bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐fat Diet Alters PP2A, TC10, and CIP4 Expression in Visceral Adipose Tissue of Rats
Authors: Jun Hye‐Seung , Hwang Kyujung , Kim Yunjung , Park Taesun
Published: April 2008

Objective: The aim of this study was to investigate a possible link between high‐fat diet (HFD)–induced obesity and the expression of protein phosphatase 2A (PP2A) and Cdc42‐interacting protein 4 (CIP4) proteins, potential downstream components of the IRS/PI3K/AKT and CAP/Cbl/TC10 pathway, respectively, in the visceral adipose tissue.

Methods and Procedures: Twenty male Sprague‐Dawley rats were randomly divided into two groups and were given either HFD or the normal diet (ND) for 8 weeks. The HFD‐induced changes in the expression of the epididymal adipose tissue genes involved in the insulin‐signaling pathways were evaluated using real‐time reverse‐transcription PCR and western blot analysis.

Results: The exposure of rats to HFD for 8 weeks resulted in a significant increase in the expression of PP2A at both the transcriptional and translational levels, along with a marked reduction in the levels of phosphorylated AKT and insulin receptor substrate‐1 (IRS‐1) in the cytosol of visceral adipocytes, compared with the ND rats. Besides, there were significant HFD‐induced decreases in the mRNA and protein levels of CIP4 and TC10 in the adipose tissue of rats.

Discussion: These data suggest that HFD might have a relevance to insulin resistance by increasing the expression of PP2A, an inhibitor of AKT activity in the phosphatidylinositol 3‐kinase (PI3K)/AKT pathway, and also by suppressing the expression of TC10 and CIP4, downstream effectors of the Cbl/CAP/TC10 insulin‐signaling cascade in the visceral adipose tissue.
Weight Loss Therapy Improves Pancreatic Endocrine Function in Obese Older Adults
Authors: Villareal Dennis T. , Banks Marian R. , Patterson Bruce W. , Polonsky Kenneth S. , Klein Samuel
Published: April 2008

Objective: Obesity and aging increase the risk of type 2 diabetes (T2D). We evaluated whether weight loss therapy improves pancreatic endocrine function and insulin sensitivity in obese older adults.

Methods and Procedures: Twenty‐four obese (BMI: 38 ± 2 kg/m2) older (age: 70 ± 2 years) adults completed a 6‐month randomized, controlled trial. Participants were randomized to diet and exercise (treatment group) or no therapy (control group). β‐Cell function (assessed using the C‐peptide minimal model), α‐cell function (assessed by the glucagon response to an oral glucose load), insulin sensitivity (assessed using the glucose minimal model), and insulin clearance rate were evaluated using a 5‐h modified oral glucose tolerance test.

Results: Body weight decreased in the treatment group, but did not change in the control group (−9 ± 1% vs. 0 ± 1%; P < 0.001). Insulin sensitivity doubled in the treatment group and did not change in the control group (116 ± 49% vs. −11 ± 13%; P < 0.05). Even though indices of β‐cell responsivity to glucose did not change (P > 0.05), the disposition index (DI), which adjusts β‐cell insulin response to changes in insulin sensitivity, improved in the treatment group compared with the control group (100 ± 47% vs. −22 ± 9%; P < 0.05). The glucagon response decreased in the treatment but not in the control group (−5 ± 2% vs. 4 ± 4%; P < 0.05). Insulin secretion rate did not change (P > 0.05), but insulin clearance rate increased (51 ± 25%; P < 0.05), resulting in lower plasma insulin concentrations.

Discussion: Weight loss therapy concomitantly improves β‐cell function, lowers plasma glucagon concentrations, and improves insulin action in obese older adults. These metabolic effects are likely to reduce the risk of developing T2D in this population.
Design and control of a flux-controllable stator-permanent magnet brushless motor drive
Authors: Zhu Xiaoyong , Chau K. T. , Cheng Ming , Yu Chuang
Published: April 2008

In this paper, a new flux-controllable stator permanent magnet (PM) brushless motor drive is proposed which is particularly attractive for electric vehicles. The key of the proposed motor is to incorporate both PM materials and dc field windings in the stator, hence offering a compact arrangement of hybrid-field excitations, while the rotor is simply composed of salient poles without windings or PMs. Thus, the flux control, including both strengthening and weakening, can be easily achieved by tuning the dc field current. Both finite element analysis and experimental results confirm that the proposed motor drive can offer effective flux control, fast speed response, wide constant-power operating range, and high efficiency over wide-speed operation.
Self-organized transient facilitated atomic transport in Pt∕Al(111)
Authors: Süle P.
Published: April 2008

