cssi/SciSciGPT-SciSciNet huggingface dataset:
Individual differences in the effect of relevant concreteness on learning and transfer of a mathematical concept

Abstract The concreteness of training materials influences learning and—perhaps more importantly—transfer. Building on prior research finding abstract representations best facilitated transfer to a game task, we conducted a similar study using training figures varying in concreteness but directly assessed transfer to modular arithmetic problems. Training figures: (a) were purely abstract, (b) were abstract but with features relevant to the transfer task, or (c) included additional concrete-relevant features. We hypothesized that concreteness—or number of relevant features—would be positively correlated with learning and transfer—especially among younger and/or lower-ability students. Although there was no overall difference in initial learning, the concrete-relevant and abstract-relevant features independently facilitated near-transfer, where concrete-relevant features supported lower-reasoning students. For far-transfer, eighth-graders benefited from the abstract-relevant features, whereas sixth-graders required additional concrete-relevant features. These findings suggest that concreteness interacts with learner and task characteristics to produce learning and transfer outcomes.
Further characterization of the long-run population distribution of a deleterious gene.

Abstract In a population of constant size, there is an equilibrium distribution for every deleterious autosomal dominant gene. This equilibrium represents the balance between selection and mutation. The purpose of this paper is to describe an approximate method of computing the equilibrium distribution and an exact method of computing its cumulants. If the surrounding population has experienced prolonged growth or decline, then an equilibrium does not develop. However, one can show that the variance of the number of carriers divided by the current population size does stabilize; this quantity is an increasing function of the growth rate.
LABORATORY SIMULATIONS OF BOW SHOCKS AND MAGNETOSPHERES

Laboratory experiments using a plasma wind generated by laser-target interaction are proposed and analyzed to investigate the creation of a shock in front of the magnetosphere and the dynamo mechanism. The proposed experiments and simulations are thought to be relevant to understanding the electron acceleration mechanisms at work in shock-driven magnetic dipole confined plasma in compact magnetized stars.
Evolutionary principles and the emergence of syntax

The belief that syntax is an innate, autonomous, species-specific module is highly questionable. Syntax demonstrates the mosaic nature of evolutionary change, in that it made use of (and led to the enhancement of) numerous preexisting neurocognitive features. It is best understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution.
Periodontal Disease in HIV-Positive Individuals: Association of Periodontal Indices with Stages of HIV Disease

Background: Periodontal disease has been previously associated with human immunodeficiency virus (HIV) infection, and HIV infection has been considered a modifier of periodontal disease. The aim of this study was to report the prevalence and severity of periodontal disease in a population of HIV-positive individuals and to investigate the association between clinical periodontal indices and the stage of HIV disease, as expressed by CD4 cell counts. Methods: Thirty-nine male HIV-positive patients were recruited and a medical history was taken. To evaluate periodontal disease, probing depth (PD), attachment level loss (AL), bleeding index (BI), and modified gingival index (MGI) were recorded. Associations between the above indices and CD4 counts were examined. Results: Immunocompromised patients (with CD4 cell counts 4 mm compared to patients with CD4 cell counts >200 cells/μl. When patients with CD4 counts <500 cells/μl were consi...
Survival in familial breast cancer patients.

This study was conducted to measure survival in breast cancer patients differing in their familiality of the disease. A total of 556 familial patients and 4551 general patients were evaluated. Survival was higher with bilateral than unilateral disease in both groups of patients. This difference was observed only when survival was measured from the first primary; it disappeared when survival was measured from the second primary. Three groups of familial patients, who likely differed in genetic risk, had similar survival curves. They were also similar to a general series patients when stage of disease was controlled and the comparison involved primarily unilateral patients. Previous reports of increased survival in familial and bilateral patients were thus not confirmed. The previous results were likely the consequence of bias arising from measuring survival from the first primary. Survival does not appear to be influenced by family history or laterality of breast cancer. Cancer 58:360–365, 1986.
The relaxation inverter

The characteristics and design of the relaxation inverter, which requires only one tube for obtaining alternating current from a d-c supply, are described in this article. This inverter is simple and reliable and can be made to provide alternating voltage having a good wave form.
STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA : V. THE RELATIONSHIP BETWEEN THE PROTEOLYTIC ACTIVITY OF PLASMA AND BLOOD COAGULATION

A fraction of globulin was prepared from human plasma which was deficient in prothrombin, thrombin, fibrinogen, plasma thromboplastin, and accelerator globulin. The preparation of globulin contained considerable potential proteolytic activity which could be activated by streptococcal fibrinolysin. This fraction of globulin accelerated the clotting of normal platelet-deficient plasma. However, the clot-accelerating effect of the globulin fraction was the same whether or not its proteolytic property had been activated. The addition of streptococcal fibrinolysin to normal platelet-deficient plasma did not accelerate coagulation. Nor did the addition of streptococcal fibrinolysin to hemophilic platelet-deficient plasma promote its coagulation. The data presented suggest that proteolysis by activated plasma proteolytic enzyme is not an essential stage in the coagulation of the blood.
Cosmic-ray production of deuterium, He3, lithium, beryllium, and boron in the Galaxy

