cssi/SciSciGPT-SciSciNet huggingface dataset:
Conformational Cycle Of A Bacterial Homolog Of Human Neurotransmitter Sodium Symporters

Neurotransmitter:sodium symporters (NSS) control the magnitude and duration of synaptic signaling through active reuptake of specific neurotransmitters. While it is known that the transmembrane sodium gradient supplies the energy for transport, the coupling mechanism to substrate translocation from its primary binding site (S1) is poorly understood. Conformational rearrangements of extracellular and cytoplasmic regions of the protein are thought to regulate alternating access to S1, and substrate binding at a second site (S2) located near the extracellular region of the transporter, to act as a symport coupler (Shi et al 2008 Mol Cell 30, 667). We used spin labeling and EPR spectroscopy to investigate the conformational dynamics of a highly homologous bacterial member of the NSS family, the leucine transporter LeuT, for which the crystal structure is known (Yamashita et al 2005 Nature 437, 215). Changes in global and local structural constraints derived from the EPR analysis and induced by sodium and leucine binding were then correlated to conformational changes in the LeuT structure in proteoliposomes. Sodium binding was found to increase the distance between the probes as assessed from global rearrangements measured in the extracellular region of LeuT. In contrast, subsequent leucine binding in the presence of sodium was found to decrease the distance between the probes. Consistent with these observations, sodium binding increases spin label mobility and water accessibility at positions within the S2 site. Furthermore, leucine binding increases spin label order and decreases water accessibility. These results suggest a model in which sodium binding to LeuT primes the transporter for substrate binding in S1 by increasing the population of an “outward-facing” conformation, exposing the substrate permeation pathway. With a filled S1, the extracellular pathway constricts, consistent with the occluded state observed in the LeuT crystal structure.
Performance characteristics of the Dimension RxL iron and total iron-binding capacity methods.

Background: Measurements of serum iron and total iron-binding capacity (TIBC) can be used to aid the diagnosis of iron deficiency and iron overload states. A variety of different methods for these measurements are commercially available. Methods: Linearity, imprecision and hemoglobin interference of homogeneous iron and TIBC methods on a Dimension® RxL analyzer were assessed. Method comparison studies were performed with a Vitros® 950 analyzer. Results: The Dimension RxL iron method was linear from 40 to 1000 μg/dl. The coefficient of variation of the iron and TIBC methods were <4% and <2%, respectively, at iron concentrations of 68 and 228 μg/dl and TIBC concentrations of 206 and 384 μg/dl. Comparison of the Vitros 950 and Dimension RxL iron methods gave a slope of 0.97, an intercept of 6.0 and r=0.99. Corresponding results for the TIBC methods were 1.02, −6.6 and r=0.97, respectively. Simulation of acute iron overload in vitro did not produce the same effect on TIBC measurements as in vivo overload. Iron recovery by the Dimension RxL method was reduced 40–60% by the addition of deferoxamine at a concentration of 200 μmol/l. Conclusions: The Dimension RxL assay provides acceptable measurements of iron and TIBC in routine patient samples. Iron measurements are unreliable in the presence of deferoxamine.
Positioning the Golgi apparatus.

Rios et al. (2004) report in this issue that the Golgi protein GMAP-210 is sufficient to confer pericentrosomal positioning and recruits γ-tubulin and associated microtubule-nucleating ring complex proteins to Golgi membranes. The results raise the possibility that short microtubules emanate from the Golgi to mediate its organization and positioning.
Romantic Nature Bites Back: Adorno and Romantic Natural History

This paper addresses the possibility of Romantic freedom and contingency as a surprising consequence of the work of natural history in Romantic culture. My understanding of the Romantic concept of ...
Deformation mechanism maps for micro-grained, ultrafine-grained, and nano-grained materials

There are several deformation mechanisms that depend on grain size and are controlled by grain boundary diffusion. These mechanisms include: Coble creep, superplastic flow (micrograin superplastic flow and high-strain rate superplastic flow), and nanograin deformation. By combining the rate-controlling equations of these mechanisms and by making assumptions regarding triple-junction creep, a deformation map based on grain size was constructed. It is demonstrated that this map can account for the locations of experimental data representing three types of deformation behavior: micrograin superplasticity, high-strain rate superplasticity, and nanograin deformation.
Behavioral epigenetics and the developmental origins of child mental health disorders

Advances in understanding the molecular basis of behavior through epigenetic mechanisms could help explain the developmental origins of child mental health disorders. However, the application of epigenetic principles to the study of human behavior is a relatively new endeavor. In this paper we discuss the ‘Developmental Origins of Health and Disease’ including the role of fetal programming. We then review epigenetic principles related to fetal programming and the recent application of epigenetics to behavior. We focus on the neuroendocrine system and develop a simple heuristic stress-related model to illustrate how epigenetic changes in placental genes could predispose the infant to neurobehavioral profiles that interact with postnatal environmental factors potentially leading to mental health disorders. We then discuss from an ‘Evo-Devo’ perspective how some of these behaviors could also be adaptive. We suggest how elucidation of these mechanisms can help to better define risk and protective factors and populations at risk.
Clinical Validation of the Welch-Allyn Pneumocheck™ Hand Held Spirometer

