cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal conductivity degradation of ceramic materials due to low temperature, low dose neutron irradiation

The thermal conductivity degradation due to low-temperature neutron irradiation is studied and quantified in terms of thermal resistance terms. Neutron irradiation is assumed to have no effect on umklapp scattering. A theoretical model is presented to quantify the relative phonon-scattering effectiveness of the three dominant defect types produced by neutron irradiation: point defects, dislocation loops and voids. Several commercial ceramics have been irradiated with fission reactor fast neutrons at low temperatures to produce defects. Materials include silicon carbide, sapphire, polycrystalline alumina, aluminum nitride, silicon nitride, beryllium oxide, and a carbon fiber composite. The neutron dose corresponded to 0.001 and 0.01 displacements per atom (dpa) for a ∼60 °C irradiation and 0.01 and 0.1 dpa for a ∼300 °C irradiation. Substantial thermal conductivity degradation occurred in all of the materials except BeO following irradiation at 60 °C to a dose of only 0.001 dpa. The data are discussed in terms of the effective increase in thermal resistance caused by the different irradiation conditions. Evidence for significant point defect mobility during irradiation at 60 and 300 °C was obtained for all of the ceramics. The thermal stability of the radiation defects was investigated by isochronal annealing up to 1050 °C.
INDIVIDUAL DIFFERENCES IN PERFORMANCE ON A LARGE-SCALE, REAL-WORLD WAYFINDING TASK

Despite hundreds of laboratory-based studies, very few researchers have investigated differences in spatial ability in large-scale, real-world settings. Laboratory-scale studies have found individual differences based on sex or gender, mathematical ability, nervousness, and previous experience. This study of 978 military college students tested whether the types of differences found in earlier laboratory studies would be found in a large-scale wayfinding task involving compass and map orienteering. Participants were required to find at least 8 of 10 points in a 4 h time period while covering about 6 km of woodland terrain. The results indicate that earlier laboratory findings are generally replicated for the large-scale task. Sex, previous experience, mathematical ability, and map-use skills were all found to be significant predictors of wayfinding performance.
Succinic dehydrogenase and cytochrome oxidase of mitochondria of chick liver, heart, and skeletal muscle during embryonic development†

The specific activities of succinic dehydrogenase (SD) and cytochrome oxidase (COX) were determined for mitochondria of chick liver, heart, and skeletal muscle from the seventh day of incubation through the time of hatching. The levels of activity of both enzymes at hatching and the rate and course of the developmental changes by which the final levels are reached are different and specific for mitochondria of the three tissues studied. During development changes in activity of both enzymes occur in parallel so that the ratio of SD/COX remains constant. Furthermore, the ratio is the same for the three types of mitochondria. Cytochrome oxidase is completely localized in the insoluble protein fraction (membrane fraction) of all mitochondria examined, and the change in COX during development varies temporally and quantitatively with the proportion of insoluble protein. When calculated on the basis of insoluble protein, specific activities of SD and COX are constant throughout development; furthermore, differences in activity among the mitochondria of the three tissues disappear. It is concluded that mitochondrial differentiation reflects the appearance of specific proportions of membranes and matrix.
Magnetic catalytic nickel particles for on-demand control of electrocatalytic processes

Magnetoswitchable control of electrochemical processes has been commonly relied on ferromagnetic spheres functionalized with a reactive moiety. Here we eliminated the need for functionalizing magnetic beads by combining the electrocatalytic and magnetic properties of nickel particles. The magnetic-controlled nickel-induced redox transformations are demonstrated for the on-demand oxidation of alcohols, sugars and amino acids. This represents the first example of a magnetoswitchable-controlled electrochemistry where the magnetic and catalytic properties are combined in the same material.
Massive acetaminophen ingestion with early metabolic acidosis and coma: treatment with IV NAC and continuous venovenous hemodiafiltration.

Context. We report the extraction of acetaminophen by continuous venovenous hemodiafiltration (CVVHD) during treatment of an acute ingestion of 200 g with a peak recorded serum acetaminophen level of 1,614 mg/L (10,652 μmol/L). Case details. The patient presented with early onset of coma, metabolic acidosis, and hypotension in the absence of significant hepatic injury. In addition to N-acetylcysteine (NAC) therapy, CVVHD was performed to manage the acid–base disturbance. Flow rate, effluent volume, and serum and effluent drug concentrations were obtained at hourly intervals. During 16 h of CVVHD the acetaminophen level dropped from 1,212 to 247 mg/L. Discussion. The average clearance of acetaminophen by CVVHD was 2.53 L/h, with removal of 24 g of acetaminophen over 16 h. As NAC is effective in preventing hepatic injury after acute acetaminophen overdose, the role of dialysis or CVVHD is limited.
SU-FF-T-393: Source Measurement for Electron Monte Carlo Calculations

