or activated endothelium, and they are major storage and delivery vehicles for pro- and antiangiogenic growth factors including VEGF-A and thrombospondin (TSP), and cytokines and chemokines, such as stromal-derived factor 1 (SDF-1). By site-specific deployment of these factors, platelets orchestrate the local angiogenic stimulus within a tissue and direct the recruitment and differentiation of circulating bone marrow–derived cells. These insights have profound clinical implications; inhibition of platelet-deployed growth factors or their receptors may be an effective strategy to block tumor growth, whereas activation of these pathways may be used to accelerate revascularization and tissue regeneration.
Plasminogen Activator Inhibitor-1 Polymorphism (4G/5G) Predicts Recurrence in Nonhyperlipidemic Postinfarction Patients
Authors: Corsetti James P. , Ryan Dan , Moss Arthur J. , Rainwater David L. , Zareba Wojciech , Sparks Charles E.
Published: December 2007

Objective—

Nonhyperlipidemic postinfarction patients are at high risk for recurrent coronary events by virtue of incident myocardial infarction (MI); however, few studies assess risk beyond incident MI. The aim of this study was to assess such risk as a function of 37 atherosclerosis-associated genetic polymorphisms and 17 blood marker variables.

Methods and Results—

Screening of polymorphisms in nonhyperlipidemic postinfarction patients revealed significant risk only for the 4G/5G insertion/deletion polymorphism in the promoter of the plasminogen-activator inhibitor-1 (PAI-1) gene. Outcome event mapping, an exploratory data analysis tool, was then applied to define a subgroup (182 patients from total study population of 846 nondiabetic patients) exhibiting maximal functional dependence of risk on the PAI-1 polymorphism. Cox multivariable regression analyses within the subgroup adjusted for significant clinical covariates and medication use as a function of the PAI-1 polymorphism and 17 atherosclerosis-associated blood markers revealed significant risk for patients homozygous for the 4G allele (hazard ratio 4.30, 95% CI 1.98 to 9.33,
P
=0.00023), and lack of significant risk-association with any blood marker.

Conclusions—

In a subgroup of normolipidemic postinfarction patients, only the PAI-1 4G/5G polymorphism was associated with recurrent risk from a set of atherosclerosis-associated genetic polymorphisms and blood markers.
CaMKII-δ Isoform Regulation of Neointima Formation After Vascular Injury
Authors: House Suzanne J. , Singer Harold A.
Published: December 2007

Objective—

The purpose of this study was to test the function of the calcium/calmodulin-dependent protein kinase II δ
2
isoform (CaMKIIδ
2
) in regulating vascular smooth muscle (VSM) cell proliferation and migration in response to vascular injury.

Methods and Results—

CaMKII isoform content was assessed in rat carotid arteries after balloon angioplasty–induced injury by Western blotting with isoform specific antibodies. Within 3 days after injury, a significant increase in CaMKIIδ
2
and decrease in CaMKIIγ isoform content was observed in both medial smooth muscle and adventitial fibroblasts. Neointimal VSM cells expressed primarily the δ
2
isoform. Incubation of the injured vessel with adenovirus encoding siRNA targeting CaMKIIδ isoforms prevented upregulation of the δ
2
isoform in the media and adventitia; inhibited cell proliferation assessed by PCNA expression in both layers and markedly inhibited neointima formation and adventitial thickening.

Conclusions—

CaMKIIδ
2
is specifically induced in VSM and adventitial fibroblasts during the response of an artery to injury and is a positive regulator of proliferation and migration in the vessel wall contributing to neointima formation and vascular remodeling. This provides a potential mechanism for Ca
2+
-dependent regulation of VSM and myofibroblast proliferation and migration in response to vascular injury or disease.
Galectin-3 Is an Amplifier of Inflammation in Atherosclerotic Plaque Progression Through Macrophage Activation And Monocyte Chemoattraction
Authors: Papaspyridonos Marianna , McNeill Eileen , de Bono Joe P. , Smith Alberto , Burnand Kevin G. , Channon Keith M. , Greaves David R.
Published: December 2007

Objective—

Galectin-3 (Gal-3) is a 26-kDa lectin known to regulate many aspects of inflammatory cell behavior. We assessed the hypothesis that increased levels of Gal-3 contribute to atherosclerotic plaque progression by enhancing monocyte chemoattraction through macrophage activation.