Pulmonary function is predictive of morbidity and mortality. Therefore, in epidemiologic studies, researchers seek to measure pulmonary function with portable spirometers feasible for use in clinics or participants’ homes. The purpose of this study was to validate a hand held spirometer, the Welch-Allyn Pneumo-check™, against standard pulmonary function tests. The authors used a convenience sample of 66 subjects. All subjects were asked to perform three vital capacity maneuvers with the Welch-Allyn Pneumocheck™ and then either a water seal spirometer or heated pneumotach in a hospital pulmonary function laboratory. The mean forced vital capacity (FVC) obtained with the Pneumocheck™ was 3.50 liters (standard deviation (SD) = 1.28) compared with 3.31 liters (SD = 1.24) for the pulmonary function laboratory. The correlation between the two measures was 0.98; the mean difference was 0.19 L (95% confidence interval = 0.12 to 0.26). The mean forced expiratory volume at one second (FEVx) was 2.31 L (SD = 1.07) for the Pneumocheck™ compared with 2.32 L (SD = 1.06) for the pulmonary function laboratory values. The correlation between the two measures was 0.99; the mean difference was 0.01 L (95% confidence interval = -0.03 to 0.04). Of the 46 subjects originally classified by the Pneumocheck™ as having FEV1/FVC ratios of less than 0.75, 10 (22%) had ratios greater than or equal to 0.75 after correcting for the FVC difference between methods. Therefore, there was an excellent correlation between the Welch-Allyn Pneumocheck™ and pulmonary function laboratory values for FVC and FEV1. Small systematic differences in FVC measures can lead to substantial misclassification rates when evaluating FEV1/FVC ratios.
Indo-european Initial Variants Dy- (Z-)/ Y-/D-.

The following paper will undertake to demonstrate an I.E. root dyu (alternating with dyu and yu )‘iungere,’ and its synonymous correlatives dyem/dyā (cf. dru drem drā ap. Brugmann, Kvg. 367), dyā-t-/dyat dyes/dyō[u]s (cf. trem/tres , ap. loc. cit.).
Pseudomonas aeruginosa: resistance and therapy.

Pseudomonas aeruginosa resistance to antimicrobials is an important therapeutic consideration. Antibiotic resistance to P. aeruginosa may be chromosomally or plasmid mediated. Resistance to P. aeruginosa may also be affected by changes in the cellular membrane or intracellular environment. P. aeruginosa is primarily a nosocomial organism that most commonly colonizes respiratory secretions and urine. The selection of an antipseudomonal antibiotic depends on its inherent in vitro activity and its resistance potential. Anti-P. aeruginosa antibiotics with a high-resistance potential include gentamicin, tobramycin, ciprofloxacin, ceftazidime, and imipenem. Anti-P. aeruginosa antibiotics with a low-resistance potential include amikacin, piperacillin, cefoperazone, cefepime, meropenem, and polymyxin B.
Community-acquired Staphylococcus aureus pneumonia among hospitalized children in Hawaii.

Background Invasive community acquired (CA) Staphylococcus aureus (SA) disease has been endemically observed in Hawaiian children. We wanted to evaluate the clinical, laboratory findings, and outcomes of methicillin-resistant SA (MRSA) and methicillin-susceptible SA (MSSA) associated pneumonia admissions. Methods We performed retrospective chart reviews of 38 culture proven SA pneumonia patients admitted to a pediatric tertiary medical center in Hawaii between January 1996 to December 2007. Results Twenty-six patients (68%) had MRSA and 12 patients (32%) had MSSA infection. The mean age of MRSA patients was 2.8 and 6.7 years for MSSA patients (P < 0.05). Pacific Islander and Native Hawaiian patients were affected disproportionately compared to non-Pacific Islander and Hawaiian groups (P < 0.0001). Demographic data, days of fever, tachypnea, hypoxia, and length of stay (LOS) were not significantly different between MRSA and MSSA infected patients. The mean LOS was 26.2 days (range 6–138 days); mean length of fever was 12.4 days. Seventy five percent (15 of 20) of patients who required intubation had MRSA. Twenty-one of the 29 (72%) total patients with pleural effusions had MRSA infection and all required chest tube placements. Two (5%) patients died; both had MRSA infection. Conclusions Younger Pacific Islander/Native Hawaiian children were affected disproportionately and had MRSA infection more frequently. MRSA infected patients appeared to have severe disease with frequent chest tube placement, intubation, and fatality. Overall, both MRSA and MSSA pneumonia resulted in prolonged hospitalization, multiple complications, and significant healthcare costs. Pediatr. Pulmonol. 2010; 45:898–905. © 2010 Wiley-Liss, Inc.
The asthma emergency department visit: treating a crisis in the midst of uncontrolled disease.

