cssi/SciSciGPT-SciSciNet huggingface dataset:
Designing cost-efficient randomized trials by using flexible recruitment strategies.

Sample size planning for clinical trials is usually based on detecting a target effect size of an intervention or treatment. Explicit incorporation of costs into such planning is considered in this article in the situation where effects of an intervention or treatment may depend on (interact with) baseline severity of the targeted symptom or disease. Because much larger sample sizes are usually required to establish such an interaction effect, investigators frequently conduct studies to establish a marginal effect of the intervention for individuals with a certain level of baseline severity. We conduct a rigorous investigation on how to determine optimum baseline symptom or disease severity inclusion criteria so that the most cost-efficient design can be used. By using a regression model with an interaction term of treatment by symptom severity, power functions were derived for various levels of baseline symptom severity. Computer algorithms and mathematical optimization were used to determine the most cost-efficient research designs assuming either single- or dual-stage screening procedures. In the scenarios we considered, impressive cost savings can be achieved by informed selection of baseline symptom severity via the inclusion criteria. Further cost-savings can be achieved if a two stage screening procedure is used and there are some known, relatively inexpensively collected, pre-screening information. The amount of total cost savings are shown to depend on the ratio of the screening and intervention costs. In our investigation, we assumed that: 1) the cost of approaching available subjects for screening is constant, and 2) all variables are normally distributed. There is a need to carry out further investigations with more relaxed assumptions (e.g., skewed data distribution). As cost becomes a more and more prominent issue in modern clinical trials, cost-saving strategies will become more and more important. Strategies, such as the ones we propose here, can help to minimize costs while maximizing knowledge generation.
Functional interaction between DNA-PK and c-Abl in response to DNA damage

How DNA damage is converted into intracellular signals that can control cell behaviour is unknown. The c-Abl protein tyrosine kinase is activated by ionizing radiation and certain other DNA-damaging agents1–5, whereas the DNA-dependent protein kinase (DNA-PK), consisting of a serine/threonine kinase and Ku DNA-binding subunits, requires DNA double-strand breaks or other DNA lesions for activation6–8. Here we demonstrate that c-Abl interacts constitutively with DNA-PK. Ionizing radiation stimulates binding of c-Abl to DNA-PK and induces an association of c-Abl with Ku antigen. We show that DNA-PK phosphorylates and activates c-Abl in vitro. Cells deficient in DNA-PK are defective in c-Abl activation induced by ionizing radiation. In a potential feedback mechanism, c-Abl phosphorylates DNA-PK, but not Ku, in vitro. Phosphorylation of DNA-PK by c-Abl inhibits the ability of DNA-PK to form a complex with DNA. We also show that treatment of cells with ionizing radiation results in phosphorylation of DNA-PK that is dependent on c-Abl. Our results support the hypothesis that there are functional interactions between c-Abl and DNA-PK in the response to DNA damage.
Optical stretching as a tool to investigate the mechanical properties of lipid bilayers.

Measurements of lipid bilayer bending moduli by various techniques produce widely divergent results. We attempt to resolve some of this ambiguity by measuring the bending modulus in a system that can rapidly process large numbers of samples, yielding population statistics. This system is based on optical stretching of giant unilamellar vesicles (GUVs) in a microfluidic dual-beam optical trap (DBOT). The microfluidic DBOT system is used here to measure three populations of GUVs with distinct lipid compositions. We find that gel-phase membranes are significantly stiffer than liquid-phase membranes, consistent with previous reports. We also find that the addition of cholesterol does not alter the bending modulus of membranes composed of a monounsaturated phospholipid.
Parent and Peer Pathways to Adolescent Delinquency: Variations by Ethnicity and Neighborhood Context

Effects of ethnicity and neighborhood quality often are confounded in research on adolescent delinquent behavior. This study examined the pathways to delinquency among 2,277 African American and 5,973 European American youth residing in high-risk and low-risk neighborhoods. Using data from a national study of youth, a meditational model was tested in which parenting practices (parental control and maternal support) were hypothesized to influence adolescents’ participation in delinquent behavior through their affiliation with deviant peers. The relationships of family and neighborhood risk to parenting practices and deviant peer affiliation were also examined. Results of multi-group structural equation models provided support for the core meditational model in both ethnic groups, as well as evidence of a direct effect of maternal support on delinquency. When a similar model was tested within each ethnic group to compare youths residing in high-risk and low-risk neighborhoods, few neighborhood differences were found. The results indicate that, for both African American and European American youth, low parental control influences delinquency indirectly through its effect on deviant peer affiliation, whereas maternal support has both direct and indirect effects. However, the contextual factors influencing parenting practices and deviant peer affiliation appear to vary somewhat across ethnic groups. Overall the present study highlights the need to look at the joint influence of neighborhood context and ethnicity on adolescent problem behavior.
Acid tolerance of acid-adapted and nonacid-adapted Escherichia coli O157:H7 strains in beef decontamination runoff fluids or on beef tissue

