cssi/SciSciGPT-SciSciNet huggingface dataset:
Methyl transfer from MeCo(III)Pc to thiophenoxide

Transfer of the cobalt-bound methyl in MeCo(III)Pc to thiophenoxide ion was studied (H2Pc is the planar macrocyclic phthalocyanine; the cobalt is held in the center in this plane). In dimethylacetamide solution, the reaction is rapid, requiring stopped flow for the kinetics, and yielding MeSPh and Co(I)Pc− in good yield. The kinetics are not simple second order, but instead approach a constant rate at high [PhS−], attributed to the reversible formation of an inert complex with PhS− occupying the vacant octahedral site in MeCo(III)Pc, on the other side of the phthalocyanine plane from the methyl group. The kinetics allow the estimation of the equilibrium constant, K, and the SN2 rate constant, k, which at 25°C have values of ca. 9·4 × 103 l mol−1 and 1·8 × 104 l mol−1, respectively. Although these values are rough, the ratio k/K is firm at 1·91 ± 0·02 s−1; this is the limit of the rate at high [PhS−]. An alternative mechanism, which is entirely consistent with the kinetics, involves a rate-determining homolysis of the CoS bond of the same complex. The mechanism is not favored because the product yields are high for a radical combination process and alternative chain processes are kinetically unacceptable. Further, the rate constant is about what would be expected from the reactivity of other nucleophiles in SN2 reactions. Further arguments in favor of the SN2 mechanism are presented. This transfer of the methyl group from Co to S is part of the possible analogy to the vitamin B12-promoted methionine synthesis in nature. The other step in the biological, enzymatic process is the transfer of methyl from the nitrogen of N-methyltetrahydrofolate to cobalt. An attempt to model this with the very reactive N-methyl-2,6-dichloropyridinium ion was unsuccessful; the reaction took an entirely different course, presumably initiated by electron transfer, but leading to substantial loss of Cl− from the pyridine. No more than 0.5% methyl transfer took place. This system does mimic well the complete natural enzymatic process.
Learning From Feedback: Spacing and the Delay―Retention Effect

Most modern research on the effects of feedback during learning has assumed that feedback is an error correction mechanism. Recent studies of feedback-timing effects have suggested that feedback might also strengthen initially correct responses. In an experiment involving cued recall of trivia facts, we directly tested several theories of feedback-timing effects and also examined the effects of restudy and retest trials following immediate and delayed feedback. Results were not consistent with theories assuming that the only function of feedback is to correct initial errors but instead supported a theoretical account assuming that delaying feedback strengthens initially correct responses due to the spacing of encoding opportunities: Delaying feedback increased the probability of correct response perseveration on the final retention test but had minimal effects on error correction or error perseveration probabilities. In a 2nd experiment, the effects of varying the lags between study, test, and feedback trials during learning provided further support for the spacing hypothesis. (PsycINFO Database Record (c) 2009 APA, all rights reserved).
Effects of Electron Bombardment on Properties of Various Glasses

Soda-lime, borosilicate, and lead glass specimens were exposed to various dosages of 2 m.e.v. electrons. The effects of the irradiation on flexural strength, density, chemical durability, heat of solution, and electrical resistivity were investigated. The results showed that for dosages up to 300 megareps several small effects were noted but were considered to be of minor significance as far as bottle serviceability is concerned.
Secondary Analysis of National Longitudinal Transition Study 2 Data A Statistical Review

This review examines published secondary analyses of National Longitudinal Transition Study 2 (NLTS2) data, with a primary focus upon statistical objectives, paradigms, inferences, and methods. Its...
Apoptosis and a re-investigation of the biologic basis for cancer therapy

Antitumor therapy has expanded beyond the previous notions of cytotoxic or biologic therapy to now include agents that induce differentiation (e.g. all trans-retinoic acid for induction of complete remission in patients with acute promyelocytic leukemia [23]) or apoptosis [91]. In fact, the phenomenon of apoptosis may be fundamental to the current understanding of carcinogenesis [11] and may also underlie the effectiveness of some forms of chemotherapy [4,5,18,39,56,59,67], radiation therapy [19,44,52,60,64, 77,78,85] and the interferons [73]. The process of apoptosis has been shown to be responsible for the normal elimination of cells with damaged DNA [81] as well as other potentially dangerous cells such as autoreactive T-lymphocytes [14]. Therefore, although much attention has been given to oncogenes that induce cellular proliferation, one can easily see how the same result (i.e. neoplasia) could be obtained when the ability of a cell to undergo apoptosis is lost.
Pushing the boundaries of technology to educate and train the next generation of crystallographers

