cssi/SciSciGPT-SciSciNet huggingface dataset:
Executive function moderates the relation between coping and depressive symptoms

Background and Objectives: Identifying risk factors early in the course of depression has important implications for prevention, given that the likelihood of recurrence increases with each successive episode. Design: This study examined relations among coping, executive functioning, and depressive symptom trajectories in a sample of remitted-depressed (n = 32) and never-depressed (ND; n = 36) young adults (aged 18–31). Methods: Participants completed a clinical interview, a measure of coping, and tasks assessing two components of executive function – inhibition and cognitive flexibility. Participants were reassessed regarding the timing and severity of depressive symptoms that had occurred during the interval period (mean = 35.16 weeks, SD = 9.03). Results: Among ND individuals, less primary control coping (e.g., problem-solving) and greater disengagement coping (e.g., avoidance) predicted increases in depressive symptoms. Greater secondary control coping (e.g., acceptance) predicted decreases in depressi...
Fractal geometry applications in turbulent combustion data analysis

Application of fractal geometry concepts is made to some premixed turbulent combustion data and the geometry is found to yield some new visual concepts in analysis of the data. Moreover, techniques through fractal interpolation are shown to aid in reconstruction of decimated data or in a reasonable construction of missing data in a low data rate acquisition situation. Application is made to hot film anemometry data in an approach cold flow and Rayleigh scattering density data in a premixed flame. The fractal character of the time series data is shown and a new visual concept of the multifractal probability density function is introduced. The different fractal character of the two data types is clearly shown. The interated function sequence technique for data reconstruction is introduced and some constraints of probability theory are removed by alternate fractal concepts.
Two-Dimensional Electrohydrodynamically Induced Colloidal Phases

Over the past decade, experiments have shown that applied electric fields can be used to assemble colloids at electrode surfaces via an apparently electrohydrodynamic attractive interaction. Recently however, it has been seen that confinement strongly influences this process, simultaneously suppressing the apparent attractions while increasing the relative importance of field-induced dipole−dipole repulsions. By varying the degree of confinement and the strength of the applied field, one can alter the relative magnitude of these competing effects. We show here that one can take advantage of this interplay for the construction of novel two-dimensional colloidal phases.
Male size influences mate fecundity and remating interval in Drosophila melanogaster

Male size influences female remating behaviour in Drosophila melanogaster. Females remated rapidly when courted by large males, independent of the size of the previous mate. Size of first mate had no general influence upon female remating interval. Possible fitness consequences for females of the observed remating pattern were examined by comparing fecundity and fertility of females singly mated to males of varying size. Females mated to small males had higher fitness than females mated to large males, due to increased fecundity on the day of mating. The significance of these apparently conflicting observations is discussed with regard to male and female reproductive patterns.
Development and validation of a Navier-Stokes code for hypersonic external flow

A new computational fluid dynamics procedure, compressible Navier-Stokes (CNS), is developed for application to hypersonic vehicle design. The CNS code uses a zonal approach, which makes it unique from standard hypersonic codes. Some of the advantages of this approach are that it alleviates the difficulties of grid generation for complex configurations, improves computational efficiency, allows incorporation of component parts, and permits grid refinement as needed. This zonal capability will allow the modeling of the external flowfield of vehicles from tip to tail. An equilibrium air model is also an available option. Validation cases include a comparison of ideal gas results with experimental data on a simple vehicle geometry at Mach 10.3 and 15-deg angle of attack. The equilibrium real-gas model is tested against published computations on a sphere cone at Mach 20.53 and 5-deg angle of attack. Computational results show good to excellent agreement with experiment and code-to-code comparisons. Grid refinement effects on skin friction and heat transfer are also documented for the sphere-cone case.
Metformin and cancer: new applications for an old drug

Metformin, one of most widely prescribed oral hypoglycemic agents, has recently received increased attention because of its potential antitumorigenic effects that are thought to be independent of its hypoglycemic effects. Several potential mechanisms have been suggested for the ability of metformin to suppress cancer growth in vitro and vivo: (1) activation of LKB1/AMPK pathway, (2) induction of cell cycle arrest and/or apoptosis, (3) inhibition of protein synthesis, (4) reduction in circulating insulin levels, (5) inhibition of the unfolded protein response (UPR), (6) activation of the immune system, and (7) eradication of cancer stem cells. There is also a growing number of evidence, mostly in the form of retrospective clinical studies that suggest that metformin may be associated with a decreased risk of developing cancer and with a better response to chemotherapy. There are currently several ongoing randomized clinical trials that incorporate metformin as an adjuvant to classic chemotherapy and aim to evaluate its potential benefits in this setting. This review highlights basic aspects of the molecular biology of metformin and summarizes new advances in basic science as well as intriguing results from recent clinical studies.
The effects of earthquake wave dispersion on the response of simple dynamic structural models

