cssi/SciSciGPT-SciSciNet huggingface dataset:
Are the odd-rank crystal field parameters independent quantities?

The relation between various odd-rank crystal field parameters is discussed in the context of the theoretical description of the spectroscopic properties of rare earth ions in crystals.
Separabilities of binary Gray codes designed over Z/sub 4/

Binary Gray codes can be designed from the Lee distance Gray codes over Z/sub 4/ with the mapping: 0/spl harr/00, 1/spl harr/01, 2/spl harr/11 and 3/spl harr/10. For these codes of length n if the Hamming distance between the Gray codes g(i) and g(j) is d, where i and j are integers, then it is proved that |i-j|>(4/15)2/sup d/ and |i-j| (7/15)2/sup d/ and |i-j|<(7/15)2/sup d/ for d even.
Closed-Loop Solution of Transient Recovery Voltage for Interrupted Induction Motor Starting

When the starting of a large (>1000 HP) induction motor is aborted and a circuit breaker interrupts the current, a transient overvoltage is observed. The magnitude of this transient is greatest for the first interrupted phase; hence the behavior of only this phase is studied. The motor at standstill is modeled as a three-phase reactor with an isolated neutral. Analysis of the transient phenomenon is intended to extend and complement Greenwood's and Glinkowski's work which are based on empirical and circuit analyses. The object is to arrive at an exact closed-loop expression that completely describes the transient recovery voltage resulting from such a transient event. An example of the application of this expression is supplied, and a simplified expression that may be used for quick calculations is also provided. Two quantities of importance, the rate of rise of recovery voltage and the peak voltage of the transient, are obtained, and a method to limit them is discussed.
Estimation of radial gradients of phase space density from POLAR observations during a quiet period prior to a sudden solar wind dynamic pressure enhancement

[1] We have analyzed POLAR electron flux data to estimate the radial gradients of electron phase space density (PSD) immediately prior to a sudden solar wind dynamic pressure enhancement at ∼1135 UT on 12 August 2001. In this event, the instantaneous flux changes from the magnetospheric compression at L ∼ 7.6 in the postmidnight magnetic local time sector are observed to be both energy and pitch angle (PA) dependent: a substantial flux increase for lower energies (<∼200 keV) particularly at smaller local PA (<∼50°) and a large flux decrease for relativistic energies that is more pronounced for a larger PA. For this event, because of the extremely steady and quiet solar wind conditions prior to the pressure impact, we can reasonably assume that the temporal variation is negligible and so deduce the spatial and pitch angle distribution of initial electron fluxes to construct the event-specific electron flux model for a localized region of the nightside outer radiation belt. PSD radial profiles are then estimated for 6.5 < L < 8.5 using the constructed electron flux model and Tsyganenko magnetospheric model for quiet times. The estimates show a positive PSD gradient for low energies (<∼a few 100 s keV at the POLAR location right after the pressure impact) and a negative gradient for relativistic energies. In addition, a rather gradual transition of the radial gradient from highly positive to more negative is found with increasing energy. The expected immediate flux responses using these estimated PSD radial gradients are qualitatively consistent with those observed, partially validating the veracity of the estimated profiles.
Probabilistic methods for stationary problems of linear transport theory

The steady state of a system of independent particles which undergo elastic collisions can be expressed in terms of the absorption probabilities of the associated Markov process. For the slab albedo problem, this representation enables the application of probabilistic methods to obtain explicit upper and lower bounds on the steady-state density. In particular, the bounds prove the 1/L, decrease of the steady-state flux as a function of the slab widthL (Fick's law).
Controlled food-chain transfer of dieldrin residues from phytoplankters to clams

The marine phytoplankter Dunaliella peircei was exposed to a concentration of 10.00μg/l of the chlorinated hydrocarbon insecticide dieldrin in sea-water solution. After 24 h exposure, the dieldrin residue level in the alga was 12.10μg/g, corresponding to a magnification factor of 1210. Clams, Rangia cuneata, allowed to feed on dieldrin-contaminated phytoplankters for 48 h exhibited a magnification of dieldrin residues in tissues up to 54 times greater than the concentration resulting from the resuspension of contaminated algal cells in clean seawater. This study demonstrates the transfer of dieldrin residues in a two-level food chain, i.e., from a contaminated alga to a bivalved mollusc allowed to feed on this alga.
Model validation and performance analysis of regenerative solid oxide cells for energy storage applications: Reversible operation

Abstract The need for electrical energy storage (EES) is being driven by the deployment of increasing amounts of intermittent renewable energy resources. In addition to their fuel flexibility, high efficiency, scalability, and long-term cost outlook, reversible (regenerative) solid oxide cell (rSOC) systems have the potential for round-trip efficiencies competitive with the other available energy storage technologies. Accordingly, the focus of the current study is to investigate modeling methods for high temperature rSOCs in order to facilitate future endeavors related to establishing optimal operating conditions and system designs. Previously developed solid oxide fuel cell (SOFC) and solid-oxide electrolytic cell (SOEC) models are integrated to form a general rSOC model. The model is first calibrated and validated based on the available experimental data in the extant literature. The validation results show that the fitting parameters extracted from the calibration study can precisely simulate the cell behavior under various operating conditions. The effects of key operating parameters, such as temperature, gas composition and fuel utilization, on the voltage–current density performance characteristic and thermoneutral voltage are then investigated. It is also observed that the total electrochemical losses of the cell can be significantly different in each operating mode (fuel cell and electrolyzing) under certain operating conditions. Advantages of pressurized operation on thermal management are also discussed.
External barium influences the gating charge movement of Shaker potassium channels

