cssi/SciSciGPT-SciSciNet huggingface dataset:
Neurotoxicology in the 1990s

During the last ten years, neurotoxicology has entered the mainstream of environmental toxicology as evidenced by numerous national and international conferences, formation of societies related to neurotoxicology, establishment and support of journals devoted to neurotoxicology and reliance of regulatory agencies on neurotoxicological endpoints. Over the last ten years, agreement seems to have been reached concerning the need for and use of neurotoxicological tests for hazard identification. With regard to the future of neurotoxicology, there are a number of important issues that deserve attention, including 1) arriving at a commonly accepted definition of neurotoxicology, 2) the impact of new technology, 3) development of biological markers for neurotoxicology, 4) neurotoxicology of chemical mixtures, 5) relationship between environmental agents and neurodegenerative diseases, 6) use of in vitro procedures in neurotoxicology, 7) risk assessment and 8) development of database for specific neurotoxicants. The last ten years have been productive ones for neurotoxicology. The next ten years should mark a new phase of development marked by significant progress in a number of important areas in environmental toxicology.
Kinetic characterization of Na,K-ATPase inhibition by Eosin

Abstract Eosin is a probe for the Na pump nucleotide site. In contrast to previous studies examining eosin effects on Na only ATPase, we examined Na,K-ATPase- and K-activated pNPPase activity in red blood cell membranes and purified renal Na,K-ATPase. At saturating ATP (3 mM) the eosin IC 50 for Na pump inhibition was 19 μM. Increasing ATP concentrations (0.2–2.5 mM) did not overcome eosin-induced inhibition, thus eosin is a mixed-type inhibitor of ATPase activity. To test if eosin can bind to the high-affinity ATP site, purified Na,K-ATPase was labeled with 20 μM FITC. With increasing eosin concentrations (0.1 μM–10 μM) the incorporation of FITC into the ATP site significantly decreases suggesting that eosin prevents FITC reaction at the high-affinity ATP site. Eosin was a more potent inhibitor of K-activated phosphatase activity than of Na,K-ATPase activity. At 5 mM pNPP the eosin IC 50 for Na pump inhibition was 3.8 ± 0.23 μM. Increasing pNPP concentrations (0.45–14.5 mM) did not overcome eosin-induced inhibition, thus eosin is a mixed-type inhibitor of pNPPase activity. These results can be fit by a model in which eosin and ATP bind only to the nucleotide site; in some pump conformations, this site is rigid and the binding is mutually exclusive and in other conformations, the site is flexible and able to accommodate both eosin and ATP (or pNPP). Interestingly, eosin inhibition of pNPPase became competitive after the addition of C 12 E 8 (0.1%) but the inhibition of ATPase remained mixed.
Epigenetic regulation of the estrogen receptor alpha promoter in the cerebral cortex following ischemia in male and female rats.

Permanent middle cerebral artery occlusion (MCAO) causes neuronal cell death in the striatum and cortex. In rodents, estradiol treatment protects the cortex from cell death in an estrogen receptor alpha (ERα) dependent manner. ERα is only transiently expressed in the cortex during neonatal development and is very low in uninjured adult cortex. Following MCAO, ERα mRNA expression is upregulated in the cortex of female rats, but the mechanism of this increase is still unknown. It is also unknown whether a similar increase in ERα expression in seen in males. In the following studies, male and vehicle or estradiol-treated ovariectomized (OVX) female rats underwent MCAO to investigate the regulation of ERα expression after ischemia. 24 hours after surgery, mRNA or genomic DNA was collected from 1mm micropunches taken from 300µm brain sections for quantitative RT-PCR or methylation-specific (MSP) PCR, respectively. Additionally, adjacent 20µm sections were processed for ERα immunohistochemistry. In OVX females, ERα mRNA and protein were increased in the ischemic cortex, but unchanged in males. We hypothesized that this increase in ERα in females is due to a reversal of gene silencing by DNA methylation. Using MSP targeting of CpG islands within the 5’ UTR of the rat ERα gene, we found that ischemia decreased methylation in the ischemic cortex of both groups of females, but there was no change in methylation in males. Using chromatin immunoprecipitation, we found that MeCP2 associates with ERα 5’UTR corresponding with the methylation status of the promoter. These data are the first to demonstrate a difference in the regulation of ERα expression in response to MCAO between males and females and that methylation of the ERα gene corresponds with mRNA levels in the brain.
Symmetry of the Higgs potential inSU(N)gauge models

Abstract After the spontaneous breakdown of a local gauge symmetry via the Higgs mechanism, it is sometimes possible to recover part or all of the original symmetry as a global symmetry. The symmetry of the Higgs potential plays a crucial role in such cases, and in this paper, it is explored in detail for a class of SU(N) gauge models. One important result is the exact global SU(N) can be recovered from the complete breakdown of the local SU(N) , but only at the expense of having a truly massless Goldstone boson, unless N is equal to or less than four.
Hypermnesia for Socratic stimuli: The growth of recall for an internally generated memory list abstracted from a series of riddles

Hypermnesia (the increase of recall with time and effort) was tested and contrasted for three conditions of input, each thought to involve different levels of cognitive processing. The basic design involved a multitrial free recall procedure, with groups differing only in the presentation of materials to be remembered. The words subjects (most superficial cognitive processing) recalled a serial list of 40 words; the pictures subjects recalled the same series of 40 pictures; and the Socratic subjects (deepest cognitive processing) recalled an internally generated memory set consisting of covert solutions to 40 riddles, which had been pretested to yield the same 40 items as those of the other groups. While all groups showed spontaneous recovery of additional items on repeated recall without further presentation, as well as faster retrieval rates in early portions of successive recall trials, the increase in the number of items recalled on each trial was greatest for the Socratic group, intermediate for the pictures group, and least for the words group, suggesting that the greater the depth of cognitive processing, the greater the magnitude of hypermnesia.
Second-site rho mutation: genetic linkage and polyC-dependent ATPase.