Background Patients with asthma who require emergency department (ED) care are burdened with asthma symptoms, are at risk for hospitalization, and use expensive resources. Objective To examine whether an ED-based surveillance system that characterized asthma symptoms and care before, during, and after an ED visit enhances our understanding of the natural history of asthma exacerbations. Methods This cross-sectional follow-up enrolled 225 adult patients who presented to 1 of 6 Illinois EDs for asthma care. Clinical characteristics before ED presentation, care provided in the EDs, and 1-month follow-up status were assessed by self-administered questionnaire, medical record review, and telephone interview, respectively. Results Persistent asthma symptoms were reported by 85.8% and 84.9% ( P = .37) of patients before their ED visit and follow-up call, respectively. For patients with persistent symptoms before the ED visit and follow-up call, 54.4% and 73.8% ( P = .02) reported using an inhaled corticosteroid, respectively. Inhaled corticosteroids were recommended for 49.4% of discharged patients with persistent symptoms. Relapse rates for return ED visits and return hospitalizations were 26.4% and 9.6%, respectively. Patients had low asthma-specific and general quality-of-life scores at follow-up. Conclusions Patients with asthma exacerbations most often had uncontrolled asthma before the ED visit that subsequently deteriorated, temporarily improved with ED treatment, and continued as uncontrolled asthma after the ED visit. Although improvements in care were reported 1 month after the ED visit, opportunities for additional improvement were observed.
Thermochemistry of glasses along joins of pyroxene stoichiometry in the system Ca2Si2O6-Mg2Si2O6-Al4O6

Abstract Enthalpies of solution in 2PbO · B2O3 at 974 K have been measured for glasses along the joins Ca2Si2O6 (Wo)-Mg2Si2O6 (En) and Mg2Si2O6-MgAl2SiO6 (MgTs). Heats of mixing are symmetric and negative for Wo-En with WH = −31.0 ± 3.6 kJ mol−. Negative heats of mixing were also found for the En-MgTs glasses (WH = −33.4 ± 3.7 kJ mol−). Enthalpies of vitrification of pyroxenes and pyroxenoids generally increase with decreasing alumina content and with decreasing basicity of the divalent cation. Heats of mixing along several glassy joins show systematic trends. When only non-tetrahedral cations mix (outside the aluminosilicate framework), small exothermic heats of mixing are seen. When both nontetrahedral and framework cations mix (on separate sublattices, presumably), the enthalpies of mixing are substantially more negative. Maximum enthalpy stabilization near compositions with Al/Si ≈ 1 is suggested.
The Politics of Development in Indigenous Panama

Since the Conquest, competition for control of natural resources between the conquerors and the conquered has largely shaped the fate of millions of indigenous people and thousands of indigenous communities across the Americas. As Latin American nations achieved independence from the Spanish Empire, they began to formulate policies that would allow national governments and their allies to prosper from wealth taken from indigenous peoples. Control of resources has bought the allegiance of a majority of the nonnative populations of Latin American nations and given nation-states the power to repress those who disagree with or are disadvantaged by national development plans. Latin American nation-states have dealt with indigenous peoples in a variety of ways. While the Guatemalan state, for example, has formulated various attempts to exterminate indigenous communities over the decades, Panama has mostly attempted to encapsulate and assimilate them. Different governing regimes have taken different approaches to putting these dominant strategies to work. Since the days of the Torrijos regime, indigenous communities and organizations have been more directly engaged in negotiating their control over resource management with the state. The current president of Panama, Mireya Moscoso, seems to be a master at speaking the language of indigenous rights and sustainable development while not doing much to empower indigenous peoples or protect Panama's ecosystems against devastating overexploitation. Nonetheless, it seems fair to note that under the Moscoso regime, indigenous communities do not seem as disadvantaged as they might be if a president less interested in rendering lip-service to indigenous rights were at the helm.
Bringing threat to the fore: participating in lifelong surveillance for genetic risk of cancer.

Purpose/objectives To explain how patients with multiple endocrine neoplasia type 2a (MEN2a) and family members conceptualize participation in lifelong surveillance in genetic cancer care. Design Qualitative naturalistic inquiry. Setting Northeastern United States. Data were collected during interviews in informants' homes. Sample 12 adult patients and 9 family members were recruited purposively through endocrinology clinics at two East Coast medical centers. Methods A grounded theory design was used. Subjects completed a demographic questionnaire and were interviewed on two occasions. In-depth interviews were audiotaped. The core concept and process variables emerged through three levels of narrative content analysis, theoretical sampling, and constant comparison. The generated theory was presented to the participants for validation. Main research variables The basic psychological issue associated with participation in lifelong surveillance and the psychosocial processes used by individuals to deal with the issues. Findings MEN2a patients and family members experience surveillance as a (Re)Minding of a threat to health. Once threat is brought to the fore, participants interpret the meaning and negotiate control of the impact of the diagnosis, related events, and consequences. Meaningful information from surveillance activities is incorporated into participants' self-image and daily lives through a process of (Re)Integration. The genetic nature of MEN2a did not emerge as a significant subcategory in relation to the core variable. Conclusions Finding meaning in the outcomes of surveillance events is a psychosocial process that is central to participation in lifelong surveillance. Genetic predisposition to cancer was a peripheral concern to subjects as they dealt with surveillance issues. Implications for nursing This investigation provides a model for the development of a grounded theory for understanding how people with other genetic cancer syndromes participate in lifelong surveillance.
Thermal alteration experiments on organic matter in recent marine sediment—III. Aliphatic and steroidal alcohols