This study assessed the acid tolerance response (ATR) of stationary phase, acid-adapted (tryptic soy broth [TSB]+1% glucose) or nonacid-adapted (glucose-free TSB) Escherichia coli O157:H7 strains (ATCC43889, ATCC43895, ATCC51658 and EO139), grown individually or in a mixed culture, prior to inoculation of beef or meat decontamination runoff (washings) fluids (acidic [pH 4.95] or nonacidic [pH 7.01]). The inoculated beef was left untreated or treated by dipping for 30s in hot water (75 degrees C) followed by 2% lactic acid (55 degrees C). Inoculated beef samples and washings were stored aerobically at 4 or 15 degrees C for 6d, and at set intervals (0, 2, and 6d) were exposed (for 0, 60, 120, and 180min) to pH 3.5 (adjusted with lactic acid) TSB plus 0.6% yeast extract. Overall, there were no significant (P0.05) differences in responses of cultures prepared as individual or mixed strains. Decontamination of meat did not affect the subsequent ATR of E. coli O157:H7 other than resulting in lower initial pathogen levels exposed to acidic conditions. In this study, E. coli O157:H7 appeared to become more tolerant to acid following incubation in acidic washings of sublethal pH (4.89-5.22) compared to nonacidic washings (pH 6.97-7.41) at 4 degrees C or in both types of washings incubated at 15 degrees C. The ATR of the pathogen inoculated into washings was enhanced when cells were previously acid-adapted and incubated at 4 degrees C. Similarly, the ATR on meat was increased by previous acid-adaptation of the inoculum in broth and enhanced by storage at 4 degrees C. Populations on treated meat were consistently lower than those on untreated meat during storage and following exposure to acid. Although on day-0 there were no significant (P0.05) differences in ATR between acid-adapted and nonacid-adapted populations on meat, acid-adapted cells displayed consistently higher resistance through day-6. This suggests that acid-adapted E. coli O157:H7 introduced on meat may become resistant to subsequent lactic acid exposure following storage at 4 degrees C.
Interspecific chemically mediated recognition in two competing stomatopods

The stomatopods Gonodactylus zacae and G. bahiahondensis occur sympatrically along the Pacific coast of Central America and appear to be in competition for cavities in hard substrates. To test if individuals of one species can distinguish among the odours of the other species, G. zacae were exposed to cavities occupied by G. bahiahondensis and were defeated by the resident. Later, the G. zacae were given the opportunity to enter cavities containing either the odours of the previous residents that had just defeated them or the odours of other, unknown G. bahiahondensis. The G. zacae were cautious, but entered the cavities containing the odours of the unknown animals. They took strong defensive action against and/or avoided cavities containing the odours of the animals that had defeated them. This suggests the ability of G. zacae to learn to identify, using chemical cues, individuals of another species.
Simulation of Crystal Growth With Facetted Interfaces

We present a method for simulation of crystal growth using completely facetted interfaces and the definition of curvature appropriate to such interfaces. The representation of these surfaces, as facets with fixed normal directions, variable distances, and semi-fixed adjacencies, is quite different from that in other methods. It is flexible as to possible growth rules, it appears to avoid the problems involved in measuring curvature and in detecting and making topological changes, and it runs relatively fast. We expect it to be a valid method to approximate growth with any isotropie or anisotropie surface energy and kinetics. The use of the method is demonstrated in dendritic crystal growth and in Ostwald ripening.
Dismembering and Remembering the Nation: The Semantics of Political Violence in Venezuela

Although political violence has played a central part in the formation of nations, its historical constitution and its role in representing nations havereceived scant attention. All too frequently the explanation of violence is equated with the identification of its causes, its form is accounted for by its function, and its function is seen in instrumental terms; violence is reduced to a practical tool used by opposing social actors in pursuit of conflicting ends. Whether treated as a cause, function, or instrument, violence is generally assumed rather than examined in its concreteness. Little attention is paid to its specific manifestations, to the way its effects are inseparably related to the means through which it is exerted, and to the meanings that inform its deployment and interpretation. In contrast, typological approaches that postulate a correspondence between types of societies and forms of violence often recognize the opacity of violence yet lose sight of the historical depth and specificity of its manifestations.
The effect of a new anti-aldosterone agent SC19886 on aldosterone-stimulated transepithelial sodium transport.

Abstract A new anti-aldosterone compound SC 19886, a 12α, 13β-etiojervane derivative, was evaluated using an isolated toad bladder preparation. Based on analysis of a Lineweaver-Burk plot. SC 19886 effect on aldosterone-stimulated short circuit current is compatible with competitive inhibition of the steroid's action on transepithelial sodium transport. At a concentration of 3·5 × 10−5 M or less. SC 19886 did not distort nonsteroid (basal) sodium transport, nor did it interfere with vasopressin-stimulated short circuit current. By comparing the dissociation constant derived from SC 19886 with values previously obtained for the spirolactone SC 14266 and spironolactone (SC9420), SC 19886 was five times more potent than SC 14266 and 28 times more effective than SC9420 in blocking aldosterone in vitro. From the washout characteristics and the results of the late addition of SC 19886 once the aldosterone stimulated transepithelial sodium transport was established, interpretation favored a mechanism of inhibition occurring via nuclear receptor occupancy by SC 19886 with resulting interruption of the aldosteroneinduced DNA-dependent RNA synthesis.
Collinearity and stability in the estimation of rainfall-runoff model parameters

