bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left hemispheric dominance during auditory processing in a noisy environment
Authors: Okamoto Hidehiko , Stracke Henning , Ross Bernhard , Kakigi Ryusuke , Pantev Christo 
Published: November 2007

Abstract

Background

In daily life, we are exposed to different sound inputs simultaneously. During neural encoding in the auditory pathway, neural activities elicited by these different sounds interact with each other. In the present study, we investigated neural interactions elicited by masker and amplitude-modulated test stimulus in primary and non-primary human auditory cortex during ipsi-lateral and contra-lateral masking by means of magnetoencephalography (MEG).

Results

We observed significant decrements of auditory evoked responses and a significant inter-hemispheric difference for the N1m response during both ipsi- and contra-lateral masking.

Conclusion

The decrements of auditory evoked neural activities during simultaneous masking can be explained by neural interactions evoked by masker and test stimulus in peripheral and central auditory systems. The inter-hemispheric differences of N1m decrements during ipsi- and contra-lateral masking reflect a basic hemispheric specialization contributing to the processing of complex auditory stimuli such as speech signals in noisy environments.
Kisspeptin and GPR54 immunoreactivity in a cohort of 518 patients defines favourable prognosis and clear cell subtype in ovarian carcinoma
Authors: Prentice Leah M , Klausen Christian , Kalloger Steve , Köbel Martin , McKinney Steven , Santos Jennifer L , Kenney Challayne , Mehl Erika , Gilks C Blake , Leung Peter , Swenerton Ken , Huntsman David G , Aparicio Samuel AJ 
Published: November 2007

AbstractBackgroundKisspeptins and their G-protein coupled receptor, GPR54 are required for GnRH release and have been associated with anti-metastatic tumour cell behaviour in model systems. The latter might suggest that their overexpression would be associated with a better prognosis in cancer. However, kisspeptin/GPR54 interactions (autocrine, paracrine, and/or endocrine) could also impact tumour behaviour in a negative manner. Here, for the first time, we associate the immunoreactivity of the kisspeptin/GPR54 ligand-receptor pair with favourable prognosis in a large cohort of ovarian carcinomas.MethodsImmunohistochemical analysis for kisspeptin and GPR54 was performed on a tissue microarray (TMA) consisting of 518 early stage ovarian carcinomas, all with linked clinical outcome data. The TMA was scored using a staining intensity scale of 0 (negative), +1 (mild-moderate), and +2 (strong). Strong staining cases were considered either kisspeptin or GPR54 positive and designated as 1, while all other cases were considered negative and designated 0. All statistical analysis was conducted using two-sided tests and a p value equal to or less than 0.05 was considered significant.ResultsKisspeptin and GPR54 immunoreactive cases show a favourable prognosis in univariable disease specific survival (p = 0.0023, p = 0.0092), as well as in overall survival (p = 0.0006, p = 0.0002). Furthermore, kisspeptin is an independent marker for favourable prognosis as determined by multivariable disease specific (p = 0.0046) and overall survival analysis (p = 0.0170), while GPR54 is an independent marker for overall survival only (p = 0.0303). Both kisspeptin positive and GPR54 positive cases are strongly associated with the ovarian carcinoma clear cell subtype (p < 0.0001, p < 0.0001), and GPR54 is significantly associated with favourable prognosis in overall survival within the clear cell subtype (p = 0.0102).ConclusionKisspeptin and GPR54 immunoreactivity are significantly associated with favourable prognosis in both disease specific and overall survival, as well as being significantly associated with the clear cell ovarian carcinoma subtype, thereby creating the first independent prognostic biomarkers specific for ovarian clear cell carcinomas.
Noise-induced switches in network systems of the genetic toggle switch
Authors: Wang Junwei , Zhang Jiajun , Yuan Zhanjiang , Zhou Tianshou 
Published: November 2007

AbstractBackgroundBistability, the capacity to achieve two distinct stable steady states in response to a set of external stimuli, arises within biological systems ranging from theλphage switch in bacteria to cellular signal transduction pathways in mammalian cells. On the other hand, more and more experimental evidence in the form of bimodal population distribution has indicated that noise plays a very important role in the switching of bistable systems. However, the physiological mechanism underling noise-induced switching behaviors remains to be fully understood.ResultsIn this paper, we investigate the effect of noises on switching in single and coupled genetic toggle switch systems inEscherichia coli. In the case of the single toggle switch, we show that the multiplicative noises resulting from stochastic fluctuations in degradation rates can induce switching. In the case of the toggle switches interfaced by a quorum-sensing signaling pathway, we find that stochastic fluctuations in degradation rates inside cells, i.e., intracellular noises, can induce synchronized switching, whereas the extracellular noise additive to the common medium can not only entrain all the individual systems to switch in a synchronous manner but also enhance this ordering behavior efficiently, leading a robust collective rhythm in this interacting system.ConclusionThese insights on the effect of noises would be beneficial to understanding the basic mechanism of how living systems optimally facilitate to function under various fluctuated environments.
Aerodynamical Research and Hydraulic Practice
Authors: Fage A. 
Published: November 2007