Abstract Recent sediments from Tanner Basin (off southern California) and Bandaras Bay (in Gulf of California) have been analyzed for normal, isoprenoid and steroidal alcohols using chromatographic (column, GLC, TLC), and spectroscopic (u.v., i.r., MS) methods, prior to and after heat-treatment (from 65 to 150°C). Normal saturated alcohols (C14-C24) and monounsaturated alcohols (C22-C24) were identified, as well as the isoprenoid alcohols, phytol and dihydrophytol. Two series of sterols (Δ5 and Δ7) were found in Tanner Basin, and Δ5-sterols and triterpenes, in Bandaras Bay sediment. Sterols from both sediments contained the corresponding stanols.
Negative-U States in the Gap in Hydrogenated Amorphous Silicon

We propose that Si-H-Si three-center bonds exist in hydrogenated amorphous silicon. These centers give rise to states in the energy gap which have a negative effective electronic correlation energy, $U$. Our model can explain many of the known properties of this material. We make suggestions about how to obtain materials which may prove useful in electronic device applications.
Separation of plasma membrane markers by glycerol-induced blistering of muscle cells.

Abstract Glycerol (50%, w/w) was found to cause blistering of chick primary myoblast and fibroblast plasma membranes and extensive blistering of 5–6-day-old-myotube plasma membranes in tissue culture. The tips of myoblasts and fibroblasts appeared to be the most sensitive portion of the plasma membrane to the blistering effect of glycerol. The glycerol-induced blistering of myotubes was reduced and delayed by brief EDTA pretreatment. Glycerol treatment (50, 15 and 8% sequentially) of myotubes was used to remove plasma membrane blisters and a plasma membrane-enriched fraction was isolated from these blisters using a modified Dextran T500-polyethylene-glycol 6000 aqueous two-phase polymer system. This fraction was found to be enriched 4.1-fold for 5′-nucleotidase activity, but not for other putative plasma membrane markers, ( Na + + K + )- ATPase activity or α-[ 125 I ] bungarotoxin binding material. Autoradiographs of α-[ 125 I ] bungarotoxin , glycerol-treated (50%, w/w) myotubes showed the plasma membrane blisters to be devoid of reduced silver grains. 5′-Nucleotidase was shown to be an ectoenzyme on myoblasts and 5-day-old myotubes and the total cellular activity was present on the cell surface. During the period of myoblast fusion and myotube formation, cell surface activity decreased to a low level while total cellular activity was elevated.
Dielectric hole burning in an electrical circuit analog of a dynamically heterogeneous system

Abstract The dielectric properties of a dynamically heterogeneous material are represented by an R – C network in order to study the effects of spectrally selective Joule heating for the situation encountered in (non-resonant) dielectric hole burning (DHB). The energy irreversibly transferred to the system is calculated for a finite number of high electric field sine waves, corresponding to the ‘burn’ cycle preceeding the polarization measurement in a DHB experiment. As a result of the residual polarization, heating continues after the externally applied voltage is set to zero. Modelling temperature-dependent relaxation times by a common negative temperature coefficient for the resistive elements is the only non-linearity of the electrical circuit analog required to reproduce most of the major features observed in DHB experiments.
Effects of truncations of the cytoplasmic tail of the luteinizing hormone/chorionic gonadotropin receptor on receptor-mediated hormone internalization.

The LH/CG receptor is a member of the family of G protein-coupled receptors and consists of a large N-terminal extracellular domain (which is responsible for binding hormone) attached to a region that spans the plasma membrane seven times, ending with an intracellularly located C-terminus. Binding of LH or human CG (hCG) to the LH/CG receptor causes a stimulation of adenylyl cyclase, presumably via activation of Gs. The binding of hormone also leads to its subsequent internalization by receptor-mediated endocytosis. In order to investigate the role of the cytoplasmic tail of this receptor in these events, we prepared a series of mutants in which progressively larger portions of the cytoplasmic tail were deleted. Deletion of 58 amino acids from the C-terminus, in which only 11 cytoplasmic residues remain, resulted in a receptor that was not expressed on the plasma membrane. Receptors rat LHR (rLHR)-t653 and rLHR-t631, in which 21 or 43 amino acids were removed, respectively, were properly expressed. These ...
Carbohydrate deposits on the surfaces of worn extended-wear soft contact lenses.

• Three different commercial extended-wear soft contact lenses worn continuously by patients for at least 28 days were stained with fluorescein isothiocyanate-labeled lectins. These lectins detected the presence of α-linked or β-linked D-mannose, D-glucose, D-galactose, L-fucose, N -acetyl-D-glucosamine, N -acetyl-D-galactosamine, and N -acetyl neuraminic acid (sialic acid) on the surfaces of the contact lenses. These saccharides are bound to other sugars that likely account for an integral part of glycoprotein and/or glycolipid deposits on lens surfaces. These tear deposits may contribute to the chemical spoilage of the lens and, furthermore, may serve as specific receptors for pathogenic microorganisms commonly implicated in extended-wear soft contact lens—associated infectious keratitis.
Assessment of Reacting and Non-Reacting Supersonic Mixing