During the course of atomic transport in a host material, impurity atoms need to surmount an energy barrier driven by thermodynamic bias or at ultralow temperatures by quantum tunneling. In the present article, we demonstrate using atomistic simulations that at ultralow temperature, transient interlayer atomic transport is also possible without tunneling when the Pt∕Al(111) impurity/host system self-organizes itself spontaneously into an intermixed configuration. No such extremely fast athermal concerted process has been reported before at ultralow temperatures. The outlined novel transient atomic exchange mechanism could be of general validity. We find that the source of ultralow temperature heavy particle barrier crossing is intrinsic and no external bias is necessary for atomic intermixing and surface alloying in Pt∕Al, although the dynamic barrier height is a few eV. The mechanism is driven by the local thermalization of the Al(111) surface in a self-organized manner arranged spontaneously by the system without any external stimulus. The core of the short lived thermalized region reaches the local temperature of ∼1000K (including a few tens of Al atoms), while the average temperature of the simulation cell is ∼3K. The transient facilitated intermixing process also takes place with repulsive impurity-host interaction potential leading to negative atomic mobility; hence, the atomic injection is largely independent of the strength of the impurity-surface interaction. We predict that similar exotic behavior is possible in other materials as well.
Anionic microsolvation in helium droplets: OH−(He)N structures from classical and quantum calculations
Authors: Coccia E. , Marinetti F. , Bodo E. , Gianturco F. A.
Published: April 2008

Diffusion Monte Carlo calculations are carried out for clusters of OH−(Σ+1) with N He4 atoms, N varying up to 15, while classical configurations from a genetic algorithm optimization are obtained up to N=20. The overall interaction potential is assembled from ab initio data for the partners using the sum-of-potentials scheme. In contrast with the cationic dopants’ behavior, the results indicate a very marked spatial delocalization and quantum features of the solvent adatoms surrounding the anionic impurity, thus making classical calculations of solvent’s spatial locations of only limited use. In spite of the generally known repulsive interaction of negative charges in He droplets, the calculations show that this polar molecular anion is solvated by a liquidlike solvent layer, reminiscent of what happens in pure helium droplets.
Effect of polydispersity on the relative stability of hard-sphere crystals
Authors: Yang Mingcheng , Ma Hongru
Published: April 2008

By extending the nonequilibrium potential refinement algorithm and lattice switch method to the semigrand ensemble, the semigrand potentials of the fcc and hcp structures of polydisperse hard-sphere crystals are calculated with the bias sampling scheme. The result shows that the fcc structure is more stable than the hcp structure for polydisperse hard-sphere crystals below the terminal polydispersity.
Binding characteristics of pyridine on Ag(110)
Authors: Hou Jin Qiang , Kang Hong Seok , Kim Ki Wan , Hahn Jae Ryang
Published: April 2008

A combination of low-temperature scanning tunneling microscopy and density functional theory calculations was used to determine the binding characteristics of single pyridine molecules at a low coverage on a silver surface. The results indicated that pyridine binds to silver through the nitrogen atom in either a perpendicular or a parallel configuration with the latter structure being more prevalent. Both configurations are produced predominantly through electrostatic interaction between nitrogen and silver atoms. This is induced by charge redistribution in the pyridine molecule and nearby silver atoms upon pyridine adsorption.
Modification of single-walled carbon nanotube electrodes by layer-by-layer assembly for electrochromic devices
Authors: Jain Vaibhav , Yochum Henry M. , Montazami Reza , Heflin James R. , Hu Liangbing , Gruner George
Published: April 2008

We have studied the morphological properties and electrochromic (EC) performance of polythiophene multilayer films on single wall carbon nanotube (SWCNT) conductive electrodes. The morphology for different numbers of layer-by-layer (LbL) bilayer on the SWCNT electrode has been characterized with atomic force microscopy and scanning electron microscope, and it was found that the LbL multilayers significantly decrease the surface roughness of the nanoporous nanotube films. The controlled surface roughness of transparent nanotube electrodes could be beneficial for their device applications. We have also fabricated EC devices with LbL films of poly[2-(3-thienyl) ethoxy-4-butylsulfonate∕poly(allylamine hydrochloride) on SWCNT electrodes, which not only have high EC contrast but also sustain higher applied voltage without showing any degradation for more than 20000cycles, which is not possible in the case of indium tin oxide electrodes. Cyclic voltammetry of the LbL films formed on SWCNT shows higher current at low potential, revealing the feasibility of SWCNT electrode as a good host for electrolyte ion insertion.
A route to increase the enhancement factor of surface enhanced Raman scattering (SERS) via a high density Ag flower-like pattern
Authors: Fang Jixiang , Yi Yan , Ding Bingjun , Song Xiaoping
Published: April 2008

We explored a route to prepare a high enhancement factor of SERS substrate via a high density of Ag flowerlike pattern. The finite difference time domain (FDTD) calculations indicate that the Ag flowerlike pattern may demonstrate a high quality SERS property owing to the high density and abundant hot spot characteristic. Using an unusually high overpotential with electrodeposition system, the fractal flowerlike patterns and the high density nanoparticle arrays were experimental synthesized. The SERS measurement of above different Ag nanostructures verified the predications from the FDTD calculation.
Estimates of the optimal density of sphere packings in high dimensions
Authors: Scardicchio A. , Stillinger F. H. , Torquato S.
Published: April 2008

