cssi/SciSciGPT-SciSciNet huggingface dataset:
1,3 Dichloro- and 1,3 dibromotetra-n-butyldistannoxane mixtures: ligand redistribution and fluxional dynamics in distannoxanes

Abstract The halogen redistribution reaction in the binary [nBu2SnCl]2O/[nBu2SnBr]2O system is examined by 119Sn- and 13C-NMR spectroscopy. Binary mixtures of [nBu2SnCl]2O and [nBu2SnBr]2O reach equilibrium rapidly at room temperature. The reactant dimers are found to be in equilibrium with all five possible mixed distannoxane dimers in the equimolar mixture. These mixed distannoxane dimers differ in the ratio of Cl and Br as well as the relative positioning of the halogens. The mechanism responsible for the rapid formation of the mixed Cl:Br distannoxane dimers is found to proceed via bimolecular collisions producing a four-centered transition state, which in turn undergoes a concerted exchange of the halogens. The equilibrium concentrations of the reactant and product dimers are well represented by a statistical distribution, indicating that Cl and Br exhibit equivalent donor abilities. At 298 K, the NMR spectral data are consistent with time-averaged structures arising from rapidly interconverting rigid ladder pairs. Lowering the temperature to 173 K failed to freeze out this fluxional process. A reversible configurational rearrangement is also observed in which rotation about the oxygenexocyclic tin bond results in the mutual exchange of halogens associated with the same exocyclic tin atom.
High speed signal processing in a programmable propagation simulator

The real-time channel simulator described is an experimental apparatus designed not only to model a wideband channel, but also as a flexible machine for experimentation on propagation models and effects. The authors describe the signal processing techniques used to model fading phenomena as well as the use of high-speed quadrature signal processing in the front end. The novel features of this simulator include the fully digital means of dividing the in-phase and quadrature inputs and generating quadrature outputs. A large dynamic memory in the computer interface makes it possible to capture input and output data for further analysis, while the fully digital quadrature processing effectively eliminates phase errors and overwrought RF processing. >
Interactions of acid–base balance and hematocrit regulation during environmental respiratory gas challenges in developing chicken embryos (Gallus gallus)

Abstract How the determinants of hematocrit (Hct) – alterations in mean corpuscular volume (MCV) and/or red blood cell concentration ([RBC]) – are influenced by acid–base balance adjustments across development in the chicken embryo is poorly understood. We hypothesized, based on oxygen transport needs of the embryos, that Hct will increase during 1 day of hypercapnic hypoxia (5%CO 2 , 15%O 2 ) or hypoxia alone (0%CO 2 , 15%O 2 ), but decrease in response to hyperoxia (0%CO 2 , 40%O 2 ). Further, age-related differences in acid–base disturbances and Hct regulation may arise, because the O 2 transport and hematological regulatory systems are still developing in embryonic chickens. Our studies showed that during 1 day of hypoxia (with or without hypercapnia) Hct increased through both increased MCV and [RBC] in day 15 (d15) embryo, but only through increased MCV in d17 embryo and therefore enhancement of O 2 transport was age-dependent. Hypercapnia alone caused a ∼14% decrease in Hct through decreased [RBC] and therefore did not compensate for decreased blood oxygen affinity resulting from the Bohr shift. The 11% (d15) and 14% (d17) decrease in Hct during hyperoxia in advanced embryos was because of an 8% and 9% decrease, respectively, in [RBC], coupled with an associated 3% and 5% decrease in MCV. Younger, d13 embryos were able to metabolically compensate for respiratory acidosis induced by hypercapnic hypoxia, and so were more tolerant of disturbances in acid–base status induced via alterations in environmental respiratory gas composition than their more advanced counterparts. This counter-intuitive increased tolerance likely results from the relatively low M ˙ O 2 and immature physiological functions of younger embryos.
Earth science: The enigma of D′′

A phase transition of Earth's most abundant mineral occurs at pressures and temperatures corresponding to those thought to exist just above Earth's core. New experiments shed light on this enigmatic D′′ region.
ADAM12 is a prognostic factor associated with an aggressive molecular subtype of high-grade serous ovarian carcinoma

ADAM metallopeptidase domain 12 (ADAM12) is a promising biomarker because of its low expression in normal tissues and high expression in a variety of human cancers. However, ADAM12 levels in ovarian cancer have not been well characterized. We previously identified ADAM12 as one of the signature genes associated with poor survival in high-grade serous ovarian carcinoma (HGSOC). Here, we sought to determine if high levels of the ADAM12 protein and/or messenger RNA (mRNA) are associated with clinical variables in HGSOC. We show that high protein levels of ADAM12 in banked preoperative sera are associated with shorter progression-free and overall survival. Tumor levels of ADAM12 mRNA were also associated with shorter progression-free and overall survival as well as with lymphatic and vascular invasion, and residual tumor volume following cytoreductive surgery. The majority of genes co-expressed with ADAM12 in HGSOC were transforming growth factor (TGF)β signaling targets that function in collagen remodeling and cell-matrix adhesion. In tumor sections, the ADAM12 protein and mRNA were expressed in epithelial cancer cells and surrounding stromal cells. In vitro data showed that ADAM12 mRNA levels can be increased by TGFβ signaling and direct contact between epithelial and stromal cells. High tumor levels of ADAM12 mRNA were characteristic of the mesenchymal/desmoplastic molecular subtype of HGSOC, which is known to have the poorest prognosis. Thus, ADAM12 may be a useful biomarker of aggressive ovarian cancer for which standard treatment is not effective.
Surface structure, topology, and liquid wetting behavior in oriented polymers

