bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a High Tip Speed Ratio H-Darrieus in the Skewed Flow on a Roof
Authors: Mertens Sander , van Kuik Gijs , van Bussel Gerard
Published: February 2009

Small wind turbines sited on a flat roof have good opportunities to become widespread. They operate in the accelerated wind above the roof and deliver the power where it is needed. Since the power produced offsets that which would otherwise be bought from the utility, they reduce energy demand and bills from the utility. Furthermore excess power can be sold back to the utility, thus producing income as well. Flow over a building separates at the roof leading edge at a certain angle. Wind turbines sited well above the roof thus operate in skewed flow. H-Darrieus operating at (flat) roofs just recently start to be at public interest, operation of an H-Darrieus in skewed flow is thus not discussed in literature until now. To examine this, a model of an H-Darrieus with high Tip Speed Ratio (λ) in skewed flow is developed. The model is based on multiple stream-tube theory: a combination of axial momentum and blade element theory on an actuator plate representation of the rotor, which is divided into multiple stream-tubes. The model shows that, for an H-Darrieus designed for skewed flow, the optimal power output in skewed flow can be up to two times the power output in normal - perpendicular to the H-Darrieus axis- flow. The spatial dimension of the H-Darrieus is responsible for this.
Wind Energy and the Hydrogen Economy
Authors: Sherif S. A. , Barbir F. , Veziroglu T. N.
Published: February 2009

The hydrogen economy is an inevitable energy system of the future where the available energy sources (preferably the renewable ones) will be used to generate hydrogen and electricity as energy carriers, which are capable of satisfying all the energy needs of human civilization. The transition to a hydrogen economy may have already begun. This paper presents a review of hydrogen energy technologies, namely technologies for hydrogen production, storage, distribution, and utilization. Possibilities for utilization of wind energy to generate hydrogen are discussed in parallel with possibilities to use hydrogen to enhance wind power competitiveness.
Quantification of Processing Parameters for Wind Turbine Blades
Authors: Cairns Douglas , Mandell John , Samborsky Daniel
Published: February 2009

All materials have an influence from the processing parameters for structural performance, but composite materials have a much more intimate materials/processing/structural performance connection due to their macroscopic inhomogeneities. In this paper, a link is provided between processing paramers, material architecture, and mechanical performance for various material architectures. In particular, a simple formula is provided to understand the fiber volume of a given part. This fiber volume is then linked with the fatigue performance. These data are indicative of the influence of processing pressures on laminate fiber volumes, independent of processing techniques and can be useful to wind turbine blade manufacturers to prepare processing conditions, a priori, to minimize expensive trial and error manufacturing development.
Inflow and Fatigue Response of the NWTC Advanced Research Turbine
Authors: Sutherland Herbert J. , Kelley Neil D. , Hand M. Maureen
Published: February 2009

The Long-term Inflow and Structural Test (LIST) program is collecting long-term inflow and structural response data to characterize the spectrum of loads on wind turbines. In one of the measurement campaigns being conducted under this program, the 42-m diameter, 600-kW NWTC Advanced Research Turbine (ART) was monitored. The turbine is an upwind, two-bladed teetered-hub machine. It has full span pitch control and a synchronous generator. The inflow was monitored with a planar array of five high-resolution sonic anemometers and supporting meteorological instrumentation located 1.5 diameters upwind of the turbine. The structural response of the turbine was measured using strain gauge circuits and an inertial measurement unit (IMU). The former were used to monitor root bending moments and the low-speed shaft torque, while the latter was used to monitor the motion of the tower and the nacelle. Auxiliary gauges measured blade pitch, rotor teeter, nacelle yaw and generator power. A total of 3299 10-minute records were collected for analysis. From this set, 1044 records are used to examine the influence of various inflow parameters on fatigue loads. Long-term fatigue loads and extreme loads are also examined.
Wind Shear and Turbulence Effects on Rotor Fatigue and Loads Control
Authors: Eggers A. J. , Digumarthi R. , Chaney K.
Published: February 2009

The effects of wind shear and turbulence on rotor fatigue and loads control are explored for a large horizontal axis wind turbine in variable speed operation from 4 to 20 m/s. Two and three blade rigid rotors are considered over a range of wind shear exponents up to 1.25 and a range of turbulence intensities up to 17%. RMS blade root flatwise moments are predicted to be very substantially increased at higher wind shear, and resultant fatigue damage is increased by many orders of magnitude. Smaller but similar trends occur with increasing turbulence levels. In-plane fatigue damage is driven by 1P gravity loads and exacerbated by turbulence level at higher wind speeds. This damage is higher by one to two orders of magnitude at the roots of the three blade rotor. Individual blade pitch control of fluctuating flatwise moments markedly reduces flatwise fatigue damage due to this source, and to a lesser degree the in-plane damage due to turbulence. The same is true of fluctuating rotor torque moments driven by turbulence and transmitted to the drive train. Blade root moments out of the plane of rotation aggregate to create rotor pitching and yawing moments transmitted to the turbine structure through the drive train to the yaw drive system and the tower. These moments are predicted to be relatively insensitive to turbulence level and essentially proportional to the wind shear exponent for the two blade rotor. Fluctuating moments are substantially reduced with individual blade pitch control, and addition of a teeter degree of freedom should further contribute to this end. Fluctuating pitching and yawing moments of the three blade rotor are substantially less sensitive to wind shear, more sensitive to turbulence level, and substantially lower than those for the two blade rotor. Mean rotor torque and hence power are essentially the same for both rotors, independent of wind shear, and somewhat reduced with individual blade pitch control of fluctuating flatwise moments. The same is true of mean rotor thrust, however fluctuations in rotor thrust are substantially reduced with individual blade pitch control. It appears, on balance, that higher wind shear coupled with turbulence effects should be accounted for in the fatigue design of large, long life turbines. Much more work is required on this problem.
An Assessment of Approximate Modeling of Aerodynamic Loads on the UAE Rotor
Authors: Eggers A. J. , Chaney K. , Digumarthi R.
Published: February 2009