Rho has been purified to homogeneity from Escherichia coli double mutant rho-115 sur-38 cells, and from rho++ and rho-115 cells. The sur-38 mutation suppresses the original rho-115 phenotype. We observe that the polyC-dependent ATPases of these three rho preparations have the same specific activities. However, the ATPase of rho from the double rho-115 sur-38 mutant is extremely heat labile, while that from rho-115 shows a heat lability intermediate between the wild type and the double mutant.
The Incidence of Apnea after Discharge in Infants Less Than 34 Weeks Gestation with Normal Pre-Discharge Pneumocardiograms

The Incidence of Apnea after Discharge in Infants Less Than 34 Weeks Gestation with Normal Pre-Discharge Pneumocardiograms
Transonic Study of Active Flutter Suppression Based on an Energy Concept

The application of active control technology to the suppression of flutter has been successfully demonstrated in the Langley transonic dynamics tunnel. This study involved the implementation of an aerodynamic-energy criterion to suppress flutter of a simplified delta-wing model. Use of this technique with both leadingand trailing-edge active controls has resulted in an increase in dynamic pressure of 22% above the basic wing flutter point and with only a trailing-edge active control has resulted in an increase in dynamic pressure of 30% above the basic wing flutter point at a Mach number of 0.9. Analytical methods used to predict the openand closedloop behavior of the model are also discussed.
Knowledge, Attitudes, and Predictors of Advance Directive Discussions of Registered Nurses

The purpose of this study was to describe nurses’ knowledge, attitudes, and experiences regarding advance directives. A secondary purpose was to examine predictors of advance directive discussions between nurses and patients. Seven-hundred and nineteen respondents, randomly selected from a list of registered nurses in the state of Ohio, completed mailed questionnaires. Descriptive t test, chi-square, and logistic regression statistics were used in the data analyses. The respondents were knowledgeable and possessed positive attitudes about advance directives. Higher self-perceived confidence in advance directive discussion skills and the experience of caring for at least one patient with a current advance directive were found to be significant predictors of advance directive discussions. These findings suggest that experience with advance directives documents is critical for nurses’ comfort and that developing interventions to further nurses’ confidence in their discussion skills may increase advance direc...
Manufacturable plastic microfluidic valves using thermal actuation

A low-cost, manufacturable, thermally actuated, plastic microfluidic valve has been developed. The valve contains an encapsulated, temperature-sensitive fluid, which expands, deflecting a thin elastomeric film into a fluidic channel to control fluid flow. The power input for thermal expansion of each microfluidic valve can be controlled using a printed circuit board (PCB)-based controller, which is suitable for mass production and large-scale integration. A plastic microfluidic device with such valves was fabricated using compression molding and thermal lamination. The operation of the valves was investigated by measuring a change in the microchannel's ionic conduction current mediated by the resistance variation corresponding to the deflection of the microvalve. Valve closing was also confirmed by the disappearance of fluorescence when a fluorescent solution was displaced in the valve region. Valve operation was characterized for heater power ranging from 36 mW to 80 mW. When the valve was actuating, the local channel temperature was 10 to 19 °C above the ambient temperature depending on the heater power used. Repetitive valve operations (up to 50 times) have been demonstrated with a flow resulting from a hydrostatic head. Valve operation was tested for a flow rate of 0.33–4.7 µL/min.
Comparison of methods for estimating wet-bulb globe temperature index from standard meteorological measurements

ABSTRACTEnvironmental heat illness and injuries are a serious concern for the Army and Marines. Currently, the Wet-Bulb Globe Temperature (WBGT) index is used to evaluate heat injury risk. The index is a weighted average of dry-bulb temperature (Tdb), black globe temperature (Tbg), and natural wet-bulb temperature (Tnwb). The WBGT index would be more widely used if it could be determined using standard weather instruments. This study compares models developed by Liljegren at Argonne National Laboratory and by Matthew at the U.S. Army Institute of Environmental Medicine that calculate WBGT using standard meteorological measurements. Both models use air temperature (Ta), relative humidity, wind speed, and global solar radiation (RG) to calculate Tnwb and Tbg. The WBGT and meteorological data used for model validation were collected at Griffin, Georgia and Yuma Proving Ground (YPG), Arizona. Liljegren (YPG: R2 = 0.709, p < 0.01; Griffin: R2 = 0.854, p < 0.01) showed closer agreement between calculated and ac...
Understanding Community Context and Adult Health Changes in China: Development of an Urbanicity Scale