Methods and Results—

Gal-3 was found to be upregulated in unstable plaque regions of carotid endarterectomy (CEA) specimens compared with stable regions from the same patient (3.2-fold,
P
<0.05) at the mRNA (n=12) and (2.3-fold,
P
<0.01) at the protein level (n=9). Analysis of aortic tissue from ApoE
−/−
mice on a high fat diet (n=14) and wild-type controls (n=9) showed that Gal-3 mRNA and protein levels are elevated by 16.3-fold (
P
<0.001) and 12.2-fold (
P
<0.01) and that Gal-3 staining colocalizes with macrophages. In vitro, conditioned media from Gal-3–treated human macrophages induced an up to 6-fold increase in human monocyte chemotaxis (
P
<0.01, ANOVA), an effect that was reduced by 66 and 60% by Pertussis Toxin (PTX) and the Vaccinia virus protein 35K, respectively. Microarray analysis of human macrophages and subsequent qPCR validation confirmed the upregulation of CC chemokines in response to Gal-3 treatment.

Conclusions—

Our data suggest that Gal-3 is both a marker of atherosclerotic plaque progression and a central contributor to the pathology by amplification of key proinflammatory molecules.
Functional Roles of a Ca
2+
-Activated K
+
Channel in Atrioventricular Nodes
Authors: Zhang Qian , Timofeyev Valeriy , Lu Ling , Li Ning , Singapuri Anil , Long Melissa K. , Bond Chris T. , Adelman John P. , Chiamvimonvat Nipavan
Published: December 2007

Since the first description of the anatomical atrioventricular nodes (AVNs), a large number of studies have provided insights into the heterogeneity of the structure as well as a repertoire of ion channel proteins that govern this complex conduction pathway between the atria and ventricles. These studies have revealed the intricate organization of multiple nodal and nodal-like myocytes contributing to the unique electrophysiology of the AVN in health and diseases. On the other hand, information regarding the contribution of specific ion channels to the function of the AVN remains incomplete. We reason that the identification of AVN-specific ion channels may provide a more direct and rational design of therapeutic target in the control of AVN conduction in atrial flutter/fibrillation, one of the most common arrhythmias seen clinically. In this study, we took advantage of 2 genetically altered mouse models with overexpression or null mutation of 1 of a small conductance Ca
2+
-activated K
+
channel isoform, SK2 channel, and demonstrated robust phenotypes of AVN dysfunction in these experimental models. Overexpression of SK2 channels results in the shortening of the spontaneous action potentials of the AVN cells and an increase in the firing frequency. On the other hand, ablation of the SK2 channel results in the opposite effects on the spontaneous action potentials of the AVN. Furthermore, we directly documented the expression of SK2 channel in mouse AVN using multiple techniques. The new insights may have important implications in providing novel drug targets for the modification of AVN conduction in the treatment of atrial arrhythmias.
Subcortical Lacunes Are Associated With Executive Dysfunction in Cognitively Normal Elderly
Authors: Carey Catherine L. , Kramer Joel H. , Josephson S. Andrew , Mungas Dan , Reed Bruce R. , Schuff Norbert , Weiner Michael W. , Chui Helena C.
Published: December 2007

Background and Purpose—

The relationship between subcortical ischemic vascular disease (SIVD) and cognition in normal elderly is unclear, in part because of methodological inconsistencies across studies. To clarify this relationship, the current study investigated a well characterized cognitively normal elderly sample (≥55 years) with quantitative MRI and psychometrically robust neuropsychological measures within a multivariate model. Converging evidence suggests that SIVD selectively impairs frontal-executive tasks by disrupting frontal-subcortical circuits. We therefore hypothesized that MRI markers of SIVD would be selectively associated with worse executive functioning.