This assessment of approximate modeling of aerodynamic loads on the UAE rotor indicates that it can be reasonably accurate when it is based on reliable 2D wind tunnel data, and when flow about the rotor blades is unstalled. This includes loads which figure importantly in the yawing of smaller wind turbines out of higher winds to minimize overshoots in power and loads. A welcome but by no means obvious finding is that the assumption of locally two dimensional flow about substantially yawed rotor blades appears to be reasonably valid even in the presence of the complex induction field due to the skewed wake effects. Dynamic stall, expanding skewed wake effects, and effects due to vortices shed inboard into the wake where the onset of deep stalled flow occurs must be accounted for to better predict side force and center of thrust location on the rotor. Rotational effects on rotor thrust, torque, and blade out-of-plane moments must be accounted for in deep stalled flow as it spreads outboard on the blades at higher wind speeds. These effects appear to be more severe at smaller rotor yaw angles, and lower tip speed ratios. Approximate modeling of these effects at zero yaw appears to be improved with the approach to and onset of fully deep stalled flow about the blades when blade aspect ratio and shape effects on non rotating section aerodynamic characteristics are included in the modeling. This matter requires substantial further study.
Structure dependence of epitaxial Pr2O3∕Si(001) on oxygen pressure during growth
Authors: Watahiki Tatsuro , Braun Wolfgang , Riechert Henning
Published: February 2009

The authors study the structure dependence of epitaxial Pr2O3 layers on Si(001) on the partial pressure of oxygen during growth using reflection high-energy electron diffraction and x-ray reflectivity. The oxygen is necessary to suppress the formation of silicide, but it also inhibits the nucleation of the crystalline oxide phase. High oxygen partial pressure during growth causes the layers to be polycrystalline or even amorphous with hexagonal contributions. It also increases silicate formation at the interface between oxide layer and Si substrate. Thus, control of oxygen during growth is very important to obtain high quality epitaxial Pr2O3 layers on Si.
Development of a vacuum packaged nanodiamond lateral field emission device
Authors: Subramanian K. , Schroeder R. , Kang W. P. , Davidson J. L.
Published: February 2009

The authors report the development of a monolithic diamond field emission device in lateral configuration operating in a vacuum package. Nanocrystalline diamond is applied in the microfabrication of planar lateral emitter diodes on a silicon-on-insulator substrate. A feasible packaging process has been developed for the device, where the diodes are die attached, wire bonded, and vacuum sealed in a cavity package. Field emission characterization measurements performed on the packaged diamond lateral vacuum devices indicate a practical construct and package for vacuum micro/nanoelectronic applications.
Electrical properties of nanotip-assisted microplasma devices
Authors: Kim Sung-O. , Ko Yang-Suk , Gu Hal-Bon
Published: February 2009

Nanotip-assisted microplasma devices have been fabricated and characterized in Ne, Ar, or Ne/2% Ar. The electrical properties of the glow discharge in three different environments, Ne, Ar, and Ne/2% Ar, have been examined with direct current (dc) bipolar-pulsed waveforms with frequencies from 2to20kHz at pressures from 300to800torr. The operating voltage of the nanotip-assisted microplasma devices was decreased around 10–20V compared with devices without a nanotip electrode. The 6×1cm panel-type microplasma device with nanotip electrodes revealed low discharge voltages around 300V.
Study of metal oxide-semiconductor capacitors with rf magnetron sputtering TiOx and TiOxNy gate dielectric layer
Authors: Albertin K. F. , Pereyra I.
Published: February 2009

Metal oxide-semiconductor capacitors with TiOx deposited with different O2 partial pressures (30%, 35%, and 40%) and annealed at 550, 750, and 1000°C were fabricated and characterized. Fourier transform infrared, x-ray near edge spectroscopy, and elipsometry measurements were performed to characterize the TiOx films. TiOxNy films were also obtained by adding nitrogen to the gaseous mixture and physical results were presented. Capacitance-voltage (1MHz) and current-voltage measurements were utilized to obtain the effective dielectric constant, effective oxide thickness, leakage current density, and interface quality. The results show that the obtained TiOx films present a dielectric constant varying from 40 to 170 and a leakage current density (for VG=−1V, for some structures as low as 1nA∕cm2, acceptable for complementary metal oxide semiconductor circuits fabrication), indicating that this material is a viable, in terms of leakage current density, highk substitute for current ultrathin dielectric layers.
Interface dependent electrical properties of amorphous InGaZnO4 thin film transistors
Authors: Lim Wantae , Jang Jung Hun , Kim S.-H. , Norton D. P. , Craciun V. , Pearton S. J. , Ren F. , Chen H.
Published: February 2009