Abstract The common use of statistical rainfall-runoff models of the regressive type lead to the problem of handling the unavoidable correlation existing between the explanatory variables of these models. The above collinearity problem is treated using ridge regression techniques. This powerful regression method is extensively presented and discussed. Examples show that collinearity has significant effects on values of rainfall-runoff model parameters and that ridge regression effectively deals with the problem, leading to well behaved model coefficients. The important issue of parameter stability is also addressed using both ridge regression and Kalman filtering as estimation procedures. It is shown that considerable data are required before parameter stability is achieved casting serious doubts on the predictive capability of models developed with usually limited historical data. Although a powerful methodology, Kalman filtering exhibited disturbing instability and lack of convergence unless special algorithms of high numerical accuracy are used.
Isolated Labium Minus Agenesis and Clitoral Foreskin Hypertrophy: Case Report and Review of the Literature

External genital hypoplasia is rare in females and is often accompanied by other abnormalities. We present a case of isolated labium minus agenesis and clitoral foreskin hypertropy with normal pubertal development and normal phenotype and genotype.
Impact of cardiac rehabilitation exercise program on left ventricular diastolic function in coronary artery disease: a pilot study.

Diastolic dysfunction is common in coronary artery disease (CAD). Exercise-based cardiac rehabilitation (CR) improves survival and quality of life but its effect on diastolic function is unclear. We sought to determine the impact of CR on diastolic function. We conducted a prospective study of CAD patients referred for 3-month outpatient CR, with pre-CR and post-CR echocardiograms. Twenty-five outpatients (age [mean ± SD], 66 ± 11 years; 7 [28 %] women; 22 [88 %] with recent acute coronary syndrome) were recruited upon beginning CR; one patient lacking follow-up was excluded from analysis. Before CR, patients’ mean ejection fraction was 61 ± 7 %; regional wall motion score index was 1.18 ± 0.28; and left ventricular diastolic dysfunction existed in 21 (88 %). Of the 24 (96 %) patients with post-CR follow-up, 12 (50 %) had improved diastolic function, 2 of the 24 (8 %) had normal diastolic function throughout, nine (38 %) remained at the same grade, and one (4 %) had worsened diastolic function. The E/e′ ratio improved significantly after CR (11.9 ± 4.5 vs. 10.7 ± 4.5; P = .048). Fourteen patients with normal or improved diastolic function had a greater decrease in left atrial volume index (−4.2 ± 6.3 vs. 1.6 ± 6.3 mL/m2; P = .04) and a greater increase in peak untwisting rate (20 ± 36 vs. −42 ± 45 °/s; P = .003) than did patients with no diastolic improvement. Three-month, exercise-based CR was associated with improved left ventricular diastolic function in half of our patients. Further large studies are needed to clarify the effect of CR on diastolic dysfunction in patients with CAD.
Skill-Based Pay and Skill Seeking

Abstract Much discussion has been devoted to why organizations might wish to use skill-based pay (e.g., its hypothesized effects on organizational outcomes and fit with organizational design and processes). However, there has been little attention given to conceptual development of the “how” of skill-based pay in terms of how it affects key employee beliefs, intentions, and behaviors. To begin to address this omission, we offer a model of perhaps the most central process, the individual employee's skill seeking under skill-based pay. Using a planned behavior approach, we propose that workers' choice of whether or not to progress through the pay structure is a function of the workers' attitudes (expectancies of the pay, training, job and personal outcomes associated with skill-based pay), subjective norms (the developmental, contribution, and achievement norms that develop under skill-based pay), and perceived behavioral control (the individual's perceived pay-related knowledge, self-efficacy, and support). Further, we propose that the design and implementation of skill-based pay play an important role in moderating whether workers' intentions to skill seek become skill-seeking behavior through their influence on perceived behavioral control.
Boron clusters (Bn, n = 2–52) produced by laser ablation of hexagonal boron nitride

Abstract We report the discovery of boron clusters (B n , n = 2–52) formed by ablation of hexagonal boron nitride with a 532 nm laser, creating species which are ionized with a 193 nm UV laser and analyzed with a time-of-flight (TOF) mass spectrometer.
Integration of psychiatric teaching with pediatrics