This article describes the evolution of educational technologies, moving from the Web 1.0 to the current Web 3.0 decade, with the aim of stimulating discussion and inspiring innovative and effective crystallography education in the Web 3.0 decade. In the last 15 years, academic crystallography has largely migrated from a research specialty to a technique employed by a broad user community. This has led to the growth of and dependence on independently funded workshops and summer schools, as well as other non-traditional curricular resources for crystallography instruction, such as web pages and online courses, which allow crystallography to be self-taught. In fact, informal courses and e-learning constitute 70–80% of all learning today, and students expect on-demand learning. Implementing modern web technologies with sound pedagogy requires skilful integration of relevant, often disparate, resources into useful and usable frameworks, enabling learners to interact, explore new situations, and use scientific reasoning skills such as hypothesis testing and model-based reasoning. The evident disproportion in implementing contemporary technologies into our global crystallography education resources requires that we shift our focus from simply imparting subject knowledge by posting largely text-based content to empowering students with the fundamental processes and skills needed for on-demand learning and practice in crystallography.
Neural crest cell migration in the developing embryo

In vertebrate embryos, neural crest cells migrate extensively to defined sites where they differentiate into a complex array of derivatives, ranging from neurons to pigment cells. Neural crest cells emerge uniformly from the neural tube but their subsequent migratory pattern is segmented along much of the body axis. What factors control this segmental migration? At trunk levels, it is imposed by the intrinsic segmentation of the neighbouring somitic mesoderm, while in the head, intrinsic information within the neural tube as well as extrinsic influences from the ectoderm are involved. A variety of cell-cell and cell-extracellular matrix interactions are thought to influence initiation and movement of neural crest cells. This review summarizes recent progress from both experimental embryology and cell biology approaches in uncovering the mechanisms underlying neural crest cell migration.
Spin effects in large-transverse-momentum exclusive scattering processes

Nucleon-nucleon scattering at large momentum transfer is analyzed within the framework of quantum-chromodynamic quark and gluon interactions. The spin dependence of the hadronic amplitude is found to be particularly sensitive to the underlying dynamical mechanisms. Detailed discussions of the quark-intercharge and Landshoff pinch-singularity contributions are given for large-angle $\mathrm{pp}$, $\mathrm{np}$, and $p\overline{p}$ elastic scattering. A possible explanation is given for the large spin-spin correlations measured by Crabb et al. We also define a new SU(2) symmetry group, $H$ spin, which generalizes conventional helicity, and is an exact symmetry of the quark-intercharge process.
A stochastic model for estimating human carrying capacity in Brazil's Transamazon Highway colonization area

Human carrying capacity for tropical agricultural populations can be estimated with a computer simulation of the agroecosystem. A stochastic model is developed for estimating carrying capacity in one of the government-directed small farmer settlement projects along Brazil's Transamazon Highway. Carrying capacity is operationally defined in terms of an empirically computed relationship between population density and probability of colonist failure with respect to various criteria. When high population density leads failure probability to exceed a maximum acceptable level, population can be considered to be above carrying capacity. Colonist failure probabilities are those that are sustainable over a long period of simulated years. High variability in crop yields appears to have a strong effect on failure probability based on comparison of deterministic and stochastic runs of the simulations. Failure probabilities are raised by variability at low population densities, but are lowered at extremely high densities where most colonists would fail in an “average” year. Effects can be tested for colonists with different backgrounds or with differing agricultural practices such as fallow times. Failure probabilities in standard runs are higher than those considered acceptable to government planners at all population densities simulated in the present study's stochastic runs (lowest density 24 persons/km2), thus lending support to the informal impression of many that the carrying capacity of most of Amazonia's uplands is low.
QT DISPERSION IN CHILDREN WITH VENTRICULAR ARRHYTHMIA AND A STRUCTURALLY NORMAL HEART

In adults, increased QT dispersion has been shown to predict arrhythmic risk as well as risk of sudden death in several clinical settings. It is not known whether or not QT dispersion is increased in children with idiopathic ventricular arrhythmia. We studied three groups of children: (1) 20 patients with idiopathic VT (aged 3-18 years; mean 11.2 years); (2) 30 patients with benign PVCs (aged 1-20 years; mean 10.5 years); and (3) 30 control subjects (aged 4-17 years; mean 12 years). Standard ECGs were reviewed and the dispersion of both QT and JT intervals was compared. No patient had structural heart disease or long QT syndrome. The QT and QTc dispersion (QT delta, QTc delta) among the three groups did not differ: QTc delta of the VT group was 70 ms +/- 30 ms, QTc delta of PVC patients was 60 ms +/- 30 ms, and the QTc delta of the control group was 65 ms +/- 30 ms. The JTc delta among the three groups did not differ as well: JTc delta of the VT group was 70 ms +/- 30 ms, the JTc delta of the PVC group was 60 msec +/- 25 msec, and the JTc delta of the control group was 70 ms +/- 30 ms. We conclude that QT and JT dispersion are not significantly altered in children with idiopathic VT or benign PVCs when compared to control subjects. QT dispersion is not a reliable marker for arrhythmic risk in children with idiopathic ventricular arrhythmias and structurally normal hearts.
Laser-induced desorption and etching processes on chlorinated Cu and solid CuCl surfaces

Time-resolved mass spectrometry is used to study the desorbed species due to laser-induced etching of a solid CuCl and a chlorinated Cu surface. The observed desorption threshold, mass distribution and kinetic energies of the desorbed atoms and molecules at 355 and 532 nm radiation show that the laser-induced etching process is not simply thermal evaporation. It is suggested that competing nonthermal mechanisms due to electronic excitations may be very important in laser-induced desorption and etching. These processes are different for a solid CuCl and a chlorinated Cu surface. For laser-induced etching of Cu surfaces, chlorination of Cu is essential; however, formation of stoichiometric CuCl is not necessary. Excess Cu in the surface layer is responsible for the observed different etching behavior of a chlorinated Cu and a solid CuCl surface. The effect of laser radiation on these surfaces and possible etching mechanisms are discussed based on the experimental observations.
Coalitions in three-person groups.