External Ba2+ speeds the OFF gating currents (IgOFF) of Shaker K+ channels but only upon repolarization from potentials that are expected to open the channel pore. To study this effect we used a nonconducting and noninactivating mutant of the Shaker K+ channel, ShH4-IR (W434F). External Ba2+ slightly decreases the quantity of ON gating charge (QON) upon depolarization to potentials near -30 mV but has little effect on the quantity of charge upon stepping to more hyperpolarized or depolarized potentials. More strikingly, Ba2+ significantly increases the decay rate of IgOFF upon repolarization to -90 mV from potentials positive to approximately -55 mV. For Ba2+ to have this effect, the depolarizing command must be maintained for a duration that is dependent on the depolarizing potential (> 4 ms at -30 mV and > 1 ms at 0 mV). The actions of Ba2+ on the gating current are dose-dependent (EC50 approximately 0.2 mM) and are not produced by either Ca2+ or Mg2+ (2 mM). The results suggest that Ba2+ binds to a specific site on the Shaker K+ channel that destabilizes the open conformation and thus facilitates the return of gating charge upon repolarization.
ON STRONG REVERSIBILITY IN P SYSTEMS AND RELATED PROBLEMS

We consider transition P systems as originally defined in the seminal paper of Gh. Paun, where he introduced the field of membrane computing. We show that it is decidable to determine, given a P system Π, whether it is strongly reversible (i.e., every configuration has at most one direct predecessor), resolving in the affirmative a recent open problem in the field. We also show that the set of all direct predecessors of a given configuration in a P system is an effectively computable semilinear set, which can effectively be expressed as a Presburger formula, strengthening an early result in the literature. We also prove other related results.
New Evidence on the Finite Sample Properties of Propensity Score Reweighting and Matching Estimators

Abstract Frolich (2004) compares the finite sample properties of reweighting and matching estimators of average treatment effects and concludes that reweighting performs far worse than even the simplest matching estimator. We argue that this conclusion is unjustified. Neither approach dominates the other uniformly across data-generating processes (DGPs). Expanding on Frolich's analysis, this paper analyzes empirical as well as hypothetical DGPs and also examines the effect of misspecification. We conclude that reweighting is competitive with the most effective matching estimators when overlap is good, but that matching may be more effective when overlap is sufficiently poor.
Current-crowding effect in multiple cantilever channel MOSFET

Abstract Multiple cantilever channel MOSFET formed by multiple fully or partially-depleted silicon gate-all-around (GAA) cantilever channels suspended between source drain (S/D) “anchors” might be a very attractive architecture as gate lengths are scaled below 100 nm. In this paper we shall demonstrate that although such an architecture may be ideal for sub-100 nm nodes it suffers from current-crowding effects towards the top cantilever channels leading to a higher current density in the cantilevers towards the top than those near the substrate. Hence, the drive current cannot be scaled linearly in such a device by stacking higher number of cantilever channels vertically without consuming additional Si real estate. It is shown that although the drive current does not saturate after a particular number of cantilevers, the drive current enhancement is lower than expected based on the effective electrical width and is dependent on the S/D series resistance.
Size effects of PVP-Pd nanoparticles on the catalytic Suzuki reactions in aqueous solution

A series of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized Pd nanoparticles with varying particle size are prepared by using the stepwise growth reaction. The effect of Pd particle size on the Suzuki reaction between phenylboronic acid and iodobenzene is investigated by the use of four Pd catalysts with mean particle sizes of 3.0, 3.9, 5.2, and 6.6 nm, respectively. The catalytic activity of the Pd nanoparticles expressed in terms of the initial turnover frequency (moles of the biphenyl product per mole of total surface Pd atoms per min) is found to be in the order of Pd (3.9 nm) > Pd (3.0 nm) ≈ Pd (5.2 nm) > Pd (6.6 nm), indicating that surface Pd atoms do not all have the same reactivity in this reaction. The general trend of increased catalytic activity with the decrease in the particle size suggests that the low-coordination number vertex and edge atoms on the particle surface are active sites for the Suzuki reaction. The lower catalytic activity for the smallest Pd nanoparticles might be due to stronge...
Competition, matching, and geographical clustering at early stages of the industry life cycle

We analyze the matching-based centripetal force leading to spatial clustering of firms within industries undergoing the early stages of their evolution. In these industries, the quality of the match between the characteristics of the inputs offered by suppliers and sought by assemblers’ are uncertain. The model also incorporates the centrifugal force preventing spatial concentration of industry. The model shows that depending on the relative strength of the centripetal and the centrifugal forces of spatial distribution, the equilibrium outcome can be either concentration of all industry workers, suppliers and assemblers in one location or dispersion. We analyze the conditions, which determine the relative strength of the two forces.
Anomalous curving of Arrhenius plots for data obtained from electro-thermal vaporization at atmospheric pressure