Abstract The extent and means by which the dispersive properties of the site geology influence the structural response to the ground shaking is examined. Based on linear wave propagation assumptions, the maximum possible response of a dynamic system is calculated along with the dispersion function, called the critical dispersion, necessary to produce this maximum or critical response. For linear systems, the critical response can be calculated from an integration on the fourier amplitude of acceleration times the critical response transfer function. The dependence of the response upon the dispersion is fairly frequency independent, and for the particular cases examined the critical dispersion induced maximum response was roughly a factor of two greater than the response derived from sets of synthetic accelerograms which included dispersion effects. The response of multi-degree of freedom linear systems is derived from the single degree of freedom, SDOF, results except that they depend on all of the natural frequencies of the system. Finally, the response of a SDOF elastoplastic system is examined in a similar manner. The critical dispersion is now amplitude dependent because the response frequency, hence the dominant excitation frequency, is also amplitude dependent. For a range of frequencies the critical response for the nonlinear system is as much as a factor of ten greater than the calculated response from realistic dispersion functions, indicating a stronger dependence of the response upon the dispersion than for the linear systems.
Spatial localization with only auditory cues: a preliminary study

This experiment investigates source point localization using only auditory cues. The idea is to determine how well humans can localize and reason about space using only sound cues, and to determine how different sound cues effect performance in such tasks. The findings from this line of research can be used in enhancing audio in virtual environments. This abstract presents first steps in this direction. The task we study here is: given a point in space near the user plus a sound cue that is modulated by the distance between the users hand and point, how well (quickly) can the user locate the point.
Facilitating the initiation of the physician's professional identity: Cornell's urban semester program.

Calling for major reform in medical education, the Carnegie Institute report ‘Educating Physicians’ espoused the importance of assisting student trainees in forming their professional identities. Here, we consider the question: At what educational stage should future physicians begin this process? The literature suggests that the process begins when students matriculate in medical school; we posit, however, that premedical students can begin their proto-professional development as college undergraduates. We describe here the pedagogy of Cornell University’s urban semester program (USP), which enables college students to participate in shadowing experiences as part of an integrated structured study programme. USP students report improved communicative competency, changes in their perceptions and attitudes toward medical practice, and powerful influences on their personal and professional development upon completion of the programme. We suggest the solution to the question of ‘When and under what conditions should shadowing take place?’ is to utilize a structure that combines the exposure of college students to the professional environment with a didactic and self-reflective curriculum, thereby supporting students in their early professional development. We conclude that educational efforts aimed at developing professional identity and behaviour can begin before students enter medical school.
Nosocomial pneumonia: epidemiology and infection control

Elderly, debilitated, or critically ill patients are at high risk for hospital acquired or nosocomial respiratory tract infection. Gram-negative bacilli,Staphylococcus aureus, and anaerobes colonizing the oropharynx are the most frequent etiologic agents. Colonization of the oropharynx may be related to the patient's age, underlying disease, nutritional status, prior exposure to antibiotics, supine position, and gastric colonization. Nosocomial pathogens may also be acquired from the hands of hospital personnel, contaminated equipment or fluids. The absence of sensitive and specific methods for accurate diagnosis remain a concern. Despite treatment with appropriate antimicrobial therapy, there is a high mortality and morbidity. Measures for the prevention of nosocomial pneumonia should include compliance with infection control principles, appropriate use of antibiotics, proper patient position, and removal of potential sources of cross colonization.
Elastic moduli of a microcracked composite with spherical inclusions of cubic anisotropy

Abstract The self-consistent mechanics method has been widely used to estimate the elastic moduli of solids containing microvoids and inclusions. In the present paper, the elastic moduli of a microcracked composite material—a matrix containing inclusions and microcracks—are studied. The study focuses on the effect of inclusion anisotropy and the interaction between microcracks and inclusions. It is established that the effect of inclusions and microcracks on overall moduli is approximately decoupled. This method is also used to estimate the elastic moduli of a microcracked polycrystal.
Optimized knot placement for B-splines in deformable image registration.

Purpose: To develop an automatic knot placement algorithm to enable the use of NonUniform Rational B-Splines (NURBS) in deformable image registration.Methods: The authors developed a two-step approach to fit a known displacement vector field (DVF). An initial fit was made with uniform knot spacing. The error generated by this fit was then assigned as an attractive force pulling on the knots, acting against a resistive spring force in an iterative equilibration scheme. To demonstrate the accuracy gain of knot optimization over uniform knot placement, we compared the sum of the squared errors and the frequency of large errors.Results: Fits were made to a one-dimensional DVF using 1–20 free knots. Given the same number of free knots, the optimized, nonuniform B-spline fit produced a smaller error than the uniform B-spline fit. The accuracy was improved by a mean factor of 4.02. The optimized B-spline was found to greatly reduce the number of errors more than 1 standard deviation from the mean error of the uniform fit. The uniform B-spline had 15 such errors, while the optimized B-spline had only two. The algorithm was extended to fit a two-dimensional DVF using control point grid sizes ranging from 8 × 8 to 15 × 15. Compared with uniform fits, the optimized B-spline fits were again found to reduce the sum of squared errors (mean ratio = 2.61) and number of large errors (mean ratio = 4.50).Conclusions: Nonuniform B-splines offer an attractive alternative to uniform B-splines in modeling the DVF. They carry forward the mathematical compactness of B-splines while simultaneously introducing new degrees of freedom. The increased adaptability of knot placement gained from the generalization to NURBS offers increased local control as well as the ability to explicitly represent topological discontinuities.
Diogenites as asteroidal cumulates: Insights from orthopyroxene major and minor element chemistry