All progressive countries possess aerodynamical laboratories in which scientific researches into the problems of flight are undertaken. Such researches have made, and are capable of making, some contribution to the progress of hydraulic practice. Many of these researches have been carried out with the aid of small-scale models, and the basic principles on which such experiments rest are first considered. It is shown that dimensional analysis indicates the form in which relations between the various parameters which govern fluid flow can best be stated, and suggests the manner in which the governing conditions must be represented on the model to obtain results of the greatest practical value. The similarity between flows of air and water under corresponding conditions is illustrated. Boundary layer flow is dealt with in some detail, and its influence on resistance and flow phenomena indicated. It is shown that turbulence in a boundary layer may have a beneficial effect on resistance. Methods of controlling flow by the use of guide vanes, slots, boundary jets, fairings, and other devices are described. Attention is directed to those features of wind tunnel design which favour steadiness of flow. The beneficial influence of a large contraction on steadiness is discussed. Brief reference is made to theoretical and experimental researches undertaken to obtain an insight into the mechanism of fully developed turbulence. The latest resistance formula for a smooth flat plate is given, together with resistance curves for pipes having a specific form of surface roughness. Some modern developments of the theory of a perfect fluid, and applications to problems of a real fluid, are briefly outlined. A method of designing axial-flow reaction turbines and pumps on lines suggested by aerofoil theory is given.
Progress in Design and Application of the Lysholm-Smith Torque Converter, with Special Reference to the Development in England
Authors: Haworth H. F. , Lysholm A. 
Published: November 2007

The Lysholm-Smith torque converter is of the closed-circuit turbine type. An approximate balance sheet is given showing the principal losses. As a torque converter is required to run at widely different primary and secondary speeds and torques the blade losses at varying inlet angles are the most important, particularly at starting and at secondary speeds, where the output torque is equal to or less than the input torque. A brief theory of the effect of blade friction is given together with the results of some experimental work with a reaction balance. The first converter was based on these results, and after it had been tested in England and Sweden, several experimental units of 100 to 150 h.p. were made. From the experience gained with these the present design was evolved. The main points to be provided for in the design and manufacture of the torque converter are set out and the experimental and production testing is described. Difficulty was found in presenting the test results in a simple form which would give the complete characteristics of the converter with all possible combinations of primary and secondary torques and speeds, but a method was devised such that if the torque-speed curve of the driving unit is given, a curve can be immediately constructed to give the combined action of the driving unit and the converter for the complete speed range. The results of experiments showing the alterations produced by various blade angles and wheel diameters are given, and various applications of this type of transmission are described, including a 1,000 h.p. variable-blade converter.
Evidence of an Influence of a Polymorphism Near the INSIG2 on Weight Loss During a Lifestyle Intervention in Obese Children and Adolescents
Authors: Reinehr Thomas , Hinney Anke , Nguyen Thuy Trang , Hebebrand Johannes 
Published: November 2007

OBJECTIVE—Homozygotes for the C-allele of the single nucleotide polymorphism (SNP) rs7566605, located ∼10 kb upstream of insulin-induced gene 2 (INSIG2), showed a slightly increased risk of becoming obese. The aim of this study was to analyze whether children homozygous for the C-allele lose less weight in an intervention than children with the GG- or GC-genotype.
RESEARCH DESIGN AND METHODS—We genotyped rs7566605 in 293 obese children (mean age 10.8 years, 45% male, mean BMI 28.1 kg/m2) who presented for a 1-year intervention. The reduction of SD score (SDS) BMI was compared based on an intention-to-treat analysis between the children with different genotypes. Blood pressure, triglycerides, insulin and glucose concentrations, and total, HDL, and LDL cholesterol were measured before and after intervention.
RESULTS—After 1 year, obese children with the CC-genotype had reduced their SDS BMI to a lower extent than obese children with GC- or GG-genotypes (recessive model P = 0.007). There was no evidence for an association of rs7566605 with the cardiovascular risk factor profile (nominal P &gt; 0.1).
CONCLUSIONS—CC-homozygotes at SNP rs7566605 in the vicinity of INSIG2 lost less weight in this lifestyle intervention. This finding further implicates this polymorphism in weight regulation.
The Role of Free-Living Daily Walking in Human Weight Gain and Obesity
Authors: Levine James A. , McCrady Shelly K. , Lanningham-Foster Lorraine M. , Kane Paul H. , Foster Randal C. , Manohar Chinmay U. 
Published: November 2007