The structure and the properties of oriented polymer surfaces were studied for three series of uniaxially oriented films of polypropylene (PP), polystyrene (PS), and poly(ethylene terephthalate) (PET). The surface structure was characterized in terms of relative crystallinity and molecular orientation along with topology and roughness by using FT-IR-ATR dichroism technique, optical microscopy and surface profilometer. In all three polymers, the surface orientation function increases with draw ratio. The relative surface crystallinity and the trans con-former also increases for PP and PET, respectively. In uniaxially drawn PP, the surface becomes rough with increasing draw ratio and the roughness is anisotropic with peaks and valleys elongated along the draw direction. For drawn PP, the equilibrium contact angles for four different liquids all exhibit anisotropy with higher values in perpendicular direction than that in parallel to the draw direction. In contrast, both drawn PET and PS films show smooth surfaces, and the equilibrium contact angles were all isotropic. When roughness is removed from the drawn PP by polishing without altering the molecular orientation, the anisotropy becomes negligible and the contact angles approach the value for undrawn PP. When surface roughness was created deliberately on undrawn PET and PS films, the contact angle anisotropy was clearly observed. Therefore, the anisotropy in surface topology rather than the molecular orientation seems to play a dominant role in developing anisotropic wetting behavior. The equilibrium contact angles for smooth surfaces have been calculated using the experimentally obtained roughness and anisotropic contact angle data from the rough surface. These values are in reasonable agreement with the measured contact angles for smooth surfaces, suggesting that the observed contact angle anisotropy can be attributed entirely to the roughness anisotropy rather than to the molecular orientation.
Microelectromechanical K-Band Switching Circuits

Two single-pole single-throw (SPST) K-band circuit designs incorporating low-loss microelectromechanical systems (MEMS) microwave shunt switches are reported. DC measurements indicate actuation voltages in the order of 20 V with an on-to-off capacitance ratio of 30. RF measurements show an isolation between the input port ad the output arm with the switch in the order of better than 15 dB across most of the frequency band. Insertion loss was measured at ?0.4 dB at 18 GHz and ?0.7 dB at 34 GHz for the two respective designs.
Nosocomial Antibiotic-Associated Diarrhea Associated with Enterotoxin-Producing Strains of Methicillin-Resistant Staphylococcus Aureus

Nosocomial Antibiotic-Associated Diarrhea Associated with Enterotoxin-Producing Strains of Methicillin-Resistant Staphylococcus Aureus
Vortex breakdown in channel flow transition

The time-dependent three-dimensional incompressible Navier-Stokes equations are used to study the mechanisms and developing structures comprising the later stages of the transition to turbulence in plane channel flow. Computer animated flow visualizatons are employed using three-dimensional vortex lines and other graphical representations. The flow visualizations clearly show the development of organized structures such as vortex loops, horse-show vortices, and vortex rings. It is noted that the development of these structures is similar to the bursting process found in turbulent channel flow.
Nd:YAG laser transurethral evaporation of the prostate (TUEP) for urinary retention.

Background and Objective Little information is available regarding the effectiveness of laser prostatectomy in patients with urinary retention from benign prostatic hyperplasia since there is no paper specifically dealing with laser prostatectomy in patients in urinary retention. Study Design/Materials and Methods Twenty two unselected consecutive patients presenting with urinary retention due to benign prostatic hypertrophy underwent transurethral evaporation of the prostate (TUEP) using a neodymium:YAG laser and total internally reflecting side-firing free beam quartz fiber. All patients failed at least one voiding trial and averaged >30 days of urinary catheter drainage preoperatively. A contact evaporation technique was used to evaporate a “TURP-like” channel in the prostatic fossa by means of a series of parallel evaporation troughs. Results Eighteen of 22 patients completed 6 months of follow up. Two patients were lost to follow up and two failed TUEP. The average AUA score dropped from 26 to 9 at 1 month and to 3.4 by 6 months postoperatively. All patients who successfully underwent TUEP were urinating spontaneously by 10 days. Average time to catheter removal was 3.5 days. Maximal uroflow was 15.7 ml/sec at 1 month and 20.3 ml/sec by 6 months. Postvoid residual preoperatively averaged 784 ml and decreased to 76 ml by 1 month. Pre- and postoperative hematocrit and serum sodium values did not vary by more than 5%. Conclusion From this preliminary series we conclude that aggressive evaporation of prostatic tissue is feasible endoscopically and provides a reliable method of near bloodless removal of tissue. © 1996 Wiley-Liss, Inc.
Process and content in an outpatient schizophrenic group

