cssi/SciSciGPT-SciSciNet huggingface dataset:
Partitioning of Total Mercury and Methylmercury to the Colloidal Phase in Freshwaters

Using tangential flow ultrafiltration, total mercury (HgT) and methylmercury (MeHg) concentrations in the colloidal phase (0.4 microm-10 kDa) were determined for 15 freshwaters located in the upper Midwest (Minnesota, Michigan, and Wisconsin) and the Southern United States (Georgia and Florida). Unfiltered concentrations were typical of those reported for freshwater and ranged from 0.9 to 27.1 ng L(-1) HgT and from 0.08 to 0.86 ng L(-1) MeHg. For some rivers, HgT and MeHg in the colloidal phase comprised up to 72% of the respective unfiltered concentration. On average, however, HgT and MeHg concentrations were evenly distributed between the particulate (>0.4 microm), colloidal, and dissolved ( 0.07), but the regression of MeHg with OC(F) was strong, especially in the upper Midwest (r2 = 0.78; p < 0.01). On a mass basis, colloidal-phase Hg concentrations were similar to those of unimpacted sediments in the Midwest. Mercury to carbon ratios averaged 352 pg of HgT/mg of C and 25 pg of MeHg/mg of C and were not correlated to ionic strength. The log of the partition coefficient (log K(D)) for HgT and MeHg ranged from 3.7 to 6.4 and was typical of freshwater values determined using a 0.4 microm cutoff between the particulate phase and the dissolved phase. Log K(D) calculated using the <10 kDa fraction as "dissolved" ranged from 4.3 to 6.6 and had a smaller standard deviation about the mean. In addition, our data support the "particle concentration effect" (PCE) hypothesis that the association of Hg with colloids in the filter-passing fraction can lower the observed log K(D). The similarity between colloidal and particulate-phase partition coefficients suggests that colloidal mass and not preferential colloidal partitioning drives the PCE.
The inhibition of growth and development of Ascaris suum larvae in vitro by proline analogs

Abstract 1. The proline analogs azetidine-2-carboxylic acid (AZ) and dehydro- l -proline (DHP) inhibited the in vitro growth and development of 3rd stage Ascaris suum larvae at concentrations as low as 0.5 mM. 2. The effects of AZ on nematode growth were antagonized by addition of proline to culture media. 3. AZ significantly reduced the rate of [ 3 H]proline incorporation, but not [ 3 H]tryptophan into an isolated cuticle preparation from A. suum larvae. 4. The decrease in rate of proline incorporation into nematode cuticle by proline analogs suggests that they exert part of their inhibitory effects on larval growth and development by disrupting normal cuticle synthesis.
Time resolved photoluminescence measurements of C60 and C70-toluene solutions☆

Abstract The photoluminescence lifetimes and spectra at room temperature of C 60 and C 70 toluene solutions are investigated. The photoluminescence spectra of C 60 solutions were found to be independent of solution concentration, laser excitation wavelength and excitation fluence. The photoluminescence spectra of C 70 toluenes solution change as excitation fluence changes; indicating competing decay pathways of the fluorescence relaxation of the upper excited singlet states. The near linear relationship between the photoluminescence intensity and the excitation fluence indicates that photoluminescence is most likely from excitonic recombination.
Effects of Viscosity and Free-Surface Nonlinearity on the Wave Motion Generated by an Oscillating Twin Hull

The hydrodynamics of a rectangular, floating twin hull under heave oscillation is analyzed to determine viscous and nonlinear effects on the radiation hydrodynamics of multi-hulls, in particular, at the resonant frequency corresponding to the piston (Helmholtz) mode of wave motions. A second-order finite-difference method based on boundary-fitted coordinates is used for the solution of the incompressible Navier-Stokes equations together with exact nonlinear viscous boundary conditions. To separate the viscosity effects from the nonlinear free-surface effects, through comparison of results, nonlinear inviscid results are also obtained using a boundary-fitted curvilinear coordinates based finite difference method. The nonlinear inviscid algorithm is based on the Eulerian-Lagrangian formulation of the nonlinear free-surface flow. The nonlinear results are compared with the linear potential-flow results obtained by Yeung and Seah [20] to quantify the combined nonlinear and viscous effects on the wave forces. The present results show the overall behavior of the wave motion to be similar to that predicted by the linear potential-flow theory [20]. Our results show that the effects of nonlinearity and viscosity on the wave motion can be significant for the Helmholtz mode, particularly for small separation distance between the hulls, which result in large vertical oscillation of the mean surface between the hulls. For small amplitudes of oscillation, the hydrodynamic pressure forces computed in the present analysis are in striking agreement with that given by the linear potential-flow analysis of Yeung and Seah [20].Copyright © 2012 by ASME
Electrical Conductivity of Potassium Chloride

The electrical conductivity of potassium chloride is discussed within the framework of a four-defect model of the crystal. The four defects are mobile anion and cation vacancies and immobile divalent cation impurities and divalent cation impurity-cation vacancy complexes. The Teltow formulation of the four-defect model fails to describe precisely the measured electrical conductivity of KCl over the entire intrinsic and extrinsic range.
Effect of Psychosocial Variables on Maximum Acceptable Weight of Lift

Fifteen male subjects classified as Type A personalities (aggressive, impatient) and fifteen Type B (passive, patient) subjects performed a psychophysical lifting task under three social facilitation conditions: alone (box lowered automatically), with a confederate of similar physical ability lowering the box, and with a confederate of superior physical ability lowering the box. Results indicated that Type A subjects worked at a higher percentage of their aerobic capacity than Type B subjects, and spent less time deciding their maximum acceptable weight. The social facilitation conditions had no significant effect on maximum acceptable weight of lift.
Longitudinal relationships between childhood, adolescent, and adult eating disorders.