The classification of places as either urban or rural is typically based on an absolute threshold of population and/or population density. However, conceptual definitions of urbanization and urbanicity encompass dimensions beyond solely population size and population density. Multiple important distinguishing urban characteristics beyond population size have been described. The crude classification of places as urban or rural coupled with infrequent updates to this information creates a measure that is prone to misclassification error. An improved measure of urbanicity would draw information from the domains that characterize urban and rural places, would be sensitive to changes over time, and would represent gradations on the continuum from rural to urban environments. The goal of the current study was to develop such a scale from existing data, test whether the scale was reliable and valid, and assess whether it provided information beyond what could be determined from the traditional urban/rural dichotomous variable. We utilized established scaling procedures from the psychometric literature to construct and evaluate a multicomponent scale to measure urban features on a continuum in China. We also provided an example of its potential contribution to health research by examining its relationship with the adult body mass index (BMI). Because the scale was constructed and tested using established scaling procedures and using a wide array of variables, it represents an improvement over previous attempts at such a scale and will provide a reliable and valid measurement tool for researchers in this arena. We demonstrate that the scale predicts the incidence of overweight/obesity populations in China, but it promises to be most useful for other economic, demographic, social welfare, and health outcomes.
Some Observations on Design and Interaction on a City Street

THIS ARTICLE IS PART of a larger research project studying the relationship between social class and architectural design and scale in the city; more specifically, the relationship between working–class life and the visual morphology of the urban street. Using Fourteenth Street in Manhattan as the locus, I identify various zones of activity along the street and the interactions found within them and then consider what role design might play in retaining the presence of working–class street life and whether the search for human scale in design depends upon an understanding of social class and sociocultural dimensions interaction, [architecture and interaction, urban planning, visual scale and social class, urban design and redevelopment]
The nature of knowledge and language in the legislative arena

The fact that state legislators belong to an oral culture affects the evaluation reports written for them. The culture affects both the nature of the knowledge generated for legislators' use and the nature of the language used to describe that knowledge.
Degradation of dynamic ON-resistance of AlGaN/GaN HEMTs under proton irradiation

SiNx-passivated AlGaN/GaN high electron mobility transistors (HEMTs) on Si substrates demonstrated high tolerance to 2 MeV proton irradiation, up to a dose of 6 × 1014 cm-2. Radiation-induced changes were observed in Hall mobility, two-dimensional electron gas sheet carrier density, sheet resistance, ON-resistance, transconductance, threshold voltage, and dynamic ON-resistance. Dynamic ON-resistance was measured by pulsing to ON-state from OFF-state quiescent points with drain voltages up to 20 V. The dynamic ON-resistance measured from high OFF-state quiescent voltages was more sensitive to irradiation than the DC and Hall parameters, making the dynamic ON-resistance measurement useful in characterizing radiation-induced degradation.
Polarization-encoded optical shadow-casting programmable logic array: simultaneous generation of multiple outputs

A scheme for designing a content-addressable memory (CAM) using polarization-encoded optical shadow-casting (POSC) is proposed. Such a programmable logic array requires comparatively less memory storage because of the built-in reduction in the truth table entries. The scheme is implemented by copying the truth table entries directly into the corresponding input pixel subcells. The proposed POSC CAM generates all its outputs simultaneously, thus eliminating the design requirement of switching either LED sources or decoding masks. For illustration, a 4-input 4-output 2 × 2 binary multiplication unit is designed using this scheme.
Nicotine replacement prescription practices of Obstetric and pediatric clinicians

Abstract Objective: To assess smoking cessation counseling and nicotine replacement therapy prescription and recommendation practices among obstetric and pediatric providers. Methods: We sent out a self-administered survey to 61 obstetric and pediatric nurse practitioners and physicians at six community health centers in the Boston area. Results: Obstetric providers were more likely to view smoking cessation counseling as their responsibility in treating pregnant women than pediatric providers did in treating infants with mothers who smoked (mean ± standard deviation [95% confidence interval] 4.5 ± 0.76 [4.2, 4.8] versus 4.0 ± 0.8 [3.7, 4.3] on a five-point scale; P Conclusion: We found that nicotine replacement therapies are commonly prescribed or recommended to pregnant smokers by obstetric providers, but less commonly to lactating women by pediatric providers.
Comment on the Paper “On the influx of small comets into the Earth's upper atmosphere”

The possibility that comets containing up to 100 tons of ice encounter the earth's atmosphere at a rate of one every 20 min is discussed. Cometary 'hail storms' were proposed to explain observed regular transient decreases in the atmospheric UV dayglow intensity. The decreases take the form of dark 'holes' up to 50 km across. The probability that clouds of objects assumed to be as dark as the nucleus of Comet Halley between the earth and moon would be detectable by ground-based electrooptical deep space telescopes is considered. Conflicting projections of the number of objects which would be detected per hour are examined. High correlations are noted between cometary passages (Comets Encke, Tuttle, Tempel) and intervals of meteor showers (Taurids, Leonids, Geminis, etc.). The holes, however, are not correlated or coincident with the showers. It is suggested that dedicated searches for the unclassified dark objects be carried out in November, when cometary fluxes are high.
The crack problem for a nonhomogeneous plane