Process and content issues were evaluated during the first six months of an outpatient schizophrenic group. Compared with groups composed of neurotic and characterological patients, the schizophrenic group scored higher in the Avoiding dimension of the Group Climate Questionnaire (GCQ-S). There was more cohesion and less interpersonal conflict as time went on. Although topics related to engagement and differentiation were discussed, there was no obvious GCQ-S evidence of these first two stages of group development. However, the data supported the presence of stage 3 (individuation) during sessions 20–26. Interpersonal topics dominated the group discussions, followed by issues involving reality-testing, expression of emotions, and advice-giving.
Effects of Elevated Temperature on Guided-wave Structural Health Monitoring

Elevated temperatures can cause significant changes in guided-wave (GW) propagation and transduction for structural health monitoring (SHM). This work focuses on GW SHM using surface-bonded piezoelectric wafer transducers in metallic plates for the temperature range encountered in internal spacecraft structures (20—150°C). First, studies done to determine a suitable bonding agent are documented. This is then used in controlled experiments to examine changes in GW propagation and transduction using PZT-5A piezoelectric wafers under quasi-statically varying temperature (also from 20 to 150°C). Modeling efforts to explain the experimentally observed increase in time-of-flight and change in sensor response peak-to-peak magnitude with increasing temperature are detailed. Finally, these results are used in detection and location of mild and moderate damage using the pulse-echo GW testing approach within the temperature range.
Electronic vs. Print Reference Sources in Public Library Collections

Summary The evolution of electronic sources has had a significant impact on reference collections in libraries, and public library reference collections are no exception. Evaluating, selecting, and organizing sources to meet the needs of public library users has always been a fundamental role of public librarians. However, now they have the added responsibility of evaluating electronic resources and deciding whether the electronic sources will supplement or replace traditional paper reference sources. Issues of authority, accessibility, cost, comfort, and user education must be carefully weighed during this evaluative process.
Grazing Incidence Synchrotron X-ray Diffraction of Polymerizing Langmuir Monolayers

Octadecyltrimethoxysilane (OTMS) was spread on the water surface of a Langmuir trough. Utilizing the high-intensity synchrotron X-ray radiation at the Advanced Photon Source at Argonne National Laboratory, the kinetics of film growth of OTMS as a function of the subphase pH was studied. In situ grazing incidence X-ray diffraction experiments at the air/water interface revealed that OTMS self-assembles into small domains and that the number of these ordered domains increases as OTMS undergoes hydrolysis/condensation reactions. The hexagonal packing of alkyl chains found in the OTMS monolayer is consistent with the ordering found in bulk OTMS by powder X-ray diffraction.
The rice homolog of the sodium/lithium tolerance gene functions as molecular chaperon in vitro

The sodium/lithium tolerance gene previously isolated from Arabidopsis thaliana (AtSLT1) and Nicotiana tabacum (NtSLT1) has been implicated in the regulation of ion homeostasis via the CaN and SPK1/Hal4 signal transduction pathways. A homologous gene from rice (OsSLT1) encoded by an intronless open-reading frame (1563 bp) on chromosome-1 was studied. The 58-kDa OsSLT1 protein contains a highly conserved C-terminal domain characteristic of the small heat-shock protein (smHSP) and α-crystallin classes of molecular chaperons. Biochemical analysis of recombinant full-length, N-terminal-truncated (lacking aa-1 to aa-217), and C-terminal-truncated (lacking aa-443 to aa-521) versions of OsSLT1 indicated that removal of the C-terminal extension enhances chaperon activity as shown by the ability of the truncated protein to prevent thermal and non-thermal aggregation of client proteins in an ATP-independent manner. The C-terminal-truncated OsSLT1 also enhanced thermotolerance of recombinant Escherichia coli. Unlike the smHSPs, which are transcriptionally activated during stress, the activity of SLT1 appears to be modulated via complex mechanisms of protein cleavage. The implication of the results in relation to the immediate cellular defenses against protein denaturation during stress and to the previously demonstrated role of SLT1 in the CaN and SPK1/Hal4 signaling pathways is discussed.
Animal models of human-derived cancer vaccines

Preclinical cancer vaccine studies must address vaccine safety, immunogenicity, and efficacy, as well as mechanism of vaccine action. Animal models of vaccines employing human tumor-associated antigen or epitopes (TAA, TAE) differ fundamentally from those employing tumor-specific antigens or epitopes (TSA, TSE). TSA and TSE vaccines will most likely demonstrate similar toxicity, immunogenicity, and efficacy in both tumor-bearing animals and patients. In contrast, TAA/TAE immunizations may have to overcome a host’s immunological tolerance to TAA/TAE expressed not only on tumor, but also on normal tissues; immunity to TAA/TAE will potentially target normal tissues and thus may induce autoimmunity. Various experimental models for human-derived TAA/TAE vaccines have been developed. These models include transgenic mice, mice with severe combined immunodeficiency (SCID), and non-human primates. Recently, unique animal models of TAA/TAE cancer vaccines have been developed, taking advantage of the discovery of animal tissue antigens with significant sequence homologies to human TAA/TAE. These models mimic perhaps most closely the situation in cancer patients.
Spontaneous Rupture of a Peripheral Artery: Report of Case

The case history of a patient with apparent spontaneous rupture of the posterior tibial artery is presented, with a brief review of the previously reported cases.
Two-dimensional electrophoretic analysis of the regulation of SOS proteins in three ssb mutants.