The production of deuterium, He3, lithium, beryllium, and boron by galactic cosmic rays in the interstellar medium, over the life of the Galaxy, is calculated. It is found that high-energy α-α reactions contribute in an essential way to the observed lithium. When allowance is made for the interchange of material between stars and the interstellar gas and for the change of cosmic-ray intensity with time, the Li6, Be9, and boron produced turn out to be ample to explain the observed abundances, and with remarkable internal consistency. Deuterium and He3 arenot produced in significant amounts, nor Li7 in sufficient amount, however. To explain the Li7/Li6 ratio measured terrestrially and in chondritic meteorites, we invoke cosmological production of Li7. This implies the production of deuterium, He3, and He4 as well, in amounts consistent with observation. The theory in its present form cannot explain a solar-system Li7/Li6 ratio of 12and stellar ratios as low as 3, but additional processes can be adduced to reconcile them. The consistency of the numbers when cosmological production is included lends additional support to the big-bang hypothesis. An incidental result is that the mean luminosity of the Galaxy over its lifetime has been about 3 times its present luminosity.
Residual Strength Analysis for Rapid Response Damage Assessment (RRDA) of Steel Ship Structures

Numerical and experimental simulations for residual strength analysis of ship structures have recently been investigated in the marine industry. The technology of residual strength analysis is mature enough to assist ocean-going vessels shortly after experiencing a damage incident. The analysis can be used to evaluate the remedial actions necessary to minimize the risk of further damage during stabilization efforts and allow for the eventual transit to a repair facility. In 2010, the American Bureau of Shipping (ABS) implemented enhancements to its Rapid Response Damage Assessment (RRDA) program, in particular to the evaluation of residual strength. An integrated software system was developed to quickly and efficiently provide guidance to the ship owner through the utilization of the analysis results.This paper highlights the residual strength analysis results of several actual RRDA cases evaluated in recent years. These results were obtained from the application of an analysis software system, which includes the ability to perform timely calculations of the hull girder ultimate strength, hull girder shear stress, buckling and local strength in the damaged condition. This paper also provides an example of the use of analysis data to provide recommendations for remedial actions during a response. The strengths and weaknesses of this current analysis procedure are discussed and conclusions about the use of this software tool in damage scenarios are evaluated by comparing the analysis results with the outcomes of the presented cases.Copyright © 2012 by ASME
Modulation of Activity of One Neuron by Subthreshold Slow Potentials in Another in Lobster Cardiac Ganglion

A direct demonstration is given of interaction between specific neurons without impulses, via graded slow potentials electrotonically spread from one cell to another. Repetitive polarizing or depolarizing current pulses of 50 to 200 msec. and subthreshold intensity were passed through an intracellular electrode in the soma of a follower cell of the isolated ganglion. When the frequency is near the natural rhythm of impulse bursts corresponding to heart beats and arising in a pacemaker cell 5 to 10 mm. posteriorly, the bursts rapidly become synchronized with the pulses. The effect disappears upon withdrawing the intracellular electrode. Brief pulses or full spikes in the follower are not effective. Hyperpolarizing long pulses attract the burst to a fixed period after the end of the pulse, depolarizations after the beginning of the pulse. The natural rhythm promptly reappears when the pulses are stopped and occasionally breaks through during weak repetitive pulses. Current pulses in postsynaptic cells also alter the threshold of a presynaptic neuron to externally applied stimuli. Some kind of direct, low resistance pathway for electrotonic spread, discriminating against spikes because of their brevity, is inferred, providing a basis for subthreshold interaction which is specific and not by way of a field effect. Due to the sensitivity of modulation of ongoing rhythms, electrotonic currents can be effective even after decrementing over several millimeters.
Compact isocontours from sampled data

Publisher Summary Data in many fields—including medical imaging, seismology and meteorology—arrive as a set of measurements taken over the vertices of a large cubic grid. Techniques for producing a visual representation from a cube of data are important in those fields. This chapter presents an enhancement to all techniques of generating isocontours from a data cube. The enhancement reduces the number of elements of any isocontour approximation and improves the shape of the elements. The first improvement typically reduces the size of a representation by about 50%, permitting faster redisplay and reducing memory requirements. The second results in better-quality pictures by avoiding the narrow elements that cause undesirable shading artifacts in many lighting models. The chapter describes a general technique for eliminating the problem of nearly degenerate triangles from edge-based interpolation. The contours produced by compact cubes may have several undesirable features: (1) the boundary of the final contour may not lie on the boundary of the defining cubic mesh, and (2) two disjoint sheets of the contour, passing near a common gridpoint, may be fused at that gridpoint.
Altered neuronal distribution of parvalbumin in anterior cingulate cortex of rabbits exposed in utero to cocaine.

