bluuebunny/crossref_metadata_2025 huggingface dataset:
DARK ENERGY FROM SCALAR FIELD WITH GAUSS–BONNET AND NON-MINIMAL KINETIC COUPLING
Authors: GRANDA L. N.
Published: January 2012

We consider a model of scalar field with non-minimal kinetic couplings to the curvature, and additional coupling to the Gauss–Bonnet four-dimensional invariant. The model presents rich cosmological dynamics and some of its solutions are analyzed. A variety of scalar fields and potentials giving rise to power-law expansion have been found. Two solutions with dynamical equation of state are considered. The first solution unifies early time power-law behavior with late time cosmological constant dominance. The second solution is able to describe a universe in the phantom phase, and depending on the parameters may describe essentially dark energy behavior, or may contain the decelerated and accelerated phases.
VANISHING DIMENSIONS AND PLANAR EVENTS AT THE LHC
Authors: ANCHORDOQUI LUIS , DAI DE CHANG , FAIRBAIRN MALCOLM , LANDSBERG GREG , STOJKOVIC DEJAN
Published: January 2012

We propose that the effective dimensionality of the space we live in depends on the length scale we are probing. As the length scale increases, new dimensions open up. At short scales the space is lower dimensional; at the intermediate scales the space is three-dimensional; and at large scales, the space is effectively higher dimensional. This setup allows for some fundamental problems in cosmology, gravity, and particle physics to be attacked from a new perspective. The proposed framework, among the other things, offers a new approach to the cosmological constant problem and results in striking collider phenomenology and may explain elongated jets observed in cosmic-ray data.
PROCESS AND PRODUCT INNOVATION IN A VERTICALLY DIFFERENTIATED INDUSTRY
Authors: BACCHIEGA EMANUELE , LAMBERTINI LUCA , MANTOVAINI ANDREA
Published: January 2012

We examine a vertically differentiated duopoly where firms invest in process and product innovation and then compete in prices under full market coverage. We show that (i) process innovation fosters (hinders) product innovation for the low-quality (high-quality) firm; (ii) the firm which is initially more efficient invests more than the rival in process innovation; (iii) if the initial differential between marginal costs is sufficiently high, the demand for the less efficient firm is nil and the duopoly equilibrium does not exist.
EFFECT OF WALL PROPERTIES ON THE PERISTALTIC FLOW OF A THIRD GRADE FLUID IN A CURVED CHANNEL
Authors: HINA S. , HAYAT T. , MUSTAFA M. , ALDOSSARY OMAR M. , ASGHAR S.
Published: January 2012

This paper discusses the effects of wall properties on the peristaltic flow of an incompressible third grade fluid in a curved channel. Series solution is obtained under the approximation of long wavelength and low Reynolds number. Relation of stream function is derived. The variations of the interesting parameters entering into the problem are carefully analyzed. It is observed that the velocity profiles are not symmetric about the central line of the curved channel. Moreover, the bolus size increases with an increase in the curvature parameter in the upper half of the channel. Whereas it is found to decrease upon increasing the curvature parameter in the lower half of the channel.
CLASSICAL GAUGE GRAVITATION THEORY
Authors: SARDANASHVILY G.
Published: January 2012

Classical gravitation theory is formulated as gauge theory on natural bundles where gauge symmetries are general covariant transformations and a gravitational field is a Higgs field responsible for their spontaneous symmetry breaking.
EFFECT OF OUTDOOR PRESSURE FLUCTUATIONS ON NATURAL VENTILATION IN A ROOM WITH TWO OPENINGS
Authors: HAN HWATAIK , KIM JUNG KYUNG , HAN CHANG-HO
Published: January 2012

We investigated the effects of outdoor pressure fluctuations on natural ventilation in a room with two openings. One opening is exposed to an oscillating outdoor pressure and the other is exposed to a fixed neutral pressure. The ventilation airflow rate depends on the amplitude and period of the outdoor pressure fluctuations, the room volume, and the sizes of the openings. Dimensionless parameters are derived from the governing equations that determine indoor pressure responses due to outdoor pressure fluctuations. The pressure responses and the airflow rates through the openings are obtained using a fourth-order Runge–Kutta method. The flow regions are categorized into a synchronized region, an opening resistance region, and a transition region, depending on the dimensionless parameters. Applications are considered using an example building space to investigate the effective air change rates depending on the size of the openings and the period of wind pressure fluctuations.
Optical and Electrical Properties of Nitrogen-Doped Diamond-Like Carbon Films Prepared by a Bipolar-Type Plasma-Based Ion Implantation
Authors: Nakao Setsuo , Soga Tetsuo , Sonoda Tsutomu , Asada Tokuhiro , Kishi Naoki
Published: January 2012

Diamond-like carbon (DLC) films are prepared by a bipolar-type plasma-based ion implantation (PBII) technique using toluene and nitrogen gases (N2), and the optical and electrical properties are examined as a function of N2 flow rate. The N concentration in the films and structural changes are also examined by Rutherford backscattering spectrometry (RBS), atomic force microscopy (AFM), and Raman spectroscopy. It is found that the deposition rate decreases, but N concentration linearly increases with increasing N2 flow rate. Granular surfaces are observed and the grains decreases in size as N2 flow rate increases. In addition, Raman analysis suggests that aromatic ring clusters and the amorphous structure increase in amount. The optical band gap and conductivity increase with increasing N concentration up to about 11 at. %, and then decrease with further increase in N concentration.
Cu(ReTaNx) Copper Alloy Films Suitable for Electronic-Device Manufacturing-Process Simplification
Authors: Lin Chon-Hsin
Published: January 2012