D URING the past two decades great changes have been taking place in the teaching of psychiatry. These changes have followed the dynamic leadership of such men as Drs. Adolph Meyer, Maefie Campbell, C. B. Farrar, Edward Strecker, Douglas Singer, Franklin R. Ebaugh, and the medical directors of the National Committee for Mental Hygiene from Thomas W. Salmon, the first, through Dr. George S. Stevenson, the present director. These and many others have given direction to the trend psychiatric education has taken. Today, as a result of their labors, basic psychiatric principles are taught in every class A medical school in the country. The history of these changes is a fascinating chapter in the growth and development of medical school curricula. The methods employed vary from school to school, but essentially they have many features in common. Active classroom work consisting of didactic lectures is reinforced by clerkships, outpatient clinic service, and interdepartmental consultation services, together with the examination of one or more patients as part of the clinical year's experience. There has been a gradual shift from the presentation of the standardized series of nosologic classifications to a consideration of the individual case with its intrinsic features. Along with this modification has come a shift in emphasis from the diagnostic to the dynamic concepts. In addition, we have noted less stress on the study of terminal conditions and more consideration of the early manifestations of maladjustments, with the aim of reclaiming the patient. To date, most psychiatric instruction has dealt primarily with the adult and his adjustments to the everyday world. However, studies of the adult have brought out at least two significant facts worthy of accent: (]) the importance of the early formative years in the development of the personality and the molding of character traits which either aid and abet or hinder the individual in making a satisfactory adjustment later in life; and (2) a growing awareness of the significant role played by mental and emotional factors in the disease process. With few exceptions, the medical student today is not adequately exposed to these two important aspects of medical practice. Is not the time for another advance in enriching the medical curriculum at hand?
Anionic binding of ruthenium red in fish extraocular muscle.

Application of Luft's ruthenium red technique to extraocular muscle of Fundulus grandis reveals dense accumulations of ruthenium red-positive material along the sarcolemma, in the synaptic cleft of the myoneural junction and in the T tubules. The granular material in the terminal sacs of the sarcoplasmic reticulum (SR), which is consistently preserved by glutaraldehyde fixation and osmium tetroxide postfixation, also reacts with ruthenium red. The intracellular ruthenium red has been seen outside the SR only where the sarcolemma obviously has been disrupted.
Simulation for Design Purposes of Magnetic Fields in Turbogenerators with Symmetrical and Asymmetrical Rotors Part I-Model Development and Solution Technique

A model the magnetic fields in turbo- generators with either symmetrical or asymmetrical rotor has been developed, and mathematically described and solutions obtained using the digital computer. The model was developed specifically for use in the design stage. It is applied to the entire cross-section of the generator and is applicable to a wide range of machine geometries.
PRODEN: A new program for calculating integrated projected populations

Two new computational methods for the evaluation and partitioning of projected, planar, and averaged slab electron densities, implemented in the program PRODEN, are presented. The new algorithms for the projection, demarcation, and integration of electron densities are described and evaluated in terms of speed and numerical accuracy. Integrated Projected Populations are analyzed and some of the advantages and limitations of the methods are discussed.
The golli-myelin basic protein negatively regulates signal transduction in T lymphocytes.

Abstract Protein kinase C (PKC) plays a critical role in signal transduction controlling T lymphocyte activation. Both positive and negative regulation of signal transduction is needed for proper control of T lymphocyte activation. We have found that a golli product of the myelin basic protein (MBP) gene can serve as a negative regulator of signaling pathways in the T lymphocyte, particularly the PKC pathway. Increased expression of golli BG21 in Jurkat T cells strongly inhibits anti-CD3e-induced IL-2-luciferase activity, an indicator of T lymphocyte activation. Golli BG21 can be phosphorylated by PKC in vitro and its phosphorylation increases in PMA-activated Jurkat cells. BG21 inhibits the PMA-induced increase in AP-1 or NF-κB activation, consistent with golli acting in a PKC-mediated cellular event. Golli BG21 inhibition of the PKC pathway is not due to a direct action on PKC activation but in the cascade following PKC activation, since BG21 neither reduces PKC enzyme activity nor blocks the membrane association of PKCθ brought on by T lymphocyte activation. The inhibitory function of BG21 is independent of its phosphorylation by PKC because a mutant BG21, in which the PKC sites have been mutated, is as effective as the wild type BG21 in inhibiting the PMA-induced AP-1 activation. Structure–function assays indicate that BG21 inhibitory activity resides in the golli domain rather than in MBP domain of the molecule. These results reveal a novel role for MBP gene products in T lymphocytes within the immune system.
Relationship between biliary tract distention and the blood flow in the aorta and right coronary and renal arteries

Summary The gallbladder and common duct of anesthetized and unanesthetized dogs were distended while simultaneous recordings of the blood flow through the aorta, the right coronary artery, and the renal arteries were made. Distention of the biliary tree failed to demonstrate any change in the blood flow of these arteries.
Cardiac potassium channels in health and disease.