A previously undescribed mutation in the ssb gene, which codes for a major single strand DNA binding protein essential for DNA repelication, was mapped on the Escherichia coli Chromosome. Three ssb mutants were analyzed under parallel physiological conditions for the induction of SOS proteins (products of recA, uvrA, and an unknown gene), the production of mutants, the induction of lambda prophage, and sensitivity to DNA damaging agents. Two-dimensional electrophoretic techniques were used to quantitate changes in the rate of synthesis of proteins. The previously unpublished position of the uvrA gene-product in the two-dimensional matrix of E. coli proteins was described. These ssb strains exhibited varying sensitivities to ultraviolet irradiation and methylmethane sulfonate that correlated with the rate of constitutive synthesis of SOS proteins, spontaneous commitment to virulent growth of lambda lysogens, and elevation of endogenous mutation rates.
Characterization of Kaolinite ζ Potential for Interpretation of Wettability Alteration in Diluted Bitumen Emulsion Separation

Initial processing of Athabasca oil sands obtained from the water-based extraction process yields stable water-in-bitumen emulsions. When the bitumen is diluted with naphtha to reduce its viscosity...
Spectroscopic measurements of Rosseland mean opacity

Abstract The first quantitative measurement of photoabsorption in the region determining Rosseland and Planck mean opacity, is obtained for an x-ray heated iron plasma, using novel techniques and instrumentation. The plasma density of 0.0113 ± 0.0013 g/cm3 and temperature of 59 ± 3 eV are accurately constrained experimentally by imaging plasma expansion and observing and modeling absorption in sodium dopant ions. The measured iron absorption spectrum is compared with several newly developed opacity models. The data constrains Rosseland and Planck group means with of order 15% precision. This is the first quantitative experimental certification of opacity models germane to radiative transfer in LTE plasmas.
Aerial spray cleaning of high voltage insulators

Abstract A parametric study is carried out on cleaning of standard-type high-voltage outdoor insulators by air-particle spray. Statistical analysis of the resulting insulator conductivities shows that corn cob particles are more effective than walnut shell particles in agreement with the basic principles of air-particle flow. Specifically, the smaller size and the flatter and bulkier shape of the corn cob particles enhance aerodynamic drag and give rise to higher particle spray velocities. More contaminants are removed from insulator surface because of the resulting higher particle kinetic energy. Nozzle size and orientation also significantly reduce the insulator conductivity through optimum combination of particle mass flow rate and particle velocity and through particle ricochet effect.
Compressive sensing network inference with multiple-description fusion estimation

We have previously introduced Multiple Description Fusion Estimation (MDFE) framework that partitions a large-scale Under-Determined Linear Inverse (UDLI) problem into smaller sub-problems that can be solved independently and in parallel. The resulting estimates, referred to as multiple descriptions, can then be fused together to compute the global estimate [1]. In this paper, we extend MDFE framework to make it compatible with Compressive Sensing (CS) network inference, where the attributes of interests (i.e. unknowns) are fluctuating rapidly over time and/or space. For this purpose, we propose a new clustering based technique to intelligently divide a large-scale compressive sensing problem into smaller sub-problems where observations between sub-spaces contain redundancy. We apply this new framework, referred to as Compressive Sensing MDFE (CS-MDFE), to three classical inference problems in networking: traffic matrix estimation, traffic matrix completion, and loss inference. Using real topologies and traces, we demonstrate how CS-MDFE can improve the estimation accuracy and speed up computation time, and how it enhances robustness against noise and failures. We also show that this framework is compatible with different CS inference techniques.
The Staff of Life: Wheat and ‘Indian Bread’ in the New World

Beginning with Columbus, the image of the Americas as a paradise became commonplace in European narratives. A key feature of this perception was the image of a natural world filled with countless e...
Localization of adipose tissue embedded biliary tree vessels by use of near-infrared diffuse photon propagation models: a computational feasibility study

Biliary tree structures are embedded in adipose tissue and, therefore, cannot be visualized directly by the surgeon during cholecystectomy operations. This can lead to inadvertent injuries with serious complications for the patient. Computational studies were performed to assess the feasibility of noninvasively localizing these structures from spectrally resolved near-infrared reflectance measurements. Methodologies were developed for vessel localization, both on the adipose tissue surface and depthwise, by use of semi-infinite and two-layer models of diffuse photon propagation in tissues, respectively. The simulation results, along with some preliminary experimental measurements on tissue-simulating phantoms, prove the feasibility of these methods and show promise for their future clinical application.
On achieving balanced power consumption in software pipelined loops