The performance of amorphous InGaZnO4 thin film transistors with three different gate dielectrics (SiO2, SiON, and SiNx) is reported. The gate dielectric films were prepared by plasma enhanced chemical vapor deposition with SiH4, N2O, and NH3 gases at 250°C. Current-voltage (C-V) and refractive index characterization showed that different film compositions were achieved when changing the flow rate of N2O in the precursor gas mixture. The use of SiNx films reduced the interfacial roughness of the channel/gate dielectric by a factor of 2.3 compared to SiO2. This results in an improvement of saturation mobility of the thin film transistors (TFTs) by a similar factor. An enhancement of subthreshold gate-voltage swing and drain current on-to-off ratio for TFTs with SiNx was also attributed to the reduction of the trap density at the channel/gate-dielectric interface.
Effect of annealing and electrical properties of high-κ thin films grown by atomic layer deposition using carboxylic acids as oxygen source
Authors: Rauwel E. , Ducroquet F. , Rauwel P. , Willinger M.-G. , Matko I. , Pinna N.
Published: February 2009

Titania and hafnia thin films were deposited by atomic layer deposition using metal alkoxides and carboxylic acids as oxygen source. The effect of annealing under nitrogen on the densification of the films and on the resulting electrical properties is presented. The as-deposited and annealed films demonstrate good dielectric permittivity and low leakage current densities due to their purity and amorphous character.
Computational and experimental studies of phase separation in pentacene:C60 mixtures
Authors: Zheng Ying , Pregler Sharon K. , Myers Jason D. , Ouyang Jiaomin , Sinnott Susan B. , Xue Jiangeng
Published: February 2009

Phase separation in molecular donor-acceptor mixtures composed of pentacene and C60 is examined using a combination of computational and experimental methods. Classical molecular dynamics simulations of the relaxation process of pentacene:C60 mixtures predict the formation of pentacene stacks and C60 clusters in the equilibrated structures. These findings are consistent with experimental observations, where x-ray diffraction and atomic force microscopy characterization of the mixed films confirm the existence of polycrystalline pentacene domains. The scanning electron and atomic force micrographs of mixed films deposited at different rates as well as with various mixing ratios show that the aggregation of pentacene, and therefore the degree of phase separation in the mixtures, can be manipulated by the processing conditions. Finally, bulk heterojunction photovoltaic devices using different pentacene:C60 mixtures as an active layer are fabricated and their photovoltaic performance characteristics are compared. It is found that the device with 1:5.5 (by weight) mixing ratio of pentacene:C60 shows nearly 400 times higher power conversion efficiency than the 1:1 device due to successful control of nanoscale phase separation that leads to better exciton diffusion and charge collection.
Bar workers’ health and environmental tobacco smoke exposure (BHETSE): symptomatic improvement in bar staff following smoke-free legislation in Scotland
Authors: Ayres J G , Semple S , MacCalman L , Dempsey S , Hilton S , Hurley J F , Miller B G , Naji A , Petticrew M
Published: February 2009

Objective:

To examine changes in the health of bar workers after smoke-free legislation was introduced.

Design:

Longitudinal study following bar workers from before legislation introduction, at 2 months after introduction and at 1 year to control for seasonal differences.

Setting:

Bars across a range of socio-economic settings in Scotland.

Participants:

371 bar workers recruited from 72 bars.

Intervention:

Introduction of smoke-free legislation prohibiting smoking in enclosed public places, including bars.

Main outcomes measures:

Change in prevalence of self-reported respiratory and sensory symptoms.

Results:

Of the 191 (51%) workers seen at 1-year follow-up, the percentage reporting any respiratory symptom fell from 69% to 57% (p = 0.02) and for sensory symptoms from 75% to 64% (p = 0.02) following reductions in exposure, effects being greater at 2 months, probably partly due to seasonal effects. Excluding respondents who reported having a cold at either baseline or 1 year, the reduction in respiratory symptoms was similar although greater for “any” sensory symptom (69% falling to 54%, p = 0.011). For non-smokers (n = 57) the reductions in reported symptoms were significant for phlegm production (32% to 14%, p = 0.011) and red/irritated eyes (44% to 18%, p = 0.001). Wheeze (48% to 31%, p = 0.006) and breathlessness (42% to 29%, p = 0.038) improved significantly in smokers. There was no relationship between change in salivary cotinine levels and change in symptoms.

Conclusions:

Bar workers in Scotland reported significantly fewer respiratory and sensory symptoms 1 year after their working environment became smoke free. As these improvements, controlled for seasonal variations, were seen in both non-smokers and smokers, smoke-free working environments may have potentially important benefits even for smokers.
Rotationally Corrected Equilibrium Tide Theory
Authors: Michelson Irving
Published: February 2009

Corrections to the classical tidal free-surface configuration are obtained for two cases of combined rotation and orbital translation. Lord Kelvin's calculation for rotation parallel to and commensurable with orbital revolution is presented in terms of an appropriate acceleration potential. Extension to fast rotation and inclined axes of rotation and orbital motion, based on Chasles' Theorem and more closely approximating the case of the Earth, follows in the same manner. In both cases the corrections to diurnal and to semi-diurnal tides vanish when the orbital plane of the disturbing body is contained within the Earth's equatorial plane, but the corrections are large for inclination values corresponding to actual Moon and Sun. Results in sharp contrast with the older theory in respect to amplitudes and phases are generally in better qualitative agreement with observations. The corrected theory should provide a more acceptable basis for the dynamical theory of ocean tides and also prove serviceable in allied studies of Earth physics, astronomy, and cosmogony.The dominant correction term in the fast-rotation tidal model is a spherical harmonic of the first degree, for which no counterpart exists in the standard tide theory. As this is of the same form precisely as the recently observed offset core of the Moon, tidal mechanics affords a new hypothesis to explain the latter phenomenon.
Regional Jointing in Southern Alberta
Authors: Babcock Elkanah A.
Published: February 2009