The plane elasticity problem for a nonhomogeneous medium containing a crack is considered. It is assumed that the Poisson's ratio of the medium is constant and the Young's modulus E varies exponentially with the coordinate parallel to the crack. First the half plane problem is formulated and the solution is given for arbitrary tractions along the boundary. Then the integral equation for the crack problem is derived. It is shown that the integral equation having the derivative of the crack surface displacement as the density function has a simple Cauchy type kernel. Hence, its solution and the stresses around the crack tips have the conventional square root singularity. The solution is given for various loading conditions. The results show that the effect of the Poisson's ratio and consequently that of the thickness constraint on the stress intensity factors are rather negligible.
SU-FF-T-511: Effect of Setup Motion and IMRT On the TCP and NTCP for Pediatric Ependymoma

Purpose: Compare the TumorControl Probability (TCP), Normal Tissue Complication Probability (NTCP) and Conformity Index (CI) of Intensity Modulated Radiation Therapy(IMRT) versus 3D Conformal Radiation Therapy (3D‐CRT) for Pediatric Ependymoma patients and quantify the effect of set‐up uncertainty (SU) and residual uncertainty (RU) on TCP and NTCP for different PTV margins. Methods and Materials: 20 Ependymoma patients treated between 1998 and 2002 using 3D‐CRT with a 5mm PTV margin were selected for this study. Two IMRT plans for each patient were created, one with identical margins (PTV=5mm) and one with no PTV margin (PTV=0mm). A direct simulation of SU was performed for each plan of each patient based on daily CBCT information obtained from 20 well‐matched patients (age, supine/prone, use of GA) on a localization protocol. A direct simulation of RU, based on post‐treatment CBCT was performed. TCP; NTCP for the cochlea, spinal cord, and brainstem; and CI were calculated for each plan. Also, a predictive IQ formula was used to compare IMRT vs. 3D‐CRT for PTV=5mm. Results:IMRT improved the TCP by 0.023±0.027 vs. 3D‐CRT (p=0.001). A TCP loss of 0.004±0.007 (p=0.02) due to SU and 0.0003±0.001 (p=0.14) due to RU was found for the IMRT with PTV=0mm plan. The NTCP for 3D‐CRT, IMRT with PTV=5mm, and IMRT with PTV=0mm was; Cochlea: 0.66±0.40, 0.29±0.35, and 0.09±0.17; Brainstem: 0.22±0.07, 0.22±0.04, 0.19±0.04; and Spinal Cord: 0.13±0.06, 0.09±0.05, 0.08±0.04; respectively. Mean NTCP change due to SU for IMRT with PTV=5mm was; Cochlea 0.02±0.11, Spinal Cord 0.007±0.01, and Brainstem 0.003±0.01. The CI was 0.64±0.12 for IMRT and 0.4±0.14 for 3D‐CRT. Predictive IQ formula was 9.98±10.3 points higher for the IMRT plan. Conclusions:IMRT improves TCP, reduces NTCP and increases the CI versus 3D‐CRT for pediatric Ependymoma patients. The setup margin required due to SU may be eliminated if daily localization is performed.
A distributed framework to improve high-performance IP

New and emerging applications in the area of high-speed processing are increasingly stretching intellectual property (IP) to provide an ever higher throughput. It becomes more and more difficult for an IP to deliver a higher throughput on a single core, as the design approaches its practical limit on frequency scaling as well as the degree of parallelism. This drives designers towards a multiprocessing approach to find an optimal balance between performance, power, cost, and design complexity. This paper presents a novel method to deliver a higher performance IP via multiprocessing. This approach uses a highly scalable architecture to create a distributed framework that enables multiple cores to work together in a pipelined manner to achieve the desired throughput. Using this approach helps the IP developer to get to market faster, and by doing so, stay ahead of the competition.
Distribution of rose bengal stained deep-sea benthic foraminifera from the Nova Scotian continental margin and Gulf of Maine

Abstract Analysis of Rose Bengal stained benthic foraminifera in six boxcores taken from the Nova Scotian margin and Gulf of Maine reveals that foraminifera are vertically stratified within surficial sediments raised from 200 to 3000 m water depth. The consistent presence of infaunal taxa within the sediments demonstrates that these tolerant of a range of low-oxygen conditions as determined by pore-water manganese profiles. The habitat depth of foraminiferal populations, defined as the depth within which 95% of the fauna is found in a subcore, varies between the stations. A shallow habitat depth of 3 cm exists in shallow water (a 202 m core) in the Gulf of Maine. The habitat depth gradually increases on the continental slope with increasing water depth, reaching 11–13 cm in cores at 2225 and 3000 m, and then shoals to 4 cm in a core taken from 4800 m water depth. We suggest that the habitat pattern is related to the flux of organic carbon to the seafloor. At shallow depths, relatively high organic carbon flux results in a shallow oxic layer. The inferred oxic layer gradually increases on the continental slope and rise with increasing water depth, due to decreased organic carbon flux to the sediment-water interface. Carbon fluxes in the deep ocean are so low that pore waters are oxic and the organic carbon content is low, creating a food-limiting environment best suited to epifaunal taxa and reflected in a shallow habitat depth.
Simulation of binary vapor condensation in the presence of an inert gas