In this study, we prepare Cu(ReTa) and Cu(ReTaNx) films via reactive cosputtering of copper (Cu), rhenium (Re), and tantalum (Ta) on a barrierless silicon (Si) substrate in an argon–nitrogen (Ar–N2) atmosphere. These Cu(ReTa) and Cu(ReTaNx) films, after annealing at 630 and 750 °C for 1 h, exhibit two values of resistivity,viz., 3.05 and 2.35 µΩ cm, respectively, showing high thermal stability without copper-silicide formation. The Cu(ReTaNx) film's up-to-750 °C high-temperature stability, while maintaining a low leakage current and resistivity, appears to make it a good candidate material for advanced barrierless metallization for simplifying related electronic-device manufacturing processes, and, consequently, reducing the related manufacturing cost. Applying X-ray diffraction (XRD), focused ion-beam microscopy, and transmission electron microscopy (TEM) to evaluate said film, we observed that the Cu seed layer-Si interface showed no detrimental reaction after the film was annealed at 750 °C for 1 h. The film, hence, is recommended for the desired purpose.
Combinatorial Deposition of Microcrystalline Silicon Films Using Multihollow Discharge Plasma Chemical Vapor Deposition
Authors: Koga Kazunori , Matsunaga Takeaki , Kim Yeonwon , Nakahara Kenta , Yamashita Daisuke , Matsuzaki Hidefumi , Kamataki Kunihiro , Uchida Giichiro , Itagaki Naho , Shiratani Masaharu
Published: January 2012

A high-pressure depletion method using plasma chemical vapor deposition (CVD) is often used to deposit hydrogenated microcrystalline silicon (µc-Si:H) films of a low defect density at a high deposition rate. To understand proper deposition conditions of µc-Si:H films for a high-pressure depletion method, Si films were deposited in a combinatorial way using a multihollow discharge plasma CVD method by which fluxes of H and SiH3radicals and their flux ratio can be varied with the distance from the discharges. The higher gas pressure brings about the higher deposition rate, whereas the process window of device quality µc-Si:H films becomes quite narrower for the higher gas pressure.
Selective Growth of Microscale GaN Pyramids on Apex of GaN Pyramids
Authors: Jo Dong Wan , Ok Jin Eun , Yun Wy il , Jeon Hun Soo , Lee Gang Suok , Jung Se Gyo , Bae Seon Min , Ahn Hyung Soo , Yang Min
Published: January 2012

We report on the growth and characterization of microscale GaN structures selectively grown on the apexes of hexagonal GaN pyramids. SiO2 near the apex of the hexagonal GaN pyramids was removed by an optimized photolithography process and subsequently subjected to selective growth of micro scale GaN structures by metal organic vapor phase epitaxy (MOVPE). The pyramidal GaN microstructures which have semi-polar {11̄01} facets, were formed only on the apexes of lower GaN pyramids. The size of the selectively grown micro GaN structures was easily controlled by the growth time. Reduction of the threading dislocation density was confirmed by transmission electron microscopy (TEM) in the selectively regrown micro GaN structures. However, stacking faults developed near the edge of the SiO2 film because of the roughness and nonuniform thickness of the SiO2 film.
Characterization of GaN-Based Light Emitting Diodes Grown on 4-in. Si(111) Substrate
Authors: Zhu Youhua , Watanabe Arata , Lu Lin , Chen Zhitao , Egawa Takashi
Published: January 2012

GaN-based light emitting diodes (LEDs) with a total thickness of 4.8 µm have been grown by metal–organic chemical vapor deposition on 4-in. Si(111) substrate. The structural property has been revealed by the measurements of high-resolution X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It can be clarified that the LEDs in sample have the good interfaces and layer periodicities for the strained-layer superlattices and multiple quantum wells. In addition, the optical property in the light output power has been evaluated. As a result, LEDs with a maximum output power of 3.3 mW and a high saturation operating current of 400 mA have exhibited the good device performance.
Micro-Square-Array InGaN-Based Light-Emitting Diode with an Insulated Ga2O3 Layer through a Photoelectrochemical Process
Authors: Lin Chia-Feng , Lin Chun-Min , Jiang Ren-Hao
Published: January 2012

InGaN-based micro-square-array light emitting diode (MSA-LED) was fabricated by filling with an insulated Ga2O3 layer around the individual micro-square patterns for a metal interconnected process. The Ga2O3 layer formed at the mesa sidewall and the bottom etched surface of the n-type GaN layer in the LED structure through a selective photoelectrochemical (PEC) wet oxidation process in H2O solution. The 25- and 15-µm-square mesa patterns of the MSA-LED structures were defined by the plasma dry and the PEC wet etching processes that a conventional broad-area LED (BA-LED) was closed to the MSA-LED for comparison. The peak wavelength blueshift of the electroluminescence spectra and the enhancement of the light output power were measured at 1.0 nm/41% and 2.5 nm/22% for the 25- and 15-µm-MSA-LED, respectively, compared with the BA-LED. The reverse leakage current of both MSA-LED structures was about 2.5×10-11 A that was lower than the BA-LED (8.3×10-9 A) at -5 V reverse bias. The PEC Ga2O3 layer acted a passivation layer to prevent the leakage current from the mesa sidewall surface and an interconnect process in the MSA-LED structures.
Further Improvement in the Light Output Power of InGaN-Based Light Emitting Diodes by Patterned Sapphire Substrate with KOH Wet-Chemical Etching on Sidewall
Authors: Tsai Chun-Fu , Su Yan-Kuin , Lin Chun-Liang
Published: January 2012