Abstract Arrhenius plots are often used in electrothermal atomization atomic absorption spectroscopy (ETA-AAS) to obtain activation energies (Ea) of vaporization processes. However, these plots are often nonlinear, and the exact cause of the curvature is not clear. This phenomenon has been attributed to multiple generation functions, diffusion of atoms through the graphite walls, changes in the size of the generating particles, changes in the surface coverage and interferences of the removal function with the supply function. This paper examines several other possibilities using computer simulations on a micro-computer. These possibilities include the effects of diffusion, errors in the assumed order of the reaction and small systematic errors. These can create curving very similar to that observed in typical ETA-AAS and should be considered before assigning the curvature to other chemical or physical properties of the system.
Reinterpretation of cloud-topped mixed-layer entrainment closure

Mixed-layer models of convective boundary layers in the atmosphere and oceans are powerful and useful tools for including important physical processes in general-circulation models of the two media as well as for diagnostic and prognostic studies of air-sea interaction and pollution dispersion. Recently, the appropriate physical and mathematical interpretation of the entrainment closure in such models has come under discussion. In mixed-layer ocean models and models of the dry convective atmospheric mixed layer, the discussion is essentially moot because, when the closure is implemented, its mathematics are independent of the physical interpretation. However, in mixed-layer models of the cloud-topped boundary layer, different physical interpretations lead to quite different mathematical formulations of the closure that yield widely differing results. In this paper, a new interpretation of the turbulence energetics for the cloud-topped case is discussed. It retains the mathematical simplicity of an earlier approach while allowing consistency with recent numerical results concerning asymmetric diffusivities. Although the definitive study of the problem, by either theoretical, observational or numerical methods, remains for the future, the interpretation of turbulence energetics presented here is sufficiently flexible to be adaptable to new results. DOI: 10.1111/j.1600-0870.1987.tb00302.x
Far Infrared Spectroscopy Of Shallow Donors In GaAs/AlGaAs Multiple-Quantum-Well Structures

Far infrared (FIR) spectroscopy has been demonstrated to be a powerful tool for studies of the electronic properties of semiconductors, particularly in investigation and characterization of shallow impurities. Recent advances in growth techniques have permitted the fabrication of repeated semiconductor heterostructures (quantum wells and superlattices) with interface abruptness on an atomic scale. For the case of Quantum Wells, simple considerations indicate that the electronic states of shallow impurities in such confining structures depend strongly on the width of the wells and/or the impurity location along the growth direction. In the present paper, recent experimental work on shallow donor impurities in GaAs/AlGaAs multiple-quantum-well (MQW) structures is reviewed. Absorption and photoconductivity studies were carried out with a FIR Fourier Transform Spectrometer in magnetic fields up to 9T. MQW samples nominally doped with Si donors in the well centers and at the well edges have been investigated for QW widths between 80Aand 450A. Results are generally in very good agreement with recent theoretical calculations. Possible use of such measurements to determine the impurity distribution along the growth direction is discussed.
Style control in the Quill document editing system

A critical problem in the design of editors for structured documents is that of style control, i.e. mapping the logical elements of the documents to their physical appearance on pages. This paper presents a novel approach to style control, used in the Quill document editing system that has been prototyped at the IBM Almaden Research Center. In our approach, the style control mechanism is an integral part of the editing system and consistent with the overall system architecture, in both its inner structure and its user interface. Properties that specify the formatting process, together with action routines for specifying complex semantics, are the basic style control primitives in the proposed approach.
26Mg states observed via 22Ne + α

Abstract We report differential cross-section measurements at 15 angles for the reaction 22 Ne (α, α 0 ) 22 Ne for 3.8 ⩽ E α ⩽ 11 MeV in steps ⩽ 15 keV and infer 92 resonances and 21 possible resonances, in many cases identifying or limiting the spin and parity. In addition, we measured inelastic scattering data from E α = 6.1 MeV ( α 1 ) and E α = 9.9 MeV ( α 2 ) to E α = 11.0 MeV.
Diffusion tensor imaging and volumetric analysis of the ventral striatum in adults with traumatic brain injury

Objectives: The aim was to determine if there are changes in the integrity and volume of the ventral striatum following severe traumatic brain injury (TBI) and if these changes relate to executive functioning.Methods: This study recruited 14 participants with severe TBI (mean age: 22 years) and 15 demographically-matched controls. All participants underwent magnetic resonance imaging with diffusion tensor imaging (DTI) and volumetric analysis at 6 months post-injury. Participants with TBI underwent neuropsychological testing and the relation between imaging data and cognitive performance was examined.Results: Differences in DTI parameters (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) were found between participants with TBI and controls. Correlations between right and left ventral striatum ADC and the executive functioning factor of the Neurobehavioural Rating Scale-Revised (NRS-R) were found. Correlations between right ventral striatum FA and the Controlled Oral Word Association T...
Alterations in sensorimotor development relationship to postnatal alcohol exposure