Abstract Two recently developed simplified models of multicomponent mass transfer are employed to determine the composition profiles during the condensation of a binary vapor (methanol-water) from an inert gas (air or helium). It is found that the profiles and the predicted outlet conditions are in excellent agreement with the results obtained using an exact solution of the Maxwell-Stefan equations to predict the mass transfer rates. It is concluded that the simplified approach to multicomponent mass transfer calculations will probably be adequate for many design problems, thereby realising important savings in computational time and computer program complexity.
Quantum cellular automaton in 1-D

Abstract Simple algebraic cellular automata and a diffusion confinement are used to model quantum behavior of a relativistic particle in a 1-D box. Comparisons and contrasts are drawn between such a quantum cellular automaton (QCA) and both orthodox and unorthodox interpretations of quantum mechanics. The persistent tension between deterministic pictures and probabilistic descriptions of quantum reality are clarified for the case of a 1-D quantum particle viewed as a cellular automaton surging for survival in space and time.
Automatic deductive systems for chemistry

Abstract Deductive systems are general programs intended to assist in the design of experiments and in data processing. In such systems no mathematical assumptions are made; only the fundamental law of conservation of energy/mass is used; and the systems have a predictive capability that does not use “state-of-the-art libraries”. Two kinds of deductive systems are available: numeric deductive systems which have computative as well as predictive capabilities, and alphanumeric deductive systems which have only predictive capabilities and can be used to predict possible reaction paths. The current status of both kinds is reviewed, and examples of the use of a fully operational numerical deductive system are discussed.
Union and separation in Edgar Allan Poe

A computer method of concept analysis is applied to a sampling of twenty-one of Poe's tales and poetry collections written from age 18 up to his death at 40, on the hypothesis of a developmental time line in his writing. Concepts are pools of words of related meaning. A computer program compares each word of the texts to a concept dictionary, assigns up to five of 168 concepts to the word, and produces concept frequency profiles of the texts. Frequencies are converted to z scores and 138 selected concepts are intercorrelated and factor analysed. Texts are then associated with the concepts dominant in each factor. Clustering of early texts and late texts at opposite ends of one of the factors supports the idea of a time line. The death of Poe's brother in 1831 and of his wife in 1847 appear to be related to the time line. Poe's early work suggests that reunion with the loved one after death is possible. Later work, specifically Eureka, deals with reunion at a cosmic level in an ultimate nullity identified with God. Several critiques of Poe's writing are shown to be at fault for failing to take the time line into account. Some aspects of concept analysis are also reviewed
The Use of Television in Teaching Basic Economics at the College Level.

The use of television in the teaching of economics is no longer new, and articles on TV may not arouse the interest that they did in the past. Nevertheless, this medium is being used and it is probable that new ways will be found to employ it as an instructional tool. Donald Paden briefly reviews some of the history of television as it has been used in teaching economics, describes some ways in which it is currently being used, and gives some thought to how it might be developed in the future.
Immunochemical analyses of lens protein separations.

Abstract Continuous flow electrophoresis, column chromatography, and isoelectric and ethanol precipitation were used for the separation of soluble lens proteins. The fractions obtained were analyzed by immunoelectrophoresis or immune double-diffusion precipitation. Almost all the fractions proved to be mixtures of greater or lesser complexity. A total of at least ten components were found. It has been shown that components with the same immunological specificity occur in a heterogeneity of forms different in solubility and electrophoretic and Chromatographic properties. These data indicate that interpretation of separation patterns based only on the occurrence of protein peaks may be misleading and point to the necessity of immunochemical analysis as an accessory procedure. The possible roles of protein interactions, aging, and genetic variations as causes of difficulty in the separation of individual lens proteins are briefly discussed.
Using genomics to understand the disease cycle of the fusarium head blight fungus, Gibberella zeae (anamorph Fusarium graminearum)

Genome sequences of more than 30 filamentous fungi are now available. For the first time, scientists studying plant-fungi interactions have access to a nearly complete picture of the metabolic and developmental capacity of these organisms. Researchers compare whole genomes, gene clusters, and individual-gene sequences to understand evolutionary relationships. In addition, large-scale analyses of gene expression are used to identify genes important to pathogenicity. With the fusarium head blight (FHB) pathogen (Gibberella zeae) as an example, we examine how genomic-sequence information can contribute to increase our understanding of plant disease and to the development of novel control strategies. In the process, we review the present techniques for genetic manipulation of G. zeae. We provide several examples of how sequence conservation served to identify specific genes of interest and how the identification of these genes can be useful to understand their role in the pathogen life cycle. Finally, we pres...
Phonon-Broadened Impurity Spectra. I. Density of States

