cssi/SciSciGPT-SciSciNet huggingface dataset:
A five-collector system for the simultaneous measurement of argon isotope ratios in a static mass spectrometer

Abstract A system is described that utilizes five separate Faraday-cup collector assemblies, aligned along the focal plane of a mass spectrometer, to collect simultaneous argon ion beams at masses 36–40. Each collector has its own electrometer amplifier and analog-to-digital measuring channel, the outputs of which are processed by a minicomputer that also controls the mass spectrometer. The mass spectrometer utilizes a 90° sector magnetic analyzer with a radius of 23 cm, in which some degree of z-direction focussing is provided for all the ion beams by the fringe field of the magnet. Simultaneous measurement of the ion beams helps to eliminate mass-spectrometer memory as a significant source of measurement error during an analysis. Isotope ratios stabilize between 7 and 9 s after sample admission into the spectrometer, and thereafter changes in the measured ratios are linear, typically to within ±0.02%. Thus the multi-collector arrangement permits very short extrapolation times for computation of initial ratios, and also provides the advantages of simultaneous measurement of the ion currents in that errors due to variations in ion beam intensity are minimized. A complete analysis takes less than 10 min, so that sample throughput can be greatly enhanced. In this instrument, the factor limiting analytical precision now lies in short-term apparent variations in the interchannel calibration factors.
Single Molecule Rectification Induced by the Asymmetry of a Single Frontier Orbital

A mechanism for electronic rectification under low bias potentials is elucidated for the prototype molecule HS-phenyl-amide-phenyl-SH. We apply density functional theory (DFT) combined with the nonequilibrium Green’s function formalism (NEGF), as implemented in the TranSIESTA computational code to calculate transport properties. We find that a single frontier orbital, the closest to the Fermi level, provides the dominant contribution to the overall transmission and determines the current. The asymmetric distribution of electron density in that orbital leads to rectification in charge transport due to its asymmetric response, shifting toward (or away from) the Fermi level under forward (or reverse) applied bias voltage. These findings provide a simple design principle to suppress recombination in molecular assemblies of dye-sensitized solar cells (DSSCs) where interfacial electron transfer is mediated by frontier orbitals with asymmetric character.
Efficiency of Measles Virus Entry and Dissemination through Different Receptors

The efficiency with which different measles virus (MV) strains enter cells through the immune cell-specific protein SLAM (CD150) or other receptors, including the ubiquitous protein CD46, may influence their pathogenicity. We compared the cell entry efficiency of recombinant MV differing only in their attachment protein hemagglutinin (H). We constructed these viruses with an additional gene expressing an autofluorescent reporter protein to allow direct detection of every infected cell. A virus with a wild-type H protein entered cells through SLAM two to three times more efficiently than a virus with the H protein of the attenuated strain Edmonston, whereas cell entry efficiency through CD46 was lower. However, these subtle differences were amplified at the cell fusion stage because the wild-type H protein failed to fuse CD46-expressing cells. We also proved formally that a mutation in H protein residue 481 (asparagine to tyrosine) results in improved CD46-specific entry. To define the selective pressure exerted on that codon, we monitored its evolution in different H protein backgrounds and found that several passages in CD46-expressing Vero cells were necessary to shift it in the majority of the MV RNA. To verify the importance of these observations for human infections, we examined MV entry into peripheral blood mononuclear cells and observed that viruses with asparagine 481 H proteins infect these cells more efficiently.
Differential subcellular localization of cholesterol, gangliosides, and glycosaminoglycans in murine models of mucopolysaccharide storage disorders

The mucopolysaccharidoses (MPSs) are a complex family of lysosomal storage disorders characterized by failure to degrade heparan sulfate (HS) and/or other types of glycosaminoglycans (GAGs) secondary to the absence of specific lysosomal enzymes. An accompanying storage of glycosphingolipids (GSLs), most notably GM2 and GM3 gangliosides, has also been documented to occur in many types of MPS disease and is believed to be caused by secondary inhibition of GSL-degradative enzymes by intracellular GAG accumulation. We have documented the presence of secondary ganglioside accumulation in mouse models of several MPS disorders (types I, IIIA, IIIB, and VII) and report that this storage is accompanied by sequestration of free cholesterol in a manner similar to that observed in primary gangliosidoses. Using confocal microscopy, we evaluated the cellular distribution of cholesterol, GM2 and GM3 gangliosides, and HS in brains of mice with MPS IIIA disease. Unexpectedly, we found that although both gangliosides often accumulated in the same neurons, they were consistently located in separate populations of cytoplasmic vesicles. Additionally, GM3 ganglioside only partially co-localized with the primary storage material (HS), and cholesterol likewise only partially co-localized with the GM2 and GM3 gangliosides. These findings raise significant questions about the mechanism(s) responsible for secondary accumulation of storage materials in MPS disease. Furthermore, given that GSLs and cholesterol are constituents of membrane rafts believed critical in signal transduction events in neurons, their co-sequestration in individual neurons suggests the presence of defects in the composition, trafficking, and/or recycling of raft components and thus possible new mechanisms to explain neuronal dysfunction in MPS disorders. J. Comp. Neurol. 480:415–426, 2004. © 2004 Wiley-Liss, Inc.
Separation of flavins and nicotinamide cofactors in Chinese hamster ovary cells by capillary electrophoresis.