The sensory, motor, and physical development of rats reared by dams, artificially reared on milk formula alone, or on milk formula combined with alcohol was examined. The rats given alcohol received 6.6 g/kg/day, which was administered either as 12 fractions distributed uniformly over 24 hours and resulted in stable blood alcohol concentrations (BACs) of 85 mg/dl, or condensed into 4 fractions over 8 hours and resulted in maximum and minimum BACs of 411 mg/dl and 45 mg/dl, respectively. Pups were reared artificially from postnatal days 4 to 12 with alcohol exposure occurring on days 4 to 10. A sensorimotor test battery was then administered from postnatal day 12 to postnatal day 30. The condensed alcohol exposure resulted in age-dependent hyperactivity, a delay in tooth eruption, disruption of balance and of the ability to use the hindlimbs in a coordinated fashion, and a delay in the acquisition of the midair righting reflex. The midair righting reflex also was disrupted by uniform alcohol exposure. Thus, postnatal alcohol exposure that produces high BACs causes more severe developmental aberrations than the same daily dose administered in a pattern producing low BACs.
Hepatic cavernous hemangioma: A potential pitfall during evaluation of gastrointestinal bleeding with 99mTc-labeled erythrocytes

The purpose of this report is to underscore one previously unreported hepatic parenchymal lesion detected during evaluation of occult lower gastrointestinal hemorrhage. In more than 90% of the patients harboring the lesion, the individual remains asymptomatic, requires no intervention, and closed biopsy is contraindicated: hepatic cavernous hemangioma. Whereas the list is expanding of normal and abnormal structures which can interfere with the interpretation of scintigraphic gastrointestinal bleeding studies accomplished with 99mTc-labeled erythrocytes, it is absolutely necessary to demonstrate intestinal transit of the activity, in order to discount detected activity in either non-hemorrhagic lesions or normal structures as the nidus of suspected bleeding.
VOC emission fluxes as a function of lateral distance from the source

There has been a great deal of recent interest in evaluating the potential for vapor transport from subsurface contamination into nearby buildings. There does not exist, however, any method for calculating whether buildings that are not directly over the source of contamination may be impacted. For simplicity, typical modeling approaches for estimating vapor migration through soil into buildings assume that the contaminated plume or soil lies directly underneath the building. The models do not take into account the lateral distance, if any, between the source of VOC emissions and the indoor space. This paper presents an approach to calculate diffusion-limited emission fluxes as a function of lateral distance and evaluates the significance of these emissions over relatively short lateral distances from the source. A theoretical, mathematical approach was used. The results show that soil-gas concentration and emission flux are both a decreasing exponential function of the lateral distance from the edge of the contaminant plume. Based on our calculations, the emission flux and the soil-gas concentration are insignificant within a relatively short lateral distance from the source (e.g., 30 m). © 2004 American Institute of Chemical Engineers Environ Prog, 23: 52–58, 2004
High prevalence of rheumatoid arthritis in yakima indians

A survey among Yakima Indian women, ages 18 to 79, in central Washington State revealed a prevalence of definite rheumatoid arthritis of 3.4%. compared with 1.4% among American women in the National Health Examination Survey (NHES). The prevalence is higher than has been observed in any previously studied population. Men were not studied. The prevalence was high in all age groups, but was most excessive among women under age 35.
Synthesis of novel fluorinated derivatives of 1,3-dimethylbarbituric acid

Abstract Synthetic utility of the novel difluoro ketene aminal 1 was extended to the preparation of a number of potentially biologically-interesting difluoro barbituric acid derivatives via initial hetero-Diels-Alder reactions of 1 with p-substituted-5-benzylidene-1,3-dimethylbarbituric acids 3. These cycloadducts 4 upon hydrolysis, provided the formal Michael addition product amides 5 which were readily converted to the respective carboxylic acids 6. The acids were dehydratively cyclized to form novel bicyclic lactones 8.
Phase-field modeling of coring structure evolution in Pu-Ga alloys

Abstract During casting of Pu–Ga alloys, the huge difference in Ga diffusivity in e (body centered cubic) and δ (face centered cubic) phases results in the formation of coring structures which consist of Ga-rich cores with Ga-poor edges. The elastic interaction among different oriented δ grains, matrix e and diffusive Ga atoms may lead to a directional diffusion and δ grain growth. A phase-field model for modeling the coring structure evolution and Ga homogenization kinetics in three dimensions is developed. The effects of diffusivity inhomogeneity, internal stresses and cooling rate on the coring structure evolution are studied.
In vitro methods for generating highly purified EBV associated tumor antigen-specific T cells by using solid phase T cell selection system for immunotherapy