Abstract Diogenites appear to be cumulates formed from one or more igneous reservoirs in the interior of asteroid 4 Vesta. Magmatism in this parent body gave rise to a series of related lithologies designated howardites, eucrites, and diogenites or “HED.” Eucrites are pigeonite/plagioclase basalts, and diogenites are orthopyroxenites. Howardites are brecciated mixtures of eucrites and diogenites. The major objective of this paper is to characterize the major and minor element chemistry of orthopyroxene in diogenites and to interpret these data in terms of a petrogenetic model. This study, which involves interpretation of ~ 1,200 high-quality electron microprobe analyses, demonstrates that the systematics of Ca, Fe, and Mg in orthopyroxene were largely reset by reaction with melt and by subsolidus exchange. However, the systematics of the minor elements Al, Cr, and Ti still effectively record their igneous history. Aluminum and Ti are highly correlated with the incompatible trace elements (e.g. Yb, Y) and thus are useful fractionation indicators. As many as twenty of the twenty-three diogenites studied may have formed from one igneous system based on Al, Cr, and Ti systematics in orthopyroxene. The Al content of the orthopyroxene in the twenty diogenites forms the basis for a fractionation sequence with Peckelsheim the least fractionated and LEW 88008 the most fractionated. Roda and Manegaon, and possibly ALHA77256, fall off the main compositional trends and may belong to different melt systems. The coupled substitutions that incorporate Al, Cr, and Ti into the orthopyroxene crystal structure are VICr3+-IVAl3+, VIAl3+-VIAl3+, and VITi4+-2IVAl3+. The dominant substitutional couple in the early stages of crystallization is VICr3+-IVAl3+ while VIAl3+-IVAl3+ is dominant in the late stages. These findings demonstrate the importance of understanding the coupled substitutions for minor elements when assessing the appropriate mineral/melt partition coefficients (D values) or when discussing whether an element is compatible or incompatible. For example, in diogenitic orthopyroxene, Al has three different compatibilities (D values) with VICr3+-IVAl3+ more compatible than VIAl3+-IVAl3+ which is more compatible than VITi4+-2IVAl3+. Based on the assumption that D Al increases during crystallization from 0.05 to 0.1 corresponding to the crystallization interval represented by Peckelsheim to LEW 88008, 60% crystallization is required. The melt parental to LEW 88008 is estimated to contain ~12 wt% Al2O3, very near plagioclase saturation.
Phylogenetic and physiological characterization of a filamentous anoxygenic photoautotrophic bacterium ‘Candidatus Chlorothrix halophila’ gen. nov., sp. nov., recovered from hypersaline microbial mats

We report the phylogenetic and physiological characterization of a mesophilic and halophilic member of the filamentous anoxygenic phototrophic (FAP) bacteria, provisionally named ' Candidatus Chorothrix halophila' gen. nov. sp. nov., that has been maintained in a highly enriched culture in our laboratory for over a decade. Phylogenetic analysis of small-subunit RNA-encoding sequences places ' Candidatus Chlorothrix halophila' in a clade that includes cultivated members of the genera Chloroflexus and Oscillochloris. Physiological studies demonstrated sulfide-dependent photosynthetic uptake of (14)C-labeled bicarbonate. Enzymatic assays for the activity of propionyl-coenzyme A synthase indicated that ' Candidatus Chlorothrix halophila' does not use the 3-hydroxypropionate cycle of Chloroflexus aurantiacus OK-70-fl for autotrophic carbon assimilation. New concepts regarding the taxonomy and phylogeny of FAP bacteria have emerged from this work.
Introduction—The Impacts of the 2008 Eruption of Kasatochi Volcano on Terrestrial and Marine Ecosystems in the Aleutian Islands, Alaska

The Aleutian Islands are situated on the northern edge of the so-called “Pacific Ring of Fire,” a 40,000-km-long horseshoe-shaped assemblage of continental landmasses and islands bordering the Paci...
STRUCTURAL ANALYSIS OF THE SUBSTOICHIOMETRIC AND STOICHIOMETRIC MICROTUBULE-INHIBITING BIPHENYL ANALOGUES OF COLCHICINE

The structures of the colchicine (COL) analogues, 2,3,4-trimethoxy-4'-acetyl-1,1'-biphenyl (TKB)and 2,3,4,4'-tetramethoxy-1,1'-biphenyl (TMB), were solved by X-ray diffraction. Their comparison with the structure of colchicine indicated the ability of both compounds to enter into a colchicine binding pocket. Comparison of TKB with 2,3,4-trimethoxy-4'-carbomethoxy-1,1'-biphenyl (TCB) showed that the methyl group of the carbomethoxy group in position 4' of TCB protrudes beyond the (C=O)-CH3 group in the same position in TKB. Superposition of both structures on the van der Waals surface of COL clearly demonstrates that TKB can fully fit within that domain, while the CH3 group of TCB protrudes beyond the COL contour. This is proposed to be the source of the inability of TCB to inhibit microtubule assembly substoichiometrically, while TKB is a very strong inhibitor. While the same steric hindrance to entering into the COL site on tubulin must exist in allocolchicine (ALLO), in its case, this is overcome by the rigidity of the three-ring structure which abolishes the loss on binding of the entropy of free rotation between the two rings of the biphenyl TCB.
Kinetics of Monolayer Bi Electrodeposition on Au(111): Surface X-ray Scattering and Current Transients