ABSTRACT Objective This study investigates the longitudinal course of eating problems from childhood though adulthood. The following questions are answered: (1) How stable are eating disorder symptoms and diagnoses over a 17-year interval from childhood to adulthood? (2) Do early childhood eating problems predict the occurrence of eating disorders in adulthood? Method An epidemiologically selected sample of approximately 800 children and their mothers received DSM -based structured psychiatric assessments in 1975, 1983, 1985, and 1992. The stability of full DSM diagnostic criteria for anorexia nervosa and bulimia nervosa, symptom scales derived from DSM criteria, and individual symptoms such as binge eating or dieting between early adolescence, late adolescence, and young adulthood was examined. Results Early adolescent bulimia nervosa is associated with a 9-fold increase in risk for late adolescent bulimia nervosa and a 20-fold increase in risk for adult bulimia nervosa. Late adolescent bulimia nervosa is associated with a 35-fold increase in risk for adult bulimia nervosa. Symptom scale scores for anorexia nervosa and bulimia nervosa correlate in the 0.3 to 0.5 range from early to late adolescence and young adulthood. For both anorexia nervosa and bulimia nervosa, gender, as well as eating symptoms at early and late adolescence, all predict young-adult eating disorder symptoms. Risk factors for the later development of eating disorders comprise eating conflicts, struggles with food, and unpleasant meals in early childhood. Conclusion The presence of eating problems in early childhood or an eating disorder in adolescence confers a strong risk for an eating disorder in young adulthood.
The Drosophila melanogaster ribosomal S6 kinase II-encoding sequence.

Abstract A cDNA encoding the Drosophila melanogaster p90 ribosomal S6 kinase II (RSK) was isolated from an eye-antennal imaginal disc library and sequenced. The conceptually translated protein is 60–63% identical to vertebrate RSK homologs and contains a perfectly conserved mitogen-activated protein kinase phosphorylation site. The gene was mapped to the base of the X chromosome in division 20 by in situ hybridization to polytene chromosomes.
Effect of impurity gettering on the efficiency of metallurgical-grade silicon solar cells

The efficiency of thin film epitaxial solar cells deposited onto low cost metallurgical-grade silicon (MGSi) was improved by the impurity gettering of the MGSi substrates. The gettering techniques investigated include (i) work damage on the back side of the wafers, (ii) intrinsic gettering using a one- and two-step thermal anneal and (iii) phosphorus gettering. The effectiveness of the various gettering techniques is evaluated from the electrical characteristics of solar cells. A one-step thermal anneal improves the solar cell efficiency from 7.9% (air mass 1) to 11.2% for 50 μm epitaxial cells. A two-step anneal further improves the efficiency to 11.8%. The phosphorus gettering gives the same efficiency as a two-step anneal but with a shorter annealing time. The improvement in cell efficiency is attributed primarily to the increase in the fill factor and short-circuit current density Jsc. Work damage in addition to a two-step anneal did not improve the overall electrical characteristics. It was also found that the cell efficiency is improved on an increase in epitaxial layer thickness. MGSi and semiconductor-grade silicon (SGSi) substrates on which are deposited epitaxial layers of the same thickness give comparable electrical results. The annealing of SGSi considerably degrades the cell performance. Computer modeling is used to analyze the current-voltage curves for the components of current losses. The major current losses for the MGSi solar cells were due to bulk recombination.
Semantic interference during object naming in agrammatic and logopenic primary progressive aphasia (PPA)

This study examined the time course of object naming in 21 individuals with primary progressive aphasia (PPA) (8 agrammatic (PPA-G); 13 logopenic (PPA-L)) and healthy age-matched speakers (n=17) using a semantic interference paradigm with related and unrelated interfering stimuli presented at stimulus onset asynchronies (SOAs) of -1000, -500, -100 and 0 ms. Results showed semantic interference (SI) (i.e. significantly slower RTs in related compared to unrelated conditions) for all groups at -500, -100 and 0 ms, indicating timely spreading activation to semantic competitors. However, both PPA groups showed a greater magnitude of SI than normal across SOAs. The PPA-L group and six PPA-G participants also evinced SI at -1000 ms, suggesting an abnormal time course of semantic interference resolution, and concomitant left hemisphere cortical atrophy in brain regions associated with semantic processing. These subtle semantic mapping impairments in non-semantic variants of PPA may contribute to the anomia of these patients.
Orbit Estimation of a Continuously Thrusting Spacecraft Using Variable Dimension Filters

