bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of the pendeo‐epitaxy effect on 2DEG mobility in III‐nitride HEMT heterostructures
Authors: Bulashevich K. A. , Karpov S. Yu. , Makarov Yu. N. , Zheleva T. S. , Shah P. B. , Derenge M. A. , Jones K. A. 
Published: April 2008

AbstractWe have analyzed theoretically the electron scattering related to the interface roughness produced by threading dislocations in the channel of an AlGaN/GaN HEMT heterostructure. On the basis of the analysis, we predict the use of the pendeo‐epitaxy for growing the transistor structure to improve the low‐temperature and roomtemperature mobility of two‐dimensional electrons by ∼80% and ∼28%, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of GaN/AlN bilayer particles by a vapor phase method
Authors: Hara K. , Mori T. , Komoda H. , Oogi Y. , Kominami H. , Nakanishi Y. 
Published: April 2008

AbstractIn contrast to the conventinal powder phosphors consisting of particles with a uniform material composition, GaN‐based nanostructure‐embedded particles, which consist of GaN quantum dots or quantum wells in the AlN matrix, has been proposed. We can expect the novel phosphors to have higher luminescence efficiencies owing to the carrier confinement effect. As a fundamental technique to fabricate such particles, the formation of bilayer particles consisting of an AlN core and a GaN surface layer has been demonstrated by using the two‐stage vapor phase method. The AlN particles were first formed by a reaction of vaporized Al and N2 gas at temperatures from 1100 to 1250 °C in the first reactor, followed by the growth of GaN on the core surface by a reaction of GaCl and NH3 at 1000 °C in the second reactor. Thus fabricated GaN/AlN bilayer particles showed cathodoluminescence dominated by the band edge emission of GaN. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphological study of non‐polar (11‐20) GaN grown on r‐plane (1‐102) sapphire
Authors: Johnston C. F. , Kappers M. J. , Barnard J. S. , Humphreys C. J. 
Published: April 2008

AbstractIn order to grow high quality non‐polar GaN‐based LED structures it is important to understand the mechanism of GaN growth by MOVPE on r‐plane (1‐102) sapphire. In this work, (11‐20) GaN epilayers have been characterised at three stages of growth using high resolution X‐ray diffraction (HRXRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Following nucleation, 3D islands were grown, then the V/III ratio was lowered and the islands coalesced to form a smooth film. A series of symmetric XRD ω‐scans obtained at different azimuthal angles revealed an anisotropy in the layers with respect to the [1‐100] and [0001] axes. AFM scans show that the islands are elongated along the [0001] axis. TEM has been used to analyse the layers further. A high density of stacking faults (5x105 cm–1) and threading dislocations (4x1010 cm–2) was found in the film with 120 s high V/III growth followed by low V/III growth. Defects were found to run perpendicular and at ∼60 degrees to the sapphire interface in uncoalesced “island” samples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessing the utility of public health surveillance using specificity, sensitivity, and lives saved
Authors: Kleinman Ken P. , Abrams Allyson M. 
Published: April 2008

AbstractIn modern surveillance of public health, data may be reported in a timely fashion and include spatial data on cases in addition to the time of their occurrence. This has lead to many recent developments in statistical methods to detect events of public health importance. However, there has been relatively little work about how to compare such methods. One powerful rationale for performing surveillance is earlier detection of events of public health significance; previous evaluation tools have focused on metrics that include the timeliness of detection in addition to sensitivity and specificity. However, such metrics have not accounted for the number of persons affected by the events. We re‐examine the rationale for this surveillance and conclude that earlier detection is preferred because it can prevent additional morbidity and mortality. On the basis this observation, we propose evaluating the number of cases prevented by each detection method, and include this information in assessing the value of different detection methods. Using this approach incorporates more information about the events and the detection and provides a sound basis for making decisions about which detection methods to employ. Copyright © 2008 John Wiley & Sons, Ltd.
Participation of Rho, ROCK‐2, and GAP activities during actin microfilament rearrangements in Entamoeba histolytica induced by fibronectin signaling
Authors: Ríos Amelia , Hernández‐Ramírez Verónica Ivonne , Moguel Mayra , Zárate Bahena Alma Iris , Rosales‐Encina José Luis , Vargas Miguel Angel , Talamás‐Rohana Patricia 
Published: April 2008