Regional joints in southern Alberta form patterns that persist over an area extending from the Rocky Mountain Foothills to the Saskatchewan border. These patterns persist vertically through a section of rocks ranging in age from Late Cretaceous to Late Paleocene.The basic unit of jointing is an orthogonal system consisting of two sets of extension fractures. Two or more orthogonal systems may be present at a given locality creating a complex pattern of joints. System I predominates and has sets trending approximately 65 °and 155°, or roughly normal and parallel to the Rocky Mountains. System II joints trend approximately 5 °and 95°, but swing about 15 °clockwise in the Drumheller area. A system having sets trending 45 °and 135 °is present near Medicine Hat.System I joints roughly parallel intermediate width (32-64 km) subsurface structural undulations described by Robinson et al. (1969). System II joints trend parallel and normal to the crest of the Sweet-grass Arch. Further study is needed to determine the age and origin of jointing.Regional joints in southern Alberta show similarities with regional joints in similar structural settings on the Appalachian Plateau and on the Central Oklahoma Plains. Within these areas orthogonal systems of regional joints trend normal and parallel to the adjacent fold belt over vast areas and through great thicknesses of sedimentary rock.
Jointing in Central Alberta
Authors: Babcock Elkanah A.
Published: February 2009

Two orthogonal joint systems were mapped in the central Alberta plains. These are made up of sets striking approximately 55 and 140 degrees (roughly normal and parallel to the Rocky Mountains) and approximately 5 and 95 degrees. These systems are a continuation of systems mapped in southern Alberta (Babcock 1973). The set orientations persist across lithologic and stratigraphic boundaries. Jointing is attributed to extension fracturing with sets normal and parallel to the Rocky Mountains probably controlled by Laramide orogenic stresses; however, a parallelism between subsurface structural undulations (Robinson et al. 1969) and joints is noted.
STUDY OF SUPERCONDUCTING STATE PARAMETERS OF TRANSITION METALS BINARY ALLOYS BY A PSEUDOPOTENTIAL APPROACH
Authors: VORA ADITYA M.
Published: February 2009

In the present article, we have reported the theoretical study of the superconducting state parameters (SSP) viz. electron–phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature TC, isotope effect exponent α and effective interaction strength N0V of a 3d-transition metal-based binary alloys using Ashcroft's empty core (EMC) model potential. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used in the present investigation to study the screening influence on the aforesaid properties. A considerable influence of various exchange and correlation functions on λ and μ* is found from the present study. The present results of the SSP are found in qualitative agreement with the available experimental data wherever they exist.
A SIMPLE METHOD TO CONSTRUCT INTEGRABLE COUPLING SYSTEM FOR THE MKdV EQUATION HIERARCHY
Authors: YU FAJUN
Published: February 2009

In this paper, we will extend Ma's method to construct the integrable couplings of soliton equation hierarchy with the Kronecker product and two-nilpotent matrix. A direct application to the MKdV spectral problem leads to a novel integrable coupling system of soliton equation hierarchy. It is shown that the study of integrable couplings using the Kronecker product is an efficient and straightforward method.
IMPROVING SOFTWARE RELIABILITY MODELING USING MACHINE LEARNING TECHNIQUES
Authors: ZOU FENGZHONG , DAVIS JOSEPH
Published: February 2009

It is well-known that software failure data often contain noise, making the reliability estimation problematic. In particular, the kind of data noise inherent in software failure data is biased. There is no upper bound for the value of a noisy data point, but there is a lower bound of zero. This may lead to over-optimistic estimation of the reliability when using maximum likelihood or least square methods based on standard software reliability models. We attempt to address this problem by modeling software failure data using machine learning techniques such as support vector machine regression and generalized additive models, which have mechanisms that are capable of dealing with data noise. We then analyse the results from machine learning modeling, and compare them to that of some generalized linear modeling techniques that are equivalent to standard software reliability models. The validity of the machine learning modeling of noisy software failure data is evaluated through this comparison.
Glucagon-mediated impairments in hepatic and peripheral tissue nutrient disposal are not aggravated by increased lipid availability
Authors: Chen Sheng-Song , Santomango Tammy S. , Williams Phillip E. , Lacy D. Brooks , McGuinness Owen P.
Published: February 2009