OBJECTIVE—Diminished daily physical activity explains, in part, why obesity and diabetes have become worldwide epidemics. In particular, chair use has replaced ambulation, so that obese individuals tend to sit for ∼2.5 h/day more than lean counterparts. Here, we address the hypotheses that free-living daily walking distance is decreased in obesity compared with lean subjects and that experimental weight gain precipitates decreased daily walking.
RESEARCH DESIGN AND METHODS—During weight-maintenance feeding, we measured free-living walking using a validated system that captures locomotion and body movement for 10 days in 22 healthy lean and obese sedentary individuals. These measurements were then repeated after the lean and obese subjects were overfed by 1,000 kcal/day for 8 weeks.
RESULTS—We found that free-living walking comprises many (∼47) short-duration (&lt;15 min), low-velocity (∼1 mph) walking bouts. Lean subjects walked 3.5 miles/day more than obese subjects (n = 10, 10.3 ± 2.5 vs. n = 12, 6.7 ± 1.8 miles/day; P = 0.0009). With overfeeding, walking distance decreased by 1.5 miles/day compared with baseline values (−1.5 ± 1.7 miles/day; P = 0.0005). The decrease in walking that accompanied overfeeding occurred to a similar degree in the lean (−1.4 ± 1.9 miles/day; P = 0.04) and obese (−1.6 ± 1.7 miles/day; P = 0.008) subjects.
CONCLUSIONS—Walking is decreased in obesity and declines with weight gain. This may represent a continuum whereby progressive increases in weight are associated with progressive decreases in walking distance. By identifying walking as pivotal in weight gain and obesity, we hope to add credence to an argument for an ambulatory future.
Sphingosine-1-Phosphate Reduces CD4+ T-Cell Activation in Type 1 Diabetes Through Regulation of Hypoxia-Inducible Factor Short Isoform I.1 and CD69
Authors: Srinivasan Suseela , Bolick David T. , Lukashev Dmitriy , Lappas Courtney , Sitkovsky Michail , Lynch Kevin R. , Hedrick Catherine C. 
Published: November 2007

OBJECTIVES—Non-obese diabetic (NOD) mice develop spontaneous type 1 diabetes. We have shown that sphingosine-1-phosphate (S1P) reduces activation of NOD diabetic endothelium via the S1P1 receptor. In the current study, we tested the hypothesis that S1P could inhibit CD4+ T-cell activation, further reducing inflammatory events associated with diabetes.
RESEARCH DESIGN AND METHODS—CD4+ T-cells were isolated from diabetic and nondiabetic NOD mouse splenocytes and treated in the absence or presence of S1P or the S1P1 receptor-specific agonist, SEW2871. Lymphocyte activation was examined using flow cytometry, cytokine bead assays, and a lymphocyte:endothelial adhesion assay.
RESULTS—Diabetic T-cells secreted twofold more γ-interferon (IFN-γ) and interleukin-17 than nondiabetic lymphocytes. Pretreatment with either S1P or SEW2871 significantly reduced cytokine secretion by ∼50%. Flow cytometry analysis showed increased expression of CD69, a marker of lymphocyte activation, on diabetic T-cells. Both S1P and SEW2871 prevented upregulation of CD69 on CD4+ cells. Quantitative RT-PCR showed that lymphocytes from diabetic NOD mice had 2.5-fold lower hypoxia-inducible factor (HIF)-1α short isoform I.1 (HIF1αI.1) mRNA levels than control. HIF1αI.1 is a negative regulator of lymphocyte activation. S1P significantly increased HIF1α I.1 mRNA levels in both control and diabetic groups. IFN-γ production and surface CD69 expression was significantly increased in lymphocytes of HIF1αI.1-deficient mice. S1P did not reduce either CD69 or IFN-γ expression in lymphocytes from HIF1αI.1-deficient mice.
CONCLUSIONS—S1P acts through the S1P1 receptor and HIF1α I.1 to negatively regulate T-cell activation, providing a potential therapeutic target for prevention of diabetes and its vascular complications.
Inhibition of AMP-Activated Protein Kinase Protects Pancreatic β-Cells From Cytokine-Mediated Apoptosis and CD8+ T-Cell–Induced Cytotoxicity
Authors: Riboulet-Chavey Audrey , Diraison Frédérique , Siew L. Khai , Wong F. Susan , Rutter Guy A. 
Published: November 2007