Purpose: Monte Carlo calculations can reproduce most measured data for electron beams with very good accuracy. It should be possible, and arguably desirable, to be able to accurately reproduce all measured data with only knowledge of the linear accelerator geometry and the initial electron source; however, information regarding the latter is not as readily available. The purpose of this study is to study the properties of the electron beam close to the electron source.Method and Materials: Radiochromic film was inserted into a film holder consisting of two thin pieces of polystyrene, and attached to the distal side of the linear acceleratorscattering foil assembly. For each electron energy, films were exposed to 50 and 100 MU. The films were scanned with a resolution of 89 microns, and images were converted to dose using film strips irradiated to known doses. For Monte Carlo calculations of the same geometry, the initial source was assumed to be Gaussian with a FWHM of 1.5 mm, and a phase space was collected between the polystyrene slabs. It was assumed that electron fluence was proportional to the film dose. Results: Agreement between measurement and calculation was generally very good, but better for higher energies. Varying the initial electron source in the Monte Carlo calculations showed that these profiles are relatively insensitive to the initial source size; profiles are dominated by scattering in the foil assembly. Conclusion: Because of the insensitivity of the profiles to exact details of the initial electron source, it may not be possible for these measurements to resolve the details of the initial source parameters. The results may have also been affected by the assumption that the electron fluence was proportional to film dose; therefore further calculations of the dose to the film (rather than fluence) need to be done.
Notes on the social impacts of artificial intelligence

IJCAI-73 devoted three sessions to the aspects of AI funding, applications, and impact. In addition, one paper (Firschein, et al, 1973) described a Delphi study of plausible AI applications and their possible impacts. I'd like to share some of my reflections on this timely burst of attention devoted to these social concerns.
Notes on Technic: “Clearing” Steel Knife Epon Sections in a Polystyrene Film Sandwich

Serial sectioning epoxy embedments by steel knife permits rapid light microscope survey of large tissue volumes, and preselection of areas of interest for electron microscopy. Acetate film (Hollander 1970) and Turtox plastic slides (West 1972) have been suggested as substrates upon which the sections may be “cleared” with an added layer of cured epoxy. In our experience, these substrates are excessively adherent to Epon, and “cleared” sections thinner than 40-50 μm cannot be released from them reliably. The following method is suitable for processing Epon sections 10 or more microns thick.
The two-dimensional in vitro passive stress-strain elasticity relationships for the steer thoracic aorta blood vessel tissue

Abstract A simple and inexpensive biaxial test apparatus was developed and is described herein for the two dimensional testing of 5 cm square specimens of the aorta blood vessel tissue. Based on the results of the in vitro biaxial specimen testing the derivation of the passive two dimensional constitutive equations relating longitudinal and tangential stress, strain, and tissue elasticity are described. This is accomplished at each of three longitudinal locations along the thoracic aorta tree and a detailed comparison of the material properties at each location is made.
Obstructive sleep apnoea and schizophrenia: a primer for psychiatrists.

Alam A, Chengappa KNR. Obstructive sleep apnoea and schizophrenia: a primer for psychiatrists Objective: The main objective of this review is to improve psychiatric clinician awareness of obstructive sleep apnoea (OSA) and its potential consequences in patients with schizophrenia. This article will also discuss the diagnosis and treatment options for OSA while considering the significant role psychiatrists can play in facilitating the diagnosis and treatment of OSA. Data sources: Ovid, Medline and PsychInfo databases were searched for articles between 1960 and 2010. Search terms used were Sleep apnoea or apnoea and schizophrenia or psychosis. The number of articles retrieved was 38. Articles were carefully reviewed for any data pertinent to OSA in patients with schizophrenia. Conclusions: OSA is a common disorder that is frequently unrecognised. As a chronic breathing condition, OSA is associated with adverse health outcomes and high mortality. OSA may co-occur with schizophrenia or evolve over time, especially with weight gain. The diagnosis should be considered whenever a patient presents with risk factors or clinical manifestations that are highly suggestive of OSA. Those who report snoring, daytime sleepiness and are obese or have a large neck circumference should be considered for an OSA diagnosis. Appropriate diagnosis and treatment of OSA can reduce daytime sleepiness, improve cardiovascular and other medical conditions, as well as reduce mortality. Psychiatrists can play very important role in suspecting OSA in their patients and making the initial referral. Furthermore, behavioural management, especially promoting weight loss and smoking cessation, are effective components of OSA treatment that psychiatrists are positioned to facilitate with their patients.
Evaluation of the 238U neutron cross-sections for incident neutron energies up to 4 keV

Abstract This report describes an evaluation of the 238U cross-sections below 4 keV. Recent measurements and re-analyses of older data are discussed. Evaluated resonance parameters are obtained for 164 s-wave and 280 p-wave levels. The capture widths of the first three s-wave levels are significantly lower than in the ENDF/B-IV evaluation. The s-wave strength function above 1.5 keV is systematically larger than in ENDF/ B-IV. Statistical and systematic uncertainties are evaluated for the resonance parameters and for the smooth backgrounds. The statistical distributions of the resonance parameters are compared with theoretically expected distributions.
Tocqueville and Guizot on democracy: from a type of society to a political regime

Did Tocqueville treat democracy as a type of society, as a political regime, or in terms of their interactions? This paper argues against the assumption that Tocqueville's concept of this relationship remained constant over his three decades as a theorist. Beginning with his literal acceptance of Guizot's doctrinaire definition of democracy as an etat social, Tocqueville then developed an eclectic political sociology. Without rejecting the significance of social organization for politics, he often reverted to Montesquieu's theory of the complex interaction between the social and political. Finally, after the Second Republic's violent end by the coup he had as a statesman sought to prevent, Tocqueville was disgusted by the pseudo-democratic Bonapartist arguments used by the Second Empire's apologists to legitimate it. His final position was that any adequate definition of democracy had to include, not only social equality, but also political liberty and the participation of citizens in a government incorpo...
Vasoconstrictor responses, and underlying mechanisms, to isoprostanes in human and porcine bronchial arterial smooth muscle.