The Center for Space Research and Assurance at the U.S. Air Force Institute of Technology investigates short-term tactical spacecraft missions that require frequent maneuvers. An important part of this research is developing methods of performing orbit determination on noncooperative spacecraft that maneuver often at unknown times with unknown thrusts. When a spacecraft performs long-duration thrusts in view of radars, traditional orbit determination, and batch least-squares routines are ineffective methods of fitting the orbit. Adaptive variable-state dimension filters allow for accurate orbit and thrust acceleration estimation during long-duration maneuvers. This work develops and evaluates routines that use both an extended and unscented augmented state Kalman filter along with interacting multiple models to estimate maneuvers. Several methods are evaluated to determine the start and conclusion of continuous maneuvers, and a multiple-model approach is introduced to determine the conclusion of low-thrus...
A Signaling Pathway Mediating Downregulation of BCL6 in Germinal Center B Cells Is Blocked by BCL6 Gene Alterations in B Cell Lymphoma

The BCL6 proto-oncogene encodes a transcriptional repressor necessary for the development of germinal centers (GCs) and directly implicated in lymphomagenesis. Post-GC development of B cells requires BCL6 downregulation, while its constitutive expression caused by chromosomal translocations leads to diffuse large B cell lymphoma (DLBCL). Herein we identify a signaling pathway that downregulates BCL6 expression in normal GC B cells and is blocked in a subset of DLBCL due to alterations in the BCL6 gene. Activation of the CD40 receptor leads to NF-kappaB-mediated induction of the IRF4 transcription factor, which, in turn, represses BCL6 expression by binding to its promoter region. A subset of DLBCL displays chromosomal translocations or mutations that disrupt the IRF4-responsive region in the BCL6 promoter and block its downregulation by CD40 signaling.
A mass spectrometric procedure for rapid identification of trace volatile metabolites.

Mass spectrometric method for rapid identification of trace volatile metabolites of respiratory atmosphere contained in isolated incubation flask
Multicultural Students in Study Abroad: Their Interests, Their Issues, and Their Constraints

Study abroad programs offer great potential to benefit students in an increasingly internationalized world and work place. Recently, a wide discussion among educators about the benefits of diversifying study abroad has developed, but students participating in study abroad may face many constraints, many of which are not faced by their majority student peers. The purpose of this study is to further assess, through a survey and focus groups, the constraints on multicultural student participation in study abroad. The results of the study indicate that institutional factors (academic scheduling difficulties, absence of relevant programs, lack of information, etc.), as well as other factors that can be moderated by institutional effort (providing encouragement, addressing financial issues, discussing family concerns, etc.), prevent students of color from participating in study abroad programs. The authors use the results of this study, along with those of the broader literature, to recommend strategies to incr...
Chemisorption and decomposition of trimethylgallium on GaAs(100).

Abstract The chemisorption and decomposition of trimethylgallium on the gallium-rich (4 × 6) and (1 × 6) GaAs(100) surfaces have been studied by temperature-programmed desorption, LEED, and Auger electron spectroscopy. Upon adsorption and subsequent heating, a fraction of a monolayer ((1.6 ± 0.7) × 1014 molecules cm−2) of trimethylgallium irreversibly dissociates into monomethylgallium surface fragments. Upon heating, methyl radicals are observed desorbing from the surface with a narrow peak at 710 K. The desorption parameters (activation energy and pre-exponential factor) of the methyl radicals depend on surface coverage, indicating significant adsorbate-adsorbate interactions. The zero coverage limit desorption parameters are: E = 46.1 ± 0.5 kcal mol and v = 1.6 × 1014±0.2 s−1. Higher coverages of trimethylgallium desorb molecularly in peaks at 500 and 350 K. After desorption of all hydrocarbon fragments the surface immediately converts into the (1 × 6) reconstruction. The excess gallium released from trimethylgallium decomposition is not incorporated in the GaAs surface and apparently resides in gallium droplets. We present structural models for the gallium-rich GaAs(100) surfaces before and after TMGa chemisorption which are consistent with all of our observations.
Time-resolved reflection surface x-ray diffraction

Methods to collect two-dimensional time-resolved x-ray diffraction patterns from surfaces/interfaces were developed. Reflection surface x-ray diffraction utilizing high brilliance x rays and a charge coupled device can achieve a time resolution as good as one second. Also, two-dimensional maps of reflectivity rocking curves can be recorded fast enough to monitor growth processes. These methods were demonstrated for the study of Ag and Pb films on Si (111)−(7×7) surfaces.
Social status constrains the stress response in the squirrel monkey.

Abstract The influence of dominance on the pituitary-adrenal and gonadal systems was evaluated in male squirrel monkeys. Basal and stress levels of plasma cortisol and testosterone were determined in eight male pairs across a 5-week period. The data indicated that squirrel monkeys have unusually high levels of steroid hormones in comparison to other species. Dominant males had higher levels of cortisol and testosterone and showed a smaller stress response than did subordinate males.
Optimum copper content of silver for YBa2Cu3O7−δ (YBCO) coated conductors

Abstract Several Ag–Cu alloys (0–0.25 at.% Cu) were studied as potential substrates for the direct pulsed laser deposition of YBCO without intermediate buffer layer. The microstructural characteristics of films and substrates were analyzed by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy, whereas the superconducting properties of the films were determined by inductive and transport methods. The properties of the YBCO films were significantly influenced by small concentrations of Cu in the substrate; YBCO films on a substrate with 0.2 at.% Cu exhibited the best superconducting properties.
Advanced fabrication methods for 3D meta-optics