This paper presented the fabrication and measurements of InGaN/GaN multiple-quantum well (MQW) light-emitting diodes (LEDs), using patterned sapphire substrate (PSS) combined with roughening technique of KOH wet-chemical etching on chip sidewall, further improvement in the light output power of InGaN-based LEDs could be obtained. For the LED with PSS structure, we can get better light extraction and higher light output power (11.5% at 20 mA) than that of the reference LED. As for the LED with PSS structure and KOH etching on sidewall, it exhibits further enhancement in light extraction and we can get the highest light output power (17.3% at 20 mA) compared with that of the reference LEDs without PSS and KOH treatment. In the results of our experiments, the roughening technique of KOH etching, reducing the totally internal reflection at LED sidewall, was demonstrated to be a simple, cost-effective and feasible method, without expensive or complicated instruments, to further improve the light extraction of InGaN-based LEDs significantly.
Applications of Carbon Nanotubes Grown by Chemical Vapor Deposition
Authors: Robertson John , Zhong Guofang , Esconjauregui C. Santiago , Bayer Bernhard C. , Zhang Can , Fouquet Martin , Hofmann Stephan
Published: January 2012

The requirements for using carbon nanotubes as vias and interconnects are described. The growth of high density forests of vertically-aligned carbon nanotubes for interconnect applications by chemical vapor deposition is described. Densities up to 1.4 ×1013 cm-2 have been achieved by maintaining a small nanotube diameter. The process integration devices is reviewed.
Direct Growth of Carbon Nanotubes on ZnO(0001̄) Substrate Surface using Alcohol Gas Source Method in High Vacuum
Authors: Iokawa Takayasu , Tsutsui Tomoyuki , Naritsuka Shigeya , Maruyama Takahiro
Published: January 2012

Using an alcohol gas source method, carbon nanotubes (CNT) were grown on a ZnO(0001̄) surface without any underlayers. At 700 °C under an ethanol pressure of 1×10-1 Pa, high-density CNTs could be grown using a Co catalyst. However, after the growth, the ZnO surface became rough, accompanied by the occurrence of striped structures along the a-axis. Reducing the growth temperature and ethanol pressure and using a Pt catalyst, CNT growth could be achieved on the ZnO(0001̄) face without the formation of surface roughness. The reaction between the catalyst and the ZnO surface was also investigated using X-ray photoelectron spectroscopy.
Characterization of Damage of Al2O3/Ge Gate Stack Structure Induced with Light Radiation during Plasma Nitridation
Authors: Takeuchi Kusumandari , Kato Kimihiko , Shibayama Shigehisa , Sakashita Mitsuo , Nakatsuka Osamu , Zaima Shigeaki
Published: January 2012

We have investigated the effects of light radiation during plasma nitridation on the electrical properties of an Al2O3/Ge gate stack structure using the pallet for plasma evaluation (PAPE) technique. From the capacitance–voltage characteristics, the flatband voltage shift due to fixed oxide charges significantly increases after light exposure with an energy higher than 7.5 eV. In addition, the density of trapped charges near the interface and the interface state density (Dit) also significantly increase after light exposure with an energy over 11.3 eV. The net density of positive fixed oxide charges, the density of trapped charges near the interface, andDitcan be reduced by post-metallization annealing (PMA) in N2ambient at 300 °C.
Near Infrared Radiation from Heated Nanostructured Tungsten
Authors: Kajita Shin , Yokochi Takanori , Ohno Noriyasu , Kumano Tomoyuki
Published: January 2012

Helium plasma irradiation to metals leads to morphology changes in nanometer scales by the formation of helium bubbles. The nanostructure significantly alters the optical property of the metal. In this study, near infrared radiations from a heated nanostructured tungsten are measured with a spectrometer. Energy balance between the influx of plasma and radiation from the sample is discussed in terms of the optical emittance. It is shown that the optical emittance is increased considerably by the morphology change in the range from visible to near infrared, and the efficiency of radiation is increased by two to three times.
Switching Current Measurements of Self-Assembled Ferroelectric PbTiO3 Nanoislands Using Scanning Probe Microscopy
Authors: Fujisawa Hironori , Yamada Kosei , Nakashima Seiji , Shimizu Masaru
Published: January 2012

We report on switching current measurements of self-assembled PbTiO3 nanoislands with an average height in the range of 4–5 nm and a width of less than 100 nm by scanning probe microscopy (SPM). A blunt SPM tip with a flat end-face with a plateau diameter of 1.8 µm was directly contacted to PbTiO3 nanoislands as a top electrode, which enabled electrical characterization of as-prepared samples without the need for fabricating top electrodes or any preprocessing. Using this SPM system, it was revealed that the nanoislands have switching charge densities as large as 140–170 µC/cm2, comparable to those of epitaxial thin films.
Growth of GaN Layer on Patterned Al/Ti Metal Mask by Metal–Organic Chemical Vapor Deposition
Authors: Park Jinsub , Moon Daeyoung , Park Sehun , Park Sung Hyun , Yoon Euijoon
Published: January 2012

We report on high-quality GaN epitaxial growth by metal–organic chemical vapor deposition (MOCVD) on a stripe-patterned GaN template using a metal mask. A multiple Al/Ti metal system with 10 µm periodicity was used as a masking layer for the epitaxial lateral overgrowth (ELOG). The overgrowth of GaN on the patterned metal mask begins at the open window region between the stripes, and then ELOG leads to the formation of a continuous layer. Micro-cathodoluminescence (µ-CL) results show the improvement of optical properties and significant strain relaxation in the overgrown GaN layer. About a 2-order reduction of threading dislocation density was observed on the overgrown GaN on metal mask regions compared with that on GaN template regions.
Improved Performance of Pentacene Thin-Film Transistors with Al2O3 Gate Dielectric: Annealing Effect on the Surface Properties
Authors: Hyung Gun Woo , Park Jaehoon , Koo Ja-Ryong , Li Zhao-Hui , Kwon Sang Jik , Cho Eou-Sik , Kim Young Kwan
Published: January 2012