The kinetics of Bi monolayer electrodeposition (underpotential deposition) on the Au(111) electrode was investigated using surface X-ray scattering and electrochemical methods. The current and X-ray intensity transients were measured simultaneously using a low-resistance drop cell that has a potential response time less than 50 μs. Three independent measurements of the Bi coverage transients were obtained, which are related to (1) the integrated charge, (2) the adsorbed Bi, irrespective of the adsorption site, and (3) the adsorbed Bi with a well-defined (2×2) structure. The zero-coverage ↔ commensurate (2×2)-Bi phase transition occurs on the millisecond time scale, 3 orders of magnitude more rapidly than the (2×2)-Bi ↔ high-coverage incommensurate (p×√3)-2Bi phase transition. Nucleation and growth kinetics was observed for both transitions involving Bi desorption. Langmuir adsorption kinetics was observed for both transitions involving Bi adsorption. Comparison of the total coverage with that measured by ...
Theoretical Calculation of Thermodynamic Properties of Polybrominated Diphenyl Ethers

The thermodynamic properties of 39 polybrominated diphenyl ethers (PBDEs) in the ideal gas phase have been calculated using Gaussian 03 on the B3LYP/6-31G(d)//B3LYP/6-31G(d) level. Their thermodynamic and other physicochemical properties show a strong dependence on the bromine substitution pattern. The PBDE congeners' enthalpies of formation increase with an increasing number of bromines. The thermodynamic properties of congeners with the same number of bromines also show dependence on the bromine substitution pattern, especially for ortho-substituted congeners. PBDE congeners with one phenyl ring fully brominated, such as 2,3,4,5,6-PeBDE, 2,3,4,4‘,5,6-HxBDE, 2,2‘,3,4,4‘,5,6-HpBDE, and 2,3,3‘,4,4‘,5,6-HpBDE, were found to be the least stable among the analogues. The effects of bromine substitution pattern have been quantitatively studied by group additivity method (GAM) based on the output of the theoretical calculations. The results of the GAM were consistent with theoretical calculations, proving that t...
Phosphorescence quenching of l(-)-tryptophan in dimethyl sulfoxide at 77 K by trivalent lanthanide ions☆

Abstract Quenching of the corrected phosphorescence emission of tryptophan in dimethyl sulfoxide by trivalent lanthanide ions Ln3+ can be interpreted in terms of a static model leading to triplet quenching constants kQT ranging from 1.3 × 101 to 9.1 × 101 M−1. The values of kQT increase with increasing spectral overlap and J values of the ground state of the appropriate lanthanide ions. The phosphorescence lifetime of tryptophan is virtually independent of [Ln3+] and has a value of 6.15 ± 0.25 s, in agreement with the static model of triplet quenching.
Takings, Litigation and Just Compensation

A constitutional right to just compensation for governmental takings implies a right to a judicial review of the adequacy of the compensation. Thus, a property owner, subjected to a takings action, can threaten to litigate if he considers compensation insufficient. This paper uses a theoretic settlement-litigation analysis to demonstrate how the litigation threat influences the size of the compensation. In addition, it revises the theoretical explanation for earlier empirical findings that certain classes of property owners often receive more than market value for their property. It is also shown that the just compensation mechanism cannot guarantee efficient takings. Extending the basic model to regulatory takings, this paper demonstrates that recent changes in the judicial doctrine of when a regulation has gone too far and demands compensation has strengthened the litigation threat of property owners. It explains why political decisionmakers are moving toward settlements with terms which are increasingly defined by legislation.
Glucocorticoid-Mediated Repression of the Oncogenic microRNA Cluster miR-17∼92 Contributes to the Induction of Bim and Initiation of Apoptosis

Synthetic glucocorticoids were one of the first effective treatments for lymphoid malignancies because of their ability to induce apoptosis and are still used in combination with other chemotherapeutic agents. Up-regulation of Bim, a proapoptotic member of the B-cell lymphoma-2 family, is an important mediator of glucocorticoid-induced apoptosis. Although glucocorticoids are known to elevate Bim mRNA and protein, little is known about the mechanism. Here, we report that glucocorticoids repress the expression of the microRNA cluster miR-17∼92, which results in elevated Bim protein expression as a mechanism by which glucocorticoids induce Bim. Using a luciferase-Bim 3' untranslated region construct, we demonstrate that glucocorticoids mediate Bim induction posttranscriptionally after miR-17∼92 repression, resulting in increased Bim protein expression. Overexpression of miR-17∼92 microRNAs decreases Bim induction and attenuates glucocorticoid-mediated apoptosis. Conversely, knockdown of miR-17∼92 increases Bim protein expression and glucocorticoid-mediated apoptosis. These findings indicate that endogenous levels of miR-17∼92 repress Bim expression in T-cell lymphoid malignancies and that glucocorticoids induce Bim expression via down-regulation of the miR-17∼92 microRNA cluster. Our findings present a novel mechanism that contributes to the up-regulation of Bim and induction of apoptosis in lymphocytes after glucocorticoid treatment. Furthermore, our work demonstrating that inhibition of miR-17∼92 increases glucocorticoid-induced apoptosis highlights the potential importance of miR-17∼92 as a therapeutic target in leukemias and lymphomas.
Concepts, Theory, and Techniques ON THE USE OF THE GEOMETRIC MEAN IN LONG-TERM INVESTMENT