A computational study of sonic jet injection into a supersonic crossflow with and without combustion was performed. The gaseous injector was 3.226 mm in diameter and was injected 30 degrees to the horizontal. Simulated conditions involved sonic injection of hydrogen into a Mach 4 air cross-stream with a jet to freestream momentum flux ratio of 2.1. The numerical flow solver used was GASP v. 4.2. The inviscid fluxes were computed in three dimensions using third-order Roe Flux in the streamwise and lateral directions and third-order Van Leer flux in the vertical direction. The algorithms were chosen because of their robustness, shock resolution capabilities and efficiency. The Mentor Supersonic Transport (SST) turbulence model was used since the algorithm has good capability of solving both wall-bounded and free-shear flows. The reaction model used for hydrogen and air was a 9 species, 18 reactions model created by Drummond. The main results of this work can be summarized as: 1) modeling of combustion does not significantly alter the mixing behavior of the solution, 2) the size of the fuel plume is larger for the analysis which includes reacting flow, 3) the difference in size and shape of the plume between the reacting and non-reacting cases increases with downstream distance from injection.Copyright © 2007 by ASME
The effect of oligomycin, gramicidin and other antibiotics on reversal of mitochondrial swelling by adenosine triphosphate.

Abstract Gramicidin D, tyrocidine, oligomycin, and gramicidin S were found to be extremely potent inhibitors of ATP-induced reversal of mitochondrial swelling caused by reduced glutathione. 50% inhibition was given by concentrations of 1·10 −10 M , 7·10 −9 M , 5·10 −8 M and 5·10 −7 M respectively. No significant inhibition was given by polymycin B, colimycin, bacitracin, antimycin A, puromycin, penicillin, streptomycin, neomycin, erythromycin or kanamycin. Oligomycin inhibits contraction with a linear dependence on concentration, suggesting it “titrates” a sensitive site stoichiometrically. Oligomycin also inhibits reversal of thyroxine-induced swelling, but much higher concentrations are required than for inhibition of GSH-induced swelling. Gramicidin D and tyrocidine in very low concentrations cause mitochondrial swelling in a buffered KCl medium, but neither antibiotic causes swelling when KCl is replaced by sucrose. Gramicidin D, tyrocidine, and gramacidin S stimulate ATPase activity and uncouple oxidative phosphorylation, whereas oligomycine is known to inhibit ATPase and phosphorylating respiration. The effect of these antibiotics on the mechano-chemical changes is considered in relation to their action on oxidative phosphorylation.
Psychosocial Adjustment of People with Chronic Pain: A Conceptual Framework of Risk and Resistance Factors

The purposes of this review article are to gather existing evidence on the contributing factors in affecting the psychosocial adjustment among people with chronic pain, and to promote a comprehensive conceptual framework in this topic by adapting Wallander and colleagues' (1989) Risk and Resistance Model of Adjustment. Our intention is to promote future empirical research that will validate this working conceptual framework and will provide and clinical guidelines for rehabilitation professionals who work with people with chronic pain.
Influence of quantum confinement on exciton-exciton Coulomb interactions in In0.04Ga0.96As Heterostructures

Spectral, temporal, and polarization resolved four-wave mixing measurements in a series of InGaAs heterostructures with varying well width reaveal that mean-field Coulomb interactions between excitons are relatively insensitive to confinement.
Avoiding the One-Size-Fits-All Curriculum: Textsets, Inquiry, and Differentiating Instruction

(2004). Issues in Education: Avoiding the One-Size-Fits-All Curriculum: Textsets, Inquiry, and Differentiating Instruction. Childhood Education: Vol. 81, No. 1, pp. 33-35.
Factors affecting initiation of growth of Clostridium botulinum.

When solutions containing glucose and phosphate were autoclaved, substances formed which altered the growth response ofClostridium botulinum 62A. Some of these substances were stimulatory and decreased the time required for the appearance of turbidity in liquid cultures. Other substances were inhibitory and delayed the appearance of growth. The inhibitory substances were removed from solution by adsorption on activated charcoal. The concentration of inhibitory substances increased with time of storage of media and autoclaved phosphate-glucose supplement.
Kinetics of Catalyst Coking in Heptane Reforming over Pt−Re/Al2O3

Previous studies have shown that five-membered ring naphthenes (C5N) are the key source of coke in n-heptane (nC7) reforming on a Pt−Re/Al2O3 catalyst. Using methylcyclopentane (MCP) as a model C5N compound, we develop a kinetic model that predicts its coking rate on the basis of the data obtained from a vibrational microbalance and a fixed-bed reactor. This rate, with an apparent activation energy of 39.7 kcal/mol, decays exponentially in coke-on-catalyst and is first order in MCP partial pressure. Its dependence on H2 is a combination of negative first and second orders. The model considers that coke deposits randomly on both clean and coked sitesa feature that permits the distinction between monolayer and multilayer coke buildup. The model correctly predicts the coking rates of ethylcyclopentane and of nC7. Moreover, it predicts the observed coke profile generated from nC7 reforming in the integral fixed-bed reactor under conditions quite different from those used in the microbalance. As such, the mode...
Immobilized IL-8 Triggers Phagocytosis and Dynamic Changes in Membrane Microtopology in Human Neutrophils

