cssi/SciSciGPT-SciSciNet huggingface dataset:
Coefficient Alpha: An Engineer's Interpretation of Test Reliability

Reliability is a fundamental concept of test construction. The most common measure of reliability, coefficient alpha, is frequently used without an understanding of its behavior. This article contributes to the understanding of test reliability by demonstrating that questions which lower reliability are inconsistent with the bulk of the test, being prone to test-taking tricks and guessing. These qualitative characteristics, obtained from focus groups, provide possible causes of lower reliability such as poorly written questions (e.g., the correct answer looks different from the incorrect answers), questions where students must guess (e.g., the topic is too advanced), and questions where recalling a definition is crucial. Quantitative findings confirm that questions lower reliability when students who answer correctly have lower overall scores than students who answer incorrectly. This phenomenon is quantified by the “gap” between these students' overall scores, which is shown to be highly correlated with other item metrics. An increasing number of concept inventory tests are being developed to assess student learning in engineering. Scores and student comments from the Statistics Concept Inventory are used to make these judgments.
Protein inhibitor of ornithine decarboxylase does not account for effect of putrescine on 3T3 cells

Abstract Putrescine and other amines are known to rapidly reduce or prevent increases in ornithine decarboxylase activity in a number of systems. We have confirmed reports of a nondialyzable inhibitor of the enzyme in serum-starved H-35 hepatoma cells exposed to serum and putrescine. In contrast, we detected little if any nondialyzable inhibitor in serum-limited Swiss 3T3 cells treated similarly. Also, evidence of a dissociable enzyme-inhibitor complex was found in H-35 cells but not in 3T3 cells. These results suggest that assimilated putrescine can reduce ornithine decarboxylase activity by mechanisms not involving a macromolecular inhibitor.
Multiple target tracking with lazy background subtraction and connected components analysis

Background subtraction, binary morphology, and connected components analysis are the first processing steps in many vision-based tracking applications. Although background subtraction has been the subject of much research, it is typically treated as a stand-alone process, dissociated from the subsequent phases of object recognition and tracking. This paper presents a method for decreasing computational cost in visual tracking systems by using track state estimates to direct and constrain image segmentation via background subtraction and connected components analysis. We also present a multiple target tracking application that uses the technique to achieve a large reduction in computation costs.
Stressed state of bodies with thermal cylindrical inclusions and cracks (plane deformation)

The thermoelastic potential of displacements and Airy stress function are used to determine stresses in infinite and semiinfinite planes with circular thermal inclusions (whose coefficients of linear thermal expansion differ from the corresponding coefficients of the matrix) subjected to uniform heating. The stress concentration is investigated in the case where inclusions are located near the boundary of the half plane. Analytic expressions are deduced for the stress intensity factors in the vicinity of a rectilinear crack located between two identical inclusions.
Influence of synthetic polymers on neutrophil migration in three‐dimensional collagen gels

In vitro studies of cell migration within three-dimensional polymeric materials are essential for understanding cell behavior and for developing new biomedical materials. Human neutrophil motility was examined in hydrated collagen gels containing various synthetic polymers. Physical mixtures of collagen and certain water-soluble polymers formed stable gels that were good substrates for cell migration. Addition of either polyethylene glycol (PEG) or the pluronictrade mark copolymer F68 did not change the morphological or mechanical properties of collagen gels, as determined by SEM and oscillatory rheometry; however, addition of either polymer significantly inhibited cell motility in both a modified 96-well chemotaxis chamber assay and a direct visual assay. Although the mechanism for this observed polymer inhibition of neutrophil migration is not yet clear, these results suggest that PEG and F68, two widely used biomedical polymers that are considered to be relatively "inert," may cause significant inhibition of cell motility.
Covert Linguistic Behavior During Writing Tasks Psychophysiological Differences between Above-Average and Below-Average Writers

The purpose of this study was to investigate the covert linguistic behavior of two groups of subjects, one classified as above-average users of language, the other as below-average users. It was hypothesized that the remedial group would manifest higher levels of subvocal motor activity than the above-average group during stimulated tasks, but that during pausing episodes that occur during writing the remedial group would manifest lower levels of subvocal activity than its counterpart. During each task, covert linguistic behavior was measured continuously by three electromyographs and was analyzed to determine physiological changes. The results confirm the hypotheses and suggest a lower level of cognitive activity on the part of the remedial group. Given that pausing episodes have come to be recognized as important periods of discourse planning, failure to utilize pauses for planning might account for qualitative differences in the writing of the two groups.
Genetics of hypertension.