AbstractIn Entamoeba histolytica little is known about the microfilament rearrangements formed by actin and ABPs. Fibronectin regulates many aspects of cell behavior involving the actin cytoskeleton and members of the Rho family of small GTPases. Using trophozoites interacted with fibronectin and glass, we present evidence related with the formation and regulation of different microfilament rearrangements and their cellular distribution, the effect of actin affecting drugs on these arrangements, and on trophozoites adhesion; we also demonstrate that actin isoforms are induced after adhesion, and also the selective participation of specific actin binding proteins such as ABP‐120 and phospho‐paxillin, regarding their location in the different actin structures. In addition, we show results that confirm the participation of EhRho, ROCK‐2, and GAP activities. We propose that fibronectin induced signaling in E. histolytica trophozoites have important consequences in the actin cytoskeleton that may affect its behavior during the invasive process in the host.
Theory and simulations of whistler wave propagation
Authors: SHAIKH DASTGEER 
Published: April 2008

AbstractA linear theory of whistler waves is developed within the paradigm of a two-dimensional incompressible electron magnetohydrodynamics model. Exact analytic wave solutions are obtained for small-amplitude whistler waves that exhibit magnetic field topological structures consistent with the observations and our simulations in a linear regime. In agreement with experiment, we find that the parallel group velocity of the wave is large compared to its perpendicular counterpart. Numerical simulations of collisional interactions demonstrate that the wave magnetic field either coalesces or repels depending upon the polarity of the associated current. In the nonlinear regime, our simulations demonstrate that the evolution of the wave magnetic field is governed essentially by the nonlinear Hall force.
Use of host population reduction to control wildlife infection: rabbits and paratuberculosis
Authors: DAVIDSON R. S. , MARION G. , WHITE P. C. L. , HUTCHINGS M. R. 
Published: April 2008

SUMMARYReduction in wildlife populations is a common method for the control of livestock infections which have wildlife hosts, but its success is dependent on the characteristics of the infection itself, as well as on the spatial and social structure of the wildlife host. Paratuberculosis (Mycobacterium avium subsp. paratuberculosis; Map) is a widespread and difficult infection to control in livestock populations and also has possible links to Crohn's disease in humans. Rabbits have recently been identified as a key wildlife species in terms of paratuberculosis persistence in the environment and risk to the wider host community, including cattle. Here we use a spatially explicit stochastic simulation model of Map dynamics in rabbit populations to quantify the effects of rabbit population control on infection persistence. The model parameters were estimated from empirical studies of rabbit population dynamics and rabbit-to-rabbit routes of Map transmission. Three rabbit control strategies were compared: single unrepeated population reductions based on removing individual animals; single unrepeated population reductions based on removal of entire social groups; and repeated annual population reductions based on removing individual animals. Unrealistically high rabbit culls (>95% population reduction) are needed if infection is to be eradicated from local rabbit populations with a single one-off population reduction event, either of individuals or social groups. Repeated annual culls are more effective at reducing the prevalence of infection in rabbit populations and eradicating infection. However, annual population reductions of >40% are required over extended periods of time (many years). Thus, using an approach which is both highly conservative and parsimonious with respect to estimating lower bounds on the time to eradicate the infection, we find that Map is extremely persistent in rabbit populations and requires significant and prolonged effort to achieve control.
Multiclonal outbreak of methicillin-resistant Staphylococcus aureus infections on a collegiate football team
Authors: HALL A. J. , BIXLER D. , HADDY L. E. 
Published: April 2008

SUMMARYAn outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) occurred in a college football team in August 2006. Of 109 players on the team roster, 88 (81%) were interviewed during a cohort investigation. Twenty-five cases were identified, six of which were culture-confirmed. Available culture isolates were typed by pulsed-field gel electrophoresis (PFGE), which identified two different MRSA strains associated with the outbreak. Playing positions with the most physical contact (offensive linemen, defensive linemen, and tight ends) had the greatest risk of infection [risk ratio (RR) 5·1, 95% confidence interval (CI) 2·3–11·5. Other risk factors included recent skin trauma (RR 1·9, 95% CI 0·95–3·7), use of therapeutic hydrocollator packs (RR 2·5, 95% CI 1·1–5·7), and miscellaneous training equipment use (RR 2·1, 95% CI 1·1–4·1). The outbreak was successfully controlled through team education and implementation of improved infection-control practices and hygiene policies.
Comment: US – Countervailing Duty Investigation of DRAMS
Authors: PRUSA THOMAS J. 
Published: April 2008