The interaction of leukocytes with surface bound ligands can be limited by the location of the molecules relative to the surface topology of the cell. In this report, we examine the dynamic response of neutrophils to IL-8-fractalkine chimera immobilized on bead surfaces, taking into account changes in receptor occupancy resulting from changes in surface topography. As a readout for receptor signaling, we observe the dynamics of calcium release in neutrophils following contact with the IL-8 coated surface. After a delay that depended on the initial area of contact and the surface density of IL-8, the cell began to phagocytose the IL-8 coated bead. This appeared to be a pre-requisite for release of calcium, which typically followed shortly after the initiation of phagocytosis. In separate experiments, effective kinetic coefficients for the formation of bonds between immobilized IL-8 and receptors on the cell surface were determined. Using these coefficients, we were able to estimate the number of bound receptors in the nascent contact zone. Kinetic modeling of the signaling response predicted that cell spreading and a concomitant increase in the density of occupied receptors would be required for the experimentally observed calcium dynamics. Postulating that there is an increase in receptor occupancy resulting from smoothing of the cell surface as it is stretched over the bead enabled us to obtain model predictions consistent with experimental observations. This study reveals the likely importance of membrane microtopology as a rate-limiting property and potential means of regulation of cell responses stimulated by two-dimensional surface interactions.
Population health status and economic growth in Chinese provinces: some policy implications

Using recent cross-sectional, public use, data set on 31 Chinese provinces, we empirically model the core determinants of life expectancy (population health status) using the Ordinary Least Squares (OLS) method, instrumental variables estimation and the relatively more efficient Hubert robust estimator. The empirical regression model results and diagnostic tests indicate that the core determinants of life expectancy are the real GDP per capita, illiteracy rates and daily visits to physicians. Using results of the robust regression estimator (mimic the instrumental variables model estimation), the statistically significant elasticities of life expectancy are 0.033 (t-ratio = 2.45) with respect to per capita real GDP, 0.41 (t-ratio = 2.54) with respect to daily visits to the physicians and is −0.026 (t-ratio = −2.26) with respect to the illiteracy rate. That is, income and daily visits to physicians are positively linked to life expectancy while the illiteracy rate stifles life expectancy production. Our fi...
Cyclic Adenosine 3′,5′-Monophosphate Responsive Element Binding Protein Phosphorylation Is Required But Not Sufficient for Activation of Corticotropin-Releasing Hormone Transcription

cAMP is a major regulator of CRH transcription. However, receptors activating CRH neurons (α-adrenergic and glutamatergic) do not signal through cAMP, suggesting that calcium phospholipid-dependent signaling synergizes with small elevations of intracellular cAMP. To test this hypothesis, we examined the relationship between activation of CRH transcription, cAMP production, and cAMP response element binding protein (CREB) phosphorylation in neuronal cultures treated with the adenylyl cyclase stimulator, forskolin, the phorbol ester, phorbol-12-myristate-13-acetate (PMA), or their combination. Forskolin, at threshold concentrations for cAMP production and CREB phosphorylation, induced CRH promoter-driven luciferase activity in 4B cells (EC50 = 0.7 μm) and CRH primary transcript in hypothalamic neurons (EC50 = 0.6 μm). PMA alone failed to activate CRH transcription despite being as effective as forskolin in phosphorylating CREB (Ser133 and Ser121). Although PMA potentiated the effect of low forskolin concentrations on CRH transcription and CREB phosphorylation, there was no correlation between phosphorylated CREB levels and activation of CRH transcription. Similarly, the calcium/calmodulin-dependent kinase inhibitor, KN-93, enhanced PMA plus forskolin-stimulated CREB phosphorylation and inhibited CRH transcription. Suppression of CREB phosphorylation by the protein kinase A inhibitor, H89, or the CREB dominant negative, A-CREB, did not affect basal but blocked forskolin-stimulated transcription. This study shows that calcium phospholipid-dependent pathways potentiate the ability of small elevations of intracellular cAMP to activate CRH transcription, providing a mechanism by which non-cAMP-dependent regulators induce CRH gene expression. In addition, the data indicate that phosphorylated CREB is essential but not sufficient for activation of CRH transcription, suggesting that full promoter stimulation requires the interaction of phosphorylated CREB with a coactivator.
Characterization of quantum dot enhanced solar cells for concentrator photovoltaics

The addition of quantum dots (QDs) or quantum wells (QW) to a solar cell allows one to extend the absorption spectrum of the solar cell to match spectral conditions under concentration. In this paper the effect of bandgap tuning using quantum dots is investigated. P-i-n GaAs concentrator solar cells, both with and without InAs QD superlattice (SL) inserted into the i-region, were fabricated. In order to investigate effects of increased InAs QD layers, between 5 and 20 stacked InAs QDs were grown. The 20 layer stack QD tuned cell showed an 11% improvement in JSC compared to the baseline from concentrations of 2–450 suns. The increased Jsc of the QD devices was shown to be a direct result of photo-generated current contributed by the QDs. The 20X QD cell gave a 1% absolute efficiency enhancement, compared to a baseline solar cell, at 400 sun intensity, showing potential for QD spectral tuning under solar concentration.
Recognition-based Segmentation of On-Line Cursive Handwriting