We have fabricated pentacene thin-film transistors (TFTs) with modified Al2O3 layers as gate dielectrics. The effects of thermal treatments on the E-beam-processed Al2O3 layers in the TFTs were investigated by using various analytical tools such as X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscope (AFM), and a contact angle method. From the results of the analyses, it was confirmed that the performance of thermally treated Al2O3 gate dielectrics is much better than that of non-treated ones. Finally, pentacene TFTs were fabricated with optimum conditions and improved electrical properties were obtained for low-voltage (below -3 V) TFTs as follows: a mobility of 0.9 cm2 V-1 s-1, a threshold voltage of -1.3 V, a sub-threshold slope of 0.12 V/decade, and an on/off current ratio of 2.2 ×105.
Determination of inflammatory and prominent proteomic changes in plasma and adipose tissue after high-intensity intermittent training in overweight and obese males
Authors: Leggate Melanie , Carter Wayne G. , Evans Matthew J. C. , Vennard Rebecca A. , Sribala-Sundaram Sarah , Nimmo Myra A.
Published: January 2012

This study aimed to determine whether 2 wk of high-intensity intermittent training (HIIT) altered inflammatory status in plasma and adipose tissue in overweight and obese males. Twelve participants [mean (SD): age 23.7 (5.2) yr, body mass 91.0 (8.0) kg, body mass index 29.1 (3.1) kg/m2] undertook six HIIT sessions over 2 wk. Resting blood and subcutaneous abdominal adipose tissue samples were collected and insulin sensitivity determined, pre- and posttraining. Inflammatory proteins were quantified in plasma and adipose tissue. There was a significant decrease in soluble interleukin-6 receptor (sIL-6R; P = 0.050), monocyte chemotactic protein-1 (MCP-1, P = 0.047), and adiponectin ( P = 0.041) in plasma posttraining. Plasma IL-6, intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), IL-10, and insulin sensitivity did not change. In adipose tissue, IL-6 significantly decreased ( P = 0.036) and IL-6R increased ( P = 0.037), while adiponectin tended to decrease ( P = 0.056), with no change in ICAM-1 posttraining. TNF-α, MCP-1, and IL-10 were not detectable in adipose tissue. Adipose tissue homogenates were then resolved using one-dimensional gel electrophoresis, and major changes in the adipose tissue proteome, as a consequence of HIIT, were evaluated. This proteomic approach identified significant reductions in annexin A2 ( P = 0.046) and fatty acid synthase ( P = 0.016) as a response to HIIT. The present investigation suggests 2 wk of HIIT is sufficient to induce beneficial alterations in the resting inflammatory profile and adipose tissue proteome of an overweight and obese male cohort.
Efficacy of Antiretroviral Therapy Switch in HIV-Infected Patients: A 10-Year Analysis of the EuResist Cohort
Authors: Oette Mark , Schülter Eugen , Rosen-Zvi Michal , Peres Yardena , Zazzi Maurizio , Sönnerborg Anders , Struck Daniel , Altmann André , Kaiser Rolf ,   the EuResist Network Study Group
Published: January 2012

Introduction: Highly active antiretroviral therapy (HAART) has been shown to be effective in many recent trials. However, there is limited data on time trends of HAART efficacy after treatment change. Methods: Data from different European cohorts were compiled within the EuResist Project. The efficacy of HAART defined by suppression of viral replication at 24 weeks after therapy switch was analyzed considering previous treatment modifications from 1999 to 2008. Results: Altogether, 12,323 treatment change episodes in 7,342 patients were included in the analysis. In 1999, HAART after treatment switch was effective in 38.0% of the patients who had previously undergone 1–5 therapies. This figure rose to 85.0% in 2008. In patients with more than 5 previous therapies, efficacy rose from 23.9 to 76.2% in the same time period. In patients with detectable viral load at therapy switch, the efficacy rose from 23.3 to 66.7% with 1–5 previous treatments and from 14.4 to 55.6% with more than 5 previous treatments. Conclusion: The results of this large cohort show that the outcome of HAART switch has improved considerably over the last years. This result was particularly observed in the context after viral rebound. Thus, changing HAART is no longer associated with a high risk of treatment failure.
Viewpoint (In)dependence of Action Representations: An MVPA Study
Authors: Oosterhof Nikolaas N. , Tipper Steven P. , Downing Paul E.
Published: January 2012

The discovery of mirror neurons—neurons that code specific actions both when executed and observed—in area F5 of the macaque provides a potential neural mechanism underlying action understanding. To date, neuroimaging evidence for similar coding of specific actions across the visual and motor modalities in human ventral premotor cortex (PMv)—the putative homologue of macaque F5—is limited to the case of actions observed from a first-person perspective. However, it is the third-person perspective that figures centrally in our understanding of the actions and intentions of others. To address this gap in the literature, we scanned participants with fMRI while they viewed two actions from either a first- or third-person perspective during some trials and executed the same actions during other trials. Using multivoxel pattern analysis, we found action-specific cross-modal visual–motor representations in PMv for the first-person but not for the third-person perspective. Additional analyses showed no evidence for spatial or attentional differences across the two perspective conditions. In contrast, more posterior areas in the parietal and occipitotemporal cortex did show cross-modal coding regardless of perspective. These findings point to a stronger role for these latter regions, relative to PMv, in supporting the understanding of others' actions with reference to one's own actions.
On the Influence of Raindrop Collision Outcomes on Equilibrium Drop Size Distributions
Authors: Prat Olivier P. , Barros Ana P. , Testik Firat Y.
Published: January 2012