Methods—

We studied 94 participants who were cognitively and functionally normal. Volumetric measures of white matter signal hyperintensity (WMH), subcortical lacunes, hippocampal volume, and cortical gray matter were obtained to predict performance on composite measures of executive functioning and episodic memory.

Results—

Hierarchical regression demonstrated that after controlling for demographic variables, MMSE, and total intracranial volume, the total number of subcortical lacunes was the only significant predictor, with a greater number of lacunes associated with poorer executive performance. Hippocampal volume best predicted episodic memory performance.

Conclusions—

Results suggest that SIVD in the form of silent lacunes corresponds to poorer executive functioning even in otherwise normal elderly, which is consistent with the hypothesis that SIVD preferentially disrupts frontal-subcortical circuits. The clinical importance of these findings is highlighted by the fact that 33% of the normal elderly participants in this study had lacunar infarcts.
Neurological Signs in Relation to Type of Cerebrovascular Disease in Vascular Dementia
Authors: Staekenborg Salka S. , van der Flier Wiesje M. , van Straaten Elisabeth C.W. , Lane Roger , Barkhof Frederik , Scheltens Philip
Published: December 2007

Background and Purpose—

The aim of this study was to describe the prevalence of a number of neurological signs in a large population of patients with vascular dementia (VaD) and to compare the relative frequency of specific neurological signs dependent on type of cerebrovascular disease.

Methods—

Seven hundred six patients with VaD (NINDS-AIREN) were included from a large multicenter clinical trial (registration number NCT00099216). At baseline neurological examination, the presence of 16 neurological signs was assessed. Based on MRI, patients were classified as having large vessel VaD (18%; large territorial or strategical infarcts on MRI), small vessel VaD (74%; white matter hyperintensities [WMH], multiple lacunes, bilateral thalamic lesions on MRI), or a combination of both (8%).

Results—

A median number of 4.5 signs per patient was presented (maximum 16). Reflex asymmetry was the most prevalent symptom (49%), hemianopia was most seldom presented (10%). Measures of small vessel disease were associated with an increased prevalence of dysarthria, dysphagia, parkinsonian gait disorder, rigidity, and hypokinesia and as well to hemimotor dysfunction. By contrast, in the presence of a cerebral infarct, aphasia, hemianopia, hemimotor dysfunction, hemisensory dysfunction, reflex asymmetry, and hemiplegic gait disorder were more often observed.

Conclusions—

The specific neurological signs demonstrated by patients with VaD differ according to type of imaged cerebrovascular disease. Even in people who meet restrictive VaD criteria, small vessel disease is often seen with more subtle signs, including extrapyramidal signs, whereas large vessel disease is more often related to lateralized sensorimotor changes and aphasia.
Gender Differences in Adolescent Risk Taking: Are They Diminishing?
Authors: Abbott-Chapman Joan , Denholm Carey , Wyld Colin
Published: December 2007

Research investigating patterns of intergenerational risk taking has produced evidence of increased risk taking of female adolescents compared with their mother's generation and a reduction in the traditional gap between levels of teenage male and female risk taking. The research is part of a larger, multistage project on factors affecting adolescent risk taking conducted between 1999 and 2003 in Tasmania, Australia, using quantitative and qualitative research methods. Findings from the study of 954 “mainstream” students in Years 11 and 12 in public and private senior secondary schools and colleges and 1,139 parents of Year 11 and 12 students in the same schools and colleges suggest that gender differences in risk taking and risk perceptions have narrowed significantly over recent decades. Although the pattern of risk activities is complex, it appears that high levels of consumption of alcohol and binge drinking are what especially distinguish the behavior of teenage girls from their mothers' generation.
Errorless Acquiescence Training
Authors: Ducharme Joseph M. , Folino Anthony , DeRosie Janine
Published: December 2007