Application of the geometric mean to holding-period returns is discussed from a statistical theory standpoint. The population geometric mean is considered a parameter of the probability distribution of returns its relationship to moments of the distribution is discussed. The sample geometric mean and its relation to sample moments is assessed through its sampling distribution it is viewed as an estimator of the population geometric mean. For application to long-term investment where a geometric mean is maximized, the distributional properties of the geometric mean should be used. The terms statistic, approximation, and parameter are differentiated.
In their own words: the life experiences of Mexican-American and white pregnant adolescents and adolescent mothers.

The results of an ethnographic study of 32 Mexican-American and 17 White adolescents are presented. Fifty percent or more of the respondents in both groups experienced parental loss during their childhood years. Little information was provided by parents to the adolescents regarding menses and physical maturation. While parent-adolescent conflict arose in both samples, the conflict for the Mexican-American adolescents centered around choice of girlfriends and boyfriends while multiple sources of conflict existed between the White respondents and their parents. White respondents were more sexually active than the Mexican-American respondents, but the latter reported more stable relationships with the father of the baby. The experiences of the adolescents are both summarized and presented in their own words.
Anisotropic damage evolution in a 0°/90° laminated ceramic-matrix composite

Abstract Anisotropic damage evolution in a 0°/90° laminated Nicalon ™ SiC fiber-reinforced calcium aluminosilicate (CAS) glass–ceramic composite during uniaxial tensile deformation has been investigated using a variety of non-invasive characterization techniques. The elastic constant reduction in the three principal directions was measured from in situ laser-generated ultrasonic velocity measurements in various sound propagation directions. They indicate that, in addition to a large drop in elastic stiffness in the loading direction, the constants characterizing the nominal elastic stiffness transverse to the loading direction were also degraded. Surface replicas taken intermittently during loading revealed that transverse softening of the elastic stiffness was associated with fiber/matrix interface damage mainly in the 0° plies, while the large softening of the elastic stiffness in the loading direction was the result of multiple matrix cracking in both the 0° and 90° plies. While the ultrasonic data allowed a detailed characterization of the anisotropic damage evolution in this laminate, acoustic emission measurements and surface replica data identified the crack initiation stress in the 90° plies and correlated it to macroscopically observable deviations of the stress–strain curve from linear elastic behavior. These matrix cracks were found to have initiated preferentially in the weak 90° plies near the 90°/0° ply boundaries.
ATTITUDES TOWARD HOMOSEXUAL BEHAVIOR: EFFECTS OF VETERAN STATUS '

The present study examined the attitudes toward homosexual behavior of veterans of United States military service and nonveterans. Using a nationwide survey as the database, 1,293 veterans did not differ from 2,330 nonveterans in approval of homosexual behavior, as over 74% of each group expressed disapproval.
Kernel Smoothing to Improve Bootstrap Confidence Intervals

SUMMARY Some studies of the bootstrap have assessed the effect of smoothing the estimated distribution that is resampled, a process usually known as the smoothed bootstrap. Generally, the smoothed distribution for resampling is a kernel estimate and is often rescaled to retain certain characteristics of the empirical distribution. Typically the effect of such smoothing has been measured in terms of the mean-squared error of bootstrap point estimates. The reports of these previous investigations have not been encouraging about the efficacy of smoothing. In this paper the effect of resampling a kernel-smoothed distribution is evaluated through expansions for the coverage of bootstrap percentile confidence intervals. It is shown that, under the smooth function model, proper bandwidth selection can accomplish a first-order correction for the one-sided percentile method. With the objective of reducing the coverage error the appropriate bandwidth for one-sided intervals converges at a rate of n-"/4, rather than the familiar n-115 for kernel density estimation. Applications of this same approach to bootstrap t and two-sided intervals yield optimal bandwidths of order n-112. These bandwidths depend on moments of the smooth function model and not on derivatives of the underlying density of the data. The relationship of this smoothing method to both the accelerated bias correction and the bootstrap t methods provides some insight into the connections between three quite distinct approximate confidence intervals.
Calcineurin B1 Is Essential for Positive but Not Negative Selection during Thymocyte Development

During development, discrete cell fates often result from variation in the intensity of a particular signal. The mechanisms underlying these seemingly analog-to-digital switches are not understood. In developing T lymphocytes, low-intensity signals through the antigen receptor result in positive selection while more intense signals give rise to negative selection. By deleting the genetic locus encoding the regulatory B1 subunit of calcineurin specifically in thymocytes, we found an absolute requirement for calcineurin in positive selection. In contrast, calcineurin activity was dispensable in several models of negative selection. Unexpectedly, we found that removal of calcineurin activity from thymocytes results in inefficient ERK activation at the double-positive stage of thymocyte development, when selection occurs. These studies clarify the mechanism by which graded signals are converted to discrete outcomes in T cell development and further indicate that the developmental roles of calcineurin likely contribute to immunosuppression by calcineurin inhibitors.
Coronary steal from a left internal mammary artery coronary bypass graft by a left upper extremity arteriovenous hemodialysis fistula.