Previous studies of rabbits exposed in utero to cocaine have revealed an increase in the number of neurons which are GABA immunoreactive in the anterior cingulate cortex (ACC), suggesting a cocaine-elicited modification in the balance of excitatory and inhibitory interactions. Of the major calcium binding proteins expressed by different subgroups of GABAergic neurons, parvalbumin has been observed in conditions involving excess excitation, and may serve to protect neurons from excitotoxicity. In the present study, we used immunocy-tochemistry to compare the effects of prenatal cocaine exposure on the postnatal development of parvalbumin immunoreactivity in interneurons of the visual cortex (VC) and ACC. We determined the number and laminar distribution of parvalbumin immunoreactive neurons, and we also assessed the distribution of parvalbumin immunoreactivity within primary, secondary and tertiary dendrites of neurons in these two cortical areas. In both ACC and VC, parvalbumin immunoreactive neurons were first observed around postnatal day 10 (P10) and their number increased rapidly from P10 to P20. At all ages studied (P10 to P60) there was no difference between cocaine-exposed and saline control animals in the number or laminar distribution of parvalbumin immunoreactive neurons in either cortical area. However, the distribution of parvalbumin immunoreactivity within dendrites revealed a significant difference between cocaine-exposed and saline control animals in ACC but not in VC. In ACC, at all ages studied, there was an increase in the number of primary, secondary and tertiary dendrites which were parvalbumin immunoreactive in cocaine-exposed animals compared with saline controls. This difference was most striking in secondary dendrites, and in laminae V and VI. The effect was observed at doses of 4 and 3 mg/kg per injection but not at 2 mg/kg per injection. In contrast to ACC, in VC there was no difference in the number of immunoreactive dendrites in cocaine-exposed animals compared with saline controls. These observations are consistent with the hypothesis that the ACC of rabbits exposed in utero to cocaine is characterized by altered excitatory/inhibitory interactions. ACC receives a dense dopaminergic input, but VC receives minimal dopaminergic innervation. Mechanisms by which the action of cocaine on the developing dopaminergic system may modify the balance of excitation and inhibition in ACC are discussed.
Reverse total shoulder arthroplasty in patients of varying body mass index.

Background Body mass index (BMI) is an independent predictor of complications after hip and knee arthroplasty. Whether similar trends apply to patients undergoing reverse total shoulder arthroplasty (RTSA) is unknown. Methods A retrospective review of primary RTSAs with a minimum 90-day follow-up were included. Complications were classified as major or minor and medical or surgical. Patients were classified into 3 groups: normal BMI (BMI 35 kg/m2). Results Of the 119 patients met our inclusion criteria, 30 (25%) had a BMI of less than 25 kg/m2; 65 (55%) had a BMI of 25 to 35 kg/m2, and 24 (20%) had BMI exceeding 35 kg/m2. Complications occurred in 30 patients (25%), comprising major in 11 (9%), minor in 19 (16%), surgical in 21 (18%), and medical in 14 (12%). The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). Patients with a BMI exceeding 35 kg/m2 had a significantly higher overall complication rate (P < .05) and intraoperative blood loss (P = .05) than the other groups. Patients with BMI of less than 25 kg/m2 had a greater overall complication rate than those with a BMI of 25 to 35 kg/m2 (P < .05). Multivariate regression analysis demonstrated BMI was the only significant determinant of overall complication rates and medical complication rates (P < .05). Conclusion Patients with a BMI exceeding 35 kg/m2 (severely obese) or a BMI of less than 25 kg/m2 have higher rates of complication after RTSA.
A NOTE ON ANGULAR DISTRIBUTION ANALYSIS

A technique is given for calculating gamma -ray angular distributions for (p gamma ) and (px gamma ) reactions. In the technique for the case of one mixing parameter delta /sub 1/, the coefficients A/sub k//A/sub o/ are plotted vs y/sub 1/ = arc tan delta /sub 1/; the resulting curve is one cycle of a sine curve, and the maximum and minimum A/sub k//A/sub o/ values are rapidly determined. For the case of two mixing parameters, A/sub k//A/sub o/ can be expressed as a product of two sine curves. The extension of this technique to the case of three mixing parameters is also described. (D.L.C.)
Prediction of a Laminar Separation Bubble Over a Controlled-Diffusion Compressor Blade

The paper describes the comparison of the prediction of the flow through a cascade of controlled-diffusion compressor blades with two Navier-Stokes solvers. Both codes solved the thin-layer N-S equations, however; one code performed implicit time marching whereas the other performed explicit time marching. Flow predictions were accomplished with the implicit code using the algebraic turbulence model of Baldwin and Lomax and the one-equation model of Spalart and Allmaras, while predictions were made with the explicit code using the two-equation model by Wilcox.Predictions were made of the detailed laser-anemometry measurements of the flow field taken previously in a low-speed cascade wind tunnel. Comparisons were also made with the experimentally measured blade surface pressures and flow visualization of the extent of the laminar leading edge separation bubble. The one-equation turbulence model was combined with an intermittency based transition-length model for comparisons with fully turbulent calculations. Both codes predicted the leading-edge separation bubble satisfactorily when using higher order turbulence models.Copyright © 2000 by ASME
From Intervention to Inquiry: A Review of Sex Ed for Caring Schools: Creating an Ethics-Based Curriculum