Simultaneous extraction, separation and quantitation of reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) in Chinese Hamster Ovary (CHO) cells were investigated. The separation of flavins and nicotinamide cofactors was performed by capillary electrophoresis with laser-induced fluorescence detection at the excitation wavelength of 325 nm. The separation protocol was established by investigating the excitation wavelength, high voltage and effects of buffer nature, pH and concentration. All endogenous fluorophores riboflavin, FAD, FMN, NADH and NADPH show wide linear range of quantitation. The limits of detection for the five compounds ranged from 4.5 to 23 nm. Extraction conditions were optimized for high-efficiency recovery of all endogenous fluorophores from CHO cells. To account for the complex matrix of cell extracts, a standard addition method was used to quantify FAD, FMN, NADH and NADPH in CHO cells. The quantitative results should be useful to reveal the metabolic status of cells. The protocols for extraction, separation and quantitation are readily adaptable to normal and cancer cell lines for the analysis of endogenous fluorophores. Copyright © 2008 John Wiley & Sons, Ltd.
Tactics of resistance in student-student interaction

This study seeks to define a “space” where otherwise marginalized students might participate more centrally in classroom literacy events. Drawing on Lave and Wenger, the study is concerned with the differential effects of a classroom literacy event on the academic identities of two students in a group of four, both of whom felt insecure as writers. Drawing on the work of Kenneth Burke and de Certeau, the study regards rhetorical maneuvers as resistance to the social designs of others. From this theoretical vantage point, using a range of methods for analyzing language as social action (derived mainly from the work of Erving Goffman), the study shows how one student's rhetorical maneuvers performed her resistance to a more dominant peer and, simultaneously, her understanding of written text; nevertheless, her authorial rights were expropriated by her peers. An adult observer (the author) did not recognize and did nothing to arbitrate the student's marginalization. The analysis identifies implicit meta-textual issues from the students' talk and suggests that a sufficiently powerful (explanatory) theory of text could help to mediate more equitable negotiations of what counts as text in classroom literacy activities.
Enzymatic Acetylation as a Means of Determining Serum Aminoglycoside Concentrations

A rapid and accurate enzymatic assay has been developed for the determination of blood serum levels of BB-K8 and other suitable aminoglycoside antibiotics.
Water Scarcity in the Middle East: Balancing Conflict, Development, and Survival in Turkey, Syria and Iraq

This article highlights the importance of water as a source of conflict in the Middle East and as an element of peacebuilding and development. It studies the internal and external factors that create and increase water scarcity – and thus the prospects for conflict – between Turkey, Syria and Iraq. The causes and impacts of water scarcity are examined and possible solutions are presented for reducing scarcity and achieving development and peace in these neighbouring countries.
An asparagine-phenylalanine substitution accounts for catalytic differences between hGSTM3-3 and other human class mu glutathione S-transferases.

The hGSTM3 subunit, which is preferentially expressed in germ-line cells, has the greatest sequence divergence among the human mu class glutathione S-transferases. To determine a structural basis for the catalytic differences between hGSTM3-3 and other mu class enzymes, chimeric proteins were designed by modular interchange of the divergent C-terminal domains of hGSTM3 and hGSTM5 subunits. Replacement of 24 residues of the C-terminal segment of either subunit produced chimeric enzymes with catalytic properties that reflected those of the wild-type enzyme from which the C-terminus had been derived. Deletion of the tripeptide C-terminal extension found only in the hGSTM3 subunit had no effect on catalysis. The crystal structure determined for a ligand-free hGSTM3 subunit indicates that an Asn212 residue of the C-terminal domain is near a hydrophobic cluster of side chains formed in part by Ile13, Leu16, Leu114, Ile115, Tyr119, Ile211, and Trp218. Accordingly, a series of point mutations were introduced into...
Preclinical evaluation in monkeys of a ribavirin regimen proposed for use in Lassa fever patients