Errorless acquiescence training (EAT) was developed as a graduated, success-focused, and short-term intervention for building social skills. The approach focuses on building the skill of acquiescence (i.e., teaching children to be flexible with the needs and will of peers). The authors predict that acquiescence would serve as a keystone, that is, a skill that when trained produces widespread improvements in child behavior, including reductions in antisocial behavior. The authors provide EAT to eight children referred to a clinical classroom for severe antisocial behavior. Consistent with errorless paradigms, key intervention components present at the initiation of intervention are systematically faded at a slow enough rate to ensure continued prosocial interactions throughout and following treatment. Children demonstrate substantial increases in acquiescent responding and other prosocial behavior as well as covariant reductions in antisocial behaviors. Acquiescence is discussed in terms of its potential as a keystone for prosocial responding in children with antisocial behavior.
Cognitive-Behavioral Interventions to Reduce Suicide Behavior
Authors: Tarrier Nicholas , Taylor Katherine , Gooding Patricia
Published: December 2007

Suicide behavior is a serious clinical problem worldwide, and understanding ways of reducing it is a priority. A systematic review and meta-analysis were carried out to investigate whether Cognitive-behavioral therapies (CBTs) would reduce suicide behavior. From 123 potential articles, 28 studies met the entry criteria. Overall, there was a highly significant effect for CBT in reducing suicide behavior. Subgroup analysis indicates a significant treatment effect for adult samples (but not adolescent), for individual treatments (but not group), and for CBT when compared to minimal treatment or treatment as usual (but not when compared to another active treatment). There was evidence for treatment effects, albeit reduced, over the medium term. Although these results appear optimistic in advocating the use of CBT in ameliorating suicidal thoughts, plans, and behaviors, evidence of a publication bias tempers such optimism.
Novel Thermally Sensitive pH-dependent Chitosan/ Carboxymethyl Cellulose Hydrogels
Authors: Huangqin Chen  , Mingwen Fan
Published: December 2007

Temperature-responsive polymers are attractive candidates for applications related to injectable delivery of biologically active therapeutics. In this study, a novel approach to provide thermally sensitive neutral solutions based on chitosan/carboxymethyl cellulose (Ch/CMC) combinations is described. The potential of thermosensitive Ch/CMC as a biomaterial is evaluated for the culture of chondrocytes, with the goal of using the Ch/CMC polymer as an injectable matrix/cell therapeutic. These formulations possess a physiological pH and can be held as liquid below room temperature for encapsulating living cells. At body temperature they form monolithic gels, thus injected in vivo, the liquid formulations turn into gel implants in situ. The sols/gels have been thoroughly characterized for rheology and morphology analysis. The use of Ch/CMC aqueous solutions as gelling systems is a new discovery of a new family of thermosetting gels highly compatible with biological compounds.
Extracellular Matrix Components as Modulators of Adult Stem Cell Differentiation in an Adipose System
Authors: Chaubey Aditya , Burg Karen J.L.
Published: December 2007

The viability of a cell-based device may be controlled post-implantation by managing the level of cellular differentiation. Cellular adhesion to extracellular matrix (ECM) proteins is fundamentally linked to tissue development, maintenance of tissue organization, and many pathological conditions. Cellular interaction with ECM regulates the proliferation and differentiation of cells. This study investigates the efficacy of ECM components (laminin and collagen) in modulating the differentiation of adult mouse bone marrow stem cells (D1) to adipocytes. This study should assist in the development of clinically viable soft-tissue implants.
Hybrid Glass Fiber-reinforced Thermoplastic Nanocomposites
Authors: Houphouët-Boigny Chrystèle , Plummer Christopher J.G. , Wakeman Martyn D. , Månson Jan-Anders E.
Published: December 2007

The feasibility of integrating thermoplastic isotactic polypropylene/ montmorillonite nanocomposite matrices into conventional fiber-reinforced composites has been investigated. Two basic processing routes were considered: long glass fiber (GF)-reinforced composites based on co-wound or co-woven yarns and glass mat reinforced composites. In each case satisfactory impregnation and consolidation were demonstrated, although at high fiber contents, this required increased pressures and/or temperatures in the presence of the montmorillonite. Flexural tests on the glass mat reinforced composites, containing relatively low GF contents, showed the use of a nanocomposite matrix to lead to the significant improvements in bending stiffness and strength.
Political Boundaries in Research
Authors: Malinski Violet
Published: December 2007