Sharon Lamb hopes to inspire a national initiative toward ethical sexuality education that looks beyond the individualistic moral or health implications of one's individual sexual decision making and toward the broad ethics of living in and belonging to communities. In Sex Ed for Caring Schools: Creating an Ethics-Based Curriculum and the companion website, Sexual Ethics for a Caring Society Curriculum (www.sexandethics.com), Lamb argues for ‘advanced’ readings in sex education, including classical, democratic, and feminist philosophers of ethics and education. I consider the additional support teachers and students might need to engage in the ethical conversations Lamb imagines while also tending to the complexities of race, sexuality, and class. In response to Lamb's call for the ethical exchange of ideas, I offer suggestions of philosophers of color, explicitly working-class thinkers, and queer theorists who would represent meaningful additions to Sex Ed for Caring Schools and the online curriculum.
Changes in bovine luteal progesterone metabolism in response to exogenous prostaglandin F2α

Abstract An experiment was conducted to determine the effect of prostaglandin F 2α (PGF 2α ) on luteal synthesis of progesterone (P 4 ) and related progestins. Sixteen beef heifers were assigned in equal numbers to four groups in a 2 × 2 factorial arrangement of treatments. The experiment consisted of two levels of PGF 2α analog (0 and 500μg) and two levels of time (4 and 24h after injection) of corpus luteum collection. All heifers were injected intravenously with saline (2ml) or PGF 2α (cloprostenol) on day 8 of the estrous cycle (estrus = day 0). Jugular blood was collected at 0, 1, 2, 3, 4 and 20, 21, 22, 23, and 24h after injection. Resulting sera were analyzed for P 4 by use of radioimmunoassay. Luteal tissue was analyzed by gas chromatography/mass spectrometry for P 4 , 20β-hydroxyprogesterone, pregnenolone, and allopregnanolone (3β-hydroxy-5α-pregnan-20-one). Treatment with PGF 2α reduced serum concentrations of P 4 as early as 1h after injection ( P 2α caused a decline in luteal P 4 ( P P P 2α caused an increase in luteal allopregnanolone over time (time × treatment interaction; P 2α promotes conversion of P 4 to the metabolite allopregnanolone.
Metabolic Effects of Glucose-Insulin-Potassium in the Ischemic Myocardium

This investigation was designed to explore the metabolic, hemodynamic, and electrocardiographic effects of glucose-insulin-potassium (GIK) solution in a model of segmental myocardial ischemia with significant but incomplete restriction of coronary blood flow. An open-chest anesthetized canine model was utilized including 11 GIK and 6 saline control experiments. The anterior descending coronary artery (LAD) was partially occluded causing an average 71% reduction in its blood flow. Thirty min following occlusion GIK or saline was infused for 30min at 3ml/min into a femoral vein. Statistically significant effects of GIK included: increased glucose uptake by the ischemic myocardium, reduced arterial free fatty acid (FFA) concentration, reduced myocardial FFA uptake, decreased coronary arterio-venous oxygen content difference, increased myocardial lactate extraction, decreased myocardial potassium egress, and reduced epicardial ST segment elevation. Heart rate, aortic and left ventricular end-diastolic pressures, and developed force in the ischemic area were unchanged. The results indicate a potentially favorable effect of GIK on the metabolism of the ischemic myocardium which may be due to the shift of substrate utilization from free fatty acids to glucose.
Robot: Mere Machine to Transcendent Mind

From the Publisher: In this mind-bending new book, Hans Moravec takes the reader on a roller-coaster ride packed with startling predictions. He tells us, for instance, that in the not-too-distant future, an army of robots will displace workers, causing massive, unprecedented unemployment. But then, says Moravec, a period of very comfortable existence will follow, as humans benefit from a fully automated economy. And eventually, as machines evolve far beyond humanity, robots will supplant us. But if Moravec predicts the end of the domination by human beings, his is not a bleak vision. Far from railing against a future in which machines rule the world, Moravec embraces it, taking the startling view that intelligent robots will actually be our evolutionary heirs.
The adsorption of corypalline and related compounds on a pyrolytic graphite electrode

Abstract Anodic current-time curves have been used to study the adsorption, from TEAP-acetonitrile solution, of corypalline (7-hydroxy-6-methoxy-N-methyl-1,2,3,4-tetrahydroisoquinoline), isocorypalline (6-hydroxy-7-methoxy-N-methyl-1,2,3,4-tetrahydroisoquinoline), and 1-methyl-corypalline. A comparison with analogous cathodic current-time curves obtained with methylene blue leads to the conclusion that, on a pyrolytic graphite electrode, these isoquinoline compounds are adsorbed in a “flat-on” configuration. This conclusion is in harmony with the postulation that the known steroselective, stereospecific oxidative coupling of 1-methylcorypal-line occurs through the adsorption of the reacting molecules on the electrode surface.
The open state gating mechanism of gramicidin a requires relative opposed monomer rotation and simultaneous lateral displacement.