Micro-Optics has expanded to include a wide variety of applications for spectral filtering, polarization filtering and beam shaping. Recently, a new class of optical elements have been introduced that can combine the spectral, polarization, and beam conditioning into the same optical element. This engineered optical functionality results in a 3D Meta-Optic structure that relies on sub-wavelength features to essentially engineer the electromagnetic fields within the structure; thereby, resulting in highly dispersive structures that spatially vary across the optical element. This talk will summarize recent results in the design, fabrication and applications of 3D Meta-Optics.
Estimating ecological production from biomass

Productivity-diversity relationships (P/D) are a vital theme in ecology, but productivity is typically not measured directly in that research. Instead, biomass (B) is the most common proxy for productivity, often as a 1:1 substitute. Unfortunately, this practice may cause error and uncertainty in P/D research, due to the fundamental difference between B and P and variable P/B ratios among and within systems. As a result, P/D research often measures a B/D relationship but interprets it as P/D. Fortunately, plausible, statistically legitimate and predictive P/B relationships can be found with careful analyses based on model selection of alternative allometric scaling equations and tests of model assumptions. Analyses are presented here for P/B relationships of 19 data sets, ranging from plant and animal populations and assemblages to ecosystems and biomes, representing over 2,300 analyzed P/B data. Models included standardized major regression (SMA) and ordinary least squares (OLS) regressions. Simple linea...
Blood Supply of Hemipelvectomy Flaps: The Anterior Flap Hemipelvectomy

In posterior flap hemipelvectomy, preservation of the gluteus maximus with the flap guarantees its viability regardless of the level of ligation of the iliac vessels. In anterior flap hemipelvectomy with the quadriceps femoris attached to the flap, the dominant blood supply is through the lateral femoral circumflex branches of the profunda vessels, which is sufficient to maintain the flap.
An experimental study on double emulsion drop breakup in uniform shear flow

Abstract In this work, the characteristics of the breakup in simple shear flow of double emulsion drops, suspended in a continuous immiscible, Newtonian phase, are studied. Double emulsions have been proposed as a medium for extraction but the breakup of drops reduces the efficiency of the extraction. Double emulsion drop breakup due to viscous forces was studied in a transparent cone-and-plate viscometer. The deformation or breakup parameter is the ratio of the applied viscous force when the drop ruptures to the surface tension force. This parameter can be correlated with the ratio of the apparent viscosity of the double emulsion drop to the viscosity of the continuous phase to yield a breakup curve. Although mechanistically double emulsion drops break up similarly to homogeneous Newtonian drops, the breakup curves for these two systems are different. It is shown that the elasticity of the double emulsion drops is in part responsible for this behavior.
Vitamins and hormones in nutrition — III. Infection

1. Infection constituted the chief etiological factor in 60 per cent of a series of 200 cases of nutritional disorders.
Evaluation of the human gonadotroph free α-subunit secretory pools by administration of gonadotropin hormone-releasing hormone into normal subjects at different phases of the ovarian cycle

The specificity of a monoclonal antibody RIA for the measurement of free α-subunit in plasma is presently documented. This RIA was used to explore the pituitary gonadotroph free α-subunit reserve in normal ovulating women stimulated with gonadotropin hormone-releasing hormone (GnRH). RIA specificity was established by means of competitive inhibition curves with various glycoprotein hormone preparations, and Sephadex G-100 exclusion chromatography of purified hFSH (1–2), hLH (LER 960) and pituitary extract. The 3.8% and 5.5% crossreactivities of hFSH 1–2 and hLH LER 960 were shown by exclusion chromatography to result in part from free α-subunit contamination in these purified preparations. Pituitary extract chromatography indicated hFSH and hLH cross-reactivity below 2.5% and 1.5%, respectively. Normal females were stimulated with GnRH throughout the cycle: 3 tests were performed on Day 7, 1 test on Day 13, 16, 17 and 22, respectively, and 2 tests on Day 24. GnRH stimulation consisted of an initial 100 μg bolus (time 0) followed at 2 h by a 12.5 μg/h constant infusion, and a second 100 μg bolus at 5 h. In all subjects, baseline free α-subunit values were below 2 ng/ml. Total free α-subunit secretion was markedly enhanced in subjects Day 13 and 16, in concert with total hLH and hFSH secretion. In the three subjects Day 7, free α-subunit was released only after the second GnRH bolus. In periovulatory subjects, free α-subunit secretion became apparent after the initial bolus and with constant GnRH infusion. In the three subjects Day 22 and 24, peak levels of free α-subunit were obtained after the second GnRH bolus. Therefore, a first GnRH bolus and GnRH infusion served to document a readily releasable and a reserve free α-subunit pituitary pool, respectively. Following the second GnRH bolus, the presence of a “residual” free α-subunit was observed.
Detection of Intact Influenza Viruses using Biotinylated Biantennary S-Sialosides

We report the modular synthesis of robust, biotinylated biantennary sialylglycoconjugates and their ability to differentiate between two type A influenza strains. This is the first demonstration of glycoconjugate-based discriminatory capture and detection of two strains of intact influenza virus, in the presence of the innate enzymatic activity of viral neuraminidases. We also demonstrate a “carboassay” using glycoconjugates as capture and reporter elements, which therefore, does not require antibodies. The capture of intact influenza viruses is of potential benefit for clinical diagnostics.
Lysophosphatidic acid modulates the healing responses of human periodontal ligament fibroblasts and enhances the actions of platelet-derived growth factor.