We investigated the effects of five different isoprostanes (8-iso PGE1, 8-iso PGE2, 8-iso PGF1α, 8-iso PGF2α and 8-iso PGF2β) on vasomotor tone in human and porcine bronchial arterial tissues. In the human bronchial arteries, 8-iso PGE2 and 8-iso PGF2α evoked powerful constrictions (magnitudes several fold greater than the responses to high millimolar KCl) with negative log concentration causing 50% excitation (EC50) values of 6.8 and 6.5, respectively; 8-iso PGE1 was less potent (EC50 not calculated, since a clear peak contraction was not obtained), while the other isoprostanes were largely ineffective. In the porcine arteries, on the other hand, all three F-ring isoprostanes as well as 8-iso PGE2 evoked constrictor responses, although the peak magnitudes were approximately 50% of the KCl-evoked response; 8-iso PGE2 and 8-iso PGF2α were the most potent, with negative log EC50 values of 6.5. We next sought to characterize the signaling pathways underlying the vasoconstrictor responses to 8-iso PGE2, since this was the most potent of the isoprostanes we tested. These responses were largely reversed by the thromboxane A2-selective (TP) prostanoid receptor antagonist ICI 192605 (10−8M; 4(Z)-6-[(2,4,5 cis)2-(2-chlorophenyl)-4-(2-hydroxy phenyl)1,3-dioxan-5-yl]hexenoic acid) as well as by the nonspecific tyrosine kinase inhibitor genistein (10−5 and 10−4M), and were reversed approximately 50% by the Rho-kinase inhibitor Y27632 (10−5M; (+)-(R)-trans-4-(1-aminoethyl)-N-(pyridyl) cyclohexanecarboxamide dihydrochloride). We conclude, therefore, that 8-iso PGE2 constricts bronchial vasculature through the activation of TP receptors, which in turn trigger tyrosine kinase and Rho-kinase activities, resulting in powerful vasoconstriction. These findings are highly relevant to lung transplantation and to exercise-induced asthma. British Journal of Pharmacology (2003) 140, 759–763. doi:10.1038/sj.bjp.0705482
Forced Torsional Oscillation From The Interior Of A Half-space

Abstract An analysis is presented of the torsional excitation of a rigid disc in bonded contact with the interior of an elastic half-space. With the aid of Hankel transforms, an exact formulation for the mixed boundary value problem is obtained as a pair of dual integral equations. After reduction of the dual integral equations to a Fredholm integral equation of the second kind, solutions to the problem are computed. Features of the problem, including a boundary-layer phenomenon, are illustrated through the results on the dynamic torque-rotation relationship, the stress field and the contact load distribution.
Assessment of pull-to-stand joint reactions in human subjects: Biomechanical analysis

A biomechanical model has been developed to quantify pull-to-stand forces and torques in both the upper and lower extremities. A 2-D sagittal plane segmental model was used. Data obtained from a force plate, instrumented pull-to-stand bar and video camera was used. Results of pull-to-stand compared to no pull-to-stand indicated a decrease in net moments at the ankle and knee joints and an increase in net moments at the shoulder and hip joints.
An algorithm for optimally fitting a wiener model

The purpose of this work is to present a new methodology for fitting Wiener networks to datasets with a large number of variables. Wiener networks have the ability to model a wide range of data types, and their structures can yield parameters with phenomenological meaning. There are several challenges to fitting such a model: model stiffness, the nonlinear nature of a Wiener network, possible overfitting, and the large number of parameters inherent with large input sets. This work describes a methodology to overcome these challenges by using several iterative algorithms under supervised learning and fitting subsets of the parameters at a time. This methodology is applied to Wiener networks that are used to predict blood glucose concentrations. The predictions of validation sets from models fit to four subjects using this methodology yielded a higher correlation between observed and predicted observations than other algorithms, including the Gauss-Newton and Levenberg-Marquardt algorithms.
Androgen receptor interactions with Oct-1 and Brn-1 are physically and functionally distinct