The problem of finding the asymptotic behavior of the maximal density ϕmax of sphere packings in high Euclidean dimensions is one of the most fascinating and challenging problems in discrete geometry. One century ago, Minkowski obtained a rigorous lower bound on ϕmax that is controlled asymptotically by 1∕2d, where d is the Euclidean space dimension. An indication of the difficulty of the problem can be garnered from the fact that exponential improvement of Minkowski’s bound has proved to be elusive, even though existing upper bounds suggest that such improvement should be possible. Using a statistical-mechanical procedure to optimize the density associated with a “test” pair correlation function and a conjecture concerning the existence of disordered sphere packings [S. Torquato and F. H. Stillinger, Exp. Math. 15, 307 (2006)], the putative exponential improvement on ϕmax was found with an asymptotic behavior controlled by 1∕2(0.77865⋯)d. Using the same methods, we investigate whether this exponential improvement can be further improved by exploring other test pair correlation functions corresponding to disordered packings. We demonstrate that there are simpler test functions that lead to the same asymptotic result. More importantly, we show that there is a wide class of test functions that lead to precisely the same putative exponential improvement and therefore the asymptotic form 1∕2(0.77865⋯)d is much more general than previously surmised. This class of test functions leads to an optimized average kissing number that is controlled by the same asymptotic behavior as the one found in the aforementioned paper.
Precise measurements of the total concentration of atmospheric CO2 and C13O2∕C12O2 isotopic ratio using a lead-salt laser diode spectrometer
Authors: Croizé Laurence , Mondelain Didier , Camy-Peyret Claude , Delmotte Marc , Schmidt Martina
Published: April 2008

We have developed a tunable diode laser spectrometer, called SIMCO (spectrometer for isotopic measurements of CO2), for determining the concentrations of C12O2 and C13O2 in atmospheric air, from which the total concentration of CO2 and the isotopic composition (expressed in delta units) δC13O2 are calculated. The two concentrations are measured using a pair of lines around 2290.1cm−1, by fitting a line profile model, taking into account the confinement narrowing effect to achieve a better accuracy. Using the Allan variance, we have demonstrated (for an integration time of 25s) a precision of 0.1ppmv for the total CO2 concentration and of 0.3‰ for δC13O2. The performances on atmospheric air have been tested during a 3 days campaign by comparing the SIMCO instrument with a gas chromatograph (GC) for the measurement of the total CO2 concentration and with an isotopic ratio mass spectrometer (MS) for the isotopic composition. The CO2 concentration measurements of SIMCO are in very good agreement with the GC data with a mean difference of Δ(CO2)=0.16±1.20ppmv for a comparison period of 45h and the linearity of the concentration between the two instruments is also very good (slope of correlation: 0.9996±0.0003) over the range between 380 and 415ppmv. For δC13O2, the comparison with the MS data shows a larger mean difference of Δ(δC13O2)=(−1.9±1.2)‰, which could be partly related to small residual fluctuations of the overall SIMCO instrument response.
The surface engineering of top electrode in inverted polymer bulk-heterojunction solar cells
Authors: Kim Jihwan , Khang Dahl-Young , Kim Ju-Hyung , Lee Hong H.
Published: April 2008

We present surface engineering of the top electrode in organic solar cells through soft contact lamination. A polymer conductor and a self-assembled monolayer material are utilized for the surface engineering of gold electrode in a polymer bulk-heterojunction solar cell. Approximately a threefold increase in the overall power conversion efficiency is shown to be realized with the surface engineering, which is made possible by the lamination.
Asymmetric double two-dimensional electron gas structures for electrical quantum metrology
Authors: Pierz K. , Hein G. , Pesel E. , Schumacher B. , Schumacher H. W. , Siegner U.
Published: April 2008

We study growth and low temperature magnetotransport of Ga(Al)As based asymmetric double two-dimensional electron gas (2DEG) structures consisting of a quantum well stacked on top of a heterojunction. These structures allow for matching the electron densities in the two parallel 2DEGs by variation of a single growth parameter without the appearance of any parasitic transport channel. At filling factor 2, we observe a 2T wide quantum Hall plateau of metrological quality with a quantized resistance of one quarter of the resistance quantum. Such structures can be used for electrical quantum metrology and to fabricate vertically integrated circuits.
Interprovincial Migration and Retirement Income Transfers among Canada's Older Population: 1996–2001
Authors: Newbold K Bruce
Published: April 2008

Given the propensity of Canadians to migrate, it is likely that migration has a large impact upon the distribution and redistribution of income across regions. Such impacts may be magnified within the older population, as their relocation involves the transfer of nonearned income such as pensions, retirement investments, or other income supplements from province to province and so return migration to a province of birth following retirement subsidizes local economies. By using methods proposed by Plane in 1999, income-based versions of demographic effectiveness are applied to evaluate the movement of nonearned income in the Canadian context among Canada's older population. The analysis uses data drawn from the 2001 Canadian Census, and focuses upon the older population (aged 60+ in 2001) who reported nonearned incomes in 2000. The paper distinguishes between four types of nonearned income, including (i) Old Age Security and Guaranteed Income Supplements; (ii) Canada/Québec pension plan benefits; (iii) Retirement Investment income; and (iv) Investment Income. The objectives of the paper are twofold. First, it documents the movement of nonearned income between Canada's provinces, focusing upon the demographic effectiveness of the observed flows. Second, the paper explores the potential for primary, return, and onward migration to redistribute nonearnings income across Canada, and the significance of regional income redistributions by each type of migration. Results illustrate the importance of migration in transferring nonearned incomes over space, and the particular importance of return migration as a vehicle to redistribute nonearned income to economically depressed provinces.
Bindings against Boundaries: Entanglements of Life in an Open World
Authors: Ingold Tim
Published: April 2008