AbstractThere are two compelling issues involved in US – Countervailing Duty Investigation of DRAMS. First, there is the question of whether creditors were ‘entrusted or directed’ to make financial contributions to Hynix, a large South Korean DRAM producer. This was the main topic addressed by the Appellate Body (AB) and is the focus of the François–Palmeter paper. Second, there is there is the question of injury assessment and nonattribution. Because the US did not appeal the Panel's decision, this aspect of the WTO dispute was not considered by the AB.
High Serum Leptin Is Associated with Attenuated Coronary Vasoreactivity
Authors: Sundell Jan , Huupponen Risto , Raitakari Olli T. , Nuutila Pirjo , Knuuti Juhani 
Published: April 2008

AbstractObjective: Hyperleptinemia, a hallmark of obesity, appears to be a risk factor for coronary artery disease. However, although leptin is a vasoactive hormone, no studies addressing leptin's effect on coronary perfusion have been performed. We examined the association between circulating leptin concentration and coronary vasoreactivity in young obese and nonobese males.Research Methods and Procedures: Myocardial blood flow was quantitated in 10 obese men (age 31 ± 7 years, BMI 34 ± 2 kg/m2) and 10 healthy matched nonobese men (age 33 ± 8 years, BMI 24 ± 2 kg/m2) using positron emission tomography and O‐15‐water. The measurements were performed basally and during adenosine infusion (140 μg/kg per minute).Results: Serum leptin was significantly higher in obese than nonobese subjects (10.3 ± 5.6 vs. 4.3 ± 2.5 ng/mL, p < 0.01). Basal myocardial blood flow was not significantly different between obese and nonobese subjects. Adenosine‐stimulated flow was blunted in obese (3.2 ± 0.6 mL/g per minute) when compared with nonobese subjects (4.0 ± 1.1 mL/g per minute, p < 0.05). Serum leptin concentration was inversely associated with adenosine‐stimulated flow in study subjects (r = −0.50, p < 0.05). This association was no longer observed after adjustment for obesity and/or hyperinsulinemia.Discussion: Hyperleptinemia and reduced coronary vasoreactivity occur concomitantly in young obese but otherwise healthy men. Moreover, the adenosine‐stimulated myocardial flow is inversely related to prevailing concentration of serum leptin. Although this relationship appears to be explained by obesity and/or hyperinsulinemia, leptin might have a role in regulation of myocardial blood supply.
Physical Activity in Confined Conditions as an Indicator of Free‐Living Physical Activity
Authors: Westerterp Klaas R. , Kester Arnold D.M. 
Published: April 2008

AbstractObjective: The main determinants of daily energy expenditure are body size and physical activity. Activity energy expenditure is the most variable component of total energy expenditure. It was assessed whether the physical activity level in confined conditions is an indicator of free‐living physical activity.Research Methods and Procedures: Activity energy expenditure was measured over 1 day in a confined environment of a respiration chamber (floor space, 7.0 m2), where activities were restricted to low‐intensity activities of daily living, and over 2 weeks in a free‐living environment using doubly labeled water. Subjects were 16 women and 29 men (age, 31 ± 10 years; BMI, 24.2 ± 2.7 kg/m2).Results: The free‐living activity level of the subjects, as a multiple of resting energy expenditure, was 1.76 ± 0.13. Activity energy expenditure in the chamber was 47 ± 13% of the value in daily life, and the two values were correlated (r = 0.50, p < 0.001; partial correlation corrected for age, gender, and BMI: 0.40, p < 0.01). The chamber value explained 25% of the total variance in free‐living activity energy expenditure.Discussion: The activity level of a subject under sedentary conditions is an indicator of activity energy expenditure in daily life, showing the importance of nonexercise activity for daily energy expenditure.
Waist Circumference, BMI, Smoking, and Mortality in Middle‐Aged Men and Women
Authors: Bigaard Janne , Tjønneland Anne , Thomsen Birthe Lykke , Overvad Kim , Heitmann Berit Lilienthal , Sørensen Thorkild I.A. 
Published: April 2008