Glucose, fat, and glucagon availability are increased in diabetes. The normal response of the liver to chronic increases in glucose availability is to adapt to become a marked consumer of glucose. Yet this fails to occur in diabetes. The aim was to determine whether increased glucagon and lipid interact to impair the adaptation to increased glucose availability. Chronically catheterized well controlled depancreatized conscious dogs ( n = 21) received 3 days of continuous parenteral nutrition (TPN) that was either high in glucose [C; 75% nonprotein calories (NPC)] or in lipid (HL; 75% NPC) in the presence or absence of a low dose (one-third basal) chronic intraportal infusion of glucagon (GN; 0.25 ng·kg−1·min−1). During the 3 days of TPN, all groups received the same insulin algorithm; the total amount of glucose infused (GIR) was varied to maintain isoglycemia (∼120 mg/dl). On day 3 of TPN, hepatic metabolism was assessed. Glucose and insulin levels were similar in all groups. GIR was decreased in HL and C + GN (∼30%) and was further decreased in HL + GN (55%). Net hepatic glucose uptake was decreased ∼15% in C + GN, and HL and was decreased ∼50% in HL + GN. Lipid alone or combined with glucagon decreased glucose uptake by peripheral tissues. Despite impairing whole body glucose utilization, HL did not limit whole body energy disposal. In contrast, glucagon suppressed whole body energy disposal irrespective of the diet composition. In summary, failure to appropriately suppress glucagon secretion adds to the dietary fat-induced impairment in both hepatic and peripheral glucose disposal. In addition, unlike increasing the percentage of calories as fat, inappropriate glucagon secretion in the absence of compensatory hyperinsulinemia limits whole body nutrient disposition.
The effect of microdialysis needle trauma on cutaneous vascular responses in humans
Authors: Hodges Gary J. , Chiu Caroline , Kosiba Wojciech A. , Zhao Kun , Johnson John M.
Published: February 2009

Microdialysis enables in-depth mechanistic study of the cutaneous circulation in humans. However, whether the insertion or presence of the microdialysis fiber (MDF) affects the skin circulation or its responses is unknown. We tested whether the cutaneous vascular response to whole body heating (WBH) was affected by MDF or by pretreatment with ice ( part 1) or local anesthesia (LA; part 2). Eleven subjects participated, 9 in part 1 and 8 in part 2 (5 participated in both). In both parts, four sites on the forearm were selected, providing untreated control, MDF only, ice or LA only, and combined MDF plus ice or LA. A tube-lined suit controlled whole body skin temperature, which was raised to ∼38°C for WBH. Skin sites were instrumented with laser-Doppler flow probes. Data were expressed as cutaneous vascular conductance (CVC). Baseline levels were not different among sites ( P > 0.05). In part 1, the internal temperature for the onset of vasodilation was higher ( P > 0.05) with MDF with or without ice pretreatment than at untreated control sites (control 36.6 ± 0.1°C, Ice 36.5 ± 0.1, MDF 36.8 ± 0.1°C, and Ice+MDF 36.8 ± 0.1°C). Peak CVC during WBH was decreased ( P < 0.05) by MDF (control 73 ± 7 vs. MDF 59 ± 6% of maximal CVC). Ice (73 ± 6% of maximal CVC) or Ice+MDF (69 ± 6% of maximal CVC) did not affect ( P > 0.05) peak CVC compared with control. In part 2, the temperature threshold for the onset of vasodilation was increased by MDF with or without LA treatment and by LA alone ( P < 0.05; control 36.6 ± 0.1°C, MDF 36.7 ± 0.1°C, LA 36.8 ± 0.1°C, and LA+MDF 36.8 ± 0.1°C). Peak CVC was decreased by MDF (control 69 ± 6% of maximal CVC vs. MDF 58 ± 8% of maximal CVC; P < 0.05). LA only (65 ± 10% of maximal CVC) or MDF in the presence of LA (73 ± 12% of maximal CVC) did not affect ( P > 0.05) peak CVC compared with control. Thus LA or MDF increases the temperature threshold for the onset of vasodilation. MDF alone decreases the peak vasodilator response in CVC to WBH; however, this attenuation did not occur if ice or LA is used before MDF placement. Ice or LA alone do not affect the peak response in CVC to WBH. How those treatments prevent or reverse the effect of MDF placement is presently unclear.
Expression of Epidermal Growth Factor Receptor or ErbB3 Facilitates Geldanamycin-Induced Down-Regulation of ErbB2
Authors: Pedersen Nina Marie , Breen Kamilla , Rødland Marianne Skeie , Haslekås Camilla , Stang Espen , Madshus Inger Helene
Published: February 2009

Overexpression of the epidermal growth factor receptor (EGFR), ErbB2, and ErbB3 promotes growth and antiapoptotic signaling. Overexpression of ErbB2 in breast cancer is associated with poor clinical outcome, and ways of down-regulating ErbB2 are important as therapeutic approaches. In contrast to EGFR, ErbB2 has been shown to be endocytosis deficient. However, down-regulation of ErbB2 can be induced by incubation of cells with geldanamycin and geldanamycin derivatives, counteracting the stabilizing function of heat shock protein 90 on ErbB2. In the present study, we have made use of stably transfected isogenic cell lines expressing ErbB2 only or ErbB2 together with EGFR and/or ErbB3. We now show that whereas ErbB2 can be down-regulated by incubation with geldanamycin in cells expressing ErbB2 only, the rate of geldanamycin-induced down-regulation increases significantly when the cells additionally express EGFR and/or ErbB3. This increase does, however, not correlate with activation/phosphorylation of ErbB2. The potential of heterodimer formation in ErbB2-positive breast cancer cells could thus turn out to be prognostically predictive with respect to outcome of treatment with geldanamycin derivatives. (Mol Cancer Res 2009;7(2):275–84)
Genetic Variation in Toll-Like Receptor Signalling and the Risk of Inflammatory and Immune Diseases
Authors: Corr Sinead C. , O’Neill Luke A.
Published: February 2009