The objective of this study is to evaluate the impact of a new parameterization of drop–drop collision outcomes based on the relationship between Weber number and drop diameter ratios on the dynamical simulation of raindrop size distributions. Results of the simulations with the new parameterization are compared with those of the classical parameterizations. Comparison with previous results indicates on average an increase of 70% in the drop number concentration and a 15% decrease in rain intensity for the equilibrium drop size distribution (DSD). Furthermore, the drop bounce process is parameterized as a function of drop size based on laboratory experiments for the first time in a microphysical model. Numerical results indicate that drop bounce has a strong influence on the equilibrium DSD, in particular for very small drops (<0.5 mm), leading to an increase of up to 150% in the small drop number concentration (left-hand side of the DSD) when compared to previous modeling results without accounting for bounce effects.
The Effects of Changes in Sea Surface Temperature and CO2 Concentration on the Quasi-Biennial Oscillation
Authors: Kawatani Yoshio , Hamilton Kevin , Noda Akira
Published: January 2012

The effects of sea surface temperature (SST) and CO2 on future changes in the quasi-biennial oscillation (QBO) are investigated using a climate model that simulates the QBO without parameterized nonstationary gravity wave forcing. Idealized model experiments using the future SST with the present CO2 (FS run) and the present SST with the future CO2 (FC run) are conducted, as are experiments using the present SST with the present CO2 (present run) and the future SST with the future CO2 (future run). When compared with the present run, precipitation increases around the equatorial region in the FS run and decreases in the FC run, resulting in increased and decreased wave momentum fluxes, respectively. In the midlatitude lower stratosphere, westward (eastward) wave-forcing anomalies form in the FS (FC) run. In the middle stratosphere off the equator, westward wave-forcing anomalies form in both the FS and FC runs. Corresponding to these wave-forcing anomalies, the residual vertical velocity significantly increases in the lower stratosphere in the FS run but decreases to below 70 hPa in the FC run, whereas residual upward circulation anomalies form in both the FS and FC runs in the middle equatorial stratosphere. Consequently, the amplitude of the QBO becomes smaller in the lower stratosphere, and the period of the QBO becomes longer by about 1–3 months in the FS run. On the other hand, in the FC run, the QBO extends farther downward into the lowermost stratosphere, and the period becomes longer by 1 month.
Color Doppler Ultrasound
Authors: Vakharia Kalpesh T. , Henstrom Douglas , Lindsay Robin , Cunnane Mary Beth , Cheney Mack , Hadlock Tessa
Published: January 2012

Objective

The gracilis muscle free flap has become a reliable means for smile reanimation for patients with facial paralysis. Because it is a buried flap, it presents a postoperative monitoring challenge. We sought to evaluate our experience with color Doppler ultrasound in the monitoring of gracilis free flap viability in the immediate postoperative setting.

Study Design

Case series with planned data collection.

Setting

Tertiary medical center.

Methods

Patients with facial paralysis treated with gracilis muscle free flap for smile reanimation performed between March 2009 and November 2010 were evaluated by color Doppler ultrasound and included in the study. Our experience with the use of the color Doppler ultrasound to monitor the gracilis muscle flap is presented.

Results

Forty‐six patients were identified. In all cases, color Doppler ultrasound was used postoperatively to assess flow through the vascular pedicle. Outcomes included an early flap survival rate of 100%, with no instances of equivocal or absent flow on either the arterial or venous side. Color Doppler ultrasound provided important objective information regarding muscle perfusion postoperatively in several instances of equivocal postoperative perfusion of the flap.

Conclusion

Color Doppler ultrasound is a safe, noninvasive method that can be performed serially to evaluate a buried free flap. We have had success in verifying normal arterial and venous flow through the pedicle using this method of monitoring of the gracilis muscle free flap during facial reanimation, and in 3 instances, it eliminated the need for wound exploration to verify appropriate muscle perfusion.
Predicting posttransplantation diabetes mellitus by regulatory T-cell phenotype: implications for metabolic intervention to modulate alloreactivity
Authors: Engelhardt Brian G. , Jagasia Shubhada M. , Crowe James E. , Griffith Michelle L. , Savani Bipin N. , Kassim Adetola A. , Lu Pengcheng , Weitkamp Jörn-Hendrik , Moore Daniel J. , Yoder Sandra M. , Rock Michael T. , Jagasia Madan
Published: January 2012

Chronic inflammation and decreased frequency of regulatory T cells (Tregs) in visceral adipose tissue contribute to the propagation of insulin resistance to diabetes mellitus. We tested the hypothesis that new-onset posttransplantation diabetes mellitus (PTDM) is associated with measurable changes in Treg subsets after allogeneic hematopoietic stem cell transplantation (HSCT). PTDM before day 100 and Treg phenotype at engraftment were determined in 36 HSCT recipients without preceding history of diabetes mellitus. Among patients with new-onset PTDM (N = 24), the frequency of circulating CLA+ (skin-homing) Tregs was decreased (1.53% vs 3.99%; P = .002) and the percentage of α4β7+ (gut-homing) Tregs was increased (17.9% vs 10.7%; P = .048). In multivariate analysis, patients with PTDM continued to demonstrate elevated ratios of α4β7+ Tregs to CLA+ Tregs (odds ratio, 18.1; P = .020). PTDM is associated with altered immune regulation after HSCT and could represent a target to modulate alloreactivity.
Differing clinical characteristics between influenza strains among young healthy adults in the tropics
Authors: Yap Jonathan , Tan Chi Hsien , Cook Alex R , Loh Jin Phang , Tambyah Paul A , Tan Boon Huan , Lee Vernon J
Published: January 2012

Background

Influenza infections may result in different clinical presentations. This study aims to determine the clinical differences between circulating influenza strains in a young healthy adult population in the tropics.