AbstractObjective: Measurement of waist circumference alone as a proxy of abdominal fat mass has been suggested as a simple clinical alternative to BMI for detecting adults with possible health risks due to obesity.Research Methods and Procedures: From 1993 to 1997, 27, 178 men and 29, 875 women, born in Denmark, 50 to 64 years of age, were recruited in the Danish prospective study Diet, Cancer and Health. By the end of the year 2000, 1465 deaths had occurred. We evaluated the relationship between waist circumference and BMI (simultaneously included in the model) and all‐cause mortality. We used Cox regression models to estimate the mortality‐rate ratios and to consider possible confounding from smoking.Results: Waist circumference among both men and women showed a strong dose‐response type of relationship with mortality when adjusted for BMI, whereas the low range of BMI was inversely associated with mortality when adjusted for waist circumference. A 10% larger waist circumference corresponded to a 1.48 (95% confidence interval: 1.36 to 1.61) times higher mortality over the whole range of waist circumference. The associations were independent of age and time since baseline examination. Restriction to never smokers showed a similar pattern, but a weakening of the associations.Discussion: Despite the high correlation between waist circumference and BMI, the combination may be very relevant in clinical practice because waist circumference for given BMI was a strong predictor of all‐cause mortality. The inverse association between BMI and mortality for given waist circumference was diminished in never smokers, particularly for high values of BMI.
The Effect of the −308A Allele of the TNF‐α Gene on Insulin Action Is Dependent on Obesity
Authors: Pihlajamäki Jussi , Ylinen Mari , Karhapää Pauli , Vauhkonen Ilkka , Laakso Markku 
Published: April 2008

AbstractObjective: Promoter polymorphisms of the tumor necrosis factor alpha (TNF‐α) gene are associated with insulin sensitivity and BMI. We investigated whether the effect of the G‐308A polymorphism of the TNF‐α gene on insulin action depends on BMI.Research Methods and Procedures: The effects of the G‐308A polymorphism on the rates of glucose and lipid oxidation and free fatty acid (FFA) levels were studied using the hyperinsulinemic euglycemic clamp combined with indirect calorimetry in 129 healthy subjects.Results: The −308A allele of the TNF‐α gene was associated with high rates of glucose oxidation (p = 0.008 adjusted for age, gender, and BMI) and lipid synthesis (p = 0.037) and suppression of FFA levels (p = 0.023) during hyperinsulinemia. In normal weight subjects (BMI < 26 kg/m2), the −308 allele was associated with high rates of glucose oxidation (p = 0.036) during the clamp but not with high rates of lipid synthesis (p = 0.896) or FFA suppression (p = 0.464). In overweight subjects (BMI ≥ 26 kg/m2), high rates of lipid synthesis and FFA suppression (p = 0.010 and p = 0.042, respectively) but not the rates of glucose oxidation during the clamp (p = 0.193) were associated with the −308A allele.Discussion: The −308A allele of the promoter of the TNF‐α gene is associated with high rates of glucose oxidation in normal weight subjects and with effective lipid storage in overweight subjects. These findings suggest an interaction of the polymorphism with obesity.
Perilipin Expression in Human Adipose Tissues: Effects of Severe Obesity, Gender, and Depot
Authors: Wang Yanxin , Sullivan Sean , Trujillo Maria , Lee Mi‐Jeong , Schneider Stephen H. , Brolin Robert E. , Kang You Hou , Werber Yaron , Greenberg Andrew S. , Fried Susan K. 
Published: April 2008