Background: Platelet-derived growth factor (PDGF) has been used to promote healing in many in vitro and in vivo models of periodontal regeneration. PDGF interacts extensively with lysophosphatidic acid (LPA). We recently showed that LPA modulates the responses of human gingival fibroblasts to PDGF. The objectives of this study were as follows: 1) to evaluate the basic interactions of LPA with primary human periodontal ligament fibroblasts (PDLFs) alone and with PDGF-BB for promoting PDLF growth and migration; 2) to determine the effects in an in vitro oral wound-healing model; and 3) to identify the LPA receptors (LPARs) expressed by PDLF.Methods: PDLF regenerative responses were measured using 1 and 10 μM LPA in the absence or presence of 1 or 10 ng/ml PDGF. Cell proliferation was determined by 5-bromo-2′-deoxyuridine (BrdU) immunohistochemistry and by cell counting. Migration responses were measured using a microchemotaxis chamber. PDLFs were grown to confluence on glass slides, a 3-mm-wide wound was me...
Are adolescent girls with a physical disability at increased risk for sexual violence

BACKGROUND: The purpose of this study was to investigate whether US female adolescents who self-reported having a physical disability or long-term health problem were more likely to report having been physically forced to have sexual intercourse than US female adolescents without a physical disability or long-term health problem. METHODS: Using data from the 2005 U.S. National Youth Risk Behavior Survey (YRBS), we employed logistic regression analyses to estimate the association between physical disability (and other variables) and the risk for sexual violence among US high school girls. RESULTS: Female high school students who reported a physical disability or long-term health problem were more likely to report having been physically forced to have sexual intercourse than those who did not (19.6% vs 9.4%;chi(2) = 14.51, p = .003). Results from our multivariate analysis reveal that this association remained significant (adjusted odds ratio [AOR], 1.57; 95% confidence interval [CI], 1.10-2.23) after adjusting for certain demographic characteristics, physical health problems, behavioral health risks, and violent conduct. CONCLUSIONS: Our findings suggest that adolescent girls in the United States with a physical disability or long-term health problem may be at increased risk for sexual violence. It is important that national efforts to reduce sexual violence consider how to address the unmet needs of children and adolescents with disabilities. As most adolescent girls spend the majority of their time in a school setting, it is of particular importance that school health professionals are aware of the current findings. Language: en
Neutron-nucleus optical model parameter effects on s-wave transmission coefficients

Abstract Numerical calculations of the s-wave transmission coefficients at a neutron energy of 1 keV for a nuclear optical model are presented in order to display the effects of model parameter variation. Particular attention is given to the effects of the surface diffuseness distance and of the strength of the imaginary part of the optical potential. Both volume and surface-peaked absorption are considered. In addition, some comments are made concerning the difficulties encountered in using one-dimensional models to infer three-dimensional behaviour of the complex scattering length.
Behavior of Li defects in solid electrolyte lithium thiophosphate Li7P3S11: A first principles study

Abstract We investigate the impact of interstitial Li and Li vacancy on the electronic structure of Li 7 P 3 S 11 and the mechanism of Li ion migration in Li 7 P 3 S 11 through first principles calculations. We find that Li 7 P 3 S 11 is a good insulator with a wide band gap of 3.5 eV. We find that both Li vacancy and interstitial Li + ion do not introduce states in the band gap hence they do not deteriorate the electronic properties of Li 7 P 3 S 11 . The calculated formation energy of Li vacancy is much larger than that of Li interstitial. The interstitial Li are found to be stable at many sites in Li 7 P 3 S 11 . More importantly, the lowest energy barrier for interstitial Li + ion diffusion in Li 7 P 3 S 11 is found to be 0.24 eV. Our calculations suggest that interstitial Li ions play a very important role on the Li 7 P 3 S 11 ionic conductivity.
Zinc Coordination Is Required for and Regulates Transcription Activation by Epstein-Barr Nuclear Antigen 1

Epstein-Barr Nuclear Antigen 1 (EBNA1) is essential for Epstein-Barr virus to immortalize naive B-cells. Upon binding a cluster of 20 cognate binding-sites termed the family of repeats, EBNA1 transactivates promoters for EBV genes that are required for immortalization. A small domain, termed UR1, that is 25 amino-acids in length, has been identified previously as essential for EBNA1 to activate transcription. In this study, we have elucidated how UR1 contributes to EBNA1's ability to transactivate. We show that zinc is necessary for EBNA1 to activate transcription, and that UR1 coordinates zinc through a pair of essential cysteines contained within it. UR1 dimerizes upon coordinating zinc, indicating that EBNA1 contains a second dimerization interface in its amino-terminus. There is a strong correlation between UR1-mediated dimerization and EBNA1's ability to transactivate cooperatively. Point mutants of EBNA1 that disrupt zinc coordination also prevent self-association, and do not activate transcription cooperatively. Further, we demonstrate that UR1 acts as a molecular sensor that regulates the ability of EBNA1 to activate transcription in response to changes in redox and oxygen partial pressure (pO2). Mild oxidative stress mimicking such environmental changes decreases EBNA1-dependent transcription in a lymphoblastoid cell-line. Coincident with a reduction in EBNA1-dependent transcription, reductions are observed in EBNA2 and LMP1 protein levels. Although these changes do not affect LCL survival, treated cells accumulate in G0/G1. These findings are discussed in the context of EBV latency in body compartments that differ strikingly in their pO2 and redox potential.
Effects of caudal fourth ventricular lactate infusion on hypoglycemia-associated MCT2, GLUT3, GLUT4, GCK, and sulfonylurea receptor-1 gene expression in the ovariectomized female rat LHA and VMH: impact of estradiol.