Abstract The nucleoside, ribavirin (1-β- d -ribofuranosyl-1,2,4-triazole-3-carboxamide), effective against high hazard viruses such as Lassa fever, may produce hematological changes in some species. This study determined the extent of these changes in monkeys given a schedule of ribavirin treatment similar to that used in Lassa fever-infected patients. Drug was administered iv in a 33 mg/kg loading dose, followed by 17 mg/kg every 6 hr for 4 days, then 8 mg/kg every 8 hr for an additional 6 days; control monkeys received an equivalent volume of saline. Red blood cell counts decreased significantly by Day 6 but returned to pretreatment levels by the third week post-treatment. Hematocrits were reduced 30% by Day 7, reached their nadir on Day 11 with a mean value of 22%. Hemoglobin values dropped to 7–8 mg/dl, remained at that level for 10 days, and gradually returned to pretreatment levels. Three days after discontinuance of drug, reticulocytes increased then returned to control levels by Day 44. Platelet levels increased during treatment, peaked on Day 14, and then returned to baseline values. No significant changes were observed in total and differential WBC counts. Haptoglobin, SGOT, SGPT, total and direct bilirubin, BUN, blood glucose, and body weight were not altered. These data indicate that the proposed therapeutic regimen of ribavirin modifies the normal hemogram of rhesus monkeys. Observed effects appear to be fully reversible with hemograms returning to normal limits upon discontinuance of ribavirin. This effect is an important consideration in the treatment of Lassa fever in man.
EVALUATION OF MULTIPOLAR EFFECTS IN THE HIGH-FIDELITY STANDARD ELECTROCARDIOGRAM BY MEANS OF FACTOR ANALYSIS.

The usefulness of factor analysis as a means of describing in both general and specific terms an equivalent cardiac generator has been explored. High-fidelity, high-frequency electrocardiograms and vectorcardiograms of 31 normal subjects have been analyzed. The information in the electrocardiogram was reduced by factor analysis to the minimum number of independent waveforms which could account for all of this information. Because the first three principal factors might or might not represent a simple dipole, the efficiency of these three principal factors to resynthesize the originally recorded electrocardiograms was compared with the efficiency of McFee vectorcardiographic leads to perform the same resynthesis. The first three principal factors contained more information than that contained in the vectorcardiographic leads, suggesting that the factors contain more than simple dipolar information. This would in turn suggest that a more complex generator than the dipole must be employed to explain the surface potentials derived from the standard electrocardiogram. With only two principal factors the precordial leads were rather easily reconstructed but reconstruction of leads I and V F was considerably more difficult. Because the principal factors represent the most commonly occurring waveforms in the group, the less perfect resynthesis of leads I and V F with two factors alone may result from lack of detection of multipolar component in the limb leads which have less in common with the precordial leads than the precordial leads do with each other.
920 PLASMA PROTEIN C LEVELS IN PATIENTS WITH SICKLE CELL DISEASE (SCD)

Vitamin-K=dependent protein C (PC) functions as a potent anticoagulant. Thrombo-embolism has been reported in kindreds with congenitally low PC levels suggesting that PC has an important role in hemostasis and that even a moderate reduction in this plasma protein may be associated with increased risk of thrombosis. Since thrombotic phenomena have important robs in the vaso-occlusive manifestations in SCD, PC was determined in 32 SCD during steady state and in controls (C). The SCD had significantly lower PC levels as compared to controls. Six SCD were also studied during vaso-occlusive crisis (VOC). During VOC there was marked decrease in PC as compared to levels during steady state (49.5 ± 6.4 and 66.1 ± 10.0, respectively. P < 0.01). Decreased levels of PC during VOC increased to initial levels or higher with clinical improvement. It is postulated that the decreased levels of PC in SCD are probably secondary to increased consumption as well as decreased production because of altered liver functions. This data suggests that decreased levels of PC may increase the risk of thrombosis in these patients.
The application of a segmented tidal mixing model to the Great Bay estuary, N.H

Measurements show that in general salt is vertically well-mixed everywhere in the Great Bay Estuary, New Hampshire except near the river entrances at the head of the estuary. Dyer and Taylor’s (1973) modified version of Ketchum’s segmented tidal prism model has been applied to the Great Bay Estuarine System in order to predict high and low water salinity distribution for a specified river flow. The theory has been modified here to account for the mixing which occurs at the junction of two branches of an estuary. The mixing parameter, which in this model is related to the tidal excursion of water in the estuary, has been determined for different segments in the estuary on the basis of a comparison between predictions and a comprehensive data set obtained for a low river flow period. Using a mixing parameter distribution based on the low river flow calibration procedure the salinity distribution has been predicted for high river flow. The resulting salinity distribution compares favorably with observations for most of the estuary. The corresponding flushing times for water parcels entering at the head of the estuary during periods of low and high river flow is 54.5 and 45.9 tidal cycles respectively.
Nonlinear magnetization of Y-Ba-Cu-O crystals

We investigate the nonlinear magnetization {ital M}({ital B}) of an YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} crystal in applied superimposed dc and ac magnetic fields {ital B} up to about 80 G. {ital M}({ital B}({ital t})) contains both even and odd harmonics of the applied fundamental audio frequency in a restricted temperature range of 1--2 K below {ital T}{sub {ital c}}. Harmonic amplitudes oscillate with both temperature and dc field. We propose a simple dynamical model based on the observed flux creep'' resistance in which temperature and field appear only in the ratio (1{minus}{ital T}/{ital T}{sub {ital c}}){sup 3/2}B. The model is in qualitative and semiquantitative agreement with the data.
Asymptotic spreading of KPP reactive fronts in incompressible space-time random flows