In this paper I argue that to inhabit the world is to live life in the open. Yet philosophical attempts to characterise the open lead to paradox. Do we follow Heidegger in treating the open as an enclosed space cleared from within, or Kant (and, following his lead, mainstream science) in placing the open all around on the outside? One possible solution is offered by Gibson in his ecological approach to perception. The Gibsonian perceiver is supported on the ground, with the sky above and the earth below. Yet in this view, only by being furnished with objects does the earth–sky world become habitable. To progress beyond the idea that life is played out upon the surface of a furnished world, we need to attend to those fluxes of the medium we call weather. To inhabit the open is to be immersed in these fluxes. Life is lived in a zone in which earthly substances and aerial media are brought together in the constitution of beings which, in their activity, participate in weaving the textures of the land. Here, organisms figure not as externally bounded entities but as bundles of interwoven lines of growth and movement, together constituting a meshwork in fluid space. The environment, then, comprises not the surroundings of the organism but a zone of entanglement. Life in the open, far from being contained within bounded places, threads its way along paths through the weather world. Despite human attempts to hard surface this world, and to block the intermingling of substance and medium that is essential to growth and habitation, the creeping entanglements of life will always and eventually gain the upper hand.
From Space Syntax to Space Semantics: A Behaviorally and Perceptually Oriented Methodology for the Efficient Description of the Geometry and Topology of Environments
Authors: Franz Gerald , Wiener Jan M
Published: April 2008

Human spatial behavior and experience cannot be investigated independently from the shape and configuration of environments. Therefore, comparative studies in architectural psychology and spatial cognition would clearly benefit from operationalizations of space that provide a common denominator for capturing its behavioral and psychologically relevant properties. This paper presents theoretical and methodological issues arising from the practical application of isovist-based graphs for the analysis of architectural spaces. Based on recent studies exploring the influence of spatial form and structure on behavior and experience in virtual environments, the following topics are discussed: (1) the derivation and empirical verification of meaningful descriptor variables on the basis of classic qualitative theories of environmental psychology relating behavior and experience to spatial properties; (2) methods to select reference points for the analysis of architectural spaces at a local level; furthermore, based on two experiments exploring the phenomenal conception of the spatial structure of architectural environments, formalized strategies for (3) the selection of reference points at a global level, and for (4), their integration into a sparse yet plausible comprehensive graph structure, are proposed. Taken together, a well formalized and psychologically oriented methodology for the efficient description of spatial properties of environments at the architectural scale level is outlined. This method appears useful for a wide range of applications, ranging from abstract architectural analysis over behavioral experiments to studies on mental representations in cognitive science.
Perception of Phosphenes and Flashed Alphabetical Characters is Enhanced by Single-Pulse Transcranial Magnetic Stimulation of Anterior Frontal Lobe: The Thalamic Gate Hypothesis
Authors: Amassian Vahe , Mari Zoltan , Sagliocco Laura , Hassan Nasser , Maccabee Peter , Cracco Joan B , Cracco Roger Q , Bodis-Wollner Ivan
Published: April 2008

Single pulses of transcranial magnetic stimulation (sTMS) restricted locally to the primary cortical areas for somatosensory and visual input, unlike the effects of repetitive stimulation, usually fail to elicit projected sensations. We tested the effect of sTMS over anterior frontal cortex in facilitating phosphenes from preceding sTMS over calcarine cortex, which alone was rarely effective in eliciting phosphenes. The combined sTMS elicited complex phosphenes, which changed with the site of frontal sTMS and the interstimulus interval. Our results show that sTMS over anterior frontal cortex also improved reporting of weakly illuminated, flashed four-letter stimuli, which permitted its statistical validation. We propose that the present demonstration of frontal cortical facilitation of visual awareness, when combined with the previous finding of projected paresthesias and sense of movement (Amassian et al, 1991 Brain114 2505 – 2520), provide evidence of a general frontal opening effect on a thalamic gate. Opening this gate facilitates entry of information from primary cortical receiving areas to thalamus. Thereby, the reciprocal thalamocortical interrelations that subserve conscious awareness of sensory stimuli could be fostered.
Acculturation and depressive symptoms in Muslim university students: Personal–family acculturation match
Authors: Asvat Yasmin , Malcarne Vanessa L.
Published: March 2008

The relationships of personal acculturation and of personal–family acculturation match to depressive symptoms were investigated in a sample of 68 Muslim university students. Two dimensions of personal and family acculturation were assessed: heritage and mainstream culture identification. Participants completed the Vancouver Index of Acculturation (Ryder, Alden, & Paulhus, 2000) and the depressive disorder subscale of the Psychiatric Diagnostic Screening Questionnaire (Zimmerman & Mattia, 1999). For personal acculturation, individuals with high personal heritage culture identification reported fewer lifetime (but not past‐year) depressive symptoms. In contrast, individuals with high personal mainstream culture identification reported more past‐year (but not lifetime) depressive symptoms. The hypothesis that a match between personal and family acculturation orientation would be associated with fewer depressive symptoms was supported for heritage culture identification only. For past‐year depression, the two match conditions (low or high personal and family heritage culture identification) were associated with significantly fewer depressive symptoms than a low personal/high family mismatch but did not differ from a high personal/low family mismatch. For lifetime depression, a high personal/high family match was associated with significantly fewer depressive symptoms than all other conditions. Findings suggests that, for Muslims, a match of high personal and high family heritage culture identification may act as a protective factor for the experience of depressive symptoms both in the short term (past year) and in the long term (lifetime).
Developmental assessment, cultural context, gender, and schooling in Zambia
Authors: Serpell Robert , Jere‐Folotiya Jacqueline
Published: March 2008