Cellular metabolic stasis is monitored in the lateral hypothalamic area (LHA) and ventromedial hypothalamic nucleus (VMH), the classically defined hypothalamic “anoretic” and “satiety” centers, respectively. Neuronal glucose (GLUT3, GLUT4) and monocarboxylate (MCT2) transporter genes are expressed in both sites, suggesting that glucose and lactate, a product of astrocytic glycolysis, may fuel aerobic respiration in local neurons. Evidence that glucose utilization in the hypothalamus, but not other brain regions, is reported to vary according to cyclic estradiol secretion suggests that this hormone may regulate uptake and/or catabolism of this fuel. We investigated the hypothesis that estradiol exerts site-specific regulatory effects on basal and insulin-induced hypoglycemia (IIH)-associated MCT2 and neuronal glucose transporter mRNA profiles, and expression of genes that encode the substrate sensor, glucokinase (GCK), and the sulfonylurea receptor-1 (SUR) subunit of the energy-dependent potassium channel, KATP, in the female rat LHA and VMH. As caudal fourth ventricular (CV4) lactate infusion intensifies hypoglycemia in this gender, we also examined whether demonstrable LHA and VMH gene responses to IIH are correspondingly amplified. MCT2, GLUT3, GLUT4, GCK, and SUR1 mRNA levels in the LHA and VMH did not differ between saline-injected ovariectomized (OVX) rats implanted with estradiol benzoate (EB) or oil (O). LHA: IIH had no impact on gene profiles, excluding SUR1, in EB-treated animals, but decreased these transcripts, with the exception of GCK, in OVX + O rats. CV4 lactate infusion in hypoglycemic OVX + EB animals suppressed each mRNA profile, but reversed IIH-associated reductions in MCT2, GLUT3, and GLUT4 gene expression in OVX + O. VMH: IIH increased MCT2 and GLUT4 transcripts in OVX + EB, but not OVX + O rats and decreased GCK mRNA in both groups. Lactate plus insulin treatment elevated VMH MCT2, GLUT3, SUR1, and GCK gene expression in EB- and O-implanted OVX rats, but augmentation of the former three profiles was greater in the presence of EB. The data show that LHA and VMH neurons exhibited dissimilar, estradiol-dependent adjustments in neuronal lactate and glucose transporter, GCK, and SUR1 gene expression during IIH, and that in the presence of estradiol, caudal hindbrain lactate infusion during IIH elicited divergent changes in MCT2, GLUT3, GCK, and SUR1 gene expression in the LHA and VMH, where these transcripts were, respectively, diminished or augmented. These results support the need to investigate the potential impact of site-specific adjustments in fuel uptake and KATP regulation of membrane voltage on general and specialized, e.g., chemosensory, neuronal functions.
Noncrystalline inclusions in erythrocytes of a rhinoceros iguana.

Summary In the following case, intracytoplasmic and intranuclear noncrystalline inclusions are found in the erythrocytes of a male Rhinoceros Iguana. Ultrastructurally, cytoplas-mic inclusions are hexagonal with sharp borders not bound by a membrane. Similar to surrounding hemoglobin in that they are amorphous, homogenous and composed of finely textured material, the inclusions are easily differentiated by their symmetry and weak electron density. Nuclear inclusions are observed causing margination of chro-matin and nucleoplasm. They are also easily distinguished by their hexagonal shape, weak electron density and the greater granularity of the surrounding nucleoplasm. The case is unusual because noncrystalline inclusions other than Heinz bodies have not yet been described in the erythrocytes of animals with nucleated red cells.
Habit Formation and U.S. Household Consumption:A Semiparametric Panel Data Analysis

Using household panel data from the PSID, a semiparametric panel data model is estimated and examined for the presence of habit formation. Previous studies in this area were based on linear models, and the semiparametric model is an improvement over the latter in that it does not specify a particular functional form on the data generating process. Estimates of the model show evidence of habit formation for a substantial percentage of the observations. An examination of households by their demographic characteristics as well as by job status yields additional information and supporting evidence on the existence of habit formation.
Energy efficient near-threshold chip multi-processing

Subthreshold circuit design has become a popular approach for building energy efficient digital circuits. One drawback is performance degradation due to the exponentially reduced driving current. This had limited subthreshold circuits to relatively low performance applications such as sensor networks. To retain the excellent energy efficiency while reducing performance loss, we propose to apply subthreshold and near-threshold techniques to chip multi-processors. We show that an architecture where several slower cores are clustered together with a shared faster L1 cache is optimal for energy efficiency, because processor cores and memory operate best at different supply and threshold voltages. In particular, SPLASH2 benchmarks show about a 53% energy improvement over the traditional CMP approach (about 70% over a single core machine).
Compressive Yield Stress of Cement Paste

Compressive yield stresses have been measured for pastes (0.35 ≤ w/c ≤ 0.50) of portland cement, calcium aluminate cement, and weakly and strongly flocculated alumina (Φ0 = 0.20) using the centrifuge sediment height technique. Equilibrium sediment heights are reached quickly, allowing all measurements to be taken during the cement's induction period. The compressive behavior showed little dependence on the compressive history. Compressive yield stress was, however, dependent upon initial volume fraction, decreasing as the initial volume fraction increases. This behavior was observed in both the cements and alumina suspensions, implying that strong dependencies on initial structure may be a general property of the compressive behavior of flocculated suspensions.
Crystal structure of the autocatalytic initiator of glycogen biosynthesis, glycogenin.