OBJECTIVE—Apoptotic destruction of insulin-producing pancreatic β-cells is involved in the etiology of both type 1 and type 2 diabetes. AMP-activated protein kinase (AMPK) is a sensor of cellular energy charge whose sustained activation has recently been implicated in pancreatic β-cell apoptosis and in islet cell death posttransplantation. Here, we examine the importance of β-cell AMPK in cytokine-induced apoptosis and in the cytotoxic action of CD8+ T-cells.
RESEARCH DESIGN AND METHODS— Clonal MIN6 β-cells or CD1 mouse pancreatic islets were infected with recombinant adenoviruses encoding enhanced green fluorescent protein (eGFP/null), constitutively active AMPK (AMPK-CA), or dominant-negative AMPK (AMPK-DN) and exposed or not to tumor necrosis factor-α, interleukin-1β, and interferon-γ. Apoptosis was detected by monitoring the cleavage of caspase-3 and DNA fragmentation. The cytotoxic effect of CD8+ purified T-cells was examined against pancreatic islets from NOD mice infected with either null or the AMPK-DN–expressing adenoviruses.
RESULTS— Exposure to cytokines, or expression of AMPK-CA, induced apoptosis in clonal MIN6 β-cells and CD1 mouse pancreatic islets. By contrast, overexpression of AMPK-DN protected against the proapoptotic effect of these agents, in part by preventing decreases in cellular ATP, and lowered the cytotoxic effect of CD8+ T-cells toward NOD mouse islets.
CONCLUSIONS— Inhibition of AMPK activity enhances islet survival in the face of assault by either cytokines or T-cells. AMPK may therefore represent an interesting therapeutic target to suppress immune-mediated β-cell destruction and may increase the efficacy of islet allografts in type 1 diabetes.
Islet Expression of M3 Uncovers a Key Role for Chemokines in the Development and Recruitment of Diabetogenic Cells in NOD Mice
Authors: Martin Andrea P. , Grisotto Marcos G. , Canasto-Chibuque Claudia , Kunkel Steven L. , Bromberg Jonathan S. , Furtado Glaucia C. , Lira Sergio A. 
Published: November 2007

OBJECTIVE—Type 1 diabetes is an autoimmune disease characterized by a local inflammatory reaction in and around islets followed by selective destruction of insulin-secreting β-cells. We tested the hypothesis that chemokines affect different mechanisms responsible for the development of diabetes in NOD mice.
RESEARCH DESIGN AND METHODS—We examined chemokine expression in islets of NOD mice and tested their functional relevance to development of diabetes using transgenic mice expressing the mouse herpesvirus 68–encoded chemokine decoy receptor M3 (NOD-M3 mice) in insulin-secreting β-cells.
RESULTS—Multiple chemokines were expressed in pancreatic islets of NOD mice before development of diabetes. Islet-specific expression of the pan-chemokine inhibitor M3 dramatically reduced leukocyte infiltration and islet destruction and completely blocked development of diabetes in NOD-M3 mice. M3 blocked diabetes by inhibiting the priming of diabetogenic cells in the pancreatic lymph nodes and their recruitment into the islets. This effect was specific to the pancreatic islets because M3 expression did not affect other ongoing autoimmune processes.
CONCLUSIONS—These results demonstrate that chemokines mediate afferent and efferent immunity in type 1 diabetes and suggest that broad chemokine blockade may represent a viable strategy to prevent insulitis and islet destruction.
Attenuation of Counterregulatory Responses to Recurrent Hypoglycemia by Active Thalamic Inhibition
Authors: Arbelaez Ana Maria , Powers William J. , Videen Tom O. , Price Joseph L. , Cryer Philip E. 
Published: November 2007