Adoptive cell transfer immunotherapy has been utilized to treat EBV related human malignancies including post-transplant lymphoproliferative diseases, Hodgkin's lymphoma and nasopharyngeal carcinoma. However, there are limited options available for tumor antigen-specific T cell purification. Here we describe a novel solid phase T cell selection system, in which monocytes or EBV transformed B-lymphocytes are immobilized on solid support for antigen-specific T cell purification. We hypothesize and prove that antigen-specific T cells recognize their cognate antigens and bind to them faster than non-antigen specific T cells. Therefore antigen-specific T cells can be concentrated on the surface after removing the non-adherent cells by washing. The optimal selection time for both EBV-specific T cells and LMP2-specific T cells is studied. Our data demonstrate that the frequency of antigen-specific T cells can be increased by >20-fold after selection. Moreover, activated antigen-specific T cells proliferate more rapidly than non-specific T cells, further increasing the frequency and purity of antigen-specific T cells. This new T cell selection system is superior to traditional repeated stimulation methods in generating tumor antigen-specific T cells. We are able to generate large quantities of highly purified T cells of subdominant antigens LMP2 within 2 weeks after T cell activation for adoptive cell transfer immunotherapy with this simple, rapid and inexpensive T cell selection system.
Using an Anti-Oppressive Framework in Social Work Practice with Lesbians

Anti-oppressive (AOP) social work practice addresses the whole person and the practitioner relates to the client in the client's social context. AOP considers personal, institutional, cultural, and economic issues and considers how these influence individuals' behaviors and their opportunities to grow into their full potential as persons living within these oppressive contexts. Lesbians live in a world that is dominated by oppression and heterosexism that can lead to a deep sense of shame regarding their sexuality. Anti-oppressive social work involves taking and supporting action to advance both individual and structural change to improve the lives of lesbian clients.
Is reminiscence adaptive? Relations among social activity level, reminiscence, and morale.

Although it is widely believed that reminiscence is adaptive during later life, research on the psychological benefits of reviewing the past has yielded inconsistent findings. In the present study,...
Not Just a Mickey Mouse Exercise: Using Disney’s The Lion King to Teach Leadership:

Disney’s animated feature The Lion King is presented as a vehicle for fostering undergraduate management and organizational behavior students’ experiential learning and application of fundamental l...
Variations of Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Evaluation of Breast Cancer Therapy Response: A Multicenter Data Analysis Challenge

Pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) time-course data allows estimation of quantitative parameters such as K (trans) (rate constant for plasma/interstitium contrast agent transfer), v e (extravascular extracellular volume fraction), and v p (plasma volume fraction). A plethora of factors in DCE-MRI data acquisition and analysis can affect accuracy and precision of these parameters and, consequently, the utility of quantitative DCE-MRI for assessing therapy response. In this multicenter data analysis challenge, DCE-MRI data acquired at one center from 10 patients with breast cancer before and after the first cycle of neoadjuvant chemotherapy were shared and processed with 12 software tools based on the Tofts model (TM), extended TM, and Shutter-Speed model. Inputs of tumor region of interest definition, pre-contrast T1, and arterial input function were controlled to focus on the variations in parameter value and response prediction capability caused by differences in models and associated algorithms. Considerable parameter variations were observed with the within-subject coefficient of variation (wCV) values for K (trans) and v p being as high as 0.59 and 0.82, respectively. Parameter agreement improved when only algorithms based on the same model were compared, e.g., the K (trans) intraclass correlation coefficient increased to as high as 0.84. Agreement in parameter percentage change was much better than that in absolute parameter value, e.g., the pairwise concordance correlation coefficient improved from 0.047 (for K (trans)) to 0.92 (for K (trans) percentage change) in comparing two TM algorithms. Nearly all algorithms provided good to excellent (univariate logistic regression c-statistic value ranging from 0.8 to 1.0) early prediction of therapy response using the metrics of mean tumor K (trans) and k ep (=K (trans)/v e, intravasation rate constant) after the first therapy cycle and the corresponding percentage changes. The results suggest that the interalgorithm parameter variations are largely systematic, which are not likely to significantly affect the utility of DCE-MRI for assessment of therapy response.
Quantitative analysis of PD 0332991 in xenograft mouse tumor tissue by a 96-well supported liquid extraction format and liquid chromatography/mass spectrometry

Phase II attrition of clinical candidates in the drug development cycle is currently a major issue facing the pharmaceutical industry. To decrease phase II attrition, there is an increased emphasis on validation of mechanism of action, development of efficacy models and measurement of drug levels at the site of action. PD 0332991, a highly specific inhibitor of cyclin-dependent kinase 4 (CDK-4) is currently in clinical development for the treatment of solid tumor. A clinical presurgical study will be required to better understand how PD 0332991 affects signaling pathways and how the intratumoral concentration of PD 0332991 correlates with plasma PK parameters and molecular alterations in breast cancer tissues after PD 0332991 treatment. Before conducting such a clinical study, it is important to evaluate PD 0332991 levels in tumor tissue samples from a xenograft mouse model for the determination of drug exposure at the site of action. Therefore, the objectives of this study were (1) to develop and validate a sensitive LC-MS/MS method to quantify PD 0332991 in mouse tumor tissues from MDA-MB-231-Luc human breast tumor xenografts in SCID-beige mice; (2) to quantify PD 0332991 levels in mouse tumor tissues after oral administration of PD 0332991 at 10 and 100mg/kg using the validated LC-MS/MS method. Both liquid-liquid extraction (LLE) and supported liquid extraction (SLE) in a 96-well format were developed and evaluated to achieve optimal extraction recovery with minimal matrix effects. The newly developed SLE method is more efficient (speed and ease) and demonstrates comparable recovery (93.1-100% at three different concentrations) compared to the traditional LLE method. The validated LC-MS/MS for PD 032291 in mouse tumor tissue homogenate method exhibited a linear dynamic range of 0.1-100 ng/mL with inter-day accuracy and precision within 15%. The validated method was successfully applied to measure PD 0332991 levels in tumor tissues in MDA-MB-231-Luc human breast tumor xenografts in SCID beige mice. The mean tumor concentrations at 6h post-oral PD 0332991 administration at 10 and 100mg/kg were 1793 (+/-1008) and 25,163 (+/-3959) ng/g, respectively.
In vitro studies of the pulsatile radiometric signal.