In patients with end-stage renal disease undergoing hemodialysis, the upper extremity arteriovenous (AV) fistula is the dialysis access recommended by the DOQI guidelines for patients with appropriate vasculature. Upper extremity AV fistulae have long periods of usefulness, high flow rates, and low associated complication rates. Placement of AV access may result in increased cardiac output and increased cardiac oxygen demand in these patients. In general, cardiovascular complications from AV access have been limited. We report a novel cardiovascular complication of AV access in an end-stage renal disease patient with a coronary artery bypass graft employing the left internal mammary artery who experienced angina while undergoing hemodialysis. The angina was mediated at least in part by cardiac catheterization laboratory-documented steal of blood flow from the internal mammary artery graft. This phenomenon suggests the need to consider the impact of upper extremity access placement on blood flow to the left internal mammary artery in patients who previously have undergone placement of a coronary artery bypass graft.
Nitrogen leaching following whole-tree and bole-only harvests on two contrasting Pacific Northwest sites

Abstract Short-term pulses of increased N leaching typically follow the harvest of forest stands, but the magnitude of these pulses after conventional bole-only (BO) and whole-tree (WT) harvests often is difficult to predict. In this study, we measured N leaching until 6 and 8 years post-harvest on two western Washington Douglas-fir ( Pseudotsuga menziesii var. menziesii ) sites: a relatively low-productivity site with a gravelly loamy sand soil formed in glacial outwash and a high-productivity site with a silt loam soil derived primarily from basalt. We tested BO and WT harvest treatments and presence/absence of 5 years of competing vegetation control (VC). Trends in the magnitude and duration of post-harvest N-leaching pulses differed between sites. At the higher-productivity site, estimated N leaching between years 3 and 8 following harvest totaled 250 and 94 kg N ha −1 in BO and WT harvest treatments with VC, respectively. At the lower-productivity site, estimated N leaching totaled 32 and 17 kg N ha −1 between years 3 and 6 following harvest in BO and WT harvest treatments with VC, respectively. In both BO and WT treatments, annual N leaching did not fall below 2 kg N ha −1 (the rate measured in mature forest stands at both sites) until year 8 at the higher-productivity site and until year 6 at the lower-productivity site. Cumulative amounts of N leached among site/treatment combinations were small compared to the soil total-N pool and ranged from 0.5% to 2.5%. The N leaching patterns among treatments at these two sites suggest that differences in soil N content and C:N ratio, post-harvest vegetation regrowth, and harvest residues influenced the amount of N leached. The major source of leached N was most likely the soil (including forest floor) rather than harvest debris, based on site and treatment comparisons. Although the maximum post-harvest pulse of 250 kg N ha −1 was much higher than values reported in most comparable studies, this level of N leaching is unlikely to be reached under operational conditions, where VC is less intensive than in this study.
Forecasting the 2006 Elections for the U.S. House of Representatives

o arrive at some understanding ofwhat is going on is hard enough,”said Abraham Kaplan, “without havingalso to meet the demand that we antici-pate what will happen next” ~1964, 351!.Political scientists have been taught todescribe and to explain phenomenarather than to predict them. Kaplan, forone, appeared to think that this wasenough. But within the rich soil of expla-nation, Kaplan admitted ~346!, lay theseed of prediction. Indeed, Carl G.Hempel and Paul Oppenheim ~1948,138!, whom Kaplan took to task for say-ing so, flatly stated that “an explanationis not fully adequate” unless it alsoserved as the basis for prediction ~quotedin Kaplan, 346!.We admit that many challengespresent themselves when we attempt topredict complicated social phenomena.But we argue that there is a danger inlimiting our research to description andexplanation. That danger is that repeatedanalysis of the same datasets will trackpatterns again and again that do not existin the reality outside our samples. Oneguard against this is to take theoriesabout politics and employ them to pre-dict events that have not yet happened.In this spirit, this paper utilizes well-known insights about congressional elec-tions to predict the 2006 elections in theU.S House of Representatives.Methods of predicting congressionalelection outcomes have fallen into twocategories. In the first, experts useddistrict- or state-level information to tryto call elections. Sometimes these predic-tions were aided by district-level polls~of varying quality!.
Use of phase analysis of gated SPECT perfusion imaging to quantify dyssynchrony in patients with mild-to-moderate left ventricular dysfunction