POU domain proteins interact positively or negatively with steroid hormone receptors, depending on the precise array of these and other factors assembled on target gene promoters. Octamer transcription factor 1 (Oct-1), a ubiquitous POU factor, is implicated in androgen induction of the mouse sex-limited protein (Slp) gene based on protein-DNA interaction studies. However, direct evidence for a role of Oct-1 in the hormone response has been difficult to obtain. Brain 1 (Brn-1), another POU factor, is more tissue-specific, expressing in brain and also in kidney, which is a major site of Slp synthesis. We compared the interaction of the androgen receptor (AR) with Oct-1 and Brn-1 to reveal the more likely candidate for regulation of Slp. In transfection, addition of either Oct-1 or Brn-1 reduced AR activation, regardless of the presence of an octamer-like sequence in the enhancer, suggesting interference was indirect. However, when the octamer-like element was changed to a consensus octamer site, Brn-1, but not Oct-1, strongly enhanced androgen activation. This correlated with Brn-l's preference for the consensus octamer sequence in DNA binding assays. Direct interaction of AR with glutathione-S-transferase-(GST)-fused Oct-1 was DNA-dependent, while Brn-l-AR association was not. Chimeric Brn-1 and Oct-1 POU domains demonstrated that the DNA-dependent AR interaction relied on the origin of the POU homeodomain. However, in the context of full-length Brn-1 and Oct-1 chimeric proteins, the POU homedomain was not sufficient to confer the distinct behaviors of these factors in vivo, but instead revealed the importance of an N-terminal transactivation domain in Brn-1. These results demonstrate that functional interaction of Oct-1 and Brn-1 with AR is determined by the precise sequence of the octamer binding site, and by differential interaction of the POU factors with AR and other components of the transcriptional machinery.
Collaborative Consultation: Improving Parent-Teacher Communication.

The parent-teacher conference is reconceptualized as collaborative consultation with teacher and parent assuming the roles of problem solvers.
The cycling of readily available phosphorus in response to elevated phosphate in acidic temperate deciduous forests

Abstract The biogeochemical cycling of phosphorus (P) in temperate forest ecosystems is poorly understood relative to nitrogen (N) cycling because of the assumption that N is the main factor that limits plant growth. This dichotomous way of understanding nutrient regimes is likely an oversimplification of these dynamic, interacting cycles within the evermore-dynamic framework of soil development. In order to better understand P cycling in temperate deciduous forests, we sought to quantify labile (resin) P flux and determine if soil shows signs of P stress. Labile P flux was quantified in nine ambient and nine elevated P plots on unglaciated eastern deciduous forests in Eastern Ohio. Anion exchange membranes (AEMs) were deployed in situ for two weeks, in the fall and the winter. Flux values were contextualized by resin P pools, N and P mineralization, and phosphatase enzyme activities determined from soil samples collected both at the time of AEM deployment and harvest. Phosphorus flux was 0.64 ± 0.23 μg P d−1 (mean ± SD) in ambient plots and 3.47 ± 2.39 μg P d−1 in amended P plots. Resin P pools were 4.16 mg kg−1 and 10.26 mg kg−1 in the control and elevated plots, respectively. Phosphorus turnover rate increased from one week in control plots, to 3 days in elevated P plots. Results indicate mild P stress relative to N, as N was mineralized (0.84 ± 0.18 mg N kg−1 d−1) while P was immobilized (−0.22 ± 0.09 mg P kg−1 d−1). The elevated P treatment did not increase P mineralization. Phosphatase enzyme activities were significantly suppressed by 34% with P amendment. Results suggest labile P is a shallow pool, but is rapidly cycling.
Situational factors and attitudes toward voluntary euthanasia

This study examines how attitudes toward voluntary euthanasia vary across categories of four situational factors: (1) type of assistance; (2) type of assistant; (3) type of illness; (4) age of the patient. The data, based on a random sample of 514 adult residents of Ohio, indicate that more active assistance is favored over less active assistance, and that voluntary euthanasia for cancer patients receives more support than does voluntary euthanasia for victims of Alzheimer's disease. The findings also suggest that, for persons who do not strongly adhere to the belief that life belongs to God, physician-assistants are preferred over nonphysician-assistants, and that voluntary euthanasia for children receives less support than does voluntary euthanasia for adults. For those who strongly adhere to the belief that life belongs to God. however, these two situational factors have less of an influence. At the microlevel, the findings appear to reflect a concern about safeguarding patients' autonomy in the decision-making process, and a concern about authoritative control of the procedure of voluntary euthanasia. At the macrolevel, the findings suggest that the influence of cultural ideology on a social movement's direction is not independent, but is instead moderated by the internal dynamics and struggles of movement organizations. This is indicated by the finding that movement leaders' attitudes toward active assistance on the part of the physician are more consistent with the attitudes of physicians than with the attitudes of the public.
Large thyroglossal duct cyst with laryngeal extension.

Background. A thyroglossal duct cyst typically presents as a long-standing neck mass that becomes symptomatic when inflamed. Hoarseness is an uncommon complaint, and its association may suggest encroachment on and destruction of the larynx. Following removal of the cyst with the Sistrunk procedure, the larynx may need to be reconstructed. Methods. A case is reported of a patient who was initially seen with hoarseness and a long-standing midline neck mass. Computed tomography (CT) demonstrated a large cystic neck mass that eroded the thyroid cartilage and encroached on the pre-epiglottic space and right paraglottic space. Although the clinical impression was that of laryngeal neoplasm, the CT diagnosis was that of a cyst. At surgery, a thyroglossal duct cyst was found and successfully removed with the Sistrunk procedure. Because the thyrohyoid membrane and thyroid perichondrium were preserved, the glottis did not require reconstruction. This case is presented and the literature of thyroglossal duct cysts that extend into the larynx is reviewed. Conclusions. The clinical and radiographic criteria that suggest encroachment of a thyroglossal duct cyst on the larynx are reviewed. The management and indications for laryngeal reconstruction are discussed.
Total synthesis and absolute configuration of rhizobactin, a structurally novel siderophore