The phonon-broadened densities of states associated with (a) a point charge, (b) an $S$-wave hydrogenic shallow donor, and (c) an exciton bound to a neutral defect are calculated. The electronic states are coupled to the lattice vibrations via the (a) longitudinal-optical, (b) piezoelectric, and (c) deformation-potential linear electron-phonon interactions. The major dynamical approximations consist of the use of the Debye model for the acoustical-phonon spectrum and the neglect of the mixing of electronic states by phonons. Within the framework of the model Hamiltonian the Fourier transforms of the densities of states are calculated exactly and analytically. For CdS, CdTe, and ZnS numerical calculations of the densities of states are presented. The density of states associated with a shallow donor in CdTe and ZnS exhibits, in lieu of a zero-phonon line, a Lorentzian peak whose width is proportional to temperature. The inclusion of the static shielding of the piezoelectric interaction by mobile charge carriers replaces the Lorentzian by a zero-phonon line plus two shoulders. The extensions of the calculation to donor-acceptor, band-impurity, interband, and intra-deep-impurity transitions are discussed.
The transmission of sound in an accoustically treated rectangular duct with boundary layer

Abstract The weighted residual method of Galerkin is applied to several rectangular ducts of various widths with a boundary layer on all four walls, two of which are lined with an acoustic material. The validity of employing the Galerkin method to problems of this type is demonstrated by performing computations to check the convergence of the method and by investigating limiting cases of the rectangular duct for which more exact results are known. In summary, the Galerkin method is a reliable method for treating the problem of sound propagation in acoustically treated ducts in which the sheared flow profile is a function of two spatial variables.
Sulfur nutrition of italian ryegrass measured by growth and mineral content

The sulfur nutrition of Italian ryegrass was studied by a nutrient solution technique. Sulfur-deficient plants were stunted and erect in appearance; upper leaves were an abnormal yellow-green. Shoot growth was affected more than root growth by changes in the amount of S supplied.
Thy-1 determinants are present on many murine hematopoietic cells other than t cells.

The development of a highly amplified immunofluorescence assay and the availability of monoclonal anti-Thy-1 antibodies have provided the methodology to reexamine the presence of Thy-1 antigen on murine lymphohematopoietic cells. The representation of this antigen is not, as previously believed, restricted to the T cell compartment of these cells. It is present on a significant number of mouse bone marrow cells (25-30%), including, as in the rat, multipotential stem cells, prothymocytes and some B cell precursors. Eosinophils and some immature myeloid cells are also antigen-positive.
Cell proliferation through forced engagement of c-Kit and Flt-3.

To investigate the potential for functional interactions between heterologous receptors, the cytoplasmic domains of 2 different receptors (c-Kit and Flt-3) were coexpressed in the interleukin-3–dependent cell line Ba/F3. The receptor signaling domains were presented in the context of fusion proteins, with c-Kit linked to the FK506 binding protein (FKBP12) and Flt-3 linked to the FRB domain of the FKBP12–rapamycin-associated protein. The fusions were brought into apposition with the use of chemical inducers of dimerization (CIDs). Two classes of CID were employed. FK1012 and its synthetic analogue AP1510 bring together 2 copies of the FKBP12 domain, thereby inducing homodimerization of the c-KitFKBP12fusion. A second type of CID, rapamycin, brings together one FKBP12 domain and one FRB domain, resulting in heterodimerization of the c-KitFKBP12 and Flt-3FRB fusions. Ba/F3 cell growth was promoted not only by FK1012- or AP1510-induced homodimerization of the c-KitFKBP12 fusion (as reported previously), but also by rapamycin-induced c-KitFKBP12–Flt-3FRB heterodimerization. These findings demonstrate the potential for a direct functional interaction between c-Kit and Flt-3.
Motor vehicle accidents in patients with an implantable cardioverter-defibrillator

OBJECTIVES. This study was designed to examine driving safety in patients at risk for sudden death after implantation of a cardioverter-defibrillator. BACKGROUND. Cardioverter-defibrillators are frequently implanted in patients at high risk for sudden death. Despite concern about the safety of driving in these patients, little is known about their actual motor vehicle accident rates. METHODS. Surveys were sent to all 742 physicians in the United States involved in cardioverter-defibrillator implantation and follow-up. Physicians were questioned about numbers of patients followed up, numbers of fatal and nonfatal accidents, physician recommendations to patients about driving and knowledge of state driving laws. RESULTS. Surveys were returned by 452 physicians (61%). A total of 30 motor vehicle accidents related to shocks from implantable defibrillators were reported by 25 physicians over a 12-year period from 1980 to 1992. Of these, nine were fatal accidents involving eight patients with a defibrillator and one passenger in a car driven by a patient. No bystanders were fatally injured. There were 21 nonfatal accidents involving 15 patients, 3 passengers and 3 bystanders. The estimated fatality rate for patients with a defibrillator, 7.5/100,000 patient-years, is significantly lower than that for the general population (18.4/100,000 patient-years, p Language: en
Thermodynamics of the iron-nitrogen system

Abstract The temperature variation of the equilibrium between N2 gas and N-Fe solid solutions has been measured. The results give the following values for the partial molar enthalpy and excess entropy of N-atoms in γ and α iron: γ: R u = −459.8 ± 29.1 kJ/mole , S xs u k = 6.59 ± 0.9 α: R u =−423.7 ± 20.1 kJ/mole. , S xs u k = 6.97 ± 1.1 The data for δ-iron show a marked deviation from Arrhenius behavior with respect to a high temperature extrapolation of the low-temperature b.c.c. data (α-iron). This deviation is discussed in terms of several models.
The 12C(α, α1γ4.43)12C reaction: Angular correlations and the 14.8 MeV level in 16O

Abstract Angular correlations in the reaction 12 C (α,α 1 γ 4.43 ) 12 C have been studied for incident energies of 10.2, 10.3 and 10.5 MeV. The data were compared to a single-level compound-nucleus theory. The data substantiate the recent assignment of J π = 6 + to the 14.8 MeV level in 16 O.
Young Athletes' Perceptions of Parental Support and Pressure.