This paper introduces a new recognition-based segmentation approach to recognizing on-line cursive handwriting from a database of 10,000 English words. The original input stream of x, y pen coordinates is encoded as a sequence of uniform stroke descriptions that are processed by six feed-forward neural-networks, each designed to recognize letters of different sizes. Words are then recognized by performing best-first search over the space of all possible segmentations. Results demonstrate that the method is effective at both writer dependent recognition (1.7% to 15.5% error rate) and writer independent recognition (5.2% to 31.1% error rate).
A cost-utility analysis of NRG Oncology/Gynecologic Oncology Group Protocol 218: incorporating prospectively collected quality-of-life scores in an economic model of treatment of ovarian cancer

Abstract Objective To estimate quality-of-life (QOL)-adjusted cost–utility with addition of bevacizumab (B) to intravenous paclitaxel/carboplatin (PC) for primary treatment of advanced-stage epithelial ovarian cancer. Methods A modified Markov state transition model of 3 regimens evaluated in GOG 218 (PC, PC+concurrent B [PCB], and PCB+maintenance B [PCB+B]) was populated by prospectively collected survival, adverse event, and QOL data from GOG 218. Progression-free survival (PFS) and overall survival (OS) were modeled using primary event data. Costs of grade 4 hypertension, grade 3–5 bowel events, and growth factor support were incorporated. QOL scores were converted to utilities and incorporated into the model. Monte Carlo probabilistic sensitivity analysis was performed to account for uncertainty in estimates. Results PC was the least expensive ($4044) and least effective (mean 1.1 quality-adjusted progression-free years [QA-PFY]) regimen. PCB ($43,703 and 1.13 QA-PFY) was dominated by a combination of PC and PCB+B. PCB+B ($122,700 and 1.25 QA-PFY) was the most expensive regimen with an incremental cost–effectiveness ratio of $792,380/QA-PFY compared to PC. In a model not incorporating QOL, the incremental cost–effectiveness ratio (ICER) of PCB+B was $632,571/PFY compared to PC. Conclusions In this cost–utility model, incorporation of QOL into an analysis of GOG 218 led to less favorable ICER (by >$150,000/QA-PFY) in regimens containing B compared with those that do not include B. Continued investigation of populations with ovarian cancer in whom the efficacy of treatment with bevacizumab is expected to be increased (or in whom QOL is expected to increase with use) is critical.
Implementing Cognitive Behavior Management Programs for Persons with Autism: Guidelines for Practitioners

Cognitive behavior modification (CBM) is a technique that allows students with exceptionalities to function independently in schools and communities. It has been widely used with persons with mild ...
REGIONAL ENTERITIS IN CHILDREN

SYNOPSIS Young adults with regional enteritis frequently can trace initial symptoms back to childhood. Why then are so few diagnoses of this disease made by paediatricians? The ill-defined character of the presenting signs is one reason. Another is the technic of barium meal examination by radiologists. Follow-through examination of the small bowel is mandatory to identify the early changes in jejunum and ileum which are commonly involved in children. Such examination is seldom performed in adults, and the child who is examined as an adult may have to wait until he is an adult to have his disease recognized.
Hayek Contra Pangloss: A Rejoinder

Whitman (1998) claims that Friedrich Hayek's theory of cultural evolution was not Panglossian. Denis's (2002) refutation relies on an overbroad definition of the term Panglossian, a misunderstanding of the implications of group selection theory, and an incomplete understanding of the nested character of evolutionary processes in Hayek's approach.
Predictors of Communication Satisfaction during Performance Appraisal Interviews.

The following study investigates the relationship between employee perceptions of communication behaviors and satisfaction with communication that occurred during a recent performance appraisal interview. In association with communication satisfaction the relationship between communication training and the amount of time elapsed between the appraisal interview and participation in this survey were also investigated. Results indicate that perceptions of understanding and the quality of communication are significant predictors of satisfaction with communication during the appraisal interview. Implications for training in the use of communication skills to improve communication during the performance appraisal interview are discussed.
Biologically active monoiodinated alpha-MSH derivatives for receptor binding studies using human melanoma cells.

AbstractThree different monolodinated radioligands of α-MSH (α-melanocyte-stimulating hormone) were compared in a binding assay with human D10 melanoma cells: [Tyr(125l)2]-α-MSH, [Tyr(125l)2, Nle4]-α-MSH, and [Tyr(125l)2, Nle4, D–Phe7]-α-MSH. They were prepared either by the classical chloramine T method or by the Enzymobead method. A simple and rapid purification scheme was developed consisting of a primary separation on reversed-phase C18 silica cartridges immediately after the iodination, followed by HPLC purification before each binding experiment. Biological testing of the three radioligands showed that they all retained high melanotropic activity in the B16 melanin assay and the Anolis melanophore assay. However, in human D10 melanoma cells, [Tyr(125l)2-α–MSH led to a high degree of non-specific binding to the cells which could not be displaced by excess α-MSH and only partially by [Nle4]α–MSH. The [Tyr(125l)2, Nle4, D-Phe7]-α–MSH tracer gave similar results but with a much lower proportion of non-s...
Wiretap Channel With Secure Rate-Limited Feedback