(1963). Coalitions in Three-Person Groups. The Journal of Social Psychology: Vol. 60, No. 2, pp. 319-326.
LEVONORGESTREL IMPLANTS AS A CONTRACEPTIVE IN CAPTIVE WHITE-TAILED DEER

Silastic implants containing levonorgestrel (LNG) were evaluated as a contraceptive in captive white-tailed deer (Odocoileus virginianus). Six adult females and six female fawns received either six or nine implants in autumn. Each implant contained 36 mg of LNG. Blood was analyzed by radioimmunoassay to determine LNG release profile for 5 mo post-implantation. Serum LNG concentrations rose significantly (P = 0.0005) 3 days post-implantation, leveled off after 7 days, and did not change (P = 0.5913) during the remaining 5 mo. Mean (±SE) LNG concentrations for all months were higher (P = 0.0377) in adult and fawn females implanted with nine versus six rods (138.1 ± 14.4 versus 56.7 ± 12.3 pg/ml, respectively). Serum LNG levels did not differ between adults and fawns. Five of the six implanted adult females had normal estrous cyclicity; three of these five adult females became pregnant in the first year. Four implanted females (two yearlings and two adults) were monitored during a second year, and housed wit...
Mortgage Finance Markets: Lessons from the Past and Keys to the Future

This special section of the journal provides an empirical examination of the mortgage market to help identify key market participants, how incentives affected behavior, and how participation in the market changed over time. The findings will help to identify lessons that can be applied to the regulation and structure of the mortgage finance industry in the future. In particular the research examines loan product choice in the subprime market under different regulatory regimes, mortgage broker compensation market penetration, and the changing role of the Federal Housing Authority (FHA).
Effect of Processing Conditions on the Formation of Aggregates and Phase Domains in Monolayers of the Hemicyanine Dye, 4-(4-(Dihexadecylamino)styryl)-N-methylpyridinium Iodide

Epifluorescence microscopy and tapping mode AFM measurements were used to study the morphology of Langmuir−Blodgett monolayers of the hemicyanine dye, 4-(4-(dihexadecylamino)styryl)-N-methylpyridinium iodide, I, prepared under conditions of varying spreading solution concentration, compression speed, aging, subphase composition, and deposition pressure. The morphology, which is the result of coexisting liquid-expanded (LE) and liquid-condensed (LC) phases, is very sensitive to film preparation conditions but relatively insensitive to deposition pressure for a given film preparation protocol. Emission images reveal the following: domain size and shape are unaffected by deposition pressure; increasing spreading solution concentration while maintaining a constant number of molecules on the surface results in increased domain size; emission from the LC domains is more highly variegated as compression speed increases; and incorporation of I- in the subphase results in an entirely new morphology, in contrast t...
Open-heart operations in patients with a spinal cord injury

Abstract Background The objective of our study was to evaluate the outcomes of open-heart surgery in patients with a spinal cord injury. Methods A retrospective analysis of all patients (n = 8) with a spinal cord injury who underwent open-heart operations in a single institution from April 1994 to November 2006 was conducted. Results All patients had a permanent spinal cord injury with levels ranging from T3 to L2 with a mean age of 62 years (range, 47–72). Seven coronary artery bypass operations and 2 aortic valve replacements were performed. The mean cardiac ejection fraction was 44% (range, 20–60). Seventy-five percent of the patients were extubated within 24 hours of the operation. A decubitus ulcer occurred in only 1 patient. The acute hospital stay averaged 14 days (range, 6–36). One patient died from multiorgan failure on postoperative day 13 giving an in-hospital 30-day mortality of 12.5%. The 5-year survival was 75% with a mean follow-up of 67 months (range, .5–129). Conclusions Open-heart operations in patients with a spinal cord injury can be performed safely with acceptable early and late outcomes.
Cervical Surgery for Cervical Intraepithelial Neoplasia and Prolonged Time to Conception of a Live Birth: A Case-Control Study