Individual participation in athletics was examined as a representative achievement-oriented activity in which perceived parental support and pressure influence adolescents' perceptions of themselves and their performance. Adolescent tennis players attending one of the three regional tennis academies indicated their perceptions of the quality of their parents' involvement in their tennis participation, their enjoyment of tennis participation, their self-esteem, and their feelings of burnout associated with tennis participation. Both females and males perceived similar levels of support from their mother and father; however, females perceived greater support from both parents than did males. Males perceived higher levels of pressure from their father than from their mother, whereas females perceived similar levels of pressure from both their father and mother. For both females and males, perceived parental support was positively associated with enjoyment of tennis participation and self-esteem. The findings are discussed as evidence of a general association between adolescents' perceptions of their parents' involvement in their achievement-oriented activities and their enjoyment of such activities and self-perception of abilities associated with those activities.
Optical Phonons in Electron Spin Relaxation

An approximate dispersion curve for the optical branch of the lattice vibration is used to estimate the spin-lattice relaxation time attributed to optical phonons. The relaxation rate is found to be ${{T}_{1}}^{\ensuremath{-}1}\ensuremath{\propto}\mathrm{exp}(\ensuremath{-}\frac{\ensuremath{\hbar}{\ensuremath{\omega}}_{0j}}{\mathrm{kT}})$, where ${\ensuremath{\omega}}_{0j}$ is an optical-phonon frequency at k=0. It is also found that if the band-width of the optical mode is narrow, if the optical-phonon energy is low, and if the lattice vibration is even, then the spin-optical phonon relaxation process can dominate the conventional acoustical processes. The applications of the theory to some experimental results are also discussed.
Palynological record from the North Atlantic region at 3 Ma: vegetational distribution during a period of global warmth

Pollen assemblages from five mid-Pliocene, deep-marine and shallow-marine sites in the North Atlantic Ocean region were analyzed quantitatively to estimate vegetational composition and terrestrial paleoclimates during a time interval centered at about 3 Ma. Three subarctic sites (58–67°N latitude) from the Norwegian Sea, northern Iceland, and the Labrador Sea yielded pollen assemblages characteristic of mixed conifer-hardwood vegetation; these assemblages have no close modern analogs, but the most similar modern vegetation is that of the Tsuga (hemlock)-northern hardwood forests of Newfoundland and Nova Scotia (45–50°N). The presence of such vegetation at these sites indicates mid-Pliocene January temperatures from 4 to 10°C warmer than today and a northward shift of the deciduous forest zone into areas presently occupied by boreal forests. Pollen assemblages from the mid-latitude (36°N) Yorktown Formation site in southeastern Virginia, USA represent Quercus-Carya-Pinus (oak-hickory-pine) forests, similar to those presently occupying much of the Atlantic coastal plain of the United States. Modern analogs for this site are located off the coasts of North Carolina and South Carolina, indicating mid-Pliocene January temperatures 3–5°C warmer than today. In southwestern Florida (27°N), pollen assemblages from the mid-Pliocene Pincrest Beds are representative of pine-dominated communities, similar to Pinus palustris/P. ellittii forests (longleaf/slash pine) growing in Florida today. Close modern analogs for the Pinecrest Beds are located at numerous sites around the Florida peninsula, indicating mid-Pliocene temperatures about the same as today for this region. These sites show a gradient from much higher than present temperatures at high latitudes to little change from present temperatures at low latitudes and low elevations; a similar pattern is shown by mid-Pliocene sea-surface and isotopic data. Such a gradient also is consistent with the northward migration of the boreal forest zone, covering sites as far north as Meighen and Banks Islands, a northward shift of the deciduous-boreal forest boundary in both North America and Europe, and little change in vegetational distribution in low elevation sites in subtropical latitudes during the mid-Pliocene warm interval. Atmospheric temperaturs estimated from vegetational distributions indicate a Pliocene to modern temperature anomaly of a similar pattern and magnitude to that indicated by sea-surface temperatures. These data are most consistent with current general circulation model simulations of climate changes in response to increased meridional heat transport.
Advanced damper with high stiffness and high hysteresis damping based on negative structural stiffness

Abstract High structural damping combined with high stiffness is achieved by negative stiffness elements. Negative incremental structural stiffness occurs when a column with flat ends is subjected to snap-through buckling. Large hysteresis (i.e., high damping) can be achieved provided the ends of the column undergo tilting from flat to edge contact. The column configuration provides high structural stiffness. Stable axial dampers with initial modulus similar to that of the parent material and with enhanced damping were designed built and tested. Effective damping of approximately two and stiffness-damping product of approximately 200 GPa were achieved in such dampers consisting of stainless steel columns. This is a significant improvement for this figure of merit (i.e., the stiffness-damping product), which generally cannot exceed 0.6 GPa for currently used damping systems.
An improvement for the McGill University Random Number Package