This paper studies the problem of secure communication over a wiretap channel p(y,z|x) with a secure feedback link of rate Rf, where X is the channel input, and Y and Z are channel outputs observed by the legitimate receiver and the eavesdropper, respectively. It is shown that the secrecy capacity, the maximum data rate of reliable communication while the intended message is not revealed to the eavesdropper, is upper bounded as Cs(Rf) les maxmin/p(x) {I(X;Y), I(X;Y |Z) + Rf}. The proof of the bound crucially depends on a recursive argument which is used to obtain the single-letter characterization. This upper bound is shown to be tight for the class of physically degraded wiretap channels. A capacity-achieving coding scheme is presented for this case, in which the receiver securely feeds back fresh randomness with rate Rf, generated independent of the received channel output symbols. The transmitter then uses this shared randomness as a secret key on top of Wyner's coding scheme for wiretap channels without feedback. Hence, when a feedback link is available, the receiver should allocate all resources to convey a new key rather than sending back the channel output.
Substitution in Household Production and the Efficiency of in-Kind Transfers

The traditional argument for in-kind transfers rests on their ability to induce greater consumption of externality-causing commodities. This paper shows that this effect will be diminished the greater the possibilities for substitution in household production. The argument rests on the distinction between market goods which can be subsidized and the commodities donors value which are produced in the household. If the price of the market good is reduced through a subsidy, consumers will react in part by producing the commodity with an altered ratio of inputs.
Debating the land question in Africa

In February 2000, twenty years after their victories brought Rhodesia's ruling white regime to the conference table, veterans of Zimbabwe's war of liberation began to occupy some of the large privately owned commercial farms that controlled Zimbabwe's most valuable land. During the next few weeks, thousands of people followed suit: by May, nearly a third of the country's large-scale commercial farms had been seized (New York Times, 27 May 2000; Moyo 1998). Armed with a court order, landowners demanded that the “squatters” be evicted, but the police demurred, and President Mugabe refused to order them to carry out the court's instructions. A few weeks earlier, voters had rejected a proposed constitutional amendment that would have strengthened the President's powers to seize white-owned land, without compensation, for redistribution to land-hungry blacks. Angry over the deteriorating economy, rising levels of corruption, and Zimbabwe's costly involvement in Congo's civil war, a majority of those who voted were unwilling to increase the President's powers, even if they supported the cause of land reform. When the veterans took matters into their own hands, Mugabe lost no time in associating with their cause. He, in turn, was accused by Western governments, the opposition Movement for Democratic Change, and the international press, of sacrificing the rule of law in order to save his own political skin.
PAIR ANNIHILATION AT A POTENTIAL BARRIER IN TIME.

We determine the probability of pair annihilation for charged scalar particles in an external electromagnetic field that is switched on for a finite interval, within the context of relativistic quantum mechanics of a single particle. We present the results of numerical calculations in several graphs. We find that this probability is extremely small for fields of the magnitude usually found in the laboratory. We also obtain a general expression for the spreading of the wave packet that represents a free relativistic scalar particle.
Micro-cycle Teaching Experiments as a Vehicle for Professional Development

This study used design experiments, specifically microteaching experiments (MTE) as a catalyst for practice-based professional development. The MTE incorporated research-based characteristics of effective professional development: it was embedded in the teachers’ daily work of planning and enacting lessons and co-constructed with the researcher to build upon students’ knowledge. Pedagogical and mathematical content knowledge was integrated into the planning, implementation, and analysis of these MTEs. In this study, we investigated: To what extent can teachers, and to what extent, engage in a MTE as an intentional method for improving teaching? Case studies were used to analyze ways teachers engaged in MTEs and how their teaching was impacted as the result of this experience.
Central cholinergic and alpha-adrenergic mediation of gastric slow wave dysrhythmias evoked during motion sickness

Motion sickness is associated with gastric slow wave disruption. Animal models of slow wave disturbances show dependence on neural and prostaglandin pathways. Roles of these pathways in circular vection-evoked gastric dysrhythmias and nausea were tested. Eight volunteers with histories of motion sickness underwent vection (60 degrees/s), during which nausea (0 = none to 3 = severe) and electrogastrographic parameters were assessed. Tachygastric activity was expressed as the signal percentage at frequencies of > 4.5 cycles/min. Circular vection induced a maximal nausea score of 2.8 +/- 0 at 513 +/- 66 s. Tachygastric activity increased from 18 +/- 2 to 37 +/- 4% (P < 0.05) and peaked before maximal nausea. Atropine reduced nausea scores to 0 +/- 0 (P < 0.01) with no increase in tachygastric activity (14 +/- 6%). In contrast, the peripheral muscarinic antagonist methscopolamine did not reduce tachygastric activity (46 +/- 4%), nausea (1.8 +/- 0.5), or time to maximal tachygastric activity (504 +/- 80 s) with vection. Phentolamine reduced nausea (1.5 +/- 0.3, P < 0.01) and tachygastric activity, and delayed their onset, whereas propranolol and naloxone had no effect. Pretreatment with oral indomethacin (50 mg) three times daily for 3 days had no effect on vection-evoked tachygastric activity or nausea. To conclude, circular vection evokes gastric dysrhythmias that correlate temporally with maximal nausea and are suppressed by atropine, but not methscopolamine, and are reduced by phentolamine. In contrast to other models of slow wave disruption, endogenous prostaglandins play no role. Thus central cholinergic pathways mediate vection-evoked dysrhythmias with additional modulation by alpha-adrenergic pathways.