Abstract Cardiac K + currents regulate resting membrane potential and action potential duration. These tasks are accomplished for the most part by four membrane currents: an inwardly rectifying current (I K1 ), a transient outward current (I To ), and rapid (I Kr ), and slow (I Ks ) delayed rectifier currents. Recent studies have revealed far greater complexity at the molecular level. I K1 may be produced by at least three genes from the Kir 2 subfamily of the supergene Kir family. The remaining currents appear to be produced by the supergene Kvα family, sometimes in association with the cytoplasmic protein Kvβ family. I To may be produced by the Kv4 subfamily, but members of the Kv1 subfamily could contribute, particularly if associated with Kvβ genes. Very rapid currents could be produced by Kv1.5, but Kvs 1.2 and 2.1 might also participate. Additional levels of complexity are possible because members within a Kv subfamily may form heterotetramers, and these, in turn, may associate with different Kvβs. The situation may be simpler for I Kr and I Ks , which at present appear to be produced by the Kv HER gene and the KvLQT1 gene, respectively. Mutations of these two genes have been linked to two forms of hereditary long QT syndrome, and heterologous expression of mutant HERGs has reproduced the pathophysiological phenotype satisfactorily. Sporadic mutations in these and other cardiac K + channel genes may provide a basis for hypersensitivity to cardioactive or cardiotoxic drugs. (Trends Cardiovasc Med 1997;7:118–124). © 1997, Elsevier Science Inc .
OSSL: a specialized language for simulating computer systems

The need for evaluating the performance of contemporary computer systems is well recognized by the manufacturers as well as the users of these systems. The evaluation is difficult because of the complexities and sophistication of the computer hardware and software system design. The computer manufacturers have produced an abundance of literature encompassing somewhat subjective evaluations of their products. Unfortunately, relatively little effort has been directed by the manufacturer toward the development of generalizable scientific tools for the purpose of a quantified evaluation of the performance of computer systems operating in a specified environment. The need for such generalizable scientific tools for studying the behavior of a given computer system in a specified environment can hardly be over-emphasized.
Matching Gas Exchange in the Bat from Flight to Torpor

SYNOPSIS. Many microchiropteran bats can reduce their metabolic rate three orders of magnitude during heterothermic torpor. This extraordinary range provides a unique insight into the adaptability of mammalian ventilatory control and function. To enable powered flight, bats have developed the highest capacity gas exchange system among mammals. However, starving during winter may account for the greatest mortality among bats that hibernate, thus imposing a strong selective pressure to decrease metabolic cost during torpor. This high capacity gas exchange system must therefore operate efficiently at very reduced rates, despite conflicting mechanical constraints imposed by an enormous functional overhead. The bat surmounts this dilemma by adjusting its control strategy to breathe intermittently during torpor. This allows instantaneous breathing rates and tidal volumes near predicted optimal levels. In addition, a passive oxygen influx coupled with a high acidotic tolerance facilitates longer intervals between the breathing bouts. The acidotic tolerance supports the endurance of these apneas because the passive efflux of carbon dioxide does not match the rate of oxygen influx. The acidotic tolerance further helps by allowing carbon dioxide to enrich the alveolar gas during apnea to levels above that of a nonacidotic, continuous pattern of breathing. Thus, the bat's carbon dioxide load can be cleared in fewer breaths when breathing resumes. By efficiently controlling a high capacity gas exchange system to meet the minuscule demands during torpor, the bat demonstrates how physiological control strategies can adapt to overcome limitations imposed by conflicting selection pressures.
Exact geometrical optics scattering by a right-angle wedge made of double-negative material

The scattering of a plane wave incident upon a right-angle wedge made of a metamaterial whose permittivity and permeability are the opposites of those of the space surrounding the wedge is considered. It is shown that geometrical optics yields the exact solution to this scattering problem, for a certain range of angles of incidence and arbitrary polarization
Intracellular pH regulates superoxide production by the macula densa

We hypothesized that elevated macula densa intracellular pH (pHi) during tubuloglomerular feedback enhances O2− production from NAD(P)H oxidase. Microdissected thick ascending limbs from rabbits wi...
Influence of recipient age on deceased donor kidney transplant outcomes in the expanded criteria donor era.

Methods We performed a retrospective single-center review of 884 deceased donor (DD) kidney transplants (KTs) in patients (pts) aged ≥40 yr. Results One hundred and four (11.8%) pts were ≥70 (mean 74), 286 (32.3%) were 60–69 (mean 64), and 494 (55.9%) were 40–59 (mean 51) yr of age; the proportion receiving expanded criteria donor (ECD) kidneys were 66%, 49%, and 30%, respectively (p < 0.001). Mean waiting time (15 months) was shorter for pts ≥70 yr compared to the other two groups combined (23 months, p = 0.002). With mean follow-up ranging from 54 to 70 months, actual pt (81% vs. 72%, p = 0.002) and graft (66% vs. 58.5%, p = 0.03) survival rates were higher in the younger compared to the two older groups, whereas death-censored graft survival was similar (76% vs. 73%, p = NS). The incidence of death with a functioning graft correlated with older recipient age group, increasing from 13% to 18% to 23% (p = 0.01). The incidence of delayed graft function was similar (31.8% overall), and renal function, morbidity, and resource utilization were similar among groups. Conclusions By directing ECD kidneys to selected older pts, waiting times are reduced and censored survival outcomes are similar to middle-aged patients, suggesting that matching strategies for graft and patient lifespan are warranted.
CUDA Implementation of ${\rm TE}^{z}$ -FDTD Solution of Maxwell's Equations in Dispersive Media