An in vitro model system was designed to permit simultaneous measurements of blood flow, blood pressure, and the pulsatile radiometric signal during flow studies with Ringer's solution and blood of hematocrit 32,41, and 51. When the in vitro system contained a cat carotid artery, increases in blood flow were associated with increases in the pulsatile radiometric signal. Changes in the pulsatile radiometric signal were linearly related to changes in mean flow and highly correlated with changes in the pulsatile flow, mean pressure, and pulsatile pressure. Results from the regression analyses suggest that the pulsatile radiometric signal may be attributed to reflection from the artery wall. When the in vitro system contained a glass cell, increases in blood flow were associated with decreases in the pulsatile radiometric signal. There was an inverse linear relationship between the pulsatile radiometric signal and mean flow, and changes in the pulsatile radiometric signal were highly and inversely correlated with changes in pulsatile flow and pulsatile pressure. These results suggest that when recording over the cutaneous microcirculation, the pulsatile radiometric signal is in part due to changes in the red blood cell scattering and absorption coefficients.
Descreening of color halftone images in the frequency domain

Scanning a halftone image introduces halftone artifacts, known as Moir´e patterns, which significantly degrade the image quality. Printers that use amplitude modulation (AM) screening for halftone printing position dots in a periodic pattern. Therefore, frequencies relating halftoning are easily identifiable in the frequency domain. This paper proposes a method for descreening scanned color halftone images using a custom band reject filter designed to isolate and remove only the frequencies related to halftoning while leaving image edges sharp without image segmentation or edge detection. To enable hardware acceleration, the image is processed in small overlapped windows. The windows are filtered individually in the frequency domain, then pieced back together in a method that does not show blocking artifacts.
Environmental Monitoring, Statistics, and the Law: Room for Improvement

Abstract Concerns over environmental degradation have led to legislation such as the Clean Water Act, the Clean Air Act, the Resource Conservation and Recovery Act, and the Comprehensive Environmental Response, Compensation, and Liability Act. Federal and state laws have mandated the creation of numerous monitoring programs to ensure or determine the integrity of the environment. Unfortunately, many of the resulting monitoring programs shed little light on the questions that they were meant to help answer because they are based on poor experimental designs and a superficial knowledge of statistics. This article briefly discusses some past environmental-monitoring designs and current regulations for monitoring at hazardous-waste sites. The deficiencies of many monitoring programs are linked to the need to improve the status of the career category “statistician” in the sphere of the environmental sciences.
73. Cats Produce a Potent CTL Response after Neonatal Gene Therapy That Can Be Blocked with CTLA4-Ig

Top of pageAbstract Although gene therapy has reduced manifestations of genetic diseases, immune responses can abrogate the effect. One approach to induce tolerance is to perform gene transfer in newborns when the immune system is immature. This has allowed a therapeutic response to be achieved for lysosomal storage diseases and hemophilia in mice. However, it is unclear if this approach would be effective in large animals with more-mature immune systems at birth, and it is unlikely that this will be effective in humans. Immune responses will likely pose a tremendous hurdle for patients with null mutations, and identification of a large animal model with a sufficiently mature immune system at birth should facilitate preclinical studies to identify ways to block an expected immune response in humans. Gene therapy experiments were performed in mucopolysaccharidosis I (MPS I) cats, which are deficient in the lysosomal enzyme |[alpha]|-L-iduronidase (IDUA) due to a 3 bp deletion. An amphotropic retroviral vector (RV) expressing the canine IDUA was injected IV into newborn cats at 10(9) or 10(10) TU/kg. The canine protein differs from the feline protein at 130 positions of 653 aa. Expression can be followed by analysis of enzyme activity in serum, as some of the enzyme produced by cells is secreted into blood. Cats achieved high serum activity that averaged 286+/|[minus]|416 (SD; N=7) U/ml and 2355+/|[minus]|2763 (SD) U/ml at 1 month after gene transfer for the low and high RV dose, respectively. However, all animals lost expression by 3 months, which was associated with the development of cytotoxic T lymphocytes (CTLs) that could kill autologous cIDUA-expressing fibroblasts, and with a marked decrease in RV RNA sequences in the liver. In contrast, antibodies to cIDUA did not develop. In an attempt to block a CTL response, two cats were treated with the immunosuppressive agent CTLA4- Ig for 2 weeks around the time of transduction with the high dose of RV. CTLA4-Ig binds to CD80 or CD86, and prevents them from stimulating an immune response by activating CD28 on the surface of lymphocytes. These cats achieved 187+/|[minus]|161 U/ml of IDUA activity in serum, which has been stable for 10 months to date, and did not develop a CTL response These data demonstrate that CTLA4-Ig can prevent a CTL response after neonatal gene therapy. Factors that reduce the efficiency of the immune system in newborn mice and/or humans include reduced secretion of cytokines by lymphocytes, and reduced levels of the co-stimulatory partners CD40 ligand and CD40. In contrast, lymphocytes from newborn humans have normal levels of CD80/CD86 and CD28. We hypothesize that the CD80/CD86 interaction with CD28 may be of particular importance in the newborn period in cats, explaining why transient CTLA4-Ig is so effective at inducing tolerance. The cat appears to be an excellent pre-clinical model for neonatal gene therapy.
A general approach for calculating the likelihood of dyadic interactions: Applications to sex preferences in rat pups and agonistic interactions in adults