CRT has been shown to be beneficial in the majority of patients with NYHA class III-IV symptoms, prolonged QRS duration, and an EF ≤35%. The use of imaging modalities to quantify dyssynchrony may help identify patients who may benefit from CRT, but do not meet current selection criteria. We hypothesize that patients with mild-to-moderate LV dysfunction have significant degrees of mechanical dyssynchrony. We compared phase analysis measures of mechanical dyssynchrony from gated SPECT imaging in patients with mild-to-moderate LV dysfunction (EF 35-50%, n = 93), with patients with severe LV dysfunction (EF ≤ 35%, n = 167), and with normal controls (EF ≥ 55%, n = 75). Furthermore, we evaluated the relationships between QRS duration and dyssynchrony and determined the prevalence of dyssynchrony in patients with mild-moderate LV dysfunction. Patients with mild-moderate LV dysfunction have more dyssynchrony than normal controls (phase SD 37.7° vs 8.8°, P < .001 and bandwidth 113.5° vs 28.7°, P < .001), but less dyssynchrony than patients with severe LV dysfunction (phase SD 37.7° vs 52.0°, P < .001 and bandwidth 113.5° vs 158.2°, P < .001). In the cohort of patients with LV EF 35-50%, there were only weak correlations between QRS duration and dyssynchrony (phase SD, r = 0.28 and bandwidth, r = 0.20). There were 73 patients with LVEF 35-50% and QRS duration <120 milliseconds of which 21 (28.8%) had mechanical dyssynchrony. Overall, 37% of patients with mild-to-moderate LV dysfunction had significant degrees of mechanical dyssynchrony. This is the largest reported study evaluating mechanical dyssynchrony in patients with mild-moderate LV dysfunction using phase analysis of gated SPECT imaging. In this study, approximately one-third of patients with mild-to-moderate LV dysfunction had significant LV mechanical dyssynchrony. With further study, phase analysis of gated SPECT imaging may help improve patient selection for CRT.
Safety impact of Gateway Monuments.

Gateway Monuments are free standing roadside structures or signage that communicate the name of a city, country or township to motorists. The placement of such monuments within state-controlled right-of-way is a relatively recent occurrence in California. As a result, the California Department of Transportation (Caltrans) initiated research to quantify the impacts that this type of signage may or may not have on crashes in their vicinity. To date, no specific research has examined the impact such features have on crashes. To determine whether these features impacted safety, the before-after study method using the Empirical Bayes technique was used, with reference groups and Safety Performance Functions adapted from existing studies, eliminating the need to calibrate new models. Results indicated that, on an individual basis, no deterioration in safety was observed at any monument site. When all sites were examined collectively (using two different scenarios), the calculated index of effectiveness values were 0.978 and 0.680, respectively, corresponding to 2.2% and 32.0% reductions in crashes. In addition to the EB method, naive study methods (with and without AADT taken into account) were applied to the study data. Results (crash reductions) from these methods also showed that the presence of Gateway Monuments did not have negative impact on traffic safety. However, the use of EB technique should be very careful employed when adopting reference groups from different jurisdictions, as these may affect the validity of EB results. In light of these results, Caltrans may continue to participate in the Gateway Monument Program at its discretion with the knowledge that roadway safety is not impacted by monuments.
Editor's puzzle: borrowing as cheaply as possible

Solutions should be sent to the editor at conitzer@cs.duke.edu with subject header SIGecom Exchanges Puzzle. The author(s) of the most elegant solution (as judged by the editor) will be allowed to publish his or her or their proof in the next issue of the Exchanges (ties broken towards earlier submissions). To make the solution accessible to a wide audience, try to minimize technical jargon in the proof. Until the winner is chosen, the editor will not give any feedback on submitted solutions and ignore any requests for hints, etc.
In Situ Electrochemical Scanning Probe Microscopy of Lithium Battery Cathode Materials: Vanadium Pentoxide (V2O5)

Atomic force microscopy was used to characterize the structural evolution of the V 2 O 5 (001) surface during the electrochemical cycling of lithium. With Li insertion, nanometer-scale pits develop at the V 2 O 5 (001) surface. The pits first appear as the composition of the crystal approaches Li0.0006V2O5. Pit nucleation and growth continue through further discharge, resulting in a micro-porous (001) surface morphology. During subsequent Li extraction, cracks develop along the V 2 O 5 axis. Surface regions in the vicinity of these cracks “swell” during ensuing lithiation reactions, suggesting that the cracks locally facilitate Li uptake.
VII. The quantum theory of solitons and other non-linear classical waves

It has been suspected for some time that certain solutions of non-linear classical field equations indicate that the corresponding quantum theory possesses interesting, even unsuspected properties [1]. A group of us in Cambridge [2] (U.K. and U.S.A.) has developed an approach to the quantum theory which consists of a systematic coupling constant expansion for various quantum mechanical objects: transition amplitudes, S-matrix elements. The first term in this expansion frequently leads to a differential equation which is identical with an equation of the classical theory. Unlike the method of the Princeton group [31,ours is not a semi-classical calculation; we do not look to the classical equations for a description of the dynamics which is then quantized by Bohr— Sommerfeld or WKB approximations. Rather we encounter “classical” equations in the full quantum theory; they determine lowest order approximations to quantum mechanical objects. Also we have a procedure for calculating higher order corrections. We shall consider theories involving a single boson field in one space dimension ~p(t,x) whose dynamics is governed by a Lagrangian density C. [The restriction to an unphysical dimensionality of space is for simplicity. The phenomena that we are describing exist also in the physical situation of three spatial dimensions. However such models necessarily contain fields with spin; this leads to computational tedium.] Of special interest will be static [time independent] solutions of the classical Euler—Lagrange equations. The full time dependent equation is
One class SVM for yeast regulation prediction