Methods

A febrile respiratory illness (FRI) (fever ≥ 37.5°C with cough and/or sore throat) surveillance program was started in 4 large military camps in Singapore on May 2009. Personnel with FRI who visited the camp clinics from 11 May 2009 to 25 June 2010 were recruited. Nasal washes and interviewer-administered questionnaires on demographic information and clinical features were obtained from consenting participants. All personnel who tested positive for influenza were included in the study. Overall symptom load was quantified by counting the symptoms or signs, and differences between strains evaluated using linear models.

Results

There were 434 (52.9%) pandemic H1N1-2009, 58 (7.1%) seasonal H3N2, 269 (32.8%) influenza B, and 10 (1.2%) seasonal H1N1 cases. Few seasonal influenza A (H1N1) infections were detected and were therefore excluded from analyses, together with undetermined influenza subtypes (44 (1.5%)), or more than 1 co-infecting subtype (6 (0.2%)). Pandemic H1N1-2009 cases had significantly fewer symptoms or signs (mean 7.2, 95%CI 6.9-7.4, difference 1.6, 95%CI 1.2-2.0,p< 0.001) than the other two subtypes (mean 8.7, 95%CI 8.5-9.0). There were no statistical differences between H3N2 and influenza B (p= 0.58). Those with nasal congestion, rash, eye symptoms, injected pharynx or fever were more likely to have H3N2; and those with sore throat, fever, injected pharynx or rhinorrhoea were more likely to have influenza B than H1N1-2009.

Conclusions

Influenza cases have different clinical presentations in the young adult population. Pandemic H1N1 influenza cases had fewer and milder clinical symptoms than seasonal influenza. As we only included febrile cases and had no information on the proportion of afebrile infections, further research is needed to confirm whether the relatively milder presentation of pandemic versus seasonal influenza infections applies to all infections or only febrile illnesses.
Robust non-linear differential equation models of gene expression evolution across Drosophila development
Authors: Haye Alexandre , Albert Jaroslav , Rooman Marianne
Published: January 2012

Background

This paper lies in the context of modeling the evolution of gene expression away from stationary states, for example in systems subject to external perturbations or during the development of an organism. We base our analysis on experimental data and proceed in a top-down approach, where we start from data on a system's transcriptome, and deduce rules and models from it without a priori knowledge. We focus here on a publicly available DNA microarray time series, representing the transcriptome of Drosophila across evolution from the embryonic to the adult stage.

Results

In the first step, genes were clustered on the basis of similarity of their expression profiles, measured by a translation-invariant and scale-invariant distance that proved appropriate for detecting transitions between development stages. Average profiles representing each cluster were computed and their time evolution was analyzed using coupled differential equations. A linear and several non-linear model structures involving a transcription and a degradation term were tested. The parameters were identified in three steps: determination of the strongest connections between genes, optimization of the parameters defining these connections, and elimination of the unnecessary parameters using various reduction schemes. Different solutions were compared on the basis of their abilities to reproduce the data, to keep realistic gene expression levels when extrapolated in time, to show the biologically expected robustness with respect to parameter variations, and to contain as few parameters as possible.

Conclusions

We showed that the linear model did very well in reproducing the data with few parameters, but was not sufficiently robust and yielded unrealistic values upon extrapolation in time. In contrast, the non-linear models all reached the latter two objectives, but some were unable to reproduce the data. A family of non-linear models, constructed from the exponential of linear combinations of expression levels, reached all the objectives. It defined networks with a mean number of connections equal to two, when restricted to the embryonic time series, and equal to five for the full time series. These networks were compared with experimental data about gene-transcription factor and protein-protein interactions. The non-uniqueness of the solutions was discussed in the context of plasticity and cluster versus single-gene networks.
Population-based incidence, mortality and quality of life in critically ill patients treated with renal replacement therapy: a nationwide retrospective cohort study in finnish intensive care units
Authors: Vaara Suvi T , Pettilä Ville , Reinikainen Matti , Kaukonen Kirsi-Maija ,   the Finnish Intensive Care Consortium
Published: January 2012

Introduction

Acute kidney injury (AKI) increases mortality and morbidity of critically ill patients. Mortality of patients treated with renal replacement therapy (RRT) is high. We aimed to evaluate the nationwide incidence of RRT-treated AKI in Finland, hospital and six-month mortality, and health-related quality of life (HRQoL) of these patients.

Methods

We performed a retrospective cohort study including all general intensive care unit (ICU) admissions in Finland in 2007 through 2008. We identified patients who had received RRT due to AKI (RRT patients) and compared these patients to ICU patients who were not treated with RRT (non-RRT patients). The HRQoL was assessed by the EQ-5D index and visual analogue scale (VAS).

Results

We analysed the final cohort of 24,904 patients, of whom 1,686 received RRT due to AKI. The incidence of RRT-treated AKI was 6.8% (95% confidence interval (CI) 6.5 to 7.1%) among ≥ 15-year-old general ICU patients, which corresponds to a yearly population-based incidence of 19.2 per 100,000 (95% CI 17.9 to 20.5/100,000). According to RIFLE (Risk, Injury, Failure) classification 26.6% (95% CI 26.0 to 27.2%) of patients had AKI (RIFLE R-F). Hospital and six-month mortality of RRT patients were 35.0% and 49.4%. At six-months, RRT patients perceived their health as good as non-RRT patients by VAS.