Abstract The actual stereoisomer of rhizobactin, N2-[2-[(R)-(1-carboxyethyl)amino]-ethyl-N6-(S)-(3-carboxy-3-)hydroxy-1-oxopropyl)-(S)-lysine 14 , has been synthesized and substantiates the conclusion that this siderophore is biochemically related to the pyruvic acid derived opines.
Characterizing Birefringent Crystal Wafers With A Scanning Laser Microscope

A near-real-time scanning laser microscope has been developed to assist in the characterization of crystal wafers used to produce integrated optical devices. This instrument is employed in an experimental program to correlate crystal anomalies with integrated device performance. A combination of polarization and masking techniques is used to generate images of higher contrast ratio and larger useful field of view than obtainable with conventional microscopy techniques. The raster-scanning beam design allows rapid image formation, which speeds the inspection operation. The addition of confocal optics increases the flexibility of the instrument and expands the useful applications to include biological and integrated structure characterization problems. Automation techniques are used to minimize the time required to inspect a given sample. A computer system prepares summarizing data displays that contain the key parameters describing the sample.
Pair potential model of substitutional solid solutions

Abstract The pair potential model previously developed [1–4] is applied to concentrated random solid solutions. It is found that the predicted lattice parameters are in agreement with observed values within an r.m.s. deviation of 0.38%. A correction is developed to allow the model to be applied to heteroelectronic phases (i.e. components have mixed electron character.) It is found that except for combinations between {Ni, Pd, Pt} and {IB, IIB} groups and for solutions where the simple metal component is the solvent that the corrected model correctly predicts the lattice parameter. The ordering energies of the A1 → L12 transitions are correctly predicted. Those for the A2 → B2 transitions deviate numerically from the observed values in such a way as to suggest the existence of another unique contribution to the ordering energy of the latter transition.
Analysis of Optimal Reconfiguration of Shipboard Power Systems

In power system reconfiguration, the status (ON/OFF) of switches are optimized such that maximum power is delivered to loads after the occurrence of a fault. The optimized reconfiguration is achieved by prioritizing power delivered to vital loads over semi-vital and nonvital loads. The formulation presented in this paper considers a new balanced hybrid (AC and DC) shipboard power system (SPS). Analysis of the nonconvex reconfiguration formulation is done by an appropriate nonconvex solver and by convex approximation. Unlike the nonconvex solution that is based on branch-and-bound methods, convex approximation significantly reduces complexity. It is shown that for the hybrid SPS reconfiguration problem, low complexity convex approximations are effective in finding optimal solutions. Cumulative distribution function (CDF) of the power delivered to loads is presented to showcase the system robustness against random fault scenarios. A combined objective of maximizing power delivery and minimizing the number of switching actions is included in the analysis. Tradeoff between power delivered and number of switching operations after reconfiguration has been discussed at steady state. A separate analysis is also included to observe the intermediate dynamic switch states while the reconfiguration is in progress to capture the trade-off more prominently.
Upper limit set for level of lightning activity on Titan

Because optically thick cloud and haze layers prevent lightning detection at optical wavelength on Titan, a search was conducted for lightning-radiated signals (spherics) at radio wavelengths using the planetary radioastronomy instrument aboard Voyager 1. Given the maximum ionosphere density of about 3000/cu cm, lightning spherics should be detectable above an observing frequency of 500 kHz. Since no evidence for spherics is found, an upper limit to the total energy per flash in Titan lightning of about 10 to the 6th J, or about 1000 times weaker than that of typical terrestrial lightning, is inferred.
Supersaturation: Effect of a high-frequency cutoff on strong optical-scintillation measurements

An expression is derived for the apparent log-amplitude variance that would result experimentally from the use of a high-frequency cutoff νe in the electronic detection system. It is shown, for the Kolmogorov spectrum and in the saturation regime, that the apparent log-amplitude variance decreases asymptotically as σT-2/5, where σT2 is the log-amplitude variance obtained from the perturbation theory. Furthermore, it is shown that theories that suppress spatial frequencies of the order 1/ρ0(L), where ρ0(L) is the lateral coherence of the wave at propagation distance L, are equivalent to suppressing high temporal frequencies in the time domain. Thus, such theories will result in a predicted log-amplitude variance that decreases asymptotically with increasing values of σT2.
Effect of reduced background radiation on photoconductive InSb detector arrays

Abstract The responsive properties of 74 photoconductive InSb detector array elements are reported. D ∗ (4.6, 840, 1) of each nominally 0.002 in. by 0.037 in. rectangular detector is equal to or greater than 1.1 × 10 11 cm-(cps) 1 2 /W. Responsive measurements were made first with a 180° field of view, and then with an average 56° field of view incorporating a cooled 3.5μ–5.0μ spectral bandpass filter. All measurements were made at a detector temperature of 77° K and a nominal background temperature of 300°K. Theoretically predicted and experimentally observed performance changes due to a reduced background are compared. Performance data is presented for blackbody and spectral detectivity, resistance, optimum bias current, and time constant. The predicted improvement factor for spectral detectivity resulting from the reduction of background radiation is 2.64. The average improvement factor for the 74 detectors reported here is 2.25.
Distinct Adhesive Behaviors of Neurons and Neural Precursor Cells during Regional Differentiation in the Mammalian Forebrain