There has been growing interest in the role of host genetic factors in humans and susceptibility to infectious and inflammatory diseases. Genetic variation in Toll-like receptors (TLRs), key innate immune receptors or their signalling molecules, have been described. Variation in certain TLRs has been linked to disease susceptibility. This genetic variation can result in an altered immune response to pathogenic challenge as well as exorbitant immune activation and inflammation, and thus may influence the pathogenesis or outcome of disease. Examples include variants of TLR4 in sepsis, malaria, inflammatory bowel disease and atherosclerosis; variants in TLR2 in tuberculosis and asthma; a variant in Mal (a key signal for TLR2 and TLR4) in malaria, tuberculosis and systemic lupus erythematosus; and variants in the kinase IRAK4 in pyogenic infections. These associations provide us with a validation for the role of TLRs in human disease, and also suggest possible strategies to limit or boost TLR function in the effort to develop new therapies.
Yield of Genetic Screening in Inherited Cardiac Channelopathies
Authors: Bai Rong , Napolitano Carlo , Bloise Raffaella , Monteforte Nicola , Priori Silvia G.
Published: February 2009

Background—

Identification of mutations in cardiac ion channel genes concurs to the diagnosis of long-QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. However, because availability of genetic screening is still limited and reimbursement policies are lacking, there is a need of evidence-based criteria to prioritize access to genetic testing for these diseases.

Methods and Results—

We determined the yield of genetic testing and cost per positive genotyping in 1394 consecutive probands. Among the 546 patients referred for long-QT syndrome-genes screening, those with clinical diagnosis of long-QT syndrome had the highest yield (64%) and lowest cost (US $8418) for each positive genotyping. Among 798 individuals screened for mutation on the
SCN5A
gene, the highest yield was obtained in patients with type 1 Brugada syndrome ECG pattern (51 of 405; 13%) corresponding to a cost of US $21441 per positive genotyping. In conclusive Brugada syndrome patients the presence of atrioventricular block (odds ratio: 3.3, CI: 1.8 to 6.1;
P
=0.0001) increases the yield (23%) of genotyping and reduces its cost (US $ 11700). Among 175 patients screened on
RyR2
gene, those with documented bidirectional ventricular tachycardia had the highest incidence (62%) of mutations and the lowest cost (US $5263) per positive genotyping. Genetic screening of unselected family members of sudden cardiac death victims and idiopathic ventricular fibrillation survivors is largely ineffective (yield of 9%) and costly (US $71430 per 1 positive genotyping).

Conclusions—

Genotyping can be performed at reasonable cost in individuals with conclusive diagnosis of long-QT syndrome and catecholaminergic polymorphic ventricular tachycardia, and in patients with type I Brugada syndrome ECG with atrioventricular block. These patients should be given priority to access genetic testing.
A Printed Muslim “Lighthouse” in Cairo al-Manār's Early Years, Religious Aspiration and Reception (1898-1903)
Authors: Ryad Umar
Published: February 2009

On the basis of fresh documents the article tried to reconstruct a historical description of the establishment of the most well-known reformist magazine al-Manār. The personal papers of its founder Muhammad Rašīd Ridā uncover new information about the background of his journalistic plans and religious aspirations after his arrival in Egypt in 1897. The paper reconsiders Ridā's early religious formation and apprenticeship in his homeland Syria; his position in the printing press in Egypt; the early funding of his magazine; his early integration in the Egyptian life; the early circulation of al-Manār; and his perspectives on the craft of printing in serving religious sciences.
Scanning electron microscope study on the egg chorion of silkmoth, Antheraea assamensis Helf. (Lepidoptera : Saturniidae)
Authors: Kumar Vineet , Kamble Chandrakant
Published: February 2009

The eggshell of Antheraea assamensis Helf. has a highly decorated chorion and its micropylar apparatus is situated at the cephalic end. Scanning electron microscopic investigation on the eggshells of A. assamensis reveals distinct patterns of structural elements viz., central cavity, micropylar rosette encircled the central cavity, and the aeropyles. The micropylar structures are at the anterior pole of the oval shaped eggs opposite to its side of distal pole. Centrally located central cavity leads into eight micropylar openings which further radiate down to the eight micropylar canals. The central cavity (5.28±0.21 μm in diameter) is encircled by a primary rosette of 16-18 cell imprints and each primary cell imprint measured 21.08±3.13 μm in length. The primary petal shaped cell imprints are followed by secondary and tertiary rows of cell imprints. Except the central cavity and micropylar rosette, the entire surface of the chorion is marked by a circular shell imprints which are boarded by aeropyles. Each cell imprint has 4-6 aeropyles and each aeropyle measured 1.06±0.01 μm in diameter. The aeropyles of A. assamensis are covered with a cup shaped like structures and the terminals of these structure has many finger like projections which may help to check the entry of pathogens or dust particles while taking the oxygen from the outside environment to the oocyte.
Features predicting the success of computerized decision support for prescribing: a systematic review of randomized controlled trials
Authors: Mollon Brent , Chong Jaron JR , Holbrook Anne M , Sung Melani , Thabane Lehana , Foster Gary
Published: February 2009

Background

Computerized decision support systems (CDSS) are believed to have the potential to improve the quality of health care delivery, although results from high quality studies have been mixed. We conducted a systematic review to evaluate whether certain features of prescribing decision support systems (RxCDSS) predict successful implementation, change in provider behaviour, and change in patient outcomes.