This letter presents the graphic processor unit (GPU) implementation of the finite-difference time domain (FDTD) method for the solution of the two-dimensional electromagnetic fields inside dispersive media. The FDTD is truncated by the convolutional perfectly matched layer (CPML) and the piecewise-linear recursive-convolution (PLRC) formulation is used for modeling dispersive media. By using the newly introduced Compute Unified Device Architecture (CUDA) technology, we illustrate the efficacy of GPUs in accelerating the FDTD computations by achieving significant speedup factors with great ease and at no extra hardware/software cost. We validate our approach by comparison to exact and other simulated results, which show favorable agreements. The effect of the GPU-CPU memory transfers on the speedup factor will be also studied.
Using satellite time-series data sets to analyze fire disturbance and forest recovery across Canada

The boreal forest biome is one of the largest on Earth, covering more than 14% of the total land surface. Fire disturbance plays a dominant role in boreal ecosystems, altering forest succession, biogeochemical cycling, and carbon sequestration. We used two time-series data sets of Advanced Very High Resolution Radiometer (AVHRR) Normalized Differenced Vegetation Index (NDVI) imagery for North America to analyze vegetation recovery after fire. The Canadian Forest Service Large Fire Database was used to identify the location of fires and calculate scaled NDVI statistics from the Pathfinder AVHRR Land (PAL) and the Global Inventory Modeling and Mapping Studies (GIMMS) AVHRR data sets. Unburned areas were also identified, based on interannual variability metrics, in order to reduce the effects of factors other than fire on the temporal behavior of scaled NDVI. Burned and unburned areas were stratified by ecoregion to ensure the presence of comparable land cover types and account for influences of local environmental variability. Temporal anomalies in NDVI for burned and unburned areas show the impacts of fire and the recovery of the forest to pre-burn levels, and indicate changes in variability that might be associated with vegetation compositional changes consistent with early successional species. The rate of recovery varied in the three episodic fire years on which we focused our analysis (1981, 1989, and 1995), but were consistently shorter than previous studies that emphasized the most impacted areas within fires. Temporal variability in the time series, represented by the difference of burned and unburned area anomalies, increased beyond the observed post-fire recovery period. This indicates residual effects of fire disturbance over the regrowth period, perhaps associated with early successional vegetation and increased susceptibility to drought. Distinct differences were noted between the PAL and GIMMS data sets, with evidence for systematic data processing artifacts remaining in the PAL time series. © 2006 Elsevier Inc. All rights reserved.
Buprenorphine treatment of opioid dependence: clinical trial of daily versus alternate-day dosing

Buprenorphine, a mu-opioid partial agonist, has demonstrated efficacy for the treatment of opioid dependence comparable to that of methadone. The clinical utility of buprenorphine would be enhanced if it could be dosed on a less than daily basis. The current study is a parallel-group outpatient clinical trial of daily versus alternate-day dosing with 8 mg sublingual (s.l.) buprenorphine. Participants were randomly assigned to daily (n = 51) or alternate-day (n = 48) schedules of active medication administration for an 11-week double-blind trial. Patients assigned to alternate-day buprenorphine received placebo every other day. Primary outcome measures were retention in treatment and urine specimens positive for opiates. Clinic attendance, dose adequacy ratings, withdrawal symptomatology, and urine specimens positive for cocaine were secondary outcome measures. Neither endpoint analysis with the intent-to-treat sample nor time course analysis with treatment completers revealed any statistically significant differences between the dosing schedules on any outcome measure. Examination of 95% confidence intervals suggested a non-significant trend for the daily dosing schedule to have superior clinical efficacy at the dose tested. Nevertheless, these results are generally consistent with previous studies of less than daily dosing with buprenorphine and support the conclusion that an alternate-day dosing schedule can be effective in and acceptable to a substantial portion of patients.
Continuation Along Bifurcation Branches for a Tumor Model with a Necrotic Core

We consider a free boundary problem for a system of partial differential equations, which arises in a model of tumor growth with a necrotic core. For any positive number R and 0<?<R, there exists a radially-symmetric stationary solution with tumor free boundary r=R and necrotic free boundary r=?. The system depends on a positive parameter μ, which describes tumor aggressiveness, and for a sequence of values μ 2<μ 3<?, there exist branches of symmetry-breaking stationary solutions, which bifurcate from these values. Upon discretizing this model, we obtain a family of polynomial systems parameterized by tumor aggressiveness factor μ. By continuously changing μ using a homotopy, we are able to compute nonradial symmetric solutions. We additionally discuss linear and nonlinear stability of such solutions.
Folding of a Highly Conserved Diverging Turn Motif from the SH3 Domain