Multiple perspectives on the assessment of children's development at the school–community interface in rural areas of Zambia are discussed in the light of several empirical studies conducted between 1974 and 2005. A longitudinal trace study of a cohort of 46 young people born into a rural, Chewa community in Katete District found that girls' scores in early childhood on a battery of ecoculturally grounded cognitive tests correlated less well than they did for boys with two educational outcomes: number of grades of schooling completed, and adult literacy scores. Conversely, ratings of the children on indigenous conceptions of intelligence by adults familiar with the children in the context of their home village lives predicted the same outcomes better for girls than for boys. A separate, linked experiment compared the performance of 76 Katete school children with that of 84 school children in the capital city of Lusaka on the US standardized Draw‐a‐Person Test (DPT) and the Panga Munthu Test (PMT), an expanded version of one of the tests developed for the Zambian trace study. Analysis of the correlations among scores on these two tests, age, and teacher ratings suggests that aptitudes evident in the home and school domains are less well integrated for rural girls than for urban boys, and that for a low‐income, rural population, the PMT taps the domain of home cognition better than school cognition, while the converse is true of the DPT. Implications for educational assessment in Zambia are discussed, and supportive documentation is cited from two ongoing programs of test development. The authors conclude that if educational testing is to support the process of enhancing educational equity across gender, family socioeconomic status, and residential location, its focus should be broadened to include other dimensions of psychological development such as multilingual and personal‐social competencies.
Locus of control and home mortgage loan behaviour
Authors: Wang Mingji , Chen Hong , Wang Lei
Published: March 2008

The present study investigated the impact of locus of control on home mortgage loan behaviours. The results showed that participants with stronger external control were more likely to purchase a lower priced home, have a lower ratio of mortgage loan amount to the total home value, and have a shorter term of mortgage loan. Moreover, among participants who have owned a home, those not using mortgage loans showed more external control than those using mortgage loans; among participants who have not owned a home but want to buy a home, those not planning to use mortgage loans showed more external control than those planning to use mortgage loans.
The Asian Psychological Association Founding Convention, Bali, Indonesia, 2006
Authors: Knowles Michael
Published: March 2008

The First Convention of the Asian Psychological Association (APsyA) was held in Bali from 18–20th August 2006. This historic event marked the founding of the APsyA which is the first association in the Asian region with an individual membership spanning the whole field of psychology. The Conference was organized under the presidency of Sarlito Sarwono and was supported institutionally by the Faculty of Psychology at the University of Indonesia, Tarumanagara University, the Catholic University of Indonesia, the Indonesian Police Force, the International Council of Psychologists, Division 52 (International Psychology) of the American Psychological Association and the International Association of Applied Psychology. The Conference attracted over 120 participants from 17 countries; its Scientific Program covered matters such as indigenous Asian psychology, the contributions of psychology towards national development, and special issues in Asia. The principal symposium of the Conference dealt with terrorism and covered research into the psychology of terrorists, the process by which people become terrorists, and the rehabilitation of terrorists.
Age‐Related Alterations in Reactivity of Cerebral Arterioles: Role of Oxidative Stress
Authors: Mayhan William G. , Arrick Denise M. , Sharpe Glenda M. , Sun Hong
Published: April 2008

Objective: Our goal was to identify the role of oxidative stress via activation of NAD(P)H oxidase in cerebrovascular dysfunction in aged rats.

Methods: We examined the reactivity of cerebral arterioles in adult and aged Fisher‐344 rats to endothelial nitric oxide synthase (eNOS)‐dependent (acetylcholine and adenosine diphosphate [ADP]) and‐independent (nitroglycerin) agonists before and during application of tempol, apocynin, and diphenyleneiodonium chloride (DPI). We used Western blot to examine subunits of NAD(P)H oxidase, eNOS, and superoxide dismutase (SOD‐1) in cerebral microvessels and parietal cortex. Finally, we measured superoxide production by cortex tissue in adult and aged rats.

Results: Acetylcholine‐and ADP‐induced, but not nitroglycerin‐induced, dilatation of cerebral arterioles was impaired in aged compared to adult rats. While tempol, apocynin, and DPI did not alter responses in adults, they alleviated impaired eNOS‐dependent vasodilatation in aged rats, without influencing responses to nitroglycerin. eNOS and p67phox proteins were increased in cerebral microvessels from aged compared to adult rats. Further, p67phox and gp91phox proteins were increased, but SOD‐1 protein was decreased, in cortex tissue of aged rats. Basal and agonist‐induced production of superoxide was elevated in aged rats.