Objective To determine whether women with a history of surgery for cervical intraepithelial neoplasia (CIN) are at an increased risk of subfertility, measured as a time to pregnancy of more than 12 months. Design Case–control study. Setting Iowa Health in Pregnancy Study (IHIPS), a population-based case–control study of preterm and small-for-gestational-age (SGA) live birth outcomes (from May 2002 through June 2005) in the USA. Sample Women with an intended pregnancy and a history of either one prior cervical surgery (n = 152), colposcopy only (n = 151), or no prior cervical surgery or colposcopy (n = 1021). Methods Cervical treatment history, pregnancy intention, time to pregnancy, and other variables were self-reported by computer-assisted telephone interviews. Odds ratios were calculated using logistic regression to estimate the risk of prolonged time to pregnancy among women with a history of cervical surgery or colposcopy alone, compared with untreated women (control group). Main outcome measure Prolonged time to pregnancy (i.e. >1 year). Results Prolonged time to pregnancy was most prevalent among treated women (16.4%), compared with untreated women (8.4%) and women with colposcopy only (8.6%) (P = 0.039). After adjusting for covariates, women with prior cervical surgery had a more than two-fold higher risk of prolonged time to pregnancy compared with untreated women (aOR 2.09, 95% CI 1.26–3.46). In contrast, women with a history of colposcopy only had a risk equivalent to that found among untreated women (aOR 1.02, 95% CI 0.56–1.89). Conclusions Women with a history of cervical treatment for CIN are at increased risk of subfertility, measured as a time to pregnancy of more than 12 months.
Partial Melting and Resolidification of Single-Component Metal Powder With a Moving Laser Beam

Partial melting and resolidification of single-component metal powders with a moving laser beam is investigated numerically. Since laser processing of metal powder is a very rapid process, the liquid layer and solid core of a partially molten powder particle may not at thermal equilibrium and have different temperatures: the temperature of the liquid part is higher than the melting point, and the temperature of the solid core is below the melting point. Therefore, the local temperature of regions with partial molten particles is within a range of temperature adjacent to the melting point, instead of at the melting point. The partial melting of the metal powder is also accompanied by shrinkage that drives out the gas in the powder bed and the powder structure is supported by the solid core of the partially melted powder particles. Melting with shrinkage and resolidification are described using a temperature transforming model. The convection driven by capillary and gravity forces in the melting liquid pool is formulated by using Darcy’s law. The effects of laser beam intensity and scanning velocity on the shape and size of the heat affected zone and molten pool are investigated.Copyright © 2005 by ASME
Attenuation in Peripheral Endothelial Function After Continuous Flow Left Ventricular Assist Device Therapy Is Associated With Cardiovascular Adverse Events

BACKGROUND Patients with heart failure (HF) have abnormal endothelial function. Although use of a continuous flow left ventricular assist device (CF-LVAD) results in significant hemodynamic improvement, the effects on systemic endothelial function are unclear. METHODS AND RESULTS Eighteen HF patients with CF-LVAD implantation were included in this prospective observational study. We measured reactive hyperemia index (RHI) before and after CF-LVAD implantation to evaluate sequential changes in endothelial function. Patients were followed clinically for the occurrence of adverse cardiovascular events, a composite of death, thrombosis, bleeding, HF, renal failure, and arrhythmia. Preoperative RHI was 1.77±0.39. Early in the postoperative period (7-14 days after operation) RHI significantly decreased to 1.19±0.31 (P<0.001, compared with preoperative RHI). At first and second follow-up (4-6 weeks and 3-7 months after operation) RHI remained lower at 1.48±0.50 (P=0.030) and 1.26±0.37 (P=0.002), respectively, compared with preoperative RHI. The decrease in early postoperative RHI relative to preoperative RHI was significantly associated with adverse cardiovascular events after CF-LVAD (age-adjusted risk ratio for 0.25 decrease in RHI, 1.35; 95% confidence interval: 1.13-1.62, P=0.001). CONCLUSIONS Peripheral endothelial function had a significant and persistent decline up to 5 months following implantation of CF-LVAD, and this decline was associated with adverse cardiovascular events. These findings may provide insight into some of the vascular complications following CF-LVAD in HF patients.
Increased biosynthesis of thromboxane A2 by diabetic platelets

. Because ADP has been reported to produce a secondary wave of platelet aggregation in diabetic subjects, and since ADP is known to enhance normal platelet biosynthesis of pro-aggregating thromboxane A2, we tested whether or not the reported increased sensitivity of diabetic platelets to ADP may also result in increased platelet biosynthesis of thromboxane A2. To test this hypothesis, 14C-arachidonic acid (14C-AA) was incubated in vitro with washed human platelets' in the presence or absence of ADP. These studies included platelets isolated from thirty normal volunteers, twenty-six diabetic subjects with and without known vascular complications, eighteen non-diabetic pregnant females and fourteen pregnancy-induced diabetic females. Data from these studies demonstrated: (i) a significant increase in the capability of diabetic platelets in response to ADP to biosynthesize thromboxane A2 from arachidonic acid when compared to platelets from normal controls (P < 0.001); (ii) a significant increase in thromboxane A2 biosynthesis by platelets from pregnancy-induced diabetic subjects over nondiabetic pregnant females (P < 0.001); (iii) a two-fold increase in thromboxane A2 biosynthesis by platelets from diabetic subjects with vascular complications when compared to those without vascular complications. Although our data also showed approximately a twofold increase in thromboxane A2 biosynthesis by platelets from diabetic subjects with greater than 10 years of the disease when compared to diabetic subjects with less than 10 years, these latter results were, however, not statistically significant. Results from these studies suggest that a relationship may exist between the markedly increased ADP-induced platelet aggregation in diabetes mellitus and the vascular complications associated with this disease. Whether or not increased capacity of the diabetic platelet to biosynthesize pro-aggregating thromboxane A2 in response to ADP or other pro-aggregating agents is per se a triggering factor in occlusive vascular diseases reported in diabetic subjects must await further studies.
PHOTODISSOCIATION OF ICN AT 266 NM AND BRCN AT 230 NM USING BRUTE FORCE ORIENTATION