Glycogen is an important storage reserve of glucose present in many organisms, from bacteria to humans. Its biosynthesis is initiated by a specialized protein, glycogenin, which has the unusual property of transferring glucose from UDP-glucose to form an oligosaccharide covalently attached to itself at Tyr194. Glycogen synthase and the branching enzyme complete the synthesis of the polysaccharide. The structure of glycogenin was solved in two different crystal forms. Tetragonal crystals contained a pentamer of dimers in the asymmetric unit arranged in an improper non-crystallographic 10-fold relationship, and orthorhombic crystals contained a monomer in the asymmetric unit that is arranged about a 2-fold crystallographic axis to form a dimer. The structure was first solved to 3.4 A using the tetragonal crystal form and a three-wavelength Se-Met multi-wavelength anomalous diffraction (MAD) experiment. Subsequently, an apo-enzyme structure and a complex between glycogenin and UDP-glucose/Mn2+ were solved by molecular replacement to 1.9 A using the orthorhombic crystal form. Glycogenin contains a conserved DxD motif and an N-terminal beta-alpha-beta Rossmann-like fold that are common to the nucleotide-binding domains of most glycosyltransferases. Although sequence identity amongst glycosyltransferases is minimal, the overall folds are similar. In all of these enzymes, the DxD motif is essential for coordination of the catalytic divalent cation, most commonly Mn2+. We propose a mechanism in which the Mn2+ that associates with the UDP-glucose molecule functions as a Lewis acid to stabilize the leaving group UDP and to facilitate the transfer of the glucose moiety to an intermediate nucleophilic acceptor in the enzyme active site, most likely Asp162. Following transient transfer to Asp162, the glucose moiety is then delivered to the final acceptor, either directly to Tyr194 or to glucose residues already attached to Tyr194. The positioning of the bound UDP-glucose far from Tyr194 in the glycogenin structure raises questions as to the mechanism for the attachment of the first glucose residues. Possibly the initial glucosylation is via inter-dimeric catalysis with an intra-molecular mechanism employed later in oligosaccharide synthesis.
Regulation of Membrane Permeability by a Two-Component Regulatory System in Pseudomonas aeruginosa

Membrane impermeability is the major contributing factor to multidrug resistance in clinical isolates of Pseudomonas aeruginosa. By using laboratory strain PAK, a spontaneous P. aeruginosa mutant (mutant PAK1-3) whose membrane had reduced permeability and which displayed increased levels of resistance to various antibiotics, especially aminoglycosides, was isolated. By complementation of the mutant with a genomic clone library derived from wild-type strain PAK, a novel two-component regulatory system (PprA and PprB) was identified and was found to be able to increase the permeability of the bacterial membrane and render PAK1-3 sensitive to antibiotics. Furthermore, specific phosphorylation of the response regulator (PprB) by histidine kinase (PprA) was observed in vitro, demonstrating that they are cognate two-component regulatory genes. Introduction of a plasmid expressing the pprB gene into randomly chosen clinical isolates (n = 17) resulted in increased sensitivity to aminoglycosides in the majority of isolates (n = 13) tested. This is the first demonstration that P. aeruginosa membrane permeability can be regulated, providing an important clue in the understanding of the mechanism of membrane impermeability-mediated multidrug resistance in P. aeruginosa.
Oviposition behavior and offspring performance in herbivorous insects: consequences of climatic and habitat heterogeneity

Th e preference–performance hypothesis predicts that when female herbivorous insects determine where to position off spring of low mobility, they will select sites that maximize development and survival of those off spring. How this critical relationship responds to variation in climatic and habitat conditions remains untested, however, despite its important consequences for population and evolutionary dynamics. Here we report on 13 years of data totaling 1348 egg clusters of the montane Gillette’s checkerspot butterfl y Euphydryas gillettii (Lepidoptera: Nymphalidae). We used these data to test the hypothesis that, in environments with climatic and habitat heterogeneity, the oviposition behavior–off spring performance relationship should vary in both space and time. Orientation of egg clusters for maximum morning sun exposure is known to aff ect developmental rate. We therefore predicted female preference for morning sun orientation to be variable and a function of climatic and habitat conditions. We found that preference for egg cluster orientation on the leaf tracked the phenology of the start of the female fl ight season but that seasonal temperatures drove most of the variation in egg cluster development time. Th e relationship between behavior and performance was also dependent upon the climatic eff ects on survival; sun-oriented egg clusters had higher survivorship in the coldest year of the four years for which measurements were made. We also examined how conifer cover aff ected larval survival and female oviposition behavior in one year. Females selected oviposition sites in more open habitat. However, when egg clusters were oriented to intercept morning sun, conifer cover increased survivorship to diapause. Finally, we found that predator activity was lower for morning sunoriented egg clusters suggesting that predation patterns may further infl uence habitat selection for oviposition. Th is study exemplifi es how the relationship between oviposition behavior and off spring performance is context-dependent: habitat and climate interact to determine preference–performance outcomes.
Novel anti-Cryptosporidium activity of known drugs identified by high-throughput screening against parasite fatty acyl-CoA binding protein (ACBP)