Abstract We study the asymptotic spreading of Kolmogorov–Petrovsky–Piskunov (KPP) fronts in space–time random incompressible flows in dimension d > 1 . We prove that if the flow field is stationary, ergodic, and obeys a suitable moment condition, the large time front speeds (spreading rates) are deterministic in all directions for compactly supported initial data. The flow field can become unbounded at large times. The front speeds are characterized by the convex rate function governing large deviations of the associated diffusion in the random flow. Our proofs are based on the Harnack inequality, an application of the sub-additive ergodic theorem, and the construction of comparison functions. Using the variational principles for the front speed, we obtain general lower and upper bounds of front speeds in terms of flow statistics. The bounds show that front speed enhancement in incompressible flows can grow at most linearly in the root mean square amplitude of the flows, and may have much slower growth due to rapid temporal decorrelation of the flows.
Effects of ionic and nonionic contrast media on in vitro and in vivo platelet activation.

Abstract An increased incidence of thromboembolic events has been associated with nonionic contrast media. Although it has been demonstrated that nonionic contrast media cause significant platelet activation in vitro, there is no reported evidence of contrast-induced platelet activation in vivo. This study investigated the effect of a nonionic contrast agent, iohexol (Omnipaque ® ), versus an ionic contrast agent, diatrizoate meglumine + diatrizoate sodium (MD-76 ® ), on both in vitro and in vivo platelet activity. Blood from normal subjects (n = 12) was incubated in vitro for 15 to 60 seconds with varying proportions of contrast media or saline solution, and analyzed by flow cytometry for markers of platelet degranulation (P-selectin) and platelet GPIIb-IIIa receptor activation (PAC-1). In vivo activation after Omnipaque was measured in patients undergoing cardiac catheterization in peripheral blood before and after contrast (n = 5), and in coronary sinus blood before and after left coronary injections (n = 8). In vitro data showed that Omnipaque incubated for 60 seconds with whole blood at ratios of 1:1 resulted in a greater percentage of platelets expressing P-selectin (median/ range) than did MD-76 (68%/38% to 90% vs 17%/1% to 53%, respectively, p
A Longitudinal Field Test of Stockout Effects on Multi-Brand Inventories

Stockouts do present a threat to a brand's stability in the marketplace. But is that threat as significant as one might initially be led to believe? The results of this study, as well as two prior efforts of similar methodology (Charlton and Ehrenberg 1976; Motes 1980), would suggest not, at least in the context of multi-brand inventories. It is strongly suggested that retailers, as well as manufacturers, need not be overly concerned about protracted adverse effects emanating from temporary stockouts at the retail level.
First-row transition metal complexes of tri(2-pyridyl)carbinol

Abstract First-row transition metal complexes of the ligand tri(2-pyridyl)carbinol (TPC) have been prepared and characterized. For Mn(II), Fe(II), Ni(II), Cu(II) and Zn(II), the complexes have the stoichiometry M(TPC)2 (ClO4)2·(H2O)n (n = 0 or 1) and the TPC coordinates as a tridentate ligand through the nitrogen atoms of the pyridyl rings. For cobalt, only a Co(III) complex with the formula Co(TPC)(TPC−)(C104)2· 1 1 2 H 2 O was isolated. This complex also has two tridentate ligands but is coordinated through the nitrogen atoms of two of the pyridyl rings and the oxygen of the carbinol group. One of the TPC ligands has undergone deprotonation while the second TPC ligand remains protonated. The complexes were characterized by their elemental analysis, IR, visible, and NMR spectra, magnetic moments, and conductivity data.
The Settlement Analysis of Raft Foundation Using RFDG Program Based on ANSYS

The development of raft foundation design guide (RFDG) used in the high-rise building was programmed based on the secondary development language of ANSYS, such as TCL/TK, APDL and UDIL. The RFDG program provides a friendly GUI, which can be used expediently for the numerical experiment. The settlement analysis of raft foundation in the case study was carried out by RFDG. At the same time, the main technique for the secondary development of ANSYS has also been discussed in this paper.
Chronic lithium treatment prevents atropine-induced supersensitivity of the muscarinic phosphoinositide response in rat hippocampus.

Abstract Rats were placed on a lithium diet for 3 weeks or an identical diet without lithium for the same period. During the third week, atropine sulfate (10 mg/kg/day) or saline was infused via subcutaneously implanted osmotic pumps. Twenty-four hours following the removal of the pumps, brain slices and membranes were prepared from the cortex and hippocampus for determination of muscarinic stimulation of phosphoinositide turnover and for receptor-binding studies. Treatment with lithium alone did not significantly affect any of the binding or response parameters measured. Administration of atropine led to (1) an upregulation of muscarinic binding sites in both cortex and hippocampus without significant alteration in the proportion of muscarinic receptor subtypes; and (2) an enhancement of the muscarinic phosphoinositide response in hippocampal slices. However, atropine did not induce supersensitivity of the hippocampal response in rats undergoing lithium administration. These results are consistent with recent suggestions that lithium's efficacy in affective disorders may be related to a dampening of musarinic supersensitivity.
Nervous system sports-related injuries:

With the evolution of sports medicine as a subspecialty comes a redirection of attention to the medical and athletic communities to the prompt recognition and timely treatment of many potentially serious conditions. Nervous system complications of sports injuries have gone largely unaddressed in the literature. It is the goal of this communication to review the wide range of nervous system injuries due to sports activities, discuss the mechanisms of such injuries, and focus attention on their prevention and management. The role of the neurologist and neurosurgeon as a sports medicine team member will be discussed, as will their roles in planning and development of programs and equipment at the secondary school, collegiate, and professional levels.
On causal nonrelativistic classical electrodynamics

The differential-difference (DD) motion equations of the causal nonrelativistic classical electrodynamics developed by the author in 1975 are shown to possess only nonrunaway, causal solutions with no discontinuities in particle velocity or position. As an example, the DD equation solution for the problem of an electromagnetic shock incident on an initially stationary charged particle is contrasted with the standard Abraham-Lorentz equation solution. The general Cauchy problem for these DD motion equations is discussed. In general, in order to uniquely determine a solution, the initial data must be more detailed than the standard Cauchy data of initial position and velocity. Conditions are given under which the standard Cauchy data will determine the DD equation solutions to sufficient practical accuracy.
The effect of tobacco mosaic virus infection on host and virus-specific protein synthesis in protoplasts.

Abstract The nature and rate of virus-specific protein synthesis were determined in tobacco mosaic virus-infected protoplasts as a function of time after inoculation. Samples of infected and mock-infected protoplasts were exposed to radioactive amino acid for relatively short sequential time periods and the consequent labeled proteins were assessed following SDS-polyacrylamide gel electrophoresis and fluorography. The synthesis of three virus-specific proteins of molecular weights 160,000, 135,000, and 17,500 was confirmed. Synthesis of all three proteins was first detected during the 5- to 7-hr postinoculation period at which time the synthetic rate of the 135,000-dalton protein was greatest. This was soon overtaken by the 17,500-dalton capsid protein, the synthetic rate of which kept increasing until it accounted for a major portion of total protoplast protein synthesis. At 1 day postinoculation, it accounted for 50% and, at not quite 2 days, 70% of the total protein synthesis. Evidence is presented to suggest that virus-specific protein synthesis occurs in addition to, rather than at the expense of, normal cellular protein synthesis.
An information theoretic model of bounded rationality

Abstract Bounded rationality forces an entity to divide its responses between those it does immediately (called adaptedness) and those it does with delay (called adaptability). Information theory is used to show how coding is related to the problem of choosing between adaptedness and adaptability.
Philosophy in the weight room: Nathalie Gassel and the crisis of self-representation

This article traces the evolution of Belgian writer Nathalie Gassel's writing practices and contends that the space of the text is akin to the artist's own self-construction as an androgynous femal...
The Effect of Budgetary Restrictions on Breast Cancer Diagnostic Decisions

We develop a finite-horizon discrete-time constrained Markov decision process (MDP) to model diagnostic decisions after mammography where we maximize the total expected quality-adjusted life years (QALYs) of a patient under resource constraints. We use clinical data to estimate the parameters of the MDP model and solve it as a mixed-integer program. By repeating optimization for a sequence of budget levels, we calculate incremental cost-effectiveness ratios attributable to consecutive levels of funding and compare actual clinical practice with optimal decisions. We prove that the optimal value function is concave in the allocated budget. Comparing to actual clinical practice, using optimal thresholds for decision making may result in approximately 22% cost savings without sacrificing QALYs. Our analysis indicates short-term follow-ups are the immediate target for elimination when budget becomes a concern. Policy change is more drastic in the older age group with the increasing budget, yet the gains in total expected QALYs related to larger budgets are predominantly seen in younger women along with modest gains for older women.
Modeling of Prosthetic Limb Rotation Control by Sensing Rotation of Residual Arm Bone

We proposed a new approach to improve the control of prosthetic arm rotation in amputees. Arm rotation is sensed by implanting a small permanent magnet into the distal end of the residual bone, which produces a magnetic field. The position of the bone rotation can be derived from magnetic field distribution detected with magnetic sensors on the arm surface, and then conveyed to the prosthesis controller to manipulate the rotation of the prosthesis. Proprioception remains intact for residual limb skeletal structures; thus, this control system should be natural and easy-to-use. In this study, simulations have been conducted in an upper arm model to assess the feasibility and performance of sensing the voluntary rotation of residual humerus with an implanted magnet. A sensitivity analysis of the magnet size and arm size was presented. The influence of relative position of the magnet to the magnetic sensors, orientation of the magnet relative to the limb axis, and displacement of the magnetic sensors on the magnetic field was evaluated. The performance of shielding external magnetostatic interference was also investigated. The simulation results suggest that the direction and angle of rotation of residual humerus could be obtained by decoding the magnetic field signals with magnetic sensors built into a prosthetic socket. This pilot study provides important guidelines for developing a practical interface between the residual bone rotation and the prosthesis for control of prosthetic rotation.
Low Temperature Electrical Performance Characteristics of Li-Ion Cells