Conclusions: Aging impairs eNOS‐dependent reactivity of cerebral arterioles via an increase in superoxide produced by activation of NAD(P)H oxidase.
Risk of Vancomycin-ResistantEnterococcus(VRE) Bloodstream Infection Among Patients Colonized With VRE
Authors: Olivier Chamion N. , Blake Ruth K. , Steed Lisa L. , Salgado Cassandra D.
Published: April 2008

Background.

Colonization with vancomycin-resistantEnterococcus(VRE) is a risk factor for subsequent VRE bloodstream infection (BSI); however, risk factors for BSI among colonized patients have not been adequately described. We sought to determine the proportion of VRE-colonized patients who subsequently develop VRE BSI and to identify risk factors for VRE BSI among these patients.

Methods.

Records of 768 patients colonized with VRE from January 2002 through June 2005 were reviewed. The proportion of patients who developed VRE BSI was calculated, and the characteristics of these patients were compared, in a 2 : 1 ratio, with those of patients who did not develop VRE BSI. To identify risk factors for VRE BSI and for death, we used univariate logistic regression analysis and then multivariate logistic regression analysis. Using pulsed-field gel electrophoresis (PFGE), we compared the isolate recovered when the patient was colonized and the isolate recovered when the patient developed VRE BSI.

Results.

Of the 768 patients colonized with VRE, 31 (4.0%) developed VRE BSI. Multivariate analysis identified the following idependent risk factors for developing VRE BSI: infection of an additional body site other than blood (adjusted odds ratio [aOR], 3.9;P= .04), admission to the hospital from a long-term care facility (aOR, 12.6;P= .04), and receipt of vancomycin (aOR, 10.6;P< .001). The independent risk factors for death among patients colonized with VRE were immunosuppression (aOR, 12.9;P= .001 ) and VRE BSI (aOR, 9.1;P= .002). Of the 31 patients who developed VRE BSI, 23 (74%) had a pair of isolates representing VRE colonization and VRE BSI. For 19 (83%) of these 23 patients, the isolate representing BSI was genetically related to the isolate representing VRE colonization: 12 pairs of isolates (52%) had identical banding patterns, 5 had closely related patterns, and 2 had possibly related patterns.

Conclusion.

Of the 768 patients colonized with VRE, 31 (4.0%) usually developed VRE BSI due to a related strain. Independent risk factors for BSI among colonized patients were admission from a long-term care facility, infection of an additional body site, and exposure to vancomycin. Independent risk factors for death were immunosuppression and VRE BSI.
The Role of GRASP55 in Golgi Fragmentation and Entry of Cells into Mitosis
Authors: Duran Juan Manuel , Kinseth Matt , Bossard Carine , Rose David W. , Polishchuk Roman , Wu Christine C. , Yates John , Zimmerman Timo , Malhotra Vivek
Published: April 2008

GRASP55 is a Golgi-associated protein, but its function at the Golgi remains unclear. Addition of full-length GRASP55, GRASP55-specific peptides, or an anti-GRASP55 antibody inhibited Golgi fragmentation by mitotic extracts in vitro, and entry of cells into mitosis. Phospho-peptide mapping of full-length GRASP55 revealed that threonine 225 and 249 were mitotically phosphorylated. Wild-type peptides containing T225 and T249 inhibited Golgi fragmentation and entry of cells into mitosis. Mutant peptides containing T225E and T249E, in contrast, did not affect Golgi fragmentation and entry into mitosis. These findings reveal a role of GRASP55 in events leading to Golgi fragmentation and the subsequent entry of cell into mitosis. Surprisingly, however, under our experimental conditions, >85% knockdown of GRASP55 did not affect the overall organization of Golgi organization in terms of cisternal stacking and lateral connections between stacks. Based on our findings we suggest that phosphorylation of GRASP55 at T225/T249 releases a bound component, which is phosphorylated and necessary for Golgi fragmentation. Thus, GRASP55 has no role in the organization of Golgi membranes per se, but it controls their fragmentation by regulating the release of a partner, which requires a G2-specific phosphorylation at T225/T249.
CompariMotif: quick and easy comparisons of sequence motifs
Authors: Edwards Richard J. , Davey Norman E. , Shields Denis C.
Published: March 2008

Summary: CompariMotif is a novel tool for making motif–motif comparisons, identifying and describing similarities between regular expression motifs. CompariMotif can identify a number of different relationships between motifs, including exact matches, variants of degenerate motifs and complex overlapping motifs. Motif relationships are scored using shared information content, allowing the best matches to be easily identified in large comparisons. Many input and search options are available, enabling a list of motifs to be compared to itself (to identify recurring motifs) or to datasets of known motifs.

Availability: CompariMotif can be run online at http://bioware.ucd.ie/ and is freely available for academic use as a set of open source Python modules under a GNU General Public License from http://bioinformatics.ucd.ie/shields/software/comparimotif/

Contact:  r.edwards@southampton.ac.uk

Supplementary information: Further details are available at http://bioinformatics.ucd.ie/shields/software/comparimotif/
Analysis of correlated mutations in HIV-1 protease using spectral clustering
Authors: Liu Ying , Eyal Eran , Bahar Ivet
Published: March 2008

Motivation: The ability of human immunodeficiency virus-1 (HIV-1) protease to develop mutations that confer multi-drug resistance (MDR) has been a major obstacle in designing rational therapies against HIV. Resistance is usually imparted by a cooperative mechanism that can be elucidated by a covariance analysis of sequence data. Identification of such correlated substitutions of amino acids may be obscured by evolutionary noise.