Methods

A literature search of Medline, EMBASE, CINAHL and INSPEC databases (earliest entry to June 2008) was conducted to identify randomized controlled trials involving RxCDSS. Each citation was independently assessed by two reviewers for outcomes and 28 predefined system features. Statistical analysis of associations between system features and success of outcomes was planned.

Results

Of 4534 citations returned by the search, 41 met the inclusion criteria. Of these, 37 reported successful system implementations, 25 reported success at changing health care provider behaviour, and 5 noted improvements in patient outcomes. A mean of 17 features per study were mentioned. The statistical analysis could not be completed due primarily to the small number of studies and lack of diversity of outcomes. Descriptive analysis did not confirm any feature to be more prevalent in successful trials relative to unsuccessful ones for implementation, provider behaviour or patient outcomes.

Conclusion

While RxCDSSs have the potential to change health care provider behaviour, very few high quality studies show improvement in patient outcomes. Furthermore, the features of the RxCDSS associated with success (or failure) are poorly described, thus making it difficult for system design and implementation to improve.
Intradural squamous cell carcinoma in the sacrum
Authors: Fukushima Tatsuki , Kasai Yuichi , Kato Ko , Fujisawa Kozo , Uchida Atsumasa
Published: February 2009

Background

Leptomeningeal carcinomatosis occurs in patients with cancer at the rate of approximately 5%; it develops particularly in patients with breast cancer, lung cancer, melanoma, leukemia, or malignant lymphoma. We describe a rare case of leptomeningeal carcinomatosis in which spinal intradural squamous cell carcinoma with no lesions in the cerebral meninges and leptomeninx, was the primary lesion.

Methods

A 64-year-old man complained of sacral pain. Although the patient was treated with analgesics, epidural block and nerve root block, sacral pain persisted. Since acute urinary retention occurred, he was operated on. The patient was diagnosed as having an intradural squamous cell carcinoma of unknown origin.

Results

Since the patient presented with a slightly decreased level of consciousness 2 months after surgery, he was subjected to MRI scanning of the brain and spinal cord, which revealed disseminated lesions in the medulla oblongata. The patient died of pneumonia and sepsis caused by methicillin-resistant Staphylococcus aureus 5 months after surgery.

Conclusion

We report the first case of a patient with intradural squamous cell carcinoma with unknown origin that developed independently in the sacrum.
Binding of long-chain α-neurotoxin would stabilize the resting state of nAChR: A comparative study with α-conotoxin
Authors: Nasiripourdori Adak , Ranjbar Bijan , Naderi-Manesh Hossein
Published: February 2009

Background

The details of interaction in a complex between potent antagonists such as long chain α-neurotoxins and α-conotoxins with nicotinic acetylcholine receptor (nAChR), and conformational changes induced by these antagonists, are not yet clear.

Modeling

In order to uncover some of these critical structural features, we conducted a docking simulation and a molecular dynamics simulation (MD) of a model of the ligand binding domain of nAChR in complex with a long-chain α-neurotoxin and an α-conotoxin.

Results

Our docking results confirm the claim thatT.nAChR is in the basal or resting state, which favors binding to the alpha-neurotoxins. Moreover, more correct "hits" for the α/γ interface upon docking for conotoxin-nAChR confirm the preference of conotoxin GI for the α/γ interface. More importantly, upon binding of α-neurotoxin, ligand-bonded nAChR is less dynamic in certain domains than the apo form of the conotoxin-AChR complex. Some critical interactions in the binding site such as the salt bridge formed between K145/D200 in the neurotoxin-nAChR complex is further stabilized during the MD simulation, while it is obviously more labile in the apo form.

Conclusion

These observations could support the claim that alpha neurotoxins stabilize the nAChR resting state.
Identification of the occurrence and pattern of masseter muscle activities during sleep using EMG and accelerometer systems
Authors: Yoshimi Hidehiro , Sasaguri Kenichi , Tamaki Katsushi , Sato Sadao
Published: February 2009

Background

Sleep bruxism has been described as a combination of different orofacial motor activities that include grinding, clenching and tapping, although accurate distribution of the activities still remains to be clarified.

Methods

We developed a new system for analyzing sleep bruxism to examine the muscle activities and mandibular movement patterns during sleep bruxism. The system consisted of a 2-axis accelerometer, electroencephalography and electromyography. Nineteen healthy volunteers were recruited and screened to evaluate sleep bruxism in the sleep laboratory.

Results

The new system could easily distinguish the different patterns of bruxism movement of the mandible and the body movement. Results showed that grinding (59.5%) was most common, followed by clenching (35.6%) based on relative activity to maximum voluntary contraction (%MVC), whereas tapping was only (4.9%).