Recent NMR structural characterization studies showed that a seven-residue segment (FKKGERL) from the src SH3 domain adopts the nativelike diverging type II β-turn in aqueous solution in support of the prediction based on the I-sites library of sequence structural motifs. We study the conformational variability and folding/unfolding thermodynamics of this peptide in explicit solvent using replica-exchange molecular dynamics simulations, which greatly enhances the sampling of the conformational space. This peptide samples three main free energy basins (nativelike, intermediate, and unfolded) separated by small barriers. The nativelike basin is fractionally populated (ΔG300K = 0.4 kcal/mol) with structures that satisfy a subset of the NMR-derived constraints. The intrinsic stability of the diverging turn is examined in relationship to the nature of three specific contacts: a turn-hydrogen bond, a mainchain-to-sidechain hydrogen bond, and an end-to-end hydrophobic contact. We have carried out simulations of mutants at the highly conserved GE positions in the sequence. The mutation E5D destabilizes the isolated diverging turn motif, contrary to the observation that this mutation stabilizes the fyn SH3 domain. The G4T mutation also destabilizes the isolated diverging turn; however, the extent of destabilization is smaller than that of the reverse mutation in the drk SH3.
Graphite electrodes as electron donors for anaerobic respiration

It has been demonstrated previously that Geobacter species can transfer electrons directly to electrodes. In order to determine whether electrodes could serve as electron donors for microbial respiration, enrichment cultures were established from a sediment inoculum with a potentiostat-poised graphite electrode as the sole electron donor and nitrate as the electron acceptor. Nitrate was reduced to nitrite with the consumption of electrical current. The stoichiometry of electron and nitrate consumption and nitrite accumulation were consistent with the electrode serving as the sole electron donor for nitrate reduction. Analysis of 16 rRNA gene sequences demonstrated that the electrodes supplied with current were specifically enriched in microorganisms with sequences most closely related to the sequences of known Geobacter species. A pure culture of Geobacter metallireducens was shown to reduce nitrate to nitrite with the electrode as the sole electron donor with the expected stoichiometry of electron consumption. Cells attached to the electrode appeared to be responsible for the nitrate reduction. Attached cells of Geobacter sulfurreducens reduced fumarate to succinate with the electrode as an electron donor. These results demonstrate for the first time that electrodes may serve as a direct electron donor for anaerobic respiration. This finding has implications for the harvesting of electricity from anaerobic sediments and the bioremediation of oxidized contaminants.
Nanoparticles in drug delivery: mechanism of action, formulation and clinical application towards reduction in drug-associated nephrotoxicity

Introduction: Over the past few decades, nanoparticles (NPs) have gained immeasurable interest in the field of drug delivery. Various NP formulations have been disseminated in drug development in an attempt to increase efficacy, safety and tolerability of incorporated drugs. In this context, NP formulations that increase solubility, control release, and/or affect the in vivo disposition of drugs, were developed to improve the pharmacokinetic and pharmacodynamic properties of encapsulated drugs.Areas covered: In this article, important properties related to NP function such as particle size, surface charge and shape are disseminated. Also, the current understanding of how NP characteristics affect particle uptake and targeted delivery is elucidated. Selected NP systems currently used in delivery of drugs in biological systems and their production methods are discussed as well. Emphasis is placed on current NP formulations that are shown to reduce drug-induced adverse renal complications.Expert opinion: For...
Authoring educational topic maps: can we make it easier?

In this paper we examine some problems related to capturing the structure and the topic name space of learning content in the context of topic map authoring. We demonstrate that the use of traditional course taxonomies as ontological resources is problematic. Based on these findings and on the results of a locally conducted study, we propose an empirically justified minimal ontology for topic maps-based e-learning. The proposed minimal set contains five relation types and is implemented in the TM4L Editor to support authors that experience difficulties in articulating and naming relationships.
A model for fatigue defect nucleation in thermite rail welds

— A fatigue model for thermite rail welds is presented in this paper. The aim of the model is to provide a means for predicting the types of rail-head fatigue defects that might form under a given set of railway operating conditions and to provide an estimate of the life consumed during stage I growth of incipient fatigue cracks. Eshelby's equivalent inclusion method is incorporated in the model so that an assessment of the effects of metallurgical discontinuities can be made. Findley's critical-plane fatigue parameter is used as the criterion for computing fatigue damage. Results from using this model indicate that pores are the more damaging of the discontinuities typically present in thermite rail welds which also contain alumina inclusions. The shape and orientation of pores is predicted to have a strong influence on rail-head fatigue defect formation in thkwermite rail welds.
'Defatting' tracheotomy in morbidly obese patients.