We introduce a general approach for calculating the expected frequency of different types of dyadic interactions between animals and illustrate it with two applications. The first application determines whether there are sex contact biases between male and female Norway rat pups. We hypothesized that opposite-sex contact biases should be small, because it is likely that differences in contact based on the sex of animals would interfere with other biological functions, such as group temperature regulation. We found a small but significant bias of 3% in opposite-sex contacts. The second application reanalyzed J. B. Calhoun’s (1962) data on antagonistic encounters between rats for two factors (sex and birth location), each with two levels. The results of these two applications suggest that sex contact biases among pups are predictive of agonistic encounters among adults and that this approach has general application to the analysis of dyadic interactions among animals.
The development of interval breast malignancies in patients with BRCA mutations

BACKGROUND At present, there is no consensus regarding how frequently BRCA mutation carriers should be screened for malignancies using breast imaging techniques. An interval malignancy is defined as a malignancy that becomes evident during the period between annual screening mammography scans; the finding of such a malignancy indicates that the malignancy either went undetected by the last breast imaging scan or developed during the interval since that last scan. METHODS The authors retrospectively reviewed the medical charts of all BRCA mutation carriers who were followed by the genetic counselor at the Columbia-Presbyterian Comprehensive Breast Center (New York, NY) between September 1995 and September 2002. RESULTS Thirteen BRCA mutation carriers elected to undergo close surveillance and thus were followed at our institution. Three of these 13 patients (23%) did not develop breast carcinoma, 4 (31%) developed breast carcinoma that was detected at the time of annual screening, and 6 (46%) developed palpable interval malignancies in less than 12 months. Among the six patients who developed interval malignancies, the mean time between the last screening mammogram and disease presentation was 5.1 months (range, 2–9 months); the average tumor size in this patient subgroup was 1.7 cm (range, 0.8–3 cm). Two of these six patients had ductal carcinoma in situ, whereas the remaining four had invasive breast carcinoma; three patients had positive lymph nodes at presentation. All six patients who developed interval disease exhibited dense breast tissue on the previous mammogram. Focused breast ultrasonography was able to identify the tumor mass in 3 of 4 patients (75%). CONCLUSIONS Nearly half of all BRCA-positive women who chose to undergo close surveillance in the current study developed malignant disease less than a year after exhibiting normal findings on screening mammography. Half of these interval malignancies were positive for lymph node involvement. These results suggest that strong consideration should be given to screening BRCA-positive women at more frequent intervals and to using additional imaging techniques, such as breast ultrasonography and/or breast magnetic resonance imaging, as a part of this screening. Cancer 2004. © 2004 American Cancer Society.
Proline Accumulation in Maize (Zea mays L.) Primary Roots at Low Water Potentials. II. Metabolic Source of Increased Proline Deposition in the Elongation Zone

The proline (Pro) concentration increases greatly in the growing region of maize (Zea mays L.) primary roots at low water potentials (ψw), largely as a result of an increased net rate of Pro deposition. Labeled glutamate (Glu), ornithine (Orn), or Pro was supplied specifically to the root tip of intact seedlings in solution culture at high and low ψw to assess the relative importance of Pro synthesis, catabolism, utilization, and transport in root-tip Pro deposition. Labeling with [3H]Glu indicated that Pro synthesis from Glu did not increase substantially at low ψw and accounted for only a small fraction of the Pro deposition. Labeling with [14C]Orn showed that Pro synthesis from Orn also could not be a substantial contributor to Pro deposition. Labeling with [3H]Pro indicated that neither Pro catabolism nor utilization in the root tip was decreased at low ψw. Pro catabolism occurred at least as rapidly as Pro synthesis from Glu. There was, however, an increase in Pro uptake at low ψw, which suggests increased Pro transport. Taken together, the data indicate that increased transport of Pro to the root tip serves as the source of low-ψw-induced Pro accumulation. The possible significance of Pro catabolism in sustaining root growth at low ψw is also discussed.
Anxiety as an “epistemic” emotion: An uncertainty theory of anxiety