Prior to the emergence of the major functional subdivisions of the mammalian forebrain--the neocortex, hippocampus, olfactory bulb, basal ganglia, and basal forebrain--the lateral aspect of the telencephalic vesicle is distinguished by early neuronal differentiation assessed by MAP2 and GAP43 expression and increased expression of the Ca(2+)-independent/immunoglobulin superfamily cell adhesion molecules (CAMs) NCAM, L1, and TAG-1. In contrast, the ventral and medial aspects of the vesicle show little early neuronal differentiation and intermediate or undetectable levels of CAM expression. We asked whether cells from these three regions acquire distinct adhesive and recognition properties that reflect their position, state of neuronal differentiation, and level of CAM expression. In a dissociation/reaggregation assay, cells from the lateral telencephalic vesicle form the largest reaggregates while ventral reaggregates are of intermediate size and medial reaggregates are the smallest. This differential adhesion has a Ca(2+)-independent component, and cells in reaggregates from each region maintain expression of CAMs and other neuronal markers consistent with their region of origin. Furthermore, cells from the lateral telencephalon can specifically sort out from medial cells. Little adhesivity is observed prior to early neuronal differentiation and the expression of Ca(2+)-independent CAMs, when the forebrain is still a prosencephalic vesicle, nor does it follow the pattern of detectable CAM expression once forebrain rudiments are formed. Thus, cells in the early developing forebrain acquire distinct adhesive and recognition properties that reflect the concurrent emergence of regional differences in neuronal differentiation and CAM expression. These differences are transient and can only be detected in the telencephalic vesicle before and during the morphogenesis of rudiments of major forebrain subdivisions.
High-Resolution, Long-Slit Spectroscopy of VY Canis Majoris: The Evidence for Localized High Mass Loss Events

High spatial and spectral resolution spectroscopy of the OH/IR supergiant VY CMa and its circumstellar ejecta reveals evidence for high mass loss events from localized regions on the star occurring over the past 1000 yr. The reflected absorption lines and the extremely strong K I emission lines show a complex pattern of velocities in the ejecta. We show that the large, dusty northwest arc, expanding at ≈50 km s-1 with respect to the embedded star, is kinematically distinct from the surrounding nebulosity and was ejected about 400 yr ago. Other large, more filamentary loops were probably expelled as much as 800–1000 yr ago, whereas knots and small arcs close to the star resulted from more recent events 100–200 yr ago. The more diffuse, uniformly distributed gas and dust is surprisingly stationary, with little or no velocity relative to the star. This is not what we would expect for the circumstellar material from an evolved red supergiant with a long history of mass loss. We therefore suggest that the high mass loss rate for VY CMa is a measure of the mass carried out by these specific ejections accompanied by streams or flows of gas through low-density regions in the dust envelope. VY CMa may thus be our most extreme example of stellar activity, but our results also bring into question the evolutionary state of this famous star. In a separate appendix, we discuss the origin of the very strong K I and other rare emission lines in its spectrum.
Temperature distribution in a vaporizing droplet with internal heat generation

Abstract The time-dependent temperature distribution within a droplet with internal heat generation and surface vaporization has been studied using a finite-difference numerical method. The heat transfer equations were nondimensionalized for computer calculations, and solutions were obtained for cases when the initial temperature is equal to and different from the surface temperature. Variation of droplet radius due to vaporization was included in the assumed model, and radial temperature distributions, relative to the surface temperature, were calculated under the assumption of constant surface temperature. Representative results are given as temperature and radius histories for a wide range of dimensionless variables. The results are applicable when surface temperature changes with time provided that the rate of change is small compared to the initial temperature transient due to heat generation.
Alterations in purine nucleotide biosynthesis induced by 2-amino-6-chloropurine.

Abstract Exposure of sarcoma 180 ascites cells to 2-amino-6-chloropurine (6-C1G) in vivo resulted in several metabolic lesions in the pathways of purine nucleotide biosynthesis. Pronounced inhibition of the incorporation of glycine-2- 14 C into the guanine and adenine nucleotides of the nucleic acids, coupled with blockade of the utilization of 4-amino-5-imidazolecarboxamide-2- 14 C solely for the formation of guanine nucleotides, indicated the presence of a site of inhibition on the pathway of purine nucleotide formation de novo . The conversion of hypoxanthine-8- 14 C to nucleic acid guanine was markedly decreased by 6-CIG, whereas the utilization of this labeled precursor for the formation of nucleic acid adenine was not lowered by this agent. Under these conditions neither the incorporation of xanthine-8- 14 C nor of guanine-8- 14 C into the guanine moiety of the nucleic acids was depressed, indicating that 6-CIG or a derivative thereof inhibited the conversion of inosine 5′-phosphate to xanthosine 5′-phosphate. Blockade of this site was confirmed by the finding that 2-amino-6-chloropurine ribonucleoside 5′-phosphate inhibited the activity of inosine 5′-phosphate dehydrogenase. Molar equivalent levels of 2-amino-6-chloropurine ribonucleoside and 2-amino-6-chloropurine ribonucleoside triacetate caused a degree of inhibition of the conversion of hypoxanthine-8- 14 C to guanine nucleotides comparable to that produced by 6-C1G. 2-Amino-6-iodopurine ribonucleoside was at least as active an inhibitor of the formation of nucleic acid guanine as the chloro-derivatives.
Efficacy of Anti‐IL‐2 Receptor Antibodies Compared to no Induction and to Antilymphocyte Antibodies in Renal Transplantation