Summary The gating mechanism of the open state of the gramicidin A (gA) channel is studied by using a new Monte Carlo Normal Mode Following (MC-NMF) technique, one applicable even without a target structure. The results demonstrate that the lowest-frequency normal mode (NM) at ∼6.5 cm −1 is the crucial mode that initiates dissociation. Perturbing the gA dimer in either direction along this NM leads to opposed, nearly rigid-body rotations of the gA monomers around the central pore axis. Tracking this NM by using the eigenvector-following technique reveals the channel's gating mechanism: dissociation via relative opposed monomer rotation and simultaneous lateral displacement. System evolution along the lowest-frequency eigenvector shows that the large-amplitude motions required for gating (dissociation) are not simple relative rigid-body motions of the monomers. Gating involves coupling intermonomer hydrogen bond breaking, backbone realignment, and relative monomer tilt with complex side chain reorganization at the intermonomer junction.
Dynamic and Efficient Key Management for Access Hierarchies

Hierarchies arise in the context of access control whenever the user population can be modeled as a set of partially ordered classes (represented as a directed graph). A user with access privileges for a class obtains access to objects stored at that class and all descendant classes in the hierarchy. The problem of key management for such hierarchies then consists of assigning a key to each class in the hierarchy so that keys for descendant classes can be obtained via efficient key derivation.We propose a solution to this problem with the following properties: (1) the space complexity of the public information is the same as that of storing the hierarchy; (2) the private information at a class consists of a single key associated with that class; (3) updates (i.e., revocations and additions) are handled locally in the hierarchy; (4) the scheme is provably secure against collusion; and (5) each node can derive the key of any of its descendant with a number of symmetric-key operations bounded by the length of the path between the nodes. Whereas many previous schemes had some of these properties, ours is the first that satisfies all of them. The security of our scheme is based on pseudorandom functions, without reliance on the Random Oracle Model.Another substantial contribution of this work is that we are able to lower the key derivation time at the expense of modestly increasing the public storage associated with the hierarchy. Insertion of additional, so-called shortcut, edges, allows to lower the key derivation to a small constant number of steps for graphs that are total orders and trees by increasing the total number of edges by a small asymptotic factor such as O(log*n) for an n-node hierarchy. For more general access hierarchies of dimension d, we use a technique that consists of adding dummy nodes and dimension reduction. The key derivation work for such graphs is then linear in d and the increase in the number of edges is by the factor O(logd − 1n) compared to the one-dimensional case.Finally, by making simple modifications to our scheme, we show how to handle extensions proposed by Crampton [2003] of the standard hierarchies to “limited depth” and reverse inheritance.
Purification and partial characterization of rat submaxillary mucin

Abstract 1. 1. A simple method for the isolation and purification of rat submaxillary mucus glycoprotein is described; it involves water extraction of the minced glands, followed by recycling gel filtration chromatography on Sephacryl S-200. 2. 2. Analysis of gross chemical composition indicates that threonine and serine account for 23 mol% of the total amino acids, while the basic amino acids lysine and histidine account for 33 mol%. Molar sugar ratios by gas-liquid chromatigraphy were sialic acid:fucose; N- acetylgalactosamine:galactose: N- acetylglucosamine:glucose:mannose 1.0:1.0:2.7:2.7:1.0:0.67:0.5. 3. 3. A comparison is made between this mucus glycoprotein and other purified mammalian mucins. This mucin shows striking similarities with human salivary mucus glycoproteins, and dissimilarities when compared to the rat sublingual glycoprotein.
Growth and etching kinetics of tetragonal lysozyme

Abstract The morphology and kinetics of the growth and dissolution of lysozyme in aqueous solutions with 2.5% NaCl and at pH=4.5 were studied in-situ with a depth resolution of 300 A (4 unit cells) by high resolution optical microscopy and digital image processing. The bulk super- or undersaturation, σ, of the solution insidea closed growth cell was controlled by temperature. The growth habit was bound by (110) and (101) faces that grew through layer spreading, although with different growth rate dependencies on supersaturation/temperature. At σ
An Appraisal Of Corporate Working Fund Requirements

THE GENERAL OBJECTIVE of this study is to appraise the factors which operate through time to bring about changes in the fund requirements of a selected list of companies.1 Included among the factors which are considered are: sales volume, price levels, business conditions, inventory valuation methods, and changes in scale of operations. A more specific objective is to examine the utility of sales volume as an index of working fund requirements. In other words, we seek to answer the question: Do the current assets of a company historically fluctuate with sales volume in a manner which is sufficiently stable to permit a generalization of its demand for funds? The scatter diagram or correlation chart is used in the analysis with sales on the horizontal axis and current assets on the vertical axis. For the several current assets-cash, accounts receivable, and inventories-a model is developed which represents the theoretical relationship that each asset is expected to bear to sales. Actual data obtained from corporate reports to stockholders covering years from 1930 to 1948 are then compared to these models. In most cases the data are first adjusted for price changes. The behavior patterns of corporate financial data generally conformed to the theoretical models. Particularly noteworthy were the indications of minimum or base stocks in the inventory-sales relationships, which suggest that the well-known fluctations in stocksales ratios may be a natural volume effect rather than a purely cyclical phenomenon. On the average, the current assets, individually and in total, varied directly and linearly with sales. The year-to-year movements of these variables often departed from the average pattern, however, because of changing economic conditions, dynamic business
Evidence for a synergistic effect of the HIV-1 envelope protein gp120 and brain-derived neurotrophic factor (BDNF) leading to enhanced expression of somatostatin neurons in aggregate cultures derived from the human fetal cortex