While a significant body of work in compilers has been devoted to reducing energy consumption in embedded systems, the role of a compiler in harnessing the power variation has not been widely explored. Since sharp power variations across time steps cause power supply noises and degrade reliability of functional blocks, power variation is a design constraint in embedded systems. With the advent of high performance embedded systems and extensive deployment of fine grain clock-gating, reducing variations in power is becoming increasingly important.This paper studies how compilation techniques, more specifically instruction scheduling, can ameliorate variations in power due to functional units during program execution. By extending our previous work on rate-optimal software pipelining, this paper formulates the problem of constructing a performance-optimal schedule that minimizes power variations as an integer linear programming (ILP) problem. The formulation can be solved using an ILP solver. We applied our approach on SPEC NAS benchmarks to construct software pipelined schedules that have minimum power variations. The benchmarks are executed on the Wattch power simulator. In comparison to the original (power-unaware) scheduler implemented in the MIPSpro compiler, our power-aware approach generates schedules which have significantly lower power variations while maintaining the same performance. Such schedules have the potential to reduce hardware cost on power delivery in designing embedded systems.
Physical theories in Galilean space-time and the origin of Schrödinger-like equations

Abstract A method to develop physical theories of free particles in space-time with the Galilean metric is presented. The method is based on a Principle of Analyticity and a Principle of Relativity, and uses the Galilei group of the metric. The first principle requires that state functions describing the particles are analytic and the second principle demands that dynamical equations for these functions are Galilean invariant. It is shown that the method can be used to formally derive Schrodinger-like equations and to determine modifications of the Galilei group of the metric that are necessary to fullfil the requirements of analyticity and Galilean invariance. The obtained results shed a new light on the origin of Schrodinger’s equation of non-relativistic quantum mechanics.
High-Productivity, Low-Cost, Gas Turbine System Modeling Software

Honeywell Engines Systems & Services has written Fast Accurate Simulation of Turbine engines (FAST), a gas turbine system modeling program. Software design and development concepts, capabilities, and improved problem solving using FAST are discussed. Software design emphasis was placed on improving an engineer’s productivity, being easy to learn and use, adding new capability, and having low development and maintenance costs. Capability to replace all legacy modeling software, and make conversion of old models to the new model format simple was also required. The result was a significant increase in the productivity of the performance engineering staff in their efforts to support the design, development, and production, of gas turbine engines. FAST has provided the performance engineering staff with a simple but powerful input language and a robust numerical solver. With FAST, the user can perform preliminary engine design, model steady-state and transient off-design conditions, perform test data analysis, perform system modeling (multiple engine, installations, and engine/vehicle), connect FAST to other software, and generate customer programs quickly with auto-code features. FAST has permitted significant orders of magnitude increase in the volume of cycle analysis coupled with a 70% reduction in engineering staff and an 80% reduction in software development staff.Copyright © 2005 by ASME
Lattice basis reduction, Jacobi sums, and hyperelliptic cryptosystems

Using the LLL-algorithm for finding short vectors in lattices, we show how to compute a Jacobi sum for the prime field Fp in Q(e2πi/n) in time O(log3p), where n is small and fixed, p is large, and p = 1 (mod n). This result is useful in the construction of hyperelliptic cryptosystems.
Effects of zinc on markers of glutamate and aspartate neurotransmission in rat hippocampus.

Receptor binding and synaptosomal uptake ofl-[3H]glutamate andl-[3H]aspartate were measured in hippocampus derived from rats maintained on zinc restricted diets from weaning. Despite near lethal zinc deficiency, these markers of excitatory amino acid neurotransmission were unaffected compared to zinc-supplemented controls. However, addition of zinc in vitro markedly inhibited binding of glutamate and aspartate to hippocampal membranes. These data suggest that zinc can modulate the receptor affinities for glutamate and aspartate and may function as a tonic inhibitor of excitatory synapses in vivo.
Business conditions, monetary policy, and expected security returns

Abstract We examine the evidence that expected security returns can be forecasted by the term premium, default premium, and dividend yield, in light of recent findings that similar security return patterns are associated with Federal Reserve monetary policy developments. We extend Fama and French's (1989) analysis by suggesting that the monetary environment influences investors' required returns, and hence the robustness of the models they propose. Our findings indicate that Fama and French's results vary dramatically across monetary environments; that is, the behavior of the business-conditions proxies and their influence on expected security returns is significantly affected by the monetary sector.
Nonequilibrium patterns of cholesterol-rich chemical heterogenieties within single fluid supported phospholipid bilayer membranes.

We have developed a simple method to introduce cholesterol- and sphingomyelin-rich chemical heterogeneities into controlled densities and concentrations within predetermined regions of another dist...
The structure of carbon filaments and associated catalytic particles formed during pyrolysis of natural gas in steel tubes

New information is presented on the structure and growth of carbon filaments formed in association with catalytic metal or metal carbide particles during pyrolysis of natural gas. The structures of the filaments and of the particles have been examined by transmission electron microscopy. The filaments are hollow, ~0.1 μm or less in diameter, and vermicular as opposed to straight. The graphite basal planes are frequently not parallel to the axis of the filament. Individual catalyst particles have been identified as (Fe,Cr)23C6 when pyrolysis occurs in a stainless steel tube and as γ-iron in a plain carbon steel tube.
POSTEXPOSURE CHEMOPROPHYLAXIS FOR OCCUPATIONAL EXPOSURE TO HIV IN THE DENTAL OFFICE