In this paper, we outline the main steps leading to the development of the winning solution for Task 2 of KDD Cup 2002 (Yeast Gene Regulation Prediction). Our unusual solution was a pair of linear classifiers in high dimensional space (∼14,000), developed with just 38 and 84 training examples, respectively, all belonging to the target class only. The classifiers were built using the support vector machine approach outlined in the paper.
Large-scale effect of aerosols on precipitation in the West African Monsoon region

We used multi-year satellite observations to study aerosol effects on the large-scale variability in precipitation of the West African Monsoon (WAM) region, which is often impacted by high concentrations of desert dust and biomass- burning smoke. We find a statistically significant precipitation reduction associated with high aerosol concentration near the coast of the Gulf of Guinea from late boreal autumn to winter. The largest aerosol-related precipitation reduction (∼1. 5m m d −1 ) is about 50% of the climatological mean precipitation in the region and occurs mainly at rain rates in the range of 2-17 mm d −1 off the northern coast of the Gulf of Guinea. This reduction cannot be linearly attributed to known climate and weather factors such as El Ni˜ no-Southern Oscillation, North Atlantic Oscillation, Atlantic sea-surface temperature, or water vapour. The fractional precipitation variance related to aerosol is about 13%, a value comparable to those related to the known climate factors. Based on the spatial pattern and seasonality of the observed precipitation reduction and its dependence on the rain rate, the observed negative correlation cannot be readily attributed to precipitation effects on aerosol by wet deposition or to rain and cloud contamination of satellite aerosol retrievals. We therefore suggest that our results can be taken as observational evidence of aerosol effects on precipitation. The aerosol associated with the observed precipitation reduction can be traced back to various African sources where large quantities of desert dust and biomass-burning smoke are emitted during much of the year. Given that the emissions of dust and smoke have varied considerably over the past several decades, in part attributable to human activities, our observed rainfall reduction may reflect an anthropogenic impact to some degree. Copyright c � 2009 Royal Meteorological Society
Seasonal Foliage Changes in the Eastern Amazon Basin Detected from Landsat Thematic Mapper Satellite Images1

Seasonal changes in tropical forests are difficult to measure from the ground, especially in areas of high species diversity and low phenological synchrony. Satellite images, which integrate individual tree canopies and cover a large spatial extent, facilitate tests for stand-level canopy phenology. Variability in near-infrared radiance (TM bands 4 and 5) of several distinct vegetation types was used to detect seasonal changes in a series of three Landsat Thematic Mapper (TM) images from the wet season to the dry season in Maraba, Brazil (eastern Amazon basin). Despite different atmospheric and instrumental conditions among the images, spectral changes were distinguishable. A phenological process (leaf aging, leaf drop, water stress) was determined from the spectral changes for each vegetation type. Changes in the spectral properties suggest that during the dry season, upland terra firme forest increased the rate of leaf exchange and some riparian vegetation was deciduous. Terra firme forest that had been altered by penetration of fires from nearby pastures increased in leaf biomass over a 14-month period. This study shows that a time series of images can provide information on temporal changes in primary vegetation and guide field studies to investigate seasonal changes that may not be detectable from the ground. RESUMO Mudan,as sazonais em florestas tropicais sao dificis para medir no campo, especialmente em areas de alta diversidade de especies e sincronia fenologica limitada. Imagens de satelite que integram copas de arvoles individuais e cobrem uma grande airea facilitam testes de fenologia da copa ao nivel da floresta. Variabilidade em radiancia no infravermelho (TM bandas 4 e 5) de alguns tipos de vegeta,co foram usadas para detectar as mudan,as sazonais em uma serie de tres imagens de Landsat Thematic Mapper (TM) da esta,co uimida a esta,co seca em Maraba', Brasil (Amazonia oriental). Apesar de condi,6es diferentes de atmosfera e instrumentos entre as imagens, mudan,as espectrais foram distinguidas. Para cada tipo de vegeta,co, um processo fenologico (envelhecimento e queda das folhas, stress hidrilo) foram determinado usando das mudan,as espectrais. Mudan,as nas propriedades espectrais sugerem que durante a esta,co seca, a floresta de terra firme aumentou a troca de folhas e parte de vegeta,co de mata ciliar perdeu suas folhas. A floresta de terra firme que foi alterada por penetra,co de fogo proveniente das pastagens proximas aumentou em sua biomassa de folhas verdes durante um periodo de 14 meses. Este estudo demonstra que uma serie de imagens pode fornecer informa,6es sobre as mudan,as temporais na vegeta,co e direciona estudos no campo sobre mudan,as sazonais que posivelmente nao poderiam detectadas detectar no campo.