Abstract Changes in the expression of somatostatin (SRIF) have been observed in the brains of HIV encephalitis. Since gp120 is thought to play a major role in AIDS-associated abnormalities in the brain, we addressed the question: Does gp120 alter the functional expression of human fetal SRIF neurons in culture and if so, is this effect fetal-age dependent? Aggregate cultures, obtained from cortices of nine fetuses (14.9–20.7 weeks), were exposed for 7 days to BDNF or BDNF+gp120; BDNF induced production of SRIF during the subsequent 24–48 h was assessed. Similar effects of BDNF and gp120 were observed in the 9 brain-cultures. A 7-day exposure to BDNF alone led to a significant increase in SRIF production (p=0.014), whereas exposure to gp120 alone did not. Co-exposure to BDNF and gp120 led to an increase in BDNF-induced SRIF production which was significantly greater than that after BDNF alone (p=0.006). These effects were BDNF- and gp120-dose dependent and they were not accompanied by changes in DNA content of the aggregates nor in lactate dehydrogenase activity in the medium; indicating that gp120 did not lead to a major loss of cell integrity. These results are consistent with a synergistic effect of BDNF and gp120 leading to enhanced functional expression of the signalling pathway(s) mediating BDNF induction of SRIF production; an effect expressed by fetal brains throughout the 2nd trimester of gestation. Thus, this culture system can serve as a model to study the mechanism(s) underlying the early interactions between gp120 BDNF in the developing human brain.
Atom Abstraction in the Scattering of State-Selected NO + ( X 1 Σ + ) on O/Al(111)

The reactive scattering of state-selected ${\mathrm{NO}}^{+}({X}^{1}{\ensuremath{\Sigma}}^{+})$ on oxygen-covered Al(111) is explored at hyperthermal collision energies. Relative ion yields and mean translational energies of scattered ${\mathrm{NO}}_{2}^{\ensuremath{-}}$ are presented as a function of oxygen exposure and ${\mathrm{NO}}^{+}$ collision energy. Above the $9\ifmmode\pm\else\textpm\fi{}1\mathrm{eV}$ threshold for reaction, ${\mathrm{NO}}_{2}^{\ensuremath{-}}$ products emerge with an average kinetic energy that depends linearly on incident ${\mathrm{NO}}^{+}$ energy. The formation of ${\mathrm{NO}}_{2}^{\ensuremath{-}}$ is assigned to the direct, Eley-Rideal abstraction of an adsorbed O atom by an incident NO molecule.
Gene delivery to glioma cells in rat brain by grafting of a retrovirus packaging cell line

Retrovirus vectors only integrate into the genome of dividing cells and can thus be used to selectively infect tumor cells in the adult rat brain. Gene delivery was assessed by using the retrovirus BAG vector, which bears the Escherichia coli lacZ gene under the MoMLV LTR promoter-enhancer element, and by histochemical staining for bacterial beta-galactosidase activity. Direct injection of this vector (90-900 cfu) into the adult rat brain, with or without prior inoculation of C6 glioma cells (2 x 10(5) cells) resulted in labeling of only a few cells as assessed 1 week later. When the psi 2-BAG packaging line was grafted into the brain, labeled psi 2-BAG cells could be found after 1 day, but not after 5 days, following grafting, suggesting that the grafted cells had been rejected and that no endogenous cells had integrated released vector, or that expression of lacZ had been turned off. In contrast, when the psi 2-BAG packaging line was grafted into a brain region, which had been inoculated previously with rat C6 glioma cells (2 x 10(5) cells), beta-galactosidase labeling of these tumor cells, identified by immunocytochemistry for glial fibrillary acidic protein and S100, could be demonstrated 10 days later. Thus, grafting of retrovirus packaging lines into adult brain provides a mean to infect tumor cells in situ. The grafted packaging cells may continue to release retrovirus particles for an extended period, thus infecting more cells at the stage of division appropriate for viral integration, as compared to inoculation of the virus alone. Grafting of retrovirus packaging cell lines could be used to selectively deliver "killer" or "suppressor" genes to tumor cells in the brain to curtail their growth.
Optical Properties Of Sputtered Si: H

Sputtered Si:H is a very promising material for use in thin-film solar cells, solar selective absorbers and optical coatings for the near infrared region. Optical property-composition relationships have been determined for Si:H coatings having wide ranges of H content and Si-H bonding. The dependence of the optical absorption edge, optical band gap and refractive index at 2 μm wavelength on H content and Si-H bonding is described. Microstructural and topographical features of the films that influence their absorption and scattering characteristics are discussed. Composition and bonding diagrams used to select deposition conditions for the desired optical properties are also presented. Finally, multilayer Si:H/Si02 all-dielectric laser mirrors with reflectances greater than 99% at 1.315, 2.7 and 3.8 μm are described to illustrate the application of these coatings.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The political economy of income taxation under asymmetric information: the two-type case