Abstract This Letter presents measurements of the CN fragment from photolysis of BrCN at 230 nm and ICN at 266 nm. Supersonically cooled samples were spatially oriented using a strong uniform electric field. An enhanced signal from the CN fragment of ICN was seen when the dissociation laser was polarized parallel to the orientation field, and the degree of enhancement agreed with calculation of a pure parallel transition. Dissociation of BrCN displayed an enhancement which fell below the upper limit assuming a pure parallel transition at a rotational temperature of 1.5 K, implying contributions from a perpendicular transition.
Theory of the neon 1 s correlation-peak intensities

The correlation-state spectrum accompanying $1s$ photoemission in atomic neon was calculated by several methods, using the sudden approximation and focusing on states that are approximately described by single-electron excitation of the form $2p\ensuremath{\rightarrow}np$. All the calculations gave satisfactory energy values, but the predicted intensities differed widely. Multiconfiguration Hartree-Fock (MCHF) orbitals and orthogonalized MCHF orbitals gave intensities in poor agreement with experiment. A final-state configuration-interaction calculation gave accurate energies for seven $2p\ensuremath{\rightarrow}np$ correlation states, but when combined with a single-determinant initial state, yielded intensities low by about a factor of 2. Initial-state configuration interaction (ISCI), including double-electron excitation of the form $2{p}^{6}\ensuremath{\rightarrow}2{p}^{4}n{p}^{2}$, etc., brought the intensities of the $2{p}^{5}\mathrm{np}$-type states into agreement with experiment. It was thus shown that ISCI is of equal importance to final-state CI in determining correlation-peak intensities. Correlation-state (or "shakeup") spectra therefore contain unique information about electron correlation in the ground state.
Catalytic behavior of potassium containing compounds for diesel soot combustion

Alkali doped oxides were synthesized and tested as catalysts for diesel soot combustion using a combinatorial method. It has been found that potassium shows better promotion of the catalytic activity than other alkali elements, and most of the potassium-rich oxides showed similar catalytic behaviors when catalysts and soot were mixed in a slurry. The influence of different mixing methods, including loose contact, tight contact and slurry (wet) mixing with different soot suspensions, on the catalytic behavior of some transition metal oxides, alkali metal carbonates and potassium-containing oxides were studied through thermogravimetry and XRD. The high activity of potassium-containing catalysts is found to be due to the intimate contact between soot and potassium cations caused by polar solvents. Potassium containing catalysts degraded after repeated thermal cycles due to the loss of potassium. It was also found that the addition of transition elements can inhibit the loss of potassium.
Clostridium perfringens toxins (type A, B, C, D, E)

Abstract Clostridum perfringens types A,B,C,D, and E produce at least 12 different antigens, referred to as toxins , that may be involved in pathogenesis . These antigens have been given the names alpha, beta, epsilon , and iota toxin (‘major’ toxins), and delta, theta, kappa (collagenase), lambda (protease), mu (hyaluronidase), nu (deoxyribonuclease), gamma and eta toxin (‘minor’ toxins). An enterotoxin and neuraminidase are also produced by certain strains. Significant progress has been made in characterizing alpha and theta toxin, and the enterotoxin, but relatively little is known about the other toxins. A variety of disease syndromes are believed to be caused by one or more of each of these toxins though their exact role in disease is not clear in most cases.
A constructional DDM model for risk management of Virtual Enterprise

To guarantee the profit, virtual enterprise (VE) has to manage its risk effectively. Due to VEpsilas distributed characteristics, such as the diversity of members and distribution of cooperative regions, we introduce a distributed decision making (DDM) model for risk management of VE. In detail, we propose a constructional DDM model, which focuses on the situation of team or enforced team relationship between partners of VE. A taboo search (TS) algorithm is designed to solve the model. Numerical examples are given to illustrate the effectiveness of the model and the proposed algorithm.
Estimating Recreation and Existence Values of Sea Otter Expansion in California Using Benefit Transfer

This article demonstrates how benefit transfer can quantify tourism and existence values. Existing literature values of sea otters and a meta analysis yield benefit estimates of several million dollars for the increased number of sea otters expected by USFWS in the next decade if the “no otter zone” is eliminated and otters allowed to expand along the Santa Barbara coast. These benefit estimates of sea otter expansion exceed the costs to commercial fishing. Thus the benefit transfer approach can contribute to a more complete economic analysis of endangered species recovery or critical habitat efforts than the current USFWS approach.
The accuracy of substituted judgments in patients with terminal diagnoses.