Occupational exposure to HIV continues to be a concern for health care workers. Preventing exposure through the use of universal precautions is the primary means of protection. New Public Health Service interagency work group recommendations for postexposure chemoprophylaxis provide information to help manage occupational exposure to HIV.
A new isolation method for rat intraepithelial lymphocytes

Intraepithelial lymphocytes (IELs) play critical roles in gut immunity. In mice, gammadelta T cells are a large component of the IEL population. In the rat, gammadelta IELs are reportedly much less common, but technical issues suggest that previous analyses should be interpreted cautiously. The study of IELs in rats has been impeded by isolation procedures that are lengthy and complex, leading to small cell yields. For this reason, it is possible that rat IELs analyzed in previous studies have not been representative of the entire IEL compartment. We report a new method for the isolation of rat IELs that is based on the selective removal of intestinal epithelial cells under conditions that leave the basement membrane undisturbed. The method is rapid and requires neither enzymatic digestion, nor surgical removal of Peyer's patches, nor vigorous mechanical manipulation of the intestine. The yield of rat IELs using this method is 5- to 10-fold greater than that reported for other methods. Morphological and phenotypic analyses demonstrated that the purified cell population is comprised of IELs and is not contaminated with lamina propria or Peyer's patch lymphocytes. Phenotypic analysis revealed five major subsets of IELs based on differential cell surface expression of CD4, CD8, and alphabeta T cell receptor (TcR). Among the alphabetaTcR- cells was a population of gammadelta T cells present at levels not previously detected. The isolation of IEL sub-populations using this methodology should facilitate studies of the function of these cells in gut immunity.
The motions of algebraic differential equations

On considere l'equation (1): P(x, y(x), y'(x))=0 sur un intervalle ouvert ICR. Il existe une equation Q(x, φ(x), φ'(x), φ''(x))=0 qui est satisfaite par tout mouvement C 2 φ de (1) pour laquelle il existe une solution C 1 y pour laquelle y0φ n'est pas une constante sur un sous intervalle de I
Wing aerodynamic loading caused by jet-induced lift associated with STOL-OTW configurations

Surface pressure distributions were obtained with model-scale STOL-OTW configurations using various nozzles designed to promote flow attachment to the wing/flap surface. The nozzle configurations included slot-types and both circular and slot nozzles with external flow deflectors. The wing aerodynamic loading caused by the jet-induced lift is presented in conventional terms of delta p/q as a function of chordwise surface distance in the nozzle centerline plane as well as outboard of the nozzle centerline. Nozzle roof/deflector angle, chordwise location of the nozzle, wing size, and flap deflection angle are included in the geometric variables affecting the wing loading.
One-body, collective contributions to parity mixing in compound nuclear states.

One-body contributions to parity mixing in compound nuclear states are discussed, with reference to the recent polarized neutron transmission experiments. The role of the {ital J}=0{sup {minus}} giant spin-dipole resonance as a mediator of parity mixing in complex nuclear states is pointed out, and an expression of the parity violating spreading width derived. The collective nature of the mixing mechanism is stressed, and an analogy with isospin mixing in nuclei is drawn.
Differences in Earnings among Black and White African Immigrants in the United States, 1980–2000: A Cross-Sectional and Temporal Analysis:

This study examines the earnings of African immigrants across three waves of U.S. Census data (1980, 1990, and 2000). The authors find that the U.S. labor market favors White male immigrants, followed by Black male and White female immigrants, and finally Black women. The authors also find that male immigrants earned more per hour than female immigrants regardless of race. Considering change over time, this study finds that the earnings gap between Black and White male immigrants is growing larger over time, the positive association between foreign work experience and earnings is attenuated over time, and for women, the positive effect of earning a college degree on earnings is growing stronger over time. These findings confirm many of the conclusions reached by other race and gender scholars; however, the authors extend this work by focusing on male and female African immigrants, who are largely under-represented in the literature, and by examining change over time.
Method of cold saline storage for prehospital induced hypothermia.

Objective. Research over the last decade has supported the use of cold intravenous (IV) fluid as a method for initiating therapeutic hypothermia in post–cardiac arrest resuscitation. However, preho...
Infection and development of Phoma medicaginis on moderately resistant and susceptible alfalfa genotypes

In North America, spring black stem and leaf spot, caused by Phoma medicaginis, is one of the most important diseases of alfalfa (Medicago sativa). Symptoms appear initially as small, dark brown to black spots that eventually enlarge and on leaves the spots are associated with chlorosis and defoliation. The infection process of P. medicaginis was previously investigated on susceptible alfalfa genotypes, but little is known about this process with alfalfa plants with differing degrees of resistance. We used light and scanning electron microscopy to follow infection and development of P. medicaginis from pycnidiospore deposition on leaf surfaces through pycnidia formation on selected susceptible and resistant alfalfa genotypes from the USDA core collection. In both old and young leaves, spore germination, penetration, development of mycelium, and pycnidia formation were delayed by approximately 24 h on moderately resistant alfalfa genotypes compared with susceptible genotypes. A similar delay in visible symptom development occurred until about 192 h after inoculation, after which the amount of chlorosis in all genotypes was similar.
A rational process for the reform of the physician payment system.