Advanced rechargeable lithium-ion batteries are presently being developed and commercialized worldwide for use in consumer electronics, military and space applications. The motivation behind these efforts involves, among other things, a favorable combination of energy and power density. For some of the applications the power sources may need to perform at a reasonable rate at subambient temperatures. Given the nature of the lithium-ion cell chemistry the low temperature performance of the cells may not be very good. At Sandia National Laboratories, we have used different electrochemical techniques such as impedance and charge/discharge at ambient and subambient temperatures to probe the various electrochemical processes that are occurring in Li-ion cells. The purpose of this study is to identify the component that reduces the cell performance at subambient temperatures. We carried out 3-electrode impedance measurements on the cells which allowed us to measure the anode and cathode impedances separately. Our impedance data suggests that while the variation in the electrolyte resistance between room temperature and -20"C is negligible, the cathode electrolyte interracial resistance increases substantially in the same temperature span. We believe that the slow interracial charge transfer kinetics at the cathode electrolyte may be responsible for the increase in cell impedance and poor cell performance.
Ethical and regulatory considerations in HIV prevention studies employing respondent-driven sampling.

Abstract Objective To review the scientific, ethical, and regulatory literature because no official guidance exists on remuneration for participant-driven recruitment or on investigators' responsibilities for informing participants of their discordant partnerships. Methods We reviewed the studies that used RDS to recruit injection-drug users (IDUs), 1995–2006, and the relevant scientific, ethical, and regulatory literature that shed light on arguments for and against practices that can be used in studies employing RDS. Results Concerns that payments can be used to buy drugs or can subvert altruistic motivations for study participation are not supported by the literature. Concerns about peers' coercion to barter coupons or surrender payments are offset by safeguards used in RDS. Remuneration shows respect for participants' time and effort in recruitment and judgment to use remuneration for personal needs. Tension between ensuring participants' confidentiality and protecting the health of network members highlights difference in roles between investigators and health care providers. Investigators can choose to rely on public health agencies for partner notification services, ask participants if and how they would like to be informed of their discordant partnerships, and offer training on how to disclose HIV status and adopt risk-reduction and harm-reduction behaviours. Conclusion Clarifying ethical and regulatory considerations is important for research sponsors, institutional review boards (IRBs), ethics review committees (ERCs), investigators, and participants. We provide a checklist of ethics and regulatory variables to be included as feasible in future studies to enhance development of evidence-based ethics.
A New Time Domain Formulation for Broadband Noise Predictions

A new analytic result in acoustics called "Formulation 1B," proposed by Farassat, is used to compute the loading noise from an unsteady surface pressure distribution on a thin airfoil in the time domain. This formulation is a new solution of the Ffowcs Williams-Hawkings equation with the loading source term. The formulation contains a far field surface integral that depends on the time derivative and the surface gradient of the pressure on the airfoil, as well as a contour integral on the boundary of the airfoil surface. As a first test case, the new formulation is used to compute the noise radiated from a flat plate, moving through a sinusoidal gust of constant frequency. The unsteady surface pressure for this test case is analytically specied from a result based on linear airfoil theory. This test case is used to examine the velocity scaling properties of Formulation 1B and to demonstrate its equivalence to Formulation 1A of Farassat. The new acoustic formulation, again with an analytic surface pressure, is then used to predict broadband noise radiated from an airfoil immersed in homogeneous, isotropic turbulence. The results are compared with experimental data previously reported by Paterson and Amiet. Good agreement between predictions and measurements is obtained. Finally, an alternative form of Formulation 1B is described for statistical analysis of broadband noise.
General shear deformation in the Pinaleno Mountains metamorphic core complex, Arizona

Abstract Granitic mylonites from the Pinaleno Mountains metamorphic core complex in southeastern Arizona record general shear deformation. The mean kinematic vorticity number ( W m ) was estimated using (1) the strain ratio ( R s ) and the angle ( Θ ) between the long axis of the strain ellipsoid with respect to the high-strain zone boundary and (2) the porphyroclast hyperbolic distribution method. W m for protomylonites and mylonites ranged from 0.6 to 0.9. Ultramylonites record lower W m values (0.1–0.3) suggesting that the incremental vorticity changed during deformation. Three-dimensional strain analysis indicates that deformation in protomylonites and mylonites approximates plane strain and has a monoclinic symmetry. The vorticity path followed by rocks tectonically exhumed in the footwall of major extensional fault systems may evolve from a significant pure shear component early in the deformation towards simple shear as overburden load decreases during uplift.
Flashover model of arcing horn in transient simulation