Objectives/Hypothesis: Standard-sized tracheostomy tubes often fit morbidly obese patients poorly because of increased submental and anterior cervical girth. The surgeon has two options to overcome this problem: Modify the tracheostomy tube to fit the patient or recontour the neck to accommodate a standard tube. The purpose of the study was to assess the safety and morbidity of the latter technique, the defatting tracheotomy. Study Design: Retrospective cohort study of 23 patients treated between 1994 and 2001 with cervical lipectomy and tracheotomy. Methods: Medical charts were reviewed for indications, demographics, body mass index, tracheotomy-related complications, and decannulation results. Results: The average age of patients was 50 years (age range, 34-77 y). The mean preoperative body mass index was 55.9 (range, 39.2-73.5). Indications for the procedure were respiratory failure requiring chronic ventilation in 16 patients (70%) and obstructive sleep apnea in 7 (30%). Four patients died postoperatively from causes unrelated to tracheotomy. The mean follow-up time of survivors was 23 months. The overall tracheotomy-related complication rate was 43%. Four patients developed wound infections in the perioperative period, one patient developed a neck abscess, and one patient required neck exploration for control of hemorrhage. Four patients (22%) developed late complications including tracheitis (1), neck abscess (1), and stenosis of the tracheocutaneous tract (2). Eight patients (44%) ultimately had decannulation. Conclusions: Defatting tracheotomy is a safe technique that allows for the placement of a standard tracheostomy tube in morbidly obese patients. It is associated with a high rate of minor infectious complications. Even so, we think that cervical lipectomy with tracheostomy tube placement is the preferred surgical option for this patient population.
2010 American College of Rheumatology Adult Fibromyalgia Criteria for Use in an Adolescent Female Population with Juvenile Fibromyalgia

Objectives To evaluate the utility of the 2010 American College of Rheumatology (ACR) adult fibromyalgia criteria for use in adolescents with juvenile fibromyalgia (JFM). Study design Participants included 47 adolescent girls diagnosed with JFM (mean age = 15.3 years) and 48 age- and sex-matched adolescents (mean age = 15.0 years) with localized chronic pain (eg, headaches or abdominal pain). A trained examiner administered the Widespread Pain Index and Symptom Severity measures and also completed a manual tender point exam. Clinicians completed a form indicating the presence of active JFM per Yunus and Masi (1985) criteria, the only available and most commonly used measure for JFM. Criterion validity analysis was performed as well as t tests comparing symptoms between JFM and controls. Results With the Yunus and Masi criteria used as the gold standard, the 2010 ACR fibromyalgia criteria showed a sensitivity of 89.4% and specificity of 87.5%. Conclusion The 2010 ACR measure appears to be a valuable tool for the identification of JFM. However, a slight modification to the 2010 ACR measure and inclusion of a clinical exam is recommended.
Pricing Model and Algorithm for Online Speciality Store with Consideration of Sale Association

An online speciality store is a kind of small retail shop on the Internet that specializes in some merchandise of the same brand or with the similar function. Putting low prices on some special items is a special pricing strategy in online speciality store, which will increase the flow of the Web site and accelerate the sales of other products. The phenomenon that there is positive sale association among different items is called as size effect in this paper. A multi-objective model was built and a particle swarm optimization algorithm was proposed to solve this holistic pricing problem. Maximum of the gross profits and sales was the objective of the model. Simulation results reveal that the model can help online speciality store get more gross profits and more sales.
Determination of triglyceride in the human myocardium by magnetic resonance spectroscopy: reproducibility and sensitivity of the method

The primary aim of this investigation was to determine the reliability and sensitivity of 1H magnetic resonance spectroscopy (1H-MRS) as a method for quantifying myocardial triglyceride (TG) conten...
Cellular Transcription Factor ZASC1 Regulates Murine Leukemia Virus Transcription

To identify cellular processes involved in retroviral infection, we employed a high-volume forward genetic screen of insertionally mutagenized somatic cells using a murine leukemia virus (MLV) vector. This approach identified a clonal cell line that exhibited approximately 10-fold reduced gene expression from MLV vectors following infection despite supporting normal levels of MLV reverse transcription and integration. The defect in this cell line was specific for the MLV long terminal repeat (LTR) promoter, as normal levels of reporter gene expression were obtained from both an internal cytomegalovirus (CMV) promoter contained within an LTR-defective MLV vector and LTR expression from an avian sarcoma and leukosis virus (ASLV) vector. Complementation and shRNA knockdown experiments demonstrated that the defective gene in these cells is ZASC1 (ZNF639), a transcription factor with strong links to cancer and inherited ataxias. We demonstrated that ZASC1 is a sequence-specific DNA binding protein with three closely related binding sites located within the MLV LTR promoter, but it does not bind to the ASLV promoter. Mutating these putative ZASC1 binding sites significantly reduced levels of MLV gene expression. While wild-type ZASC1 activated expression from the MLV promoter, a green fluorescent protein-ZASC1 fusion protein showed dominant-negative inhibition of MLV gene expression. These studies identify the cellular transcription factor ZASC1 as an activator of MLV gene expression and provide tools that should be useful in studying the links between ZASC1 and human diseases.
Patient safety and medical malpractice: a case study

The system of tort liability for medical malpractice is frequently criticized for poorly performing its theoretical functions of compensating injured patients, deterring negligence, and dispensing corrective justice. Working from an actual malpractice case involving serious injury but no apparent negligence, the authors explore these criticisms from the perspectives of both the plaintiff-patient and the defendant-physician. They then examine the tort system through the lens of patient safety and conclude that the tensions between the system and patient safety initiatives suggest a need to reexamine our attachment to adversarial dispute resolution in health care. They propose targeted reforms that could improve the functioning of the system and create incentives to improve safety and quality.