Background: Patients' loved ones often make end-of-life treatment decisions, but the accuracy of their substituted judgments and the factors associated with accuracy are poorly understood. Objectiv...
The cultural transmission of acquired variation: Effects on genetic fitness

Abstract In a cultural species individuals acquire some aspects of their phenotypes by imitating conspecifics. Presumably, cultural transmission has some adaptive function in such species. Some authors have suggested that one such function may be the ability to transmit phenotypes that have been modified by learning or some other form of phenotypic plasticity. To examine this hypothesis we have compared the genetic fitness of cultural and noncultural individuals in three different models. In each model the environment is assumed to be variable, either in space or time, and learning modifies each individual's phenotype so as to increase the individual's fitness in the local environment. Cultural individuals transmit the modified phenotype to their offspring, while noncultural individuals do not. The models are different in the following ways: two models assume a dichotomous phenotype, one in a temporally varing environment and one in a spatially varying environment; the third model assumes a quantitative phenotype in a temporally variable environment. The two models which assume a temporally varying environment yield similar results. Genetic transmission is favored in highly autocorrelated environments while cultural transmission in environments with intermediate autocorrelation. In the spatially varying model cultural transmission is always favored.
Thermal signature identification system (TheSIS): a spread spectrum temperature cycling method

NASA GSFC’s Thermal Signature Identification System (TheSIS) 1) measures the high order dynamic responses of optoelectronic components to direct sequence spread-spectrum temperature cycling, 2) estimates the parameters of multiple autoregressive moving average (ARMA) or other models the of the responses, 3) and selects the most appropriate model using the Akaike Information Criterion (AIC). Using the AIC-tested model and parameter vectors from TheSIS, one can 1) select high-performing components on a multivariate basis, i.e., with multivariate Figures of Merit (FOMs), 2) detect subtle reversible shifts in performance, and 3) investigate irreversible changes in component or subsystem performance, e.g. aging. We show examples of the TheSIS methodology for passive and active components and systems, e.g. fiber Bragg gratings (FBGs) and DFB lasers with coupled temperature control loops, respectively.
Improved stimulus representation by short interspike intervals in primary auditory cortex.

We analyzed the receptive field information conveyed by interspike intervals (ISIs) in the auditory cortex. In the visual system, different ISIs may both code for different visual features and convey differing amounts of stimulus information. To determine their potential role in auditory signal processing, we obtained extracellular recordings in the primary auditory cortex (AI) of the cat while presenting a dynamic moving ripple stimulus and then used the responses to construct spectrotemporal receptive fields (STRFs). For each neuron, we constructed three STRFs, one for short-ISI events (ISI 15 ms); and one including all events. To characterize stimulus encoding, we calculated the feature selectivity and event information for each of the STRFs. Short-ISI spikes were more feature selective and conveyed information more efficiently. The different ISI regimens of AI neurons did not represent different stimulus features, but short-ISI spike events did contribute over-proportionately to the full spike train STRF information. Thus short-ISIs constitute a robust representation of auditory features, and they are particularly effective at driving postsynaptic activity. This suggests that short-ISI events are especially suited to provide noise immunity and high-fidelity information transmission in AI.
Low-cost, concurrent checking of pointer and array accesses in C programs

Illegal pointer and array accesses are a major cause of failure for C programs. We present a technique called ‘guarding’ to catch illegal array and pointer accesses. Our implementation of guarding for C programs works as a source-to-source translator. Auxiliary objects called guards are added to a user program to monitor pointer and array accesses at run time. Guards maintain attributes to catch out of bounds array accesses and accesses to deallocated memory. Our system has found a number of previously unreported errors in widely-used Unix utilities and SPEC92 benchmarks. Many commonly used programs have bugs which may not always manifest themselves as a program crash, but may instead produce a subtly wrong answer. These programs are not routinely checked for run-time errors because the increase in execution time due to run-time checking can be very high. We present two techniques to handle the high cost of run-time checking of pointer and array accesses in C programs: ‘customization’ and ‘shadow processing’. Customization works by decoupling run-time checking from original computation. A user program is customized for guarding by throwing away computation not relevant for guarding. We have explored using program slicing for customization. Customization can cut the overhead of guarding by up to half. Shadow processing uses idle processors in multiprocessor workstations to perform run-time checking in the background. A user program is instrumented to obtain a ‘main process’ and a ‘shadow process’. The main process performs computations from the orignal program, occasionally communicating a few key values to the shadow process. The shadow process follows the main process, checking pointer and array accesses. The overhead to the main process which the user sees is very low – almost always less than 10%. © 1997 by John Wiley & Sons, Ltd.
Cumulative Gains Model Quality Metric

This paper proposes a more comprehensive look at the ideas of KS and Area Under the Curve (AUC) of a cumulative gains chart to develop a model quality statistic which can be used agnostically to evaluate the quality of a wide range of models in a standardized fashion. It can be either used holistically on the entire range of the model or at a given decision threshold of the model. Further it can be extended into the model learning process.
Progesterone production in granulosa cells of the domestic fowl: effects of incubation media, pH, cell density and some other factors