Conclusion

It was concluded that the tapping, clenching, and grinding movement of the mandible could be effectively differentiated by the new system and sleep bruxism was predominantly perceived as clenching and grinding, which varied between individuals.
Apical membrane maturation and cellular rosette formation during morphogenesis of the zebrafish lateral line
Authors: Hava David , Forster Ulrike , Matsuda Miho , Cui Shuang , Link Brian A. , Eichhorst Jenny , Wiesner Burkhard , Chitnis Ajay , Abdelilah-Seyfried Salim
Published: February 2009

Tissue morphogenesis and cell sorting are major forces during organ development. Here, we characterize the process of tissue morphogenesis within the zebrafish lateral line primordium, a migratory sheet of cells that gives rise to the neuromasts of the posterior lateral line organ. We find that cells within this epithelial tissue constrict actin-rich membranes and enrich apical junction proteins at apical focal points. The coordinated apical membrane constriction in single Delta D-positive hair cell progenitors and in their neighbouring prospective support cells generates cellular rosettes. Live imaging reveals that cellular rosettes subsequently separate from each other and give rise to individual neuromasts. Genetic analysis uncovers an involvement of Lethal giant larvae proteins in the maturation of apical junction belts during cellular rosette formation. Our findings suggest that apical constriction of cell membranes spatially confines regions of strong cell-cell adhesion and restricts the number of tightly interconnected cells into cellular rosettes, which ensures the correct deposition of neuromasts during morphogenesis of the posterior lateral line organ.
Expression of the proneural gene encoding Mash1 suppresses MYCN mitotic activity
Authors: Álvarez-Rodríguez Rubén , Pons Sebastián
Published: February 2009

Murine Mash1 (Ascl1) is a member of the basic helix-loop-helix family of transcription factors and has been described to promote differentiation in some neural precursors. The process of differentiation is coordinated with a concomitant cell-cycle arrest, but the molecular mechanism of this process is unclear. Here, we describe for the very first time a direct regulation of an oncogene by a proneural gene. When expressed in proliferating cerebellar granular precursors, expression of the proneural gene encoding Mash1 promotes cell-cycle exit and differentiation, whereas expression of the oncogene MYCN has the opposite effect, promoting the proliferation of these cells in the absence of sonic hedgehog. Moreover, Mash1 overexpression neutralizes MYCN-induced proliferation. We now propose that the mechanism of antagonism between both molecules is based on opposite functions in the transcriptional regulation of the E-box motif, particularly in the E-boxes within the cyclin-D2 promoter, with MYCN acting as a transcriptional activator and Mash1 as a repressor. In agreement with this result, overexpression of cyclin D2 suppressed the anti-proliferative activity of Mash1.
Whi2p links nutritional sensing to actin-dependent Ras-cAMP-PKA regulation and apoptosis in yeast
Authors: Leadsham Jane E. , Miller Katherine , Ayscough Kathryn R. , Colombo Sonia , Martegani Enzo , Sudbery Pete , Gourlay Campbell W.
Published: February 2009

Elucidating the mechanisms by which eukaryotic cells coordinate environmental signals with intracellular `fate' decisions, such as apoptosis, remains one of the important challenges facing cell biologists. It has recently emerged that the dynamic nature of the actin cytoskeleton is an important factor in the linkage of sensation of extracellular stimuli to signalling mechanisms that regulate programmed cell death. In yeast, actin has been shown to play a role in the regulation of apoptosis as cells prepare themselves for quiescence in the face of nutritional exhaustion, by facilitating the shutdown of Ras-cAMP-PKA pathway activity. Here, we demonstrate that the loss of Whi2p function, a protein known to influence cell cycle exit under conditions of nutritional stress, leads to cell death in yeast that displays the hallmarks of actin-mediated apoptosis. We show that actin-mediated apoptosis occurs as a result of inappropriate Ras-cAMP-PKA activity in Δwhi2 cells. Cells lacking Whi2p function exhibit an aberrant accumulation of activated Ras2 at the mitochondria in response to nutritional depletion. This study provides evidence that the shutdown of cAMP-PKA signalling activity in wild-type cells involves Whi2p-dependent targeting of Ras2p to the vacuole for proteolysis. We also demonstrate for the first time that Whi2p-dependent regulation of cAMP-PKA signalling plays a physiological role in the differentiation of yeast colonies by facilitating elaboration of distinct zones of cell death.
Lost in translation: An interpretative phenomenological analysis of mental health professionals' experiences of empathy in clinical work with an interpreter
Authors: Pugh Matthew A. , Vetere Arlene
Published: February 2009

Objectives. Although empathy is considered by many to be fundamental to psychotherapeutic practice, little is known about how working with an interpreter may affect empathy in clinical work. Accordingly, the present study aims to provide an exploration of mental health professionals' experiences of empathy in clinical work with an interpreter.

Design. A qualitative methodology was utilized in order to provide a rich understanding of participants' shared experiences of empathy in work with an interpreter. Data were gathered using a semi‐structured interviewing approach. Interpretative phenomenological analysis (IPA) was chosen as the method of analysis as this would provide a highly descriptive and in‐depth account of participants' experiences.

Method. Interviews were conducted with 10 mental health professionals regularly working with linguistic interpreters. Interviews were transcribed and analysed using IPA.

Results. The analysis yielded four major themes which described the effects of translation upon empathic dialogues with service‐users; changes in the quality of empathic communication with service‐users; the effects of cultural similarities and dissimilarities upon empathy within client–interpreter and client–professional dyads; and opportunities for the interpreter to enrich participants' understanding of service‐users' perspectives.

Conclusions. The difficulties participants encountered in work with an interpreter highlight a need for training in cross‐language empathy for interpreters and mental health professionals, and encourage the use of transcultural models of psychotherapy in work with non‐English speaking service‐users. Some of the difficulties associated with adopting traditional humanistic models of empathy, which tend to centralize the therapist within empathic processes, when working with interpreters are also discussed.