This paper documents and provides code for two new entry points which increase the flexibility of the McGill University Random Number Package. With these additions the user can access internal locations containing the pseudo-random integers that control the random sequences produced by the generator. A detailed example of the use of the new entry points is provided. Finally, some comments about the documentation of random number generators are made.
A novel non-ataxic guinea pig strain with cerebrocortical and cerebellar abnormalities

This is the first description of GS guinea pigs, a partially inbred, non-ataxic, albino Peruvian (long-hair) strain with abnormal motor behavior and seizures. GS guinea pigs show gross and microscopic cerebellar and microscopic cerebrocortical abnormalities compared to Hartley strain animals. There is little difference between GS and short-hair guinea pig strains in Purkinje cell function, electrically evoked Ca2+ transients or immune responsiveness. The GS strain may prove useful in studying altered functions of the cerebellum in human disease.
Lipophosphoglycan-like glycoconjugate of Tritrichomonas foetus and Trichomonas vaginalis.

Abstract Lipophosphoglycan-like glycoconjugates were isolated, purified and partially characterized from Tritrichomonas foetus and Trichomonas vaginalis . Cell surface radiolabeling of both trichomonads by the galactose oxidase/NaB[ 3 H] 4 technique indicated that the glycoconjugate was located on the cell surface of the parasites. The glycoconjugates were extracted from the delipidated residue fraction with the solvent, water/ethanol/diethylether/pyridine/NH 4 OH (15:15:5:1:0.017) and were purified to homogeneity by Sepharose CL-4B followed by octyl-Sepharose chromatography and methanol precipitation. The glycoconjugates migrated as broad bands upon SDS-PAGE. The T. foetus glycoconjugate contained large amounts of fucose along with some mannose, galactose, glucosamine and glucose and trace amounts of galactosamine and inositol. The T. vaginalis glycoconjugate appeared to contain large amounts of glucosamine and galactose along with some glucose, mannose and traces of galactosamine and inositol. The surface-labeled glycoconjugates from both parasites was found to be deaminated with nitrous acid and susceptible to phosphatidylinositol-specific phospholipase C, indicating the presence of a phospholipid anchor. Furthermore, these glycoconjugate were found to contain phosphate and were labile to hydrolysis by mild acid, strongly suggesting that the intact molecule is related to Leishmania lipophosphoglycans (LPG). The most striking and the unique features of these glycoconjugate molecules are the presence of large amounts of fucose in T. foetus and glucosamine in T. vaginalis along with the presence of galactosamine in both parasites. These results indicate that these glyconjugates are new types of LPG-like molecules expressed on the trichomonad cell surface and are structurally distinct from Leishmania LPG.
The Bone Marrow: Friend or Foe of the Heart?

Every day, the bone marrow produces billions of cells. Hematopoietic stem cells (HSC) are rare but can make any type of blood cell. The idea to harness their pluripotency to repair failing hearts has created excitement in the cardiovascular community. As an interesting by-product of a trial
Passive detection method for synchronizing with resonant oscillations of bubbles

In medical ultrasound, microbubbles might be grown in a body fluid to create a bolus of high scattering fluid for study of circulatory or urinary tract dynamics. Microbubble creation and growth via rectified diffusion has been investigated for chirps with a temporally decreasing frequency to drive the growing bubbles at resonance. A method is considered for control of the ultrasound frequency and amplitude to maintain the bubbles at a desired size or growth rate. If the frequency of the ultrasound growth or maintenance field can be modulated over a significant portion of a bubble resonance curve, the modulation of the backscattered or transmitted waveform by the resonance can be used to keep the frequency centered on the resonance, and the amplitude can be adjusted to maintain the desired growth rate. >
Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

A new deep-sea laser Raman spectrometer (DORISS—Deep Ocean Raman In Situ Spectrometer) is used to observe the preferential dissolution of CO2 into seawater from a 50%–50% CO2–N2 gas mixture in a set of experiments that test a proposed method of CO2 sequestration in the deep ocean. In a first set of experiments performed at 300 m depth, an open-bottomed 1000 cm 3 cube was used to contain the gas mixture; and in a second set of experiments a 2.5 cm 3 funnel was used to hold a bubble of the gas mixture in front of the sampling optic. By observing the changing ratios of the CO2 and N2 Raman bands we were able to determine the gas flux and the mass transfer coefficient at 300 m depth and compare them to theoretical calculations for air–sea gas exchange. Although each experiment had a different configuration, comparable results were obtained. As expected, the ratio of CO2 to N2 drops off at an exponential rate as CO2 is preferentially dissolved in seawater. In fitting the data with theoretical gas flux calculations, the boundary layer thickness was determined to be ~42 Am for the gas cube, and ~165 Am for the gas funnel reflecting different boundary layer turbulence. The mass transfer coefficients for CO2 are kL=2.82 � 10 � 5 m/s for the gas cube experiment, and kL=7.98 � 10 � 6 m/s for the gas funnel experiment.
Thermally-Induced Extrusion of Sulfur Dioxide from Allyl Alkyl Sulfones. Use of the Rearrangement for the Synthesis of Dihydrojasmone

Abstract For some time we have been interested in the mechanistic and potential synthetic applications of the thermal transformation illustrated in equation (1)1.