The flashover performance of an arcing horn in a transmission line is important in lightning surge analysis. Many flashover models have been proposed for transient simulations, but they are only validated over a limited range of waveforms, which is very limited relative to what may be encountered in the field. This paper compares four flashover models of the arcing horn of a 220kV transmission line insulator under standard lightning impulses and as installed in a twin-circuit, 220kV transmission line. The results provide insight into appropriate models for simulating flashover behavior of the arcing horn in transmission line.
Implications of False Positive Serology of Toxoplasma gondii in a Pre-transplant Patient

### Patient A 21-year-old white male with cystic fibrosis. ### Chief Complaint Pre-transplant workup in preparation for bilateral lung transplant. ### Past Medical History Cystic fibrosis diagnosed at age 3, onset of insulin-dependent diabetes around age 20, and multiple hospitalizations for pulmonary and gastrointestinal complications. ### Family and Social History The patient lives with his father and stepmother, has a pet bearded dragon, and has multiple tattoos and piercings. His stepmother has a cat, but he does not clean the litter box. ### Principal Laboratory Findings The pre-transplant workup included several tests for infectious diseases, tests of organ function, radiology studies, and markers of malignancy. The only significant finding was a positive Toxoplasma gondii ( T. gondii ) IgM titer (≥1:40) (reference values for IgM: negative; <1:40, positive; ≥1:40) and IgG (1:2048) (reference values for IgG: negative; < 1:16, equivocal; ≥1:16 – <1:256, positive; ≥1:256). Testing was done by indirect immunofluorescence assay (IFA) in April 2012 in our hospital laboratory. The patient was treated with sulfadiazine, leucovorin, and pyrimethamine. Three months later (July), he returned for follow-up testing. Real-time polymerase chain reaction (PCR) for T. gondii DNA performed by a reference laboratory was negative. One month later (August), Toxoplasma serology was performed by enzyme-linked immunosorbent assay (ELISA) by a different reference laboratory and showed an elevated IgM of 0.95 IU/mL (reference values: negative; <0.55 IU/mL, equivocal; ≥ 0.55–< 0.65 IU/mL, positive; ≥ 0.65 IU/mL) and a normal level of IgG (<4 IU/mL). At this time, PCR was repeated and was …
Effect of Temporal Acquisition Parameters on Image Quality of Strain Time Constant Elastography

Ultrasound methods to image the time constant (TC) of elastographic tissue parameters have been recently developed. Elastographic TC images from creep or stress relaxation tests have been shown to provide information on the viscoelastic and poroelastic behavior of tissues. However, the effect of temporal ultrasonic acquisition parameters and input noise on the image quality of the resultant strain TC elastograms has not been fully investigated yet. Understanding such effects could have important implications for clinical applications of these novel techniques. This work reports a simulation study aimed at investigating the effects of varying windows of observation, acquisition frame rate, and strain signal-to-noise ratio (SNR) on the image quality of elastographic TC estimates. A pilot experimental study was used to corroborate the simulation results in specific testing conditions. The results of this work suggest that the total acquisition time necessary for accurate strain TC estimates has a linear dependence to the underlying strain TC (as estimated from the theoretical strain-vs.-time curve). The results also indicate that it might be possible to make accurate estimates of the elastographic TC (within 10% error) using windows of observation as small as 20% of the underlying TC, provided sufficiently fast acquisition rates (>100 Hz for typical acquisition depths). The limited experimental data reported in this study statistically confirm the simulation trends, proving that the proposed model can be used as upper bound guidance for the correct execution of the experiments.
Positive and Negative Regulation of Phosphoinositide 3-Kinase-Dependent Signaling Pathways by Three Different Gene Products of the p85α Regulatory Subunit

Phosphoinositide (PI) 3-kinase is a key mediator of insulin-dependent metabolic actions, including stimulation of glucose transport and glycogen synthesis. The gene for the p85α regulatory subunit yields three splicing variants, p85α, AS53/p55α, and p50α. All three have (i) a C-terminal structure consisting of two Src homology 2 domains flanking the p110 catalytic subunit-binding domain and (ii) a unique N-terminal region of 304, 34, and 6 amino acids, respectively. To determine if these regulatory subunits differ in their effects on enzyme activity and signal transduction from insulin receptor substrate (IRS) proteins under physiological conditions, we expressed each regulatory subunit in fully differentiated L6 myotubes using adenovirus-mediated gene transfer with or without coexpression of the p110α catalytic subunit. PI 3-kinase activity associated with p50α was greater than that associated with p85α or AS53. Increasing the level of p85α or AS53, but not p50α, inhibited both phosphotyrosine-associated and p110-associated PI 3-kinase activities. Expression of a p85α mutant lacking the p110-binding site (Δp85) also inhibited phosphotyrosine-associated PI 3-kinase activity but not p110-associated activity. Insulin stimulation of two kinases downstream from PI-3 kinase, Akt and p70 S6 kinase (p70S6K), was decreased in cells expressing p85α or AS53 but not in cells expressing p50α. Similar inhibition of PI 3-kinase, Akt, and p70S6K was observed, even when p110α was coexpressed with p85α or AS53. Expression of p110α alone dramatically increased glucose transport but decreased glycogen synthase activity. This effect was reduced when p110α was coexpressed with any of the three regulatory subunits. Thus, the three different isoforms of regulatory subunit can relay the signal from IRS proteins to the p110 catalytic subunit with different efficiencies. They also negatively modulate the PI 3-kinase catalytic activity but to different extents, dependent on the unique N-terminal structure of each isoform. These data also suggest the existence of a mechanism by which regulatory subunits modulate the PI 3-kinase-mediated signals, independent of the kinase activity, possibly through subcellular localization of the catalytic subunit or interaction with additional signaling molecules.
Optimal foraging and the traveling salesman