In many ways, the current political climate is antithetical to sound research. As an example, Roye shares her experiences attempting to obtain funding to study ways to promote risk-reduction behaviors among sexually active teens when the political agenda focuses on abstinence only. She details a program of funded research that she embarked on prior to the current administration. She describes how she found her work blocked, as she attempted to continue with research designed to identify factors associated with heterosexual anal intercourse among female teens. Her purpose was to design prevention strategies for reducing the incidence of HIV/AIDS among young women of color. She further describes her feelings when finding herself on the hit list of scientists whose work was deemed objectionable for ideological reasons and she shares current activities that various organizations are engaged in to protest the political obstruction of scientific investigation.
Boundaries: Ethical Implications for What It Means to Be Therapeutic in the Nurse-Person Relationship
Authors: Milton Constance L.
Published: December 2007

The nurse-person relationship is sometimes regarded as the essence of professional nursing practice. Many biomedical nursing definitions and connotations have emerged over time for what it means to practice professional nursing with boundaries in a therapeutic nurse-person relationship. In this column the author compares, contrasts, and offers a unique disciplinary perspective with regard to these terms. Ethical implications for developing professional relationships through the nursing disciplinary lens of the human becoming school of thought are explored.
The Relation of Meditation to Power and Well-Being
Authors: Tae Sook Kim  , Jeong Sook Park  , Myung Ae Kim
Published: December 2007

The purpose of this research is to examine the relation of meditation to power and well-being in Korean adults. Using a quasi-experimental design, meditation was provided through a chakra meditation music program over a 4 week period. The Power as Knowing Participation in Change Tool and the Well-Being Picture Scale were used, after being translated into Korean. Statistically significant interaction effects of power and group (p < .001), and well-being and group (p < .05) were found. Meditation has a potential to facilitate power and well-being in the human and environmental field patterning process.
Feeling Listened To: A Lived Experience of Humanbecoming
Authors: Kagan Paula N.
Published: December 2007

The purpose of this study is to discover the structure of the universal lived experience of feeling listened to, a phenomenon of health and quality of life related to the human-to-human relationship. This Parse research method study included 10 adults who shared their experiences of feeling listened to. The structure, feeling listened to is unreserved affirmation amid potential irreverence arising with the liberating contentment of benevolent affiliations, is the central finding of the study. This finding was connected to humanbecoming theory and extant literature, contributing to nursing knowledge, expanding the theory, and enhancing understanding about feeling listened to.
Active Vibration Control of a Micro-Actuator for Hard Disk Drives using Self-Sensing Actuator
Authors: Yamada Hiroyuki , Sasaki Minoru , Nam Yoonsu
Published: December 2007

In this article, active vibration control of a micro-actuator for hard disk drives using self-sensing actuation is presented. The micro-actuators used in this article are a slider type and a suspension type. The self-sensing performance of the installing position is compared and evaluated. An assembly including these micro-actuators may not be able to sense some vibration of suspension modes. Feedback control results of direct velocity feedback and positive position feedback are presented. The feasibility of these self-sensing approaches as a vibration suppression control on the micro-actuator was verified. Using the slider type micro-actuator, the sway mode spike signal in power spectrum density was suppressed by 76% using the direct velocity feedback control, and by 60% using the positive position feedback control. Using the suspension type micro-actuator, the suspension second bending mode spike signal in power spectrum density was reduced by 74% using the direct velocity feedback control, and by 96% using the positive position feedback control. The control scheme using self-sensing signals can partially dampen the suspension modes.
Modal Identification, Model Updating and Nonlinear Analysis of a Reinforced Concrete Bridge
Authors: El-Borgi S. , Neifar M. , Cherif F. , Choura S. , Smaoui H.
Published: December 2007