The apparent ubiquity of progressive taxation in advanced democracies has animated research by political economists in the past decade, but little progress has been made in modeling political equilibria over tax policy when labor supply is elastic with respect to taxation. Here, we postulate an economy with two worker types (wage capacities), in which the unskilled are more numerous than the skilled. Preferences are quasi-linear in income and leisure. One political party represents each worker type. A tax policy is any feasible incentive-compatible menu of pre- and post-tax incomes from which each worker must choose. This policy space is three-dimensional. Workers vote stochastically. The equilibrium concept for political competition is party-unanimity Nash equilibrium (PUNE)—thus, parties are both vote-seeking and representative. The set of political equilibria is characterized. We prove that, if the class of unskilled workers is not too large (but greater than one-half), then there always exist equilibria in which a regressive tax policy wins. If, however, that class is sufficiently numerous, or inequality is sufficiently great, then the victory of a progressive policy is guaranteed in all equilibria.
The Emily Cooley Lecture. Etiology and Pathogenesis of Acquired Hemolytic Anemia

The demonstration of recurrent lymphadenitis attributable to CMV during periods of hemolysis in a patient with chronic acquired hemolytic anemia of autoimmune type, led to the investigation of the possible etiologic relationship between this virus and acquired hemolytic anemia. In children a frequent association was demonstrated. Previously unrecognized clinical manifestations attributable to CMV were frequently observed. In this age group lymphadenopathy was a prominent finding in the majority of the cases and appeared to correspond to periods of rapid virus multiplication. It was noted that the predominant cellular lesion was not the well known pathognomonic large inclusion-bearing cell which is a comparatively rare end state in the cellular response to the virus but less fully developed cellular lesions representing early and intermediate states. Recognition of these lesions permitted a rough appraisal of the extent of viral activity and showed that the latter generally correlated well with the hemolytic process. A basis for active infection by an ordinarily occult virus was sought and frequently found in an apparent impairment of the normal immune mechanism expressed clinically by extreme susceptibility to intercurrent infections and frequently associated with organic defects conducive to such a state. In young infants age-determined susceptibility alone seemed to explain the lack of resistance to the occult viral agent. The findings led to the following interrelated hypotheses: 1. The presence of CMV in AHA is not fortuitous or coincidental but reflects a (not necessarily exclusive) etiologic relationship. 2. Acute, intermittent, or chronic hemolysis in AHA is related to primary or reactivated latent infection with CMV or other occult viruses in individuals susceptible by virtue of physiologically or pathologically impaired immunity, the cause of which is apparent in symptomatic forms but not as yet in the idiopathic type. 3. The pathogenesis of AHA involves viremia or the presence of noninfective viral particles or products in the circulation. Infection within the RE system as opposed to sites less accessible to the circulation, such as epithelium, permits their discharge into the blood stream and determines hemolysis. 4. The demonstration of the same agent in autoimmune and non-autoantibody AHA suggests a unified concept of pathogenesis in which erythrocyte autoantibodies represent a variable secondary response to heterogenetic stimuli of viral origin. 5. In the light of this theory the role of autoantibodies in autoimmune AHA is likely to be at most contributory, as also indicated by the frequent dissociation of hemolysis and antiglobulin reaction, and earlier data bearing on this question need to be reevaluated.
Mesoporous silica nanoparticles for high capacity adsorptive desulfurization

Desulfurized JP-8 fuel is of great interest for use as the hydrogen feedstock of fuel cells. The refractory aromatic sulfur species present, however, are particularly challenging to remove through traditional methods. We report the first use of mesoporous silica nanoparticles (MSN) for desulfurization and the material displays a four-fold greater performance towards JP-8 fuel over previous sorbents. The bulk form of mesoporous silica shows three-fold greater level of desulfurization. Silver-impregnated nanoparticle and bulk MCM-41 were found to have saturation adsorption capacities of 32.6 mgS g−1 and 25.4 mgS g−1, respectively. MSN display a high capacity for the notoriously difficult to remove 4,6-dimethyldibenzothiophene along with a two-fold improvement in breakthrough capacity over previously published materials, of 0.98 mgS g−1 at 10 ppmwS.
Infra)structures of Volunteering

We report on the results of a diary study of the everyday volunteering and help giving of individuals in the millennial generation. We describe the breadth of work structures implicated in volunteering, the social structures implicated in volunteering, and the interdependencies between the two. We analyze the roles that technology plays in volunteering with a particular focus on the forms of infrastructure that are constituted through the work and social structures of this philanthropic activity. Finally, we reflect on design opportunities for infrastructures where work and social structures meet to support more everyday, ubiquitous forms of volunteering.
Myeloperoxidase: friend and foe