UNLABELLED Analysis of the resource-based relative value scale (RBRVS) for physician payment indicates that in 1996, hourly reimbursement rates will be unrelated to the intensity of work and income will be unrelated to hours worked. A "consensus method" of payment is proposed as an alternative to the RBRVS. METHOD As with the method of the RBRVS study, a pilot survey asked a specialty-representative cohort of physicians to assign dimensionless numbers to the relative value of work in 15 specialties using the Hsiao et al. definition of work intensity as "time modified by, a) mental effort, b) clinical judgment, c) technical skill, and d) physical effort under stress." The consensus method is similar to that of the Hsaio method, except there is no mathematical transformation of the raw data to establish specialty work values once the data are collected. A comparative analysis was then made of work hours, reimbursement rates, and annual income with 1) the customary prevailing and reasonable system (CPR, pre-1992), 2) the RBRVS system (1996), and 3) the proposed consensus system. RESULTS The RBRVS intends that physicians be reimbursed on the basis of time and intensity of work. Neither the CPR nor the RBRVS systems accomplish this objective when the data and computational methods of the Physician Payment Review Commission are used with independently determined work intensity to compute hourly reimbursement rates in the specialties. The consensus method shows the desired direct linear correlation of income with both length of the physician's work week and intensity of effort. It rates the primary care specialties as a group more highly than the RBRVS. CONCLUSION The proposed consensus method meets the original intent of the RBRVS to reimburse physicians on the basis of the resource input of time as modified by the criteria of Hsiao et al.
Lipoxygenase-catalyzed oxidation of linolenic acid at subfreezing temperatures

Abstract Samples containing linolenic acid, potassium borate buffer, and lipoxygenase were frozen at two different rates to −78.5 °C, then reacted at temperatures of −5, −10, or −15 °C. Oxidation products of linolenic acid (hydroperoxides) were determined at various times by measuring the absorbance of thawed samples at 234 nm. The ultimate accumulation of oxidation products of linolenic acid decreased with decreasing temperature. Ultimate values obtained at −5, −10, and −15 °C represented, respectively, 73, 59, and 47% of the ultimate value obtained at 0 °C. The two freezing rates studied had no effect on ultimate accumulation of oxidation products of linolenic acid at −5, −10, or −15 °C. The relationship between ultimate accumulation of oxidation products and subfreezing storage temperature cannot be explained on the basis of greater irreversible denaturation of lipoxygenase as the subfreezing temperature was lowered. The pattern of decreased ultimate accumulation of product as the subfreezing temperature was lowered can perhaps be attributed to: (i) progressively greater reversible denaturation of the enzyme as the subfreezing temperature was lowered, and/or (ii) progressive increases in resistance to diffusion of substrate and reaction products as the subfreezing temperature was lowered.
Bi)sulfate adsorption on quasiperfect Pt(111) facets from acidic aqueous electrolytes as monitored by optical techniques

The adsorption of (bi)sulfate on quasiperfect Pt(111) facets was monitored by simultaneous reflectance spectroscopy (RS) and second harmonic generation (SHG) while scanning the potential linearly b...
Viability of Escherichia Coli on English Walnut Meats (Juglans regia)

SUMMARY The effect of walnut meats on Escherichia coli viability was evaluated. Water-washed and unwashed English walnut meats were immersed in E. coli suspension under controlled conditions. Meats were dried at room temperature, packed in plastic bags in 50-g quantities, and stored under various conditions at room temperature and in the cold. Periodic examination of meats by bag over eight months revealed the following. The E. coli population was reduced 99% during two days of drying on unwashed substrate, but not on washed substrate. On the one hand, both unwashed and washed nuts stored at room temperature failed to show any E. coli after three and four months storage respectively; on the other hand, there was no significant loss of E. coli viability on either unwashed or washed nuts stored in the cold up to 240 days. The effect of walnut tannin extract on E. coli was determined. This effect was greater on cells suspended in saline than on cells suspended in 0.1% peptone water. In 0.9% saline, 1 × 107 cells were killed at 0.62% walnut tannin concentration and 1 × 106 cells at 0.1670, both within 1 hr, whereas 2.5% tannin concentration was required to kill 1 × 107 cells in 0.1% peptone water within 2 hr. The reliability of E. coli as the index organism to detect insanitation in English walnut meats is discussed.
Excellent online friendships: an Aristotelian defense of social media

I defend social media's potential to support Aristotelian virtue friendship against a variety of objections. I begin with Aristotle's claim that the foundation of the best friendships is a shared life. Friends share the distinctively human and valuable components of their lives, especially reasoning together by sharing conversation and thoughts, and communal engagement in valued activities. Although some have charged that shared living is not possible between friends who interact through digital social media, I argue that social media preserves the relevantly human and valuable portions of life, especially reasoning, play, and exchange of ideas. I then consider several criticisms of social media's potential to host friendships, and refute or weaken the force of these objections, using this conception of a distinctively human shared life. I conclude that we should use the shared life to evaluate features of social media and norms for users' conduct.
Multi-Frequency Time-Division multiple-access (MF-TDMA) resource packing