Abstract The objective of this study was to determine the optimal conditions for the short term incubation of chicken granulosa cells. Compared to mechanically-dispersed cells, collagenase-treatment yielded granulosa cells of greater viability and responsiveness to ovine LH (oLH) stimulation. The rate of progesterone secretion by enzyme-dispersed chicken granulosa cells was subsequently compared in five different culture media during incubation periods of up to 24 hr. Under room air as the gas phase, Medium 199 (M199) containing Hank's salts and Ham's F-12 medium (F-12) were the most effective, whereas Krebs-Ringer bicarbonate-buffered glucose solution (KRBG) and Dulbecco's medium were the poorest. When pH and the ionic strength of KRBG was maintained by continuous gassing with O 2 :CO 2 (95:5), progesterone production was similar to that obtained with Hepes-buffered M199. The pH optimum was found to be 7.4, although within the range of 6.6–8.5 granulosa cells remained responsive to LH stimulation. The optimal cell density was observed to be 1 × 10 4 to 5 × 10 5 /ml. Although time course studies showed that both basal and stimulated progesterone production peaked by about 12 hr of incubation regardless of the media composition, the amounts released were significantly greater in M199 and F-12 during more prolonged (up to 24 hr) incubations. Glucose, a key medium ingredient for hormone-stimulated steroidogenesis, could be replace by pyruvate. On the other hand, lactate was inhibitory. It is concluded that the mature ovarian follicles of the domestic fowl are an excellent source of pure granulosa cells that can be obtained in high yield after a brief treatment with collagenase. These cells remain viable up to 24 hr and continue to produce large amounts of progesterone in response to LH when incubated in an appropriate medium and at optimal cell density.
Memory switching in amorphous arsenic triselenide

Observations of memory switching in thin films of amorphous As2Se3 have been made at various film thickness. The distribution of threshold voltages for a given thickness shows a strong peak which is attributed to the intrinsic switching mechanism. A plot of the most probable threshold voltage vs film thickness shows the switching process to be field controlled. Microscopic evidence is presented for strong Joule heating caused by capacitive discharge upon filament formation.
Thirteenth-Century Diplomatic Envoys: Nuncii and Procuratores

So much confusion has prevailed concerning the nature of mediaeval diplomatic envoys that a closer study of their character appears worth undertaking. Such a study ought to employ legal writings to elucidate the diplomatic documents and to use diplomatic documents to exercise a factual control upon the discussions by legal writers. An investigation of these sources reveals that previous studies of the types of mediaeval envoys err in two ways: they discuss kinds of emissaries, such as the ambassador and the legate, actually not widely employed,' and they confuse those types which were commonly used. Practically all secular diplomatic agents of the thirteenth century were either nuncii or procuratores. Nuncii had been in use for centuries,2 but procuratores appeared only in the thirteenth century (or a little earlier).' The latter supplemented, but did not supplant, the earlier type of envoy. Recent writers on mediaeval diplomacy, such as G. P. Cuttino, Henry S. Lucas, Gaines Post,4 Frangois Ganshof, Pierre Chaplais, and Garrett Mattingly, discuss the nuncius and the procurator very briefly, and except for Mattingly somewhat incorrectly or
Measurement of penetration depth λ(T) in YBa2Cu3O7−δ thin film

Abstract We present the magnetic penetration depth λ(T) in two laser ablated YBa2Cu3O7−δ thin films, determined by the two-coil method. The slope of 1 λ 2 (T) near Tc, the only exactly measurable quantity, extrapolates to 930A at T = 0, which compares well with 830A in the high quality single crystal recently reported by Hardy , and which exhibited a linear T dependence at low T. For T
Molecular cytogenetic analysis of a duplication Xp in a male: further delineation of a possible sex influencing region on the X chromosome

We describe a male infant with severe mental retardation and autism with a duplication of the short arm of the X chromosome. Chromosome painting confirmed the origin of this X duplication. Molecular cytogenetic analysis with fluorescence in situ hybridization (FISH) identified one copy of the zinc finger protein on the X chromosome (ZFX) and two copies of the steroid sulfatase gene (STS), further delineating the breakpoints. Based on cytogenetic and molecular comparisons of cases from the literature of sex-reversal in dup(X),Y patients and our patient, we suggest that a possible secondary sex-influencing gene involved in the regulation of sex determination or testis morphogenesis is present at the distal Xp21.1 to p21.2 region.
Dispersion of seismic waves near a small explosion

The characteristics of the ground vibrations caused by the detonation of small dynamite charges were studied at distances from ten to 3070 ft from the point of detonation. The motion which was observed could be separated into several types on the basis of velocity and particle motion paths. The major part of the recorded motion following the arrival of body waves exhibited strong dispersion. A comparison of this dispersion with that theoretically predicted for Rayleigh waves by Love, Sezawa, and others, showed that these motions are probably Rayleigh waves of the first and second types. The complex particle motion orbits observed near the shot point are probably a result of the overlap of these two normal modes of surface wave propagation.
Quartic form of the slowly decaying imaginary distance beam propagation method

The governing equation of the slowly decaying imaginary distance beam propagation method (SD-ID-BPM) is further modified, for calculating the eigenmodes in optical fibers and waveguides. Its convergence is analyzed in detail and compared to the earlier version of SD-ID-BPM and other methods. It is demonstrated that the method described here can converge to the same desired accuracy within fewer propagation steps than the earlier version of SD-ID-BPM and other methods. Since the governing equation of the SD-ID-BPM is a partial differential equation with higher order derivatives, it might be interesting if the discretization in the transverse x-y plane is performed by applying the numerical techniques for partial differential equations with higher order derivatives.
LOGISTICS : PERSPECTIVES FOR THE 1990S