Conclusions

The population-based incidence of AKI treated with RRT was 19.2 per 100,000 in Finland and 6.8% of all general ICU patients. The hospital and six-month mortality rates were lower than previously reported for ICU-treated RRT patients.
Characterization of Silver Doped Hydroxyapatite Prepared by EDTA Chelate Decomposition Method
Authors: Celik Kubra , Ergun Celaletdin , Kizil Huseyin
Published: January 2012

In this study, Ag doped hydroxyapatite (HA) samples prepared by EDTA chelate decomposition method were characterized with X-Ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy (SEM) and antimicrobial sensitivity test. Hydroxyapatite (Ca10(PO)6(OH)2) and NaCaPO4 (rhenanite) phases were observed while Ag was present in the form of Ag2O. Results showed that microstructurally controlled HA-based composites with NaCaPO4 interphase can be prepared, which significantly enhances sinterability of hydroxyapatite at 1100° C without formation of any undesired second phases, such as tricalcium phosphate (TCP) known to decrease the stability of HA. The antibacterial sensitivity was tested with E.Coli gram-negative bacteria. The radius of circle enclosing the sample increases with increasing Ag content in the structure as an indication of the region of non-bacterial activity.
Exorcizing the Spectres of Colonialism in Contemporary Sikhism and Postcolonial Thought
Authors: Shani Giorgio
Published: January 2012

This review discusses Arvind-Pal S. Mandair’s Religion and the Specter of the West: Sikhism, India, Postcoloniality, and the Politics of Translation (hereafter RSW), published in 2009 by Columbia University Press.
Valences of the Dialectic
Authors: Mandair Arvind-Pal S.
Published: January 2012

This is a response by the author Arvind-Pal S. Mandair to the contributors of the Review Forum discussing his work Religion and the Specter of the West: Sikhism, India, Postcoloniality, and the Politics of Translation (hereafter RSW), published in 2009 by Columbia University Press.
Burocracia como organização, poder e controle
Authors: Faria José Henrique de , Meneghetti Francis Kanashiro
Published: January 2012

O objetivo central deste trabalho consiste em analisar a forma como Maurício Tragtenberg e Fernando Cláudio Prestes Motta concebem a burocracia. Os objetivos específicos são: compreender as principais características da burocracia segundo Weber, autor central que orienta as obras de Tragtenberg e de Prestes Motta; atingir o entendimento de burocracia expresso na obra de Tragtenberg; apreender o entendimento de burocracia segundo a obra de Prestes Motta; analisar as relações entre os entendimentos de burocracia de Tragtenberg e de Prestes Motta. São levados em consideração nas análises dos autores e do conceito de burocracia: a trajetória intelectual; a ordem das produções; as epistemologias; o espaço e o tempo histórico; a dimensão semântica, ideológica e cultural; questionamentos que se revelam importantes para se compreender o desenvolvimento teórico do conceito. Chegou-se à conclusão de que, apesar das diferenças nas trajetórias intelectuais de Tragtenberg e Prestes Motta, a burocracia é entendida por ambos como organização, poder e controle.
Qualificação profissional a distância: avaliação da transferência de treinamento
Authors: Zerbini Thaís , Abbad Gardênia
Published: January 2012

O objetivo da pesquisa é identificar variáveis explicativas da aplicação de habilidades ensinadas aos participantes de um curso de qualificação profissional a distância, via internet. Foram aplicadas as escalas, submetidas à validação estatística: Ambiente de Estudo e Procedimentos de Interação, Estratégias de Aprendizagem, Reação aos Procedimentos Instrucionais, Reação ao Desempenho do Tutor e Transferência de Treinamento. A coleta de dados foi realizada em três momentos distintos. O modelo de regressão múltipla teve como variável critério a média das respostas de 470 participantes aos itens da escala de Transferência de Treinamento. As variáveis preditoras foram as médias das respostas dos participantes aos itens das demais escalas. Os resultados revelaram que o participante que percebeu favoravelmente o seu Contexto de Estudo e os Procedimentos Instrucionais do curso e utilizou com mais frequência as estratégias de aprendizagem Elaboração e Monitoramento da Compreensão, foi também aquele que relatou maior ocorrência de Transferência de Treinamento.
Crianças pré-escolares e suas concepções de família
Authors: Dessen Maria Auxiliadora , Ramos Patrícia Cristina Campos
Published: January 2012

Para compreender o desenvolvimento e a diversidade da família contemporânea, faz-se necessário conhecer as concepções de família na perspectiva de crianças pré-escolares. Participaram deste estudo 33 crianças com idades de três, quatro e cinco anos: 15 do Grupo A (ambos os genitores com ocupação remunerada) e 18 do Grupo B (apenas o pai com ocupação remunerada). Os participantes foram entrevistados sobre suas concepções de família e referiram-se à composição familiar, à coabitação e ao cumprimento das funções de provedora, cuidadora e socializadora. As crianças consideraram como parte da composição da família: o núcleo familiar, membros da família extensa, padrinhos, amigos e animais de estimação. Porém, houve maior ênfase à função socializadora no Grupo B do que no Grupo A e as definições foram mais abstratas e complexas entre crianças de cinco anos. Os dados indicam que as concepções das crianças sobre os atuais modos de vida das famílias precisam ser investigadas em uma perspectiva longitudinal e transcultural.
Adolescência e organização de personalidade borderline: caracterização dos vínculos afetivos
Authors: Jordão Aline Bedin , Ramires Vera Regina Röhnelt
Published: January 2012