Results: HIV-1 protease sequences from patients subjected to different specific treatments (set 1), and from untreated patients (set 2) were subjected to sequence covariance analysis by evaluating the mutual information (MI) between all residue pairs. Spectral clustering of the resulting covariance matrices disclosed two distinctive clusters of correlated residues: the first, observed in set 1 but absent in set 2, contained residues involved in MDR acquisition; and the second, included those residues differentiated in the various HIV-1 protease subtypes, shortly referred to as the phylogenetic cluster. The MDR cluster occupies sites close to the central symmetry axis of the enzyme, which overlap with the global hinge region identified from coarse-grained normal-mode analysis of the enzyme structure. The phylogenetic cluster, on the other hand, occupies solvent-exposed and highly mobile regions. This study demonstrates (i) the possibility of distinguishing between the correlated substitutions resulting from neutral mutations and those induced by MDR upon appropriate clustering analysis of sequence covariance data and (ii) a connection between global dynamics and functional substitution of amino acids.

Contact:  bahar@ccbb.pitt.edu

Supplementary information: Supplementary data are available at Bioinformatics online.
Developing a beam trawl for sampling estuarine fish and crustaceans: assessment of a codend cover and effects of different sizes of mesh in the body and codend
Authors: Rotherham Douglas , Broadhurst Matt K. , Gray Charles A. , Johnson Daniel D.
Published: April 2008

Rotherham, D., Broadhurst, M. K., Gray, C. A., and Johnson, D. D. 2008. Developing a beam trawl for sampling estuarine fish and crustaceans: assessment of a codend cover and effects of different sizes of mesh in the body and codend. – ICES Journal of Marine Science, 65: 687–696. An experiment was carried out in the Clarence River (New South Wales, Australia) to test the hypotheses that fish and crustacean catches in an experimental beam trawl were affected by a codend cover and the sizes of mesh in the body and codend. The cover had no obvious effects on the catches retained in the codend. Similarly, in comparisons between trawl bodies made from 26- and 41-mm diamond-shaped mesh, there were no differences in the assemblages of fish caught, or in the mean numbers entering the codends. For one species of fish (Acanthopagrus australis), however, there were differences in the proportions caught between the trawl bodies across different size classes. There was also some evidence to suggest that mesh size in the body of the trawl influenced the size selection of school prawns (Metapenaeus macleayi). For most finfish, there were no differences in catches between codends made from 20-mm and from 29-mm mesh hung on the bar (i.e. square-shaped mesh). In contrast, mesh size in the codend was important for the size selectivity of school prawns, with smaller carapace lengths at 50% retention in the 20-mm codend. We conclude that use of a 41-mm mesh in the body and a 20-mm square mesh in the codend of the beam trawl would be appropriate for future sampling with this gear in estuaries of New South Wales. A similar experimental approach to ours is needed in adapting the beam trawl to estuaries in other parts of the world, or in developing other types of research trawl.
Nonrecurrent MECP2 duplications mediated by genomic architecture-driven DNA breaks and break-induced replication repair
Authors: Bauters Marijke , Van Esch Hilde , Friez Michael J. , Boespflug-Tanguy Odile , Zenker Martin , Vianna-Morgante Angela M. , Rosenberg Carla , Ignatius Jaakko , Raynaud Martine , Hollanders Karen , Govaerts Karen , Vandenreijt Kris , Niel Florence , Blanc Pierre , Stevenson Roger E. , Fryns Jean-Pierre , Marynen Peter , Schwartz Charles E. , Froyen Guy
Published: April 2008

Recurrent submicroscopic genomic copy number changes are the result of nonallelic homologous recombination (NAHR). Nonrecurrent aberrations, however, can result from different nonexclusive recombination-repair mechanisms. We previously described small microduplications at Xq28 containing MECP2 in four male patients with a severe neurological phenotype. Here, we report on the fine-mapping and breakpoint analysis of 16 unique microduplications. The size of the overlapping copy number changes varies between 0.3 and 2.3 Mb, and FISH analysis on three patients demonstrated a tandem orientation. Although eight of the 32 breakpoint regions coincide with low-copy repeats, none of the duplications are the result of NAHR. Bioinformatics analysis of the breakpoint regions demonstrated a 2.5-fold higher frequency of Alu interspersed repeats as compared with control regions, as well as a very high GC content (53%). Unexpectedly, we obtained the junction in only one patient by long-range PCR, which revealed nonhomologous end joining as the mechanism. Breakpoint analysis in two other patients by inverse PCR and subsequent array comparative genomic hybridization analysis demonstrated the presence of a second duplicated region more telomeric at Xq28, of which one copy was inserted in between the duplicated MECP2 regions. These data suggest a two-step mechanism in which part of Xq28 is first inserted near the MECP2 locus, followed by breakage-induced replication with strand invasion of the normal sister chromatid. Our results indicate that the mechanism by which copy number changes occur in regions with a complex genomic architecture can yield complex rearrangements.
Retrograde amnesia for visual memories after hippocampal damage in rats
Authors: Epp Jonathan , Keith Julian R. , Spanswick Simon C. , Stone Jared C. , Prusky Glen T. , Sutherland Robert J.
Published: April 2008