Multi-Frequency Time-Division (MF-TDMA) techniques allow a large community of users to share bandwidth efficiently. Resources can be allocated based on user demands and user capabilities. The resources allocated to each individual user must be packed together in the spectrum available to the system while maintaining certain constraints based on user capabilities. Increasing the resource packing efficiency directly increases system bandwidth efficiency. This paper describes the MF-TDMA packing problem, defines a packing algorithm, and evaluates the packing performance under various scenarios.
Eye Movement Preparation Modulates Neuronal Responses in Area V4 When Dissociated from Attentional Demands

We examined whether the preparation of saccadic eye movements, when behaviorally dissociated from covert attention, modulates activity within visual cortex. We measured single-neuron and local field potential (LFP) responses to visual stimuli in area V4 while monkeys covertly attended a stimulus at one location and prepared saccades to a potential target at another. In spite of the irrelevance of visual information at the saccade target, visual activity at that location was modulated at least as much as, and often more than, activity at the covertly attended location. Modulations of activity at the attended and saccade target locations were qualitatively similar and included increased response magnitude, stimulus selectivity, and spiking reliability, as well as increased gamma and decreased low-frequency power of LFPs. These results demonstrate that saccade preparation is sufficient to modulate visual cortical representations and suggest that the interrelationship of oculomotor and attention-related mechanisms extends to posterior visual cortex.
Low-density lipoprotein receptor-related protein 1: A physiological Aβ homeostatic mechanism with multiple therapeutic opportunities

Low-density lipoprotein receptor-related protein-1 (LRP1) is the main cell surface receptor involved in brain and systemic clearance of the Alzheimer's disease (AD) toxin amyloid-beta (Aβ). In plasma, a soluble form of LRP1 (sLRP1) is the major transport protein for peripheral Aβ. LRP1 in brain endothelium and mural cells mediates Aβ efflux from brain by providing a transport mechanism for Aβ across the blood-brain barrier (BBB). sLRP1 maintains a plasma 'sink' activity for Aβ through binding of peripheral Aβ which in turn inhibits re-entry of free plasma Aβ into the brain. LRP1 in the liver mediates systemic clearance of Aβ. In AD, LRP1 expression at the BBB is reduced and Aβ binding to circulating sLRP1 is compromised by oxidation. Cell surface LRP1 and circulating sLRP1 represent druggable targets which can be therapeutically modified to restore the physiological mechanisms of brain Aβ homeostasis. In this review, we discuss how increasing LRP1 expression at the BBB and liver with lifestyle changes, statins, plant-based active principles and/or gene therapy on one hand, and how replacing dysfunctional plasma sLRP1 on the other regulate Aβ clearance from brain ultimately controlling the onset and/or progression of AD.
Effect of Endurance Training on Glycerol Kinetics During Strenuous Exercise in Humans

Glycerol kinetics were evaluated during high-intensity exercise in five untrained and five endurance-trained subjects. Glycerol rate of appearance (Ra) in plasma was determined by infusing [2H5]glycerol during rest and 60 minutes of cycle ergometer exercise performed at 70% V02 peak. Mean plasma glycerol concentration was greater in trained than untrained subjects throughout exercise (P<.05). The average glycerol Ra during exercise and the integrated lipolytic response to exercise, expressed as total glycerol Ra above baseline, were both greater in trained (7.85 +/- 0.72 micromol x kg(-1) x min(-1) and 289 +/- 50 micromol x kg(-1) x h(-1), respectively) than in untrained (5.68 +/- 0.90 micromol x kg(-1) x min(-1), and 198 +/- 31 micromol x kg(-1) x h(-1), respectively) subjects (P<.05). We conclude that whole-body lipolytic rates are greater in endurance-trained athletes than in sedentary controls during high-intensity exercise performed at the same relative intensity.
Simulation of reactive nanolaminates using reduced models: II. Normal propagation

Abstract Transient normal flame propagation in reactive Ni/Al multilayers is analyzed computationally. Two approaches are implemented, based on generalization of earlier methodology developed for axial propagation, and on extension of the model reduction formalism introduced in Part I. In both cases, the formulation accommodates non-uniform layering as well as the presence of inert layers. The equations of motion for the reactive system are integrated using a specially-tailored integration scheme, that combines extended-stability, Runge–Kutta–Chebychev (RKC) integration of diffusion terms with exact treatment of the chemical source term. The detailed and reduced models are first applied to the analysis of self-propagating fronts in uniformly-layered materials. Results indicate that both the front velocities and the ignition threshold are comparable for normal and axial propagation. Attention is then focused on analyzing the effect of a gap composed of inert material on reaction propagation. In particular, the impacts of gap width and thermal conductivity are briefly addressed. Finally, an example is considered illustrating reaction propagation in reactive composites combining regions corresponding to two bilayer widths. This setup is used to analyze the effect of the layering frequency on the velocity of the corresponding reaction fronts. In all cases considered, good agreement is observed between the predictions of the detailed model and the reduced model, which provides further support for adoption of the latter.
Dietary fluoride; the effect of maternal ingestion on offspring.

Dr. Burt, with a background of Australian education, was asked to take a “tough,” but objective look at the supplementation of the mother's diet with fluoride to prevent dental caries in her offspring.