Background Cryptosporidium parvum causes an opportunistic infection in AIDS patients, and no effective treatments are yet available. This parasite possesses a single fatty acyl-CoA binding protein (CpACBP1) that is localized to the unique parasitophorous vacuole membrane (PVM). The major goal of this study was to identify inhibitors from known drugs against CpACBP1 as potential new anti-Cryptosporidium agents.
NOMAD buoys: an overview of forty years of use

The Navy Oceanographic Meteorological Automatic Device (NOMAD) buoy was developed by the U.S. Navy (USN) in the late 1940s as an offshore autonomous meteorological platform. Between 1951 and 1970, 21 NOMAD buoys were built and deployed in a wide range of locations. In 1974, the National Data Buoy Center (NDBC) acquired several of these NOMAD buoys, and since that time has used the hulls as meteorological and oceanographic data buoys. The NOMAD buoy has excellent performance characteristics and is the principal hull used on NDBC's remote stations in the north Pacific and Atlantic Oceans. NDBC modified the internal compartmentation and structural design of the buoy to reduce its acquisition cost, and has constructed 24 additional NOMAD hulls of this value-engineered (VE) design. The NOMAD design has also been adapted for use by Environment Canada, and it was the basis for a boat-shaped buoy developed in Japan. This paper reviews the history of the NOMAD buoy's development, highlights its physical characteristics, discusses its accomplishments in the 40 years of use as an ocean data acquisition system (ODAS) buoy, and describes plans for future NDBC applications of the buoy.
CTR-S: a logic for specifying contracts in semantic web services

A requirements analysis in the emerging field of Semantic Web Services (SWS) (see http://daml.org/services/swsl/requirements/) has identified four major areas of research: intelligent service discovery, automated contracting of services, process modeling, and service enactment. This paper deals with the intersection of two of these areas: process modeling as it pertains to automated contracting. Specifically, we propose a logic, called CTR-S,which captures the dynamic aspects of contracting for services.Since CTR-S is an extension of the classical first-order logic, it is well-suited to model the static aspects of contracting as well. A distinctive feature of contracting is that it involves two or more parties in a potentially adversarial situation. CTR-S is designed to model this adversarial situation through its novel model theory, which incorporates certain game-theoretic concepts. In addition to the model theory, we develop a proof theory for CTR-S and demonstrate the use of the logic formodeling and reasoning about Web service contracts.
Effect of diet orange soda on urinary lithogenicity.

Studies have shown that certain beverages decrease urinary lithogenicity by increasing urine citrate excretion. Diet Sunkist Orange soda had the highest concentration of citrate and total alkali content among 12 diet sodas previously assayed. We studied the effect of Diet Sunkist Orange soda consumption on urinary chemistry. Nine healthy men and women ages 26–54 years completed the study. During the control period, subjects drank 36 oz of water for 3 days in addition to their own, self-selected diet and recorded a food diary. During the study period, the subjects drank three 12-oz cans of Diet Sunkist Orange soda a day instead of water, and replicated their diets from the control period. In each period, the subjects performed 24-h urine collections on days 2 and 3. Urine chemical analysis was performed, including urinary citrate levels and pH. Diet Sunkist Orange soda increased urinary citrate excretion by 60 mg/day, which was not statistically significant (95% CI −75 to 195, P value 0.34). There was no significant change in pH from the control period to the study period (pH: 6.29–6.21; 95% CI: −0.09 to 0.25, P = 0.30). Urine volumes and creatinine excretions were not significantly different between the control and study periods. Despite the relatively high citrate and total alkali content of Diet Sunkist Orange soda, the volume consumed in this study (36 oz per day) did not provide sufficient potential base to significantly alter urine composition in healthy subjects with normocitraturia. The effect of Diet Sunkist Orange soda on urinary chemistry in patients with hypocitraturia and nephrolithiasis is not likely to have a clinically significant effect to prevent calcium or uric acid stones.
Thermochemical Investigations of Hydrogen-Bonded Solutions. Part 9. Comparison of Mobile Order Theory and the Kretschmer-Wiebe Association Model for Predicting Pyrene Solubilities in Binary Alcohol + Alcohol Solvent Mixtures

A relatively simple expression is developed for predicting the solubility of an inert crystalline solute in binary alcohol + alcohol solvent mixtures based upon the Kretschmer-Wiebe association model. The predictive accuracy of the newly-derived expression is compared to equation(s) derived previously from Mobile Order theory. Computations show that both models accurately describe the solubility behavior of pyrene in the 24 binary solvent systems studied. Average absolute deviations between observed and predicted values were 2.0% and 2.2% for the Kretschmer-Wiebe and Mobile Order predictive equations, respectively.