AbstractObjective: Perilipins are phosphoproteins that are localized to the surface of triacylglycerol droplets within adipocytes where they regulate the rate of lipolysis. We sought to determine the effects of severe obesity and depot [omental (Om) vs. subcutaneous (Sc)] on perilipin expression in the adipose tissue of individuals.Research Methods and Procedures: Samples of Om and Sc adipose tissues obtained at surgery from severely obese subjects and fat aspirations from nonobese subjects were analyzed for perilipin protein and mRNA levels by Northern and Western analysis.Results: Perilipin A (periA) was the major perilipin expressed in adipose tissues. periA mRNA relative abundance was significantly lower in Sc adipose tissue from severely obese compared to that from nonobese subjects. Western blotting of adipose tissue extracts showed that periA protein levels expressed relative to tissue protein or fat cell surface area were significantly lower (∼ −40%) in abdominal Sc adipose tissue from severely obese compared to that from nonobese subjects. However, the calculated mass of perilipin per fat cell did not differ between the two groups. Perilipin mRNA levels were higher in Sc compared to Om adipose tissue from obese individuals (p < 0.025; n = 26; 17 women, 9 men); however, periA protein levels did not differ. In addition, perilipin protein, but not mRNA, levels were higher in Sc adipose tissue from obese men than from women (p < 0.025).Discussion: Variations in perilipin expression may contribute to the higher basal lipolytic rates observed in obese compared to nonobese individuals and in obese women compared to obese men.
Low Resting and Sleeping Energy Expenditure and Fat Use Do Not Contribute to Obesity in Women
Authors: Weinsier Roland L. , Hunter Gary R. , Zuckerman Paul A. , Darnell Betty E. 
Published: April 2008

AbstractObjective: Determine whether sleeping and resting energy expenditure and sleeping, resting, and 24‐hour fuel use distinguish obesity‐prone from obesity‐resistant women and whether these metabolic factors explain long‐term weight gain.Research Methods and Procedures: Forty‐nine previously overweight but currently normal‐weight women were compared with 49 never‐overweight controls. To date, 87% of the 98 women have been re‐evaluated after 1 year of follow‐up, without intervention, and 38% after 2 years. Subjects were studied at a General Clinical Research Center after 4 weeks of tightly controlled conditions of energy balance and macronutrient intake. Forty‐nine obesity‐prone weight‐reduced women were group‐matched with 49 never‐overweight obesity‐resistant controls. All were premenopausal, sedentary, and normoglycemic. Energy expenditure and fuel use were assessed using chamber calorimetry. Body composition was assessed using DXA.Results: At baseline, percent body fat was not different between the obesity‐prone and control women (33 ± 4% vs. 32 ± 5%, respectively; p = 0.22). Analysis of covariance results show that after adjusting for lean and fat mass, sleeping and resting energy expenditure of obesity‐prone women was within 2% of controls. Neither sleeping nor resting energy expenditure nor sleeping, resting, or 24‐hour fuel use was significantly different between the groups (p > 0.25). None of the metabolic variables contributed significantly to patterns of weight gain at 1 or 2 years of follow‐up.Discussion: The results suggest that when resting and sleeping energy expenditure and fuel use are assessed under tightly controlled conditions, these metabolic factors do not distinguish obesity‐prone from obesity‐resistant women or explain long‐term weight changes.
Maternal Obesity and Infant Heart Defects
Authors: Cedergren Marie I. , Källén Bengt A.J. 
Published: April 2008

AbstractObjective: This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women.Research Methods and Procedures: In a case‐control study, prospectively collected information was obtained from Swedish medical health registers. The study included 6801 women who had infants with a cardiovascular defect and, as controls, all delivered women (N = 812, 457) during the study period (1992 to 2001). Infants with chromosomal anomalies or whose mothers had pre‐existing diabetes were excluded. Obesity was defined as BMI >29 kg/m2, and morbid obesity was defined as BMI >35 kg/m2. Comparisons were made with average weight women (BMI = 19.8 to 26 kg/m2).Results: In the group of obese mothers, there was an increased risk for cardiovascular defects compared with the average weight mothers [adjusted odds ratio (OR) = 1.18; 95% CI, 1.09 to 1.27], which was slightly more pronounced for the severe types of cardiovascular defects (adjusted OR = 1.23; 95% CI, 1.05 to 1.44). With morbid obesity, the OR for cardiovascular defects was 1.40 (95% CI, 1.22 to 1.64), and for severe cardiovascular defects, the OR was 1.69 (95% CI, 1.27 to 2.26). There was an increased risk for all specific defects studied among the obese women, but only ventricular septal defects and atrial septal defects reached statistical significance.Discussion: In this sample, a positive association was found between maternal obesity in early pregnancy and congenital heart defects in the offspring. A suggested explanation is undetected type 2 diabetes in early pregnancy, but other explanations may exist.