Abstract This paper attempts to provide a conceptual framework placing anxiety in a perceived control perspective. We analyse the basic cognitive components of anxiety with reference to the need for control, both pragmatic and epistemic. We address the difference between fear and anxiety by pointing to the special role played in anxiety by the need for epistemic control and uncertainty reduction. We examine some typical “questions” of anxiety, and some typical “answers” or coping strategies, with special reference to their relationships with either need for control. We focus on the need for epistemic control, its relationship with pragmatic control, its impact on the amount of anxiety experienced, and its role in anxiety-proneness. We address worry and its relationships with anxiety and the needs for control. Finally, we compare our approach with related models, point to its implications for clinical treatment, and discuss the interplay of conscious and unconscious processes in anxiety.
T regulatory cell function in idiopathic minimal lesion nephrotic syndrome

The purpose of this study was to test the hypothesis that, in idiopathic minimal lesion nephrotic syndrome (IMLNS), the T regulatory (T reg) cell suppressor mechanism is deficient, thereby enhancing cytokine release by T effector cells. Twenty-one patients with IMLNS, eight healthy controls and two patients with nephrotic syndrome and membranoproliferative glomerulonephritis were studied. The percentage of T reg cells was similar in the healthy controls and in patients with IMLNS in relapse or in remission. Thymidine incorporation in autologous T effector cells, as well as expression of the regulatory cytokine interleukin (IL)-10, was significantly reduced in patients in relapse when compared with patients in remission and healthy subjects. IL-2 expression was also reduced in patients in relapse but did not achieve statistical significance. In a different set of experiments, T cells, from subjects with IMLNS in remission, when stimulated with antiCD3-antiCD28 antibodies, secreted increased levels of cytokines. No such increase in cytokines was observed when cells from healthy controls were stimulated with same mitogen. The impaired T reg cell function observed in these patients may have pathogenic and therapeutic implications, because it could explain the persistence of the proposed pathogenic cytokines observed in the patients with IMLNS.
Diurnal Influences on Serum Luteinizing Hormone Responses to Opiate Receptor Blockade with Naloxone or to Luteinizing Hormone-Releasing Hormone in the Immature Female Rat

AbstractThe major objective of these studies was to determine whether there is a temporal pattern in the gonadotropin response of immature rats to luteinizing hormone-releasing hormone (LHRH) or the opiate antagonist, naloxone. Thirty-day-old female rats were injected at 3-hr intervals over a 24-hr period with either naloxone (2.5 mg/kg body wt) or LHRH (8 ng/100 g body wt). Animals were decapitated 15 min later and serum samples were assayed for luteinizing hormone (LH) by radioimmunoassay. The serum LH response to naloxone and LHRH varied significantly with the time of day. Naloxone administration had no statistically significant (P > 0.05) effect on levels of serum LH at 1500 and 1800 hr compared to levels in saline-injected controls, but induced a significant rise in serum LH at all other times. Naloxone had its greatest effect during the late evening and early morning hours (2100 to 0900 hr). A similar, but not identical, pattern of LH responsiveness to LHRH was observed, with the two rhythms being t...
Cognitive Communicative Challenges in TBI: Assessment and Intervention in the Long Term

Neurocognitive stall is defined as a failure or lag in achieving later emerging cognitive milestones, representing an increasing “gap” in neurocognitive, social, and educational functioning after e...
Bovine factor Xa and bovine trypsin: A comparison with respect to inhibition by some amidines and guanidines

Abstract The enzymatic activity of activated bovine blood clotting factor X toward the synthetic substrate N α-benzoyl- l -arginine ethyl ester and the inhibitory effects of a series of low molecular weight synthetic aromatic amidine and guanidine compounds on that activity were studied using the steady-state kinetic method. The kinetic parameters, Km and κcat, and the apparent dissociation constant Ki′ for each inhibitor, were determined for activated factor X hydrolysis of Bz-Arg-OEt at 37 °C, pH 7.8 in 0.1 n NaCl and 0.001 m CaCl2. The same constants were determined for bovine β-trypsin under identical conditions. Comparison of kinetic constants determined for both enzymes shows that activated factor X binds the substrate Bz-Arg-OEt less efficiently than β-trypsin by several orders of magnitude. However, binding of the inhibitors benzamidine, p-aminobenzamidine, pentamidine, M&B 4596, phenylguanidine, and p-guanidinobenzoic acid is similar for both enzymes. The results indicate that these two closely related serine proteases differ little in the structural arrangement and accessibility of the anionic “pocket” at which these inhibitors bind. The large differences observed with respect to substrate binding activity probably reflect substantial structural differences between the two enzymes at secondary sites adjacent to the primary anionic site.
Employee Ingratiation: The Role of Management

Ingratiation, a political process to seek one's own self-interest, may be detrimental to an organization if it becomes excessive. Traditionally, ingratiation has been viewed as a set of individually-initiated behaviors. This paper attempts to show that ingratiation is organizationally induced as well as individually initiated and that it is the interaction of these two forces that determines the amount of ingratiatory behavior in an organization. A set of potentially testable propositions regarding causes of ingratiation is developed and discussed.