The relative efficacy of anti-IL-2 receptor antibodies (IL2R Abs) and antilymphocyte antibodies in preventing acute rejection and improving graft survival after renal transplantation is poorly defined. In particular, the benefits of these agents in specific subgroups, such as recipients with different degrees of HLA mismatch, are unknown. Using the SRTR database, we compared IL2R Abs to no induction and to antilymphocyte antibody induction in 48 948 first renal transplant recipients in the United States between 1998 and 2003 with respect to acute rejection and graft failure. IL2R Abs decreased acute rejection at 6 months (OR: 0.81(0.75-0.87)), and reduced graft failure (HR: 0.90(0.84-0.95)), compared to no induction over a follow-up of 1059 days. Compared to IL2R Abs, antilymphocyte Abs were associated with decreased acute rejection (OR: 0.90(0.83-0.99)) at 1 year, but were not associated with improved graft survival (OR: 1.08(1.00-1.18)) over a follow-up of 732 days. The benefit of IL2R Abs in reducing acute rejection increased significantly with greater HLA mismatch (p = 0.007). IL2R Abs remain an important option in the management of renal transplant patients, and may be particularly useful in specific patient subsets.
Effect of surface roughness and surface texture on scuffing

Abstract This paper discusses the results of disk tests designed to examine the effect of surface roughness and surface texture on scuffing and related behavior. AISI 9310 steel disk of varying surface roughness and surface texture, along with a MIL-L-7808G lubricant, were used. It is shown that, under otherwise comparable situations, (a) an increase in the composite surface roughness increases the coefficient of friction at scuffing, decreases the scuff failure load, and decreases the critical temperature, (b) the cross-ground disks give a lower coefficient of friction at scuffing and a higher scuff failure load than the circumferentially-ground disks, but nearly the same critical temperature, and (c) an increase in the sliding velocity or sum velocity, at a constant sliding-to-sum velocity ratio, decreases the coefficient of friction at scuffing, decreases the scuff failure load, and decreases the critical temperature. The superior performance of the cross-ground disks compared with the circumferentially-ground disks is attributed to the effect of surface texture on microelastohydrodynamic action. The variations of the oil film thickness ratio at scuffing, the coefficient of friction at scuffing, and the critical temperature with respect to surface roughness, surface texture, and operating variables have been shown to correlate well with a dimensionless parameter ξ ƒ .
Influence of thermally induced scission and crosslinking on the post-scission inflation of circular elastomeric membranes

Abstract When an elastomeric material is deformed and subjected to temperatures above some characteristic value Tcr (near 100 °C for natural rubber), macromolecular chains and crosslinks undergo scission, recoiling and re-crosslinking. The process depends on time and temperature and continues until the temperature decreases below Tcr. Compared to the virgin material, the new material system has modified properties (reduced stiffness) and permanent set on removal of the applied load. A constitutive theory that accounts for these changes in macromolecular structure is used to simulate an experiment involving the inflation of an initially flat circular membrane. The membrane is initially at a temperature T The temperature is returned to its original value and the pressure is gradually removed. It is shown that compressive stresses may develop as the pressure is reduced. If the membrane is removed from its support, it will have developed a permanently curved shape. Results of a numerical simulation are presented that compares the initial inflated shape to the permanently curved shape.
4: A Philosophical Consideration of Recent Research on Teacher Effectiveness

uninformed or unintelligible. Criticism of the second kind is useful because it is pertinent to the research effort and directed to reparable defects. Criticism of the third kind, though apparently significant, cannot be heeded because the remedy is unknown or because its implications are that the shop must be closed and a new calling found. Except for some contributions in philosophy of science, educational researchers of my acquaintance place most philosophical criticism of their work in the first and third categories. Wolman (1971), for example, thought the deficiencies of philosophical criticism were serious enough to warrant an attempt by psychologists to build their own philosophy of science, rather than having to depend on the often misguided and destructive critiques of philosophers. Lazersfeld (1962) concluded that many philosopher-critics have no idea of the workaday world of the empirical researcher, and as one consequence the social scientist may "have to muddle along without benefit of the explicating clergy" (p. 470). The educational researcher's preference, understandably, is for criticism of the second kind. This kind of criticism can be met and resolved without radical
The international political economy of (un)sustainable consumption and the global financial collapse