It is generally believed that the hippocampus is not required for simple discrimination learning. However, a small number of studies have shown that hippocampus damage impairs retention of a previously learned visual discrimination task. We propose that, although simple discrimination learning may proceed in the absence of the hippocampus, it plays an important role in this type of learning when it is intact. In order to test the role of the hippocampus in simple discrimination learning, we performed a series of experiments utilizing a two-choice picture discrimination task. Our experiments confirm that rats readily learn simple two-choice picture discriminations after hippocampus damage. However, if such discriminations are first learned while the hippocampus is intact, subsequent hippocampus damage causes severe retrograde amnesia for the discriminations. Furthermore, retrograde amnesia for simple picture discriminations was equally severe when the interval between training and damage was 1 d or 60 d; remote picture memories are not spared. Similarly, the rule or schema underlying a recently or remotely acquired picture discrimination learning set was lost after hippocampus damage. The severity of retrograde amnesia for simple picture discriminations is negatively correlated with the volume of spared hippocampus tissue. Thus, the hippocampus plays an essential role in long-term memories supporting simple picture discriminations.
AFLP‐based differentiation in north Atlantic species of Carex sect. Phacocystis
Authors: Nakamatte Esther , Arnstein Lye Kåre
Published: April 2008

A total of 59 plants from 30 populations of 15 species of Carex sect. Phacocystis (including Carex bicolor as outgroup) from eastern Canada and northern Europe were investigated for genetic differentiation of taxa using AFLP. Seven species were studied with material from both Europe and America, three species were investigated with North American material only and five species with European material only. The neighbour joining analysis (NJ) indicates that Carex bicolor may not belong to section Phacocystis, while all other investigated species clearly belong to this section. The sorting of the species according to NJ and UPGMA is mostly in accordance with accepted taxonomy, but with the exceptions that the American C. bigelowii ssp. bigelowii may be specifically distinct from European C. bigelowii ssp. rigida, and C. stans should perhaps not be considered a subspecies or variety of C. aquatilis, but either as a separate species or as a hybrid between C.aquatilis and C. bigelowii. North American C. aquatilis is heterogenic and may contain more than one species.
The evaluation of tailored and web‐based information for new fathers
Authors: Fletcher R. , Vimpani G. , Russell G. , Keatinge D.
Published: April 2008

Background  Information and advice on infant health and development have been shown to be well received by new parents and to lead to more confident and nurturing parenting. However, in spite of the accumulating evidence highlighting the importance of fathers to the well‐being of their families, fathers rarely access and utilize ‘parenting’ information. Tailored information for fathers delivered via email and Internet may provide an alternate route for support for fathers. This study aimed to assess father's readiness to utilize electronic information tailored to father's role.

Methods  Two hundred and fifty‐three fathers from antenatal classes in two Australian cities were offered email and web‐based information on seven topics: baby play, breastfeeding, post‐natal depression, father–infant bonding, sex after birth, work–family balance and fussy babies. Of 137 who completed consent forms, a total of 105 fathers selected three topics and 67 fathers provided 149 topic evaluations.

Results  Most respondents were from managerial, professional or skilled occupations and had higher educational qualifications than the general population of fathers. The most popular topics were those that related to father–infant interaction (baby games and father–infant bonding), and the least popular were breastfeeding and sex after the birth. Respondents rated the information as satisfactory and most (78%) indicated that it changed their approach to fathering. Although the websites provided were available through the Internet, few fathers had previously accessed them.

Conclusions  Information tailored to new father's perspectives provided through email or Internet may increase new fathers' access to useful knowledge and support. Important health topics such as breastfeeding may not currently be perceived as particularly relevant to fathers in the antenatal period. Portals designed to filter existing websites could facilitate the use of parenting information by new fathers.
Updated growth curves for Turkish children aged 15 days to 60 months
Authors: Gökçay G. , Furman A. , Neyzi O.
Published: April 2008

Background  Growth reference values are useful in paediatric health care as a health indicator. Secular changes in height for age values are also known to affect the timing of puberty and brain weight. Different populations may be at different stages of this secular trend. It is, therefore, necessary to periodically update the growth reference values for each population to identify these changes. The aim of this study was to update the growth reference values for Turkish infants and young children.

Methods  Background information and height/length, weight and head circumference measurements on a sample of 2391 boys and 2102 girls were obtained from Well Child Clinic Records. The LMS method was used for the analyses. The percentage of exclusive breastfeeding was 62% at 4 months and 26.6% at 6 months. The continuation rate of breastfeeding at 12 months was 62.5%.

Results  Comparison with previous Turkish data showed an increase in height of 0.9 cm for boys and 1.1 cm for girls at age 5 years. The increase in weight was 0.220 kg in girls, while a decrease of 0.160 kg was noted in boys. Comparison with the 2000 US and Swedish values indicated that population differences may exist in pre‐pubertal years.

Conclusion  This study provides an enhanced instrument to evaluate the growth of Turkish infants and young children.