Abstract Optimal foraging models are examined that assume animals forage for discrete point resources on a plane and attempt to minimize their travel distance between resources. This problem is similar to the well-known traveling salesman problem: A salesman must choose the shortest path from his home office to all cities on his itinerary and back to his home office again. The traveling salesman problem is in a class of enigmatic problems, called NP-complete, which can be so difficult to solve that animals might be incapable of finding the best solution. Two major results of this analysis are: (1) The simple foraging strategy of always moving to the closest resource site does surprisingly well. More sophisticated strategies of “looking ahead” a small number of steps, choosing the shortest path, then taking a step, do worse if all the resource sites are visited, but do slightly better (less than 10%) if not all the resource sites are visited. (2) Short cyclical foraging routes resulted when resources were allowed to renew. This is suggested as an alternative explanation for “trap-lining” in animals that forage for discrete, widely separated resources.
Effects of temperature on ultrasound production by infant albino rats.

The influence of temperature on production of ultrasonic distress calls by infant Wistar rats was investigated. Call rates of pups aged 2 to 18 days were recorded at ambient levels chosen to provide for a decline in body temperature (2° and 20°C), an increase in body temperature (40°C), and minimal changes in body temperature (35°C). Isolated pups were exposed to each temperature for 4 1/2 min, during which ultrasounds from 30 to 50 kHz were monitored. Low ambient temperatures consistently elicited high rates of ultrasound production, although call rate was not inversely proportional to ambient temperature. High ambient temperatures were ineffective in eliciting increased calling. Calling was infrequent at the neutral temperature, indicating that nonthermal stimuli associated with the isolation condition are relatively ineffective in eliciting ultrasound production. Decline in call rate beyond 8 days of age is apparently related to developing homeothermy which reduces the survival value of distress calls in attracting the mother.
Beyond the Herring Sandwich Phenomenon A Holistic Constructivist Approach to Teacher Education

This article explains how key principles of holistic constructivism were used to revise a graduate teacher education program and develop a portfolio model of evaluation. The program is built around individualized portfolios, applied projects, collaborative work, student evaluation, and professional presentation of student work. Three students in the program discuss how the principles of the revised program and the portfolio process affected their education and their teaching. The authors present strategies for helping teacher education students create innovative educational programs in their schools.
The Constructive, Destructive, and Reconstructive Power of Social Norms

Despite a long tradition of effectiveness in laboratory tests, normative messages have had mixed success in changing behavior in field contexts, with some studies showing boomerang effects. To test a theoretical account of this inconsistency, we conducted a field exper- iment in which normative messages were used to promote householdenergyconservation.Aspredicted,adescriptive normative message detailing average neighborhood usage produced either desirable energy savings or the undesir- able boomerang effect, depending on whether households were already consuming at a low or high rate. Also as predicted, adding an injunctive message (conveying social approval or disapproval) eliminated the boomerang effect. The results offer an explanation for the mixed success of persuasive appeals based on social norms and suggest how such appeals should be properly crafted.
Valuation of tropical rainforests: philosophical and practical issues in the use of contingent valuation

Abstract This paper explores the possibility of using a large scale multi-country contingent valuation study for making decisions concerning global resources in the specific context of valuing a large set of tropical rainforests. Before considering the practical issues involved in implementing such a study, the paper addresses philosophical issues related to the use of contingent valuation including the role of passive use motives such as altruism and the role of information. The implications of empirically based criticisms which argue that contingent valuation results are unreliable are also considered. The main portion of the paper sketches the practical difficulties likely to be encountered in actually implementing a large contingent valuation study in multiple countries which seeks to value a common set of tropical rainforests. Some key study design choices are discussed.
Older Women, Leadership, and Encore Careers

This chapter considers the opportunities for older women to obtain leadership positions in this stage of their lives. In addition, opportunities to reenter the workforce are discussed. These occasions, known as “encore careers,” can provide meaning, as well as an opportunity for leadership. Encore careers can be defined as work in the second half of one’s life that may combine sustained income, greater personal meaning, and social impact. The concept and definition of leadership are introduced, as are the concepts of role models, mentors, and coaches. Specific examples of older women’s leadership and ways of obtaining leadership positions are suggested.