Neutrophilic polymorphonuclear leukocytes (neutrophils) are highly specialized for their primary function, the phagocytosis and destruction of microorganisms. When coated with opsonins (generally complement and/or antibody), microorganisms bind to specific receptors on the surface of the phagocyte and invagination of the cell membrane occurs with the incorporation of the microorganism into an intracellular phagosome. There follows a burst of oxygen consumption, and much, if not all, of the extra oxygen consumed is converted to highly reactive oxygen species. In addition, the cytoplasmic granules discharge their contents into the phagosome, and death of the ingested microorganism soon follows. Among the antimicrobial systems formed in the phagosome is one consisting of myeloperoxidase (MPO), released into the phagosome during the degranulation process, hydrogen peroxide (H2O2), formed by the respiratory burst and a halide, particularly chloride. The initial product of the MPO-H2O2-chloride system is hypochlorous acid, and subsequent formation of chlorine, chloramines, hydroxyl radicals, singlet oxygen, and ozone has been proposed. These same toxic agents can be released to the outside of the cell, where they may attack normal tissue and thus contribute to the pathogenesis of disease. This review will consider the potential sources of H2O2 for the MPO-H2O2-halide system; the toxic products of the MPO system; the evidence for MPO involvement in the microbicidal activity of neutrophils; the involvement of MPO-independent antimicrobial systems; and the role of the MPO system in tissue injury. It is concluded that the MPO system plays an important role in the microbicidal activity of phagocytes.
Development and validation of a new in vitro assay designed to measure contact allergen-triggered oxidative stress in dendritic cells

Background Selected contact allergens are known to induce phenotypic and functional maturation of dendritic cells (DCs). Such changes occurring in DCs have been employed as assay readouts to predict skin-sensitizing potentials of small chemicals.
Random walks supported on random points ofZ/nZ

This paper considers random walks on the integers modn supported onk points and asks how long does it take for these walks to get close to uniformly distributed. Ifk is a constant, Greenhalgh showed that at least some constant timesn 2/(k−1) steps are necessary to make the distance of the random walk from the uniform distribution small; here we show that ifn is prime, some constant timesn 2/(k−1) steps suffice to make this distance small for almost all choices ofk points. The proof uses the Upper Bound Lemma of Diaconis and Shahshahani and some averaging techniques. This paper also explores some cases wherek varies withn. In particular, ifk=⌊(logn) a ⌋, we find different kinds of results for different values ofa, and these results disprove a conjecture of Aldous and Diaconis.
Relationship between parental discipline and children's ability to cope with stress

A questionnaire was developed to assess the use of disciplinary methods by parents regarding their children's approach to fearful situations. The predictive validity of this tool was evaluated by correlational analyses with the assessment of fear (behavioral, subjective, and physiological) in their children during hospitalizations for surgery. The results confirmed the usefulness of the questionnaire. Parents who reported use of positive reinforcement, modeling, and persuasion as ways of encouraging the child to deal with fearful situations had children who were low in anxiety during the actual stressful life experience. The reported use of punishment, force, or reinforcement of dependency was correlated with higher anxiety. Differences in the use of these methods by mothers and fathers are reported. The reliability of the questionnaire and its relationship to social desirability and the sex of the child are discussed.
Pressure-driven Fermi surface reconstruction of chromium

We have observed a massive reconstruction of the Fermi surface of single crystal chromium as a function of high pressure and high magnetic fields caused by the spin-flip transition, with multiple new orbits appearing above 0.93 GPa. In addition, some orbits have field-induced effective masses of \ensuremath{\sim}0.06--0.07 ${m}_{e}$, seen only at high magnetic fields. Based on the temperature insensitivity displayed by the oscillation amplitudes at these frequencies, we attribute the orbits to quantum interference rather than to Landau quantization.
Study on urine polyelectrolytes of cats with natural and experimental urolithiasis.

Abstract Urine polyelectrolytes (UPE) were isolated from control cats, naturally obstructed cats, and two groups of experimental cats (castrated and intact). The molecular weight distribution of the control and naturally obstructed UPE in different salt solutions indicated an increased precipitation of the UPE of the naturally obstructed cats. The amino acid content showed similar composition of the matrix of urinary claculi from the two experimental groups, although the composition of the UPE was different. The amino acid composition of the UPE from all groups showed a greater ratio of acidic to basic amino acids. Mucopolysaccharide content showed a possible major role for amino sugar-containing compounds in the aggregation of the organic matrix. From the data, the theory of an active mucoprotein matrix, formed from UPE, acting as a nucleating agent appeared to be supported.
Sheet beam extended interaction klystron (EIK) in W band

A W-band sheet-beam extended interaction klystron (EIK) has been fabricated and tested. The EIK integrates a 3-cavity circuit with our previously demonstrated 20-kV, 3.5-A beamstick. The EIK has produced a saturated peak output power of over 7.5 kW and a small-signal gain of almost 40 dB, in very good agreement with our simulations.
Bin1 Attenuation Suppresses Experimental Colitis by Enforcing Intestinal Barrier Function

Background Inflammatory bowel disease (IBD) is associated with defects in intestinal barriers that rely upon cellular tight junctions. Thus, identifying genes that could be targeted to enforce tight junctions and improve barrier function may lead to new treatment strategies for IBD.