Adopted at the 1992 Earth Summit and elaborated at the Johannesburg Conference a decade later, sustainable consumption occupies an increasingly prominent political position. Numerous governmental ministries and supranational organisations have produced sustainable consumption plans. However, actual programmatic initiatives have been limited to modest information and education campaigns as policy proposals are constrained by political contexts. Researchers have documented flows of materials and energy, but have disregarded the political and economic dynamics that animate throughput movements. Inattention to factors that propel the global metabolism, scholarship largely failed to anticipate the ongoing global financial collapse. Work on the household economics and macroeconomics of consumption is reviewed and an international political economy of (un)sustainable consumption is developed. Realignment of the global economic order will require renegotiation of the tacit agreements that the USA strikes with its...
Induction of epidermis and inhibition of neural fate by Bmp-4

DURING gastrulation in vertebrates, ectodermal cells choose between two fates, neural and epidermal. The nervous system forms in response to signals from the Spemann organizer1,2; ectoderm that does not receive these signals becomes epidermis. Unexpectedly, however, in Xenopus, neural tissue also forms when cell-cell communication within the ectoderm is disrupted by cell dissociation3,4 or by antagonists of the growth factor activin5-7. These observations suggest that epidermal specification depends on local signalling, by activin or a close relative, and that neural tissue forms when this communication is blocked6. Here we report that bone morphogenesis protein 4 (Bmp-4), a relative of activin that is expressed in the embryo at the time of ectodermal fate determination8,9, is a potent epidermal inducer and neural inhibitor, the first reported in any vertebrate. Activin can inhibit neuralization by inducing mesoderm, but does not induce epidermis. Moreover, the dominant-negative activin receptor, which stimulates neuralization when expressed in the embryo5,6, blocks Bmp-4 in our assay. Our findings demonstrate that epidermal fate can be induced, and thus provide further evidence that neural specification is under inhibitory control in vertebrates.
Recognizing geons from superquadratics fitted to range data

This paper attempts to relate two influential families of 3D shape primitives, superquadrics and geons. Superquadric surfaces have attracted considerable interest recently as part models for representation of 3D objects. Here, we explore their utility for a different purpose, i.e. for shape discrimination. We investigate how well the estimated superquadric parameters can reflect certain intuitive geometric attributes of elongated objects, such as axis shape (straight or bent), type of cross-sectional edges (straight or curved), and variation of cross-section size along the axis (constant, tapered, or increasing-and-decreasing). Parameters of the best-fitting superquadric are estimated for real as well as synthetic range images, obtained from a large number of viewpoints, of models belonging to 12 shape classes based on the above geometric attributes. These shape classes correspond to a ‘collapsed’ set of 36 different geons. Five features derived from the estimated superquadric parameters are used to distinguish between these 12 shape classes. Classification error rates are estimated for k-nearest-neighbour and binary tree classifiers. The effects of varying the range image resolution, noise level and the model elongation are also investigated. The results indicate that existing methods of superquadric parameter estimation are quite sensitive to noise in range values and also do not work well for ‘rough’, coarse-surfaced objects. However, for low-noise real range images of objects with ‘smooth’ surfaces, numerical features derived from estimated superquadric parameters can be used with a binary tree classifier to infer qualitative shape properties with about 80% reliability.
An internal-variable constitutive model for semisolid slurries at high solid fractions

A mathematical model is proposed to represent the thixotropic behavior of semisolid slurries at high solid fractions (ƒs > 0.6), as occurs in dispersion-strengthened metal-matrix composite processing. The model assumes that the slurry behaves as a viscoplastic porous medium saturated with liquid phase and hardened or softened, depending on the shear rate and solid fraction. The model is validated by comparison of its predictions with a recent set of experimental data on Sn-Pb alloys.
A tabular parsing algorithm with error recovery

In this article, a general tabular parsing algorithm is developed which permits isolated errors due to deletion, replacement, or insertion of a word or phrase, and which finds the derivation with minimum errors.
Evidence inconsistent with a role for the Bcg gene (Nramp1) in resistance of mice to infection with virulent Mycobacterium tuberculosis.

The superior resistance of some strains of mice over others to infection with certain intracellular pathogens, including the vaccine strain of Mycobacterium bovis, bacillus Calmette Guerin (BCG), is determined by a gene associated with a small segment of chromosome 1 designated by Ity/Lsh/Bcg locus, referred to here as the Bcg locus. DBA/2 mice containing the dominant resistant allele of the Bcg gene (Bcgr), major histocompatibility complex-compatible BALB/c mice containing the recessive susceptible allele (Bcgs), and congenic C.D2-N20 Bcgr, which are genetically the same as BALB/c mice except for possessing a small piece of DBA/2 chromosome 1 containing the Bcg locus, were used to determine whether the Bcg gene determines resistance to infection with the virulent H37Rv strain of Mycobacterium tuberculosis (Mtb). According to the survival times of Bcgr and Bcgs mice infected via either the intravenous or respiratory route, Bcgr mice proved much less, rather than more, resistant to Mtb infection than Bcgs mice. Shorter survival times of Bcgr mice were associated with an inferior capacity to control Mtb growth in their lungs and to retard the development of Mtb-induced pathology in this organ. Resistance to Mtb infection was a dominant trait in the F1 progeny of Bcgr and Bcgs mice. The results show that resistance to Mtb is not determined by the resistance allele of the Bcg gene nor by the recently isolated candidate Bcg gene Nramp1, located in the Bcg locus.