A demanda clínica atual inclui um número significativo de pacientes borderlines. Esse estudo buscou realizar uma revisão de literatura abrangente e não sistemática sobre os vínculos afetivos de adolescentes com indicadores de personalidade borderline. Foram consultadas bases de dados nacionais e internacionais, privilegiando-se publicações a partir de 1995, no referencial psicanalítico. Os estudos encontrados foram discutidos em três grupos: adolescência e cultura contemporânea, características da organização borderline na adolescência e vínculos afetivos desses adolescentes. Discute-se a importância dos vínculos de apego inseguro, a questão da psicopatologia materna e o papel das experiências traumáticas na história de vida desses pacientes.
Análise do conteúdo das leishmanioses em livros didáticos de ciências e biologia indicados pelo Programa Nacional de Livros Didáticos (2008/2009)
Authors: França Viviane Helena de , Margonari Carina , Schall Virgínia Torres
Published: January 2012

Realizou-se análise do conteúdo das leishmanioses em livros didáticos de ciências e biologia, indicados pelo Programa Nacional do Livro Didático - PNLD/2008 e PNLEM/2009. Os critérios de análise reportaram aos seguintes temas: compromisso social, relação entre saúde e ambiente, qualidade científica, correção dos conceitos e ilustrações. Foram analisados sete dos 13 livros de ciências indicados pelo PNLD/2008 e todos os nove livros de biologia do PNLEM/2009; esses foram adotados em escolas públicas brasileiras no período letivo de 2008 a 2011. Todos os livros apresentaram incorreções científicas, linguagem descontextualizada e lacunas de informação, desfavorecendo a construção do conhecimento e não estabelecendo relações com aspectos históricos, socioculturais e econômicos associados às doenças. Tais constatações, somadas a achados semelhantes na literatura, levam à proposição de que o tema saúde deveria ter tratamento em separado, constituindo-se como volume específico, considerando a sua transversalidade e potencial para estabelecer diálogos para uma formação cidadã.
Termorregulación de lagartos en la formación de profesores de ciencias naturales y educación ambiental
Authors: Daza-Pérez Erika Patricia , Pérez-Miranda Royman
Published: January 2012

Se estudiaron las propuestas científicas sobre termorregulación en lagartos para integrar un modelo a partir del cual, mediante un cuestionario y análisis de contenido, se analizaron las explicaciones sobre el fenómeno presentadas por profesores de ciencias en formación pertenecientes a un programa de Licenciatura en Ciencias Naturales. Los modelos de los profesores distan del modelo científico. Con base en ello se presenta una propuesta y se argumenta sobre la importancia de hacer objeto de trabajo dicha temática en la formación de esos profesores.
Anesthetic induction and recovery of Hippocampus reidi exposed to the essential oil of Lippia alba
Authors: Cunha Mauro Alves da , Silva Bruno Ferreira da , Delunardo Frederico Augusto Cariello , Benovit Simone Cristina , Gomes Levy de Carvalho , Heinzmann Berta Maria , Baldisserotto Bernardo
Published: January 2012

The aim of this study was to identify the times of anesthetic induction and recovery in slender seahorses (Hippocampus reidi) that were exposed to the essential oil of Lippia alba (EO), as well as the efficacy of EO as a stress-reducing agent in the transport of this species. Slender seahorses were placed in 1-L aquaria containing different concentrations of EO (0, 10, 20, 50, 150, 300 and 450 µL L-1), and after induction, fish were transferred to aquaria that were free of anesthetic to evaluate their recovery time. In an additional experiment, slender seahorses were transported in plastic bags with 15 µL L-1 of EO for 4 or 24 h. The increased concentration of EO proportionally decreased the time required for the induction of anesthesia. EO treatment (15 µL L-1) inhibited the increase in blood glucose levels that was provoked by transportation for 4 or 24 h. Transportation for 24 h also decreased the number of lymphocytes and increased the neutrophil count, and these effects were avoided with the addition of EO to the water. These results demonstrate that EO was effective as an anesthetic at concentrations of 10-20 µL L-1 for slight sedation and transport and at 150 µL L-1 for deep anesthesia in the slender seahorse.
Occurrence of ticks (Acari: Ixodidae) on human hosts, in three municipalities in the State of Pará, Brazil
Authors: Serra-Freire Nicolau Maués
Published: January 2012

Assuming the existence of tick parasitism in humans in the State of Pará, an aggregate observational study was developed along a transversal line in three cities of the State, during two years. Interviews and examinations of 2,160 townspeople and tourists were carried out, without discrimination of ethnic, sex, age, or social status, and classified for effects analyzed for four bands of age, six types of activities in the society, and two sexes. Larvae, nymphs, and adults of ticks had been identified with cases of parasitism involving six species, of the genus Amblyomma, the genus Ixodes, Rhipicephalus sanguineus, Anocentor nitens, and Ornithodorus talaje (the first case registered in Pará), infecting human beings. Adults and agricultural workers were most frequently attacked, followed by students. A. cajennense and R. sanguineus are the species most frequent in the parasitism affecting humans, and A. cajennense is the dominant species. The statistical prevalence was largest in Cachoeira do Arari, Ilha do Marajó. In Santarém the greatest average intensity of parasitism was for R. sanguineus, and in the other locations it wasfor A. cajennense. Agricultural workers faced the greatest risk from parasitism, and to place in practice elementary measures of prevention would reduce by 25% the number of cases.