The decade of the 1980s has been witness to a long period of stable, sustained economic growth in the American economy, with moderate inflation, favourable interest rates, and steady growth in GNP. The decade has been remarkably free of the economic turmoil that marred the 1970s ‐ double digit inflation, double digit prime interest rates, the energy crisis. Nevertheless, the last nine years have brought with them profound changes in the national economy and in the global marketplace which will radically alter the way a modern enterprise does business. Some of the most significant changes will occur in the firm's logistics processes and practices. These changes will present challenges, and opportunities, to every firm in every industry. The Fortune 500 of the year 1999 will consist of those companies who understand the challenges and seize the opportunity which they represent ‐ the opportunity to fashion a logistics system which is tuned to the realities of the future.
Enrichment of anaerobic polychlorinated biphenyl dechlorinators from sediment with iron as a hydrogen source.

Abstract Little is known about anaerobic polychlorinated biphenyl (PCB) dechlorination, although it is believed that some microorganisms are capable of respiring PCBs, gaining energy for growth from PCB dechlorination. If this is the case, the amendment of appropriate electron donors to contaminated sediment should stimulate dechlorination. The effect of elemental iron (Fe0) addition, an easily amended electron donor, on the microbial dechlorination of the PCB congeners 3,4,5-trichlorobiphenyl (3,4,5-CB) and 2,2′,3,4,4′,5,5′-heptachlorobiphenyl (2,2′,3,4,4′,5,5′-CB) was investigated in microcosms containing estuarine sediment from Baltimore Harbor. Results showed that the addition of 0.1 g Fe0/g sediment reduced the lag time for removal of doubly flanked para chlorines by approximately 100 days. Because Fe0 is a source of cathodic hydrogen (H2), the effect of direct H2 addition to sediment microcosms was also tested. The addition of 0.001 atm H2 in the headspace generated the same dechlorination activity and reduction in lag time as the addition of 0.1 g Fe0/g. Higher concentrations of Fe0 or H2 increased the lag prior to dechlorination. Additional results showed that an alkaline pH (⩾7.5), high [Fe2+] (3.3 g/L), or HS− (⩾0.1 mg/L total sulfide) inhibited dechlorination. Elevated concentrations of Fe2+, OH−, and HS− are products of Fe0 oxidation or increased microbial activity (methanogenesis, homoacetogenesis, and sulfate reduction), both of which would result from the amendment of large quantities of Fe0 or H2 to sediment. This research shows that not only can PCB dechlorination be stimulated through the addition of electron donor, but implies that the dechlorinators are enriched by the continuous addition of low concentrations of H2, similar to other known dechlorinators, such as the dehalorespirer Dehalococcoides ethenogenes. These results suggest that the direct addition of controlled amounts of Fe0 to sediments may be an effective remediation tool to reduce the lag period prior to dechlorination at PCB-impacted sites. They also suggest that PCB dechlorinators may be enriched using techniques similar to those used with known dehalorespirers.
Ethanol sensitivity and subunit composition of NMDA receptors in cultured striatal neurons.

Abstract Assessment of ethanol (EtOH) sensitivity was combined with analysis of N -methyl- d -aspartate (NMDA) NR1-NR2 subunit composition in primary cultured striatal neurons. Subunit composition was determined by western blot analysis; assessment of ifenprodil and spermine sensitivity during whole-cell patch-clamp recordings. From 3–21 days in culture, NR2B was the only NR2 subunit detected using NR2 subunit specific antibodies; NMDA-induced currents were strongly inhibited by the NR2B-selective antagonist ifenprodil. Two populations of neurons were identified at all ages in culture: those in which NMDA-induced current was or was not potentiated by 100 μM spermine. This suggested that the striatal neurons expressed functional NMDARs which lacked or contained the NR1 N-terminal cassette. The EtOH sensitivity did not differ between these two populations of neurons nor did it change with age in culture at all concentrations of EtOH studied. Human embryonic kidney (HEK) 293 cells containing NR1-1a or NR1-1b with either the NR2A or NR2B subunits did not differ in their EtOH sensitivity. Thus, it would appear that the presence or absence of the N-terminal cassette does not affect the EtOH sensitivity of recombinant NMDARs and native NMDARs expressed in cultured striatal neurons.
Suicide and epilepsy: A review of the literature

Abstract The authors systematically survey the clinical reports and mortality studies of suicide among epileptic patients. Of the 1,150 deaths of epileptics represented in the mortality studies cited, an average 5.0% of the deaths resulted from suicide, whereas the suicide rate in the U.S. general population is 1.4%. However, methodologic problems, particularly a lack of group comparability, in the investigations reviewed indicate the need for further research. Nevertheless, the cumulative evidence of an increased suicide risk among epileptic persons emphasizes the necessity for physicians to be alert to possible suicidal tendencies in their epileptic patients.