This article proposes a rational methodology for the structural assessment of a reinforced concrete bridge in Tunisia. This methodology is based on ambient vibration measurement of the bridge, identification of its modal signature, finite element model updating and nonlinear analysis. The selected case study is an eight-span bridge with a continuous slab. Each span is simply supported at rubber bearings and has a length of 25 m. Because of the repetitive geometry of the bridge, ambient vibration tests were conducted on one span using a data acquisition system with nine force-balance accelerometers placed at selected locations. The Enhanced Frequency Domain Decomposition (EFDD) technique was applied to extract the dynamic characteristics of the bridge. A 3-D finite element model was developed and updated to obtain reasonable correlation between experimental and numerical modal properties. The parameter selected for the updating is the modulus of elasticity of the concrete in each concrete element of the finite element model. A decrease of its value indicates the possibility of damage or stiffness reduction. We demonstrate that using the EFDD technique in combination with model updating and nonlinear analysis provides valuable information for the evaluation of the bridge structural condition.
On the Design Criteria of Dynamic Vibration Absorbers for Controlling Friction-Induced Oscillations
Authors: Chatterjee S.
Published: December 2007

The present article investigates the efficacy of a dynamic vibration absorber (DVA) in suppressing friction-induced instability. A two-degree-of-freedom model, incorporating tangential and normal mode-coupling along with the velocity-weakening friction characteristic (the so-called Stribeck effect), represents the minimal phenomenological model of the primary system. The DVA is aligned at an angle to the direction of sliding. A method of selecting the best parameters of the DVA is discussed. The design criteria are based on minimal detuning and maximum stability and robustness against all possible parametric perturbations. Robustness of the design is analysed using the ε-pseudospectra of the Jacobian matrix.
Robust Synchronization of a Class of Nonlinear Systems: Applications to Chaotic Coupled Electromechanical Systems
Authors: Bowong Samuel , Xiaohua Xia
Published: December 2007

This article treats the robust synchronization problem of a class of nonlinear systems from a control theoretical point of view. Because of the tremendous complexity of nonlinear systems, the problem is restricted to chaotic electromechanical devices. The results are discussed in the context of complete synchronization. A new dynamic output feedback is applied to perform synchronization in spite of master/slave mismatches. The main idea is to construct an augmented dynamical system from the synchronization error system, which is itself uncertain. The advantage of this method over the existing results is that the synchronization time is explicitly computed. Numerical simulations are provided to verify the operation of the proposed algorithm.
Criteria for Yielding or Failure of Cellular Materials
Authors: Abrate Serge
Published: December 2007

Sandwich structures are used extensively in marine structures and other applications. Cellular materials such as foams, honeycomb, and balsa wood used as core materials in sandwich structures are subjected to multiaxial loadings. Concentrated loads, impacts, and explosions can result in large deformations and damage, and yield or failure criteria are needed to predict the end of the elastic phase. Yielding or failure of isotropic foams is generally dependent on the hydrostatic stress, a feature that these materials share with many polymers, concrete, and soils. Appropriate criteria which are different from those traditionally used for metals have been classified in four major categories. Similarities between seemingly different criteria and between foams and other materials are brought out. Foams can also be anisotropic as honeycomb and balsa wood, and the anisotropy has to be accounted for in addition to the differences in strength in tension and compression in various directions. Suitable anisotropic criteria are shown to be the extensions of criteria previously used for isotropic materials and methods to present these criteria in a unified manner or to systematically extend isotropic criteria are discussed. Finally the strain rate effects and size effects are discussed.
Prefibrotic myelofibrosis: is this diagnosis valid?
Authors: Peterson LoAnn
Published: December 2007

Wilkins and colleagues evaluate the utility of the World Health Organization (WHO) diagnostic criteria intended to separate cases previously classified as essential thrombocythemia (ET) into 2 groups: “true ET” and “prefibrotic myelofibrosis.” Focusing on bone marrow histology, the authors found substantial variation in classification of cases.