OBJECTIVE—Hypoglycemia, the limiting factor in the glycemic management of diabetes, is the result of the interplay of therapeutic insulin excess and compromised glycemic defenses. The key feature of the latter is an attenuated sympathoadrenal response to hypoglycemia that typically follows an episode of recent antecedent iatrogenic hypoglycemia, a phenomenon termed hypoglycemia-associated autonomic failure (HAAF) in diabetes. We investigated the role of cerebral mechanisms in HAAF by measuring regional brain activation during recurrent hypoglycemia with attenuated counterregulatory responses and comparing it with initial hypoglycemia in healthy individuals.
RESEARCH DESIGN AND METHODS—We used [15O]water and positron emission tomography to measure regional cerebral blood flow as a marker of brain synaptic activity during hyperinsulinemic hypoglycemic clamps (55 mg/dl [3.0 mmol/l]) in the naïve condition (day 1) and after ∼24 h of interval interprandial hypoglycemia (day 2) in nine healthy adults.
RESULTS—Interval hypoglycemia produced attenuated sympathoadrenal, symptomatic, and other counterregulatory responses to hypoglycemia on day 2, a model of HAAF. Synaptic activity in the dorsal midline thalamus during hypoglycemia was significantly greater on day 2 than day 1 (P = 0.004).
CONCLUSIONS—Greater synaptic activity associated with attenuated counterregulatory responses indicates that the dorsal midline thalamus plays an active inhibitory role in reducing sympathoadrenal and symptomatic responses to hypoglycemia when previous hypoglycemia has occurred, the key feature of HAAF in diabetes.
Cover Picture: Liquid Crystalline Peptide Nanowires (Adv. Mater. 22/2007)
Authors: Han T. H. , Kim J. , Park J. S. , Park C. B. , Ihee H. , Kim S. O. 
Published: November 2007

AbstractLiquid‐crystalline peptide nanowires consisting of aromatic dipeptides are easily prepared by a sonication in a volatile organic solvent, report Hyotcherl Ihee, Sang Ouk Kim, and co‐workers on p. 3924. The colloidal nematic liquid crystalline phase of the rigid nanowires allows for a macroscopically ordered morphology of the nanowires under an external electric field. The cover image presents a broad field view of nanowires oriented by an electric field between two electrodes.
Preparation and properties of natural rubber nanocomposites with solid‐state organomodified montmorillonite
Authors: Sun Yuhai , Luo Yuanfang , Jia Demin 
Published: November 2007

AbstractA novel organomodified montmorillonite prepared by solid‐state method and its nanocomposites with natural rubber were studied. The nanocomposites were prepared by traditional rubber mixing and vulcanizing process. The properties of solid‐state organomodified montmorillonite were investigated by Fourier‐transform infrared spectroscopy (FITR) and thermogravimetric analysis (TGA). The dispersion of the layered silicate in rubber matrix was characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the nanocomposites consisting of solid‐state organomodified montmorillonite and natural rubber are obtained. The solid‐state organomodified montmorillonite can not only accelerate the curing process, but also improve the mechanical and aging resistance properties of NR. The properties improvement caused by the fillers are attributed to partial intercalation of the organophilic clay by NR macromolecules. In addition, the dynamic mechanical analysis (DMA) results showed a decrease of tanδmax and increase of Tg when the organoclay is added to the rubber matrix, which is due to the confinement of the macromolecular segments into the organoclay nanolayers and the strong interaction between the filler and rubber matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preconcentration and matrix elimination for the determination of Pb(II), Cd(II), Ni(II), and Co(II)by 8‐hydroxyquinoline anchored poly(styrene‐divinylbenzene) microbeads
Authors: Aşkun Hakan , Gülbakan Basri , Çelikbıçak Ömür , Uzun Cengiz , Güven Olgun , Salih Bekir 
Published: November 2007

AbstractPoly(styrene‐divinylbenzene), PS‐DVB, microbeads were modified with 8‐hydroxyquinoline (8‐HQ) following nitration, reduction of NO2 to NH2, and conversion of NH2 to diazonium salt. Characterization of pristine, NO2, NH2, NN+Cl−, and 8‐QH functional groups modified microbeads was made by Fourier transform‐infrared spectrometry (FTIR) and porosimetry. Total reflectron‐X‐ray florescence spectrometer (TXRF) was used to test the affinity of the 8‐HQ modified microbeads to toxic metal ions. 8‐HQ‐modified microbeads were used to examine the adsorption capacity, recovery, preconcentration, and the matrix elimination efficiency for Pb(II), Cd(II), Ni(II), and Co(II) ions as a function of changing pH, initial metal‐ion concentrations, and also equilibrium adsorption time of the studied metal ions. Preconcentration factors for the studied toxic metal ions were found to be more than 500‐fold and recovery between 93.8% and 100.6%. Ultratrace toxic metal‐ion concentrations in sea water were determined easily by using modified microbeads. Reference sea‐water sample was used for the validation of the method, and it was found that recovery, preconcentration, and the matrix elimination were performed perfectly. For the desorption of the toxic metal ions, 3M of HNO3 was used and desorption ratio shown to be more than 96%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008