Hypertension is the most prevalent cardiovascular disorder. In the 1999 to 2000 NHANES survey, the prevalence of hypertension progressively increased from 7.2% in those aged 18 to 39 to 30.1% in 40 to 59 year olds and 65.4% in those 60 and older. 1 Risk of both coronary atherosclerosis and stroke increase exponentially as blood pressure rises (see Fig. 1). 2 Although the relative risk for stroke increases more rapidly than coronary disease, at any pressure, the absolute risk for coronary disease is considerably greater than for stroke. An insight into this finding comes from autopsy studies that show that the carotid and intracerebral vascular beds are relatively protected from atherosclerosis as compared to the coronary circulation, particularly at lower blood pressures (see Fig. 2). 3,4 Probably the major means whereby hypertension accelerates atherosclerosis is through pressure-driven convection of LDL and other atherogenic particles into the arterial intima. 5–8 Indeed, without at least arterial pressures, atherosclerosis does not exist in the vascular tree 9 even in patients with homozygous familial hypercholesterolemia. 10,11 Increased turbulence (a rare occurrence in the human circulatory system) does not increase atherosclerosis. Rather, higher sheer stress is a strong stimulus for release of nitric oxide that locally decreases risk of atherosclerosis. Focal areas of low sheer stress are at inherently increased risk of atherosclerotic disease (such as the coronary arteries where flow stops during each systole). 12
Control of parvovirus DNA replication by a tetracycline-regulated repressor.

Autonomous parvoviruses are small, single strand DNA viruses which preferentially replicate in transformed and tumor cells, causing cell death by expression of the cytotoxic nonstructural protein, NS1. Several parvoviruses of the rodent group, including LuIII, efficiently infect human transformed cell lines. The potential for systemic use of these viruses in targeting metastases might be enhanced if NS1 expression and viral replication could be controlled by an innocuous drug such as tetracycline. We therefore substituted prokaryotic tetracycline operator sequences for part of P4 of LuIII, the promoter responsible for transcription of the mRNAs for nonstructural proteins. The resulting construct unexpectedly showed constitutive expression in transiently transfected cells, as indicated by efficient excision and amplification of viral replicative form (RF) DNA. This was apparently due to self-stimulatory transcriptional transactivation by NS1. This problem was overcome by cotransfection with a plasmid expressing a chimera of the repressor of the tetracycline operon with a KRAB transrepression domain. These conditions allowed efficient control of transcription and RF amplification by the tetracycline derivative, doxycycline. These observations form a basis for developing a therapeutic agent based on a drug- controlled parvovirus.
Differentiation of approximately specified functions

(1991). Differentiation of Approximately Specified Functions. The American Mathematical Monthly: Vol. 98, No. 9, pp. 847-850.
Questioning Colonia Consolidation in a Mexican Border City: Charity and the Charms of the Narcomundo in a Neoliberal Political Economy

Abstract This article examines two drags on organizing for self‐help community development in Agua Prieta, Sonora. The first is U.S.‐based, church‐led charity in two forms: “forays,” which bring outreach groups to disadvantaged barrios of the city for very brief periods; and more consistent charity provision via Evangelical Protestant churches. The second is the drug trade, which exacerbates a social climate of accumulation, competition, and personal enrichment. The study analyzes charity and drugs together under the rubric of new patron‐client ties that both reflect and reinforce the culture of neoliberalism on the border. The article closes with a brief account of an alternative model for development which seeks to avoid the traps of dependency on charity, drugs, and the state: a subsistence‐ and sustainability‐oriented permaculture model of development that would enhance security and community cohesion through food production, resource conservation, and affordable green housing.
Flecainide: A new antiarrhythmic agent

Abstract PVCs (trigger mechanisms) and the vulnerability of the myocardium to sustain a life-threatening ventricular tachycardia (substrate) are two variables in the sudden death equation. Physicians treating patients at risk for sudden death should consider PVC frequency and vulnerability as interrelated variables. Risk assessment musttake into consideration both variables. Antiarrhythmic drug efficacy can be assessed in terms of a reduction in trigger mechanisms (PVCs) as well as decreasing myocardial vulnerability (induction of VT at PES). Flecainide acetate, at a reduced dosage of 100 mg twice daily, is effective in both aspects, markedly decreasing PVC frequency and preventing VT induction at PES testing. Holter monitoring and electrophysiologic testing evaluate different aspects of the problem. With the addition of an agent as potent as flecainide, which is devoid of many of the bothersome side effects previously limiting antiarrhythmic therapy, an agent is now available that may be useful to treat both the trigger mechanism and the substrate in sudden death. We must be careful not to worsen the situation through the profound effects of flecainide on depolarization and refractoriness that in some patients cause life-threatening arrhythmias to be more frequent.
An architecture for word learning using bidirectional multimodal structural alignment

Learning of new words is assisted by contextual information. This context can come in several forms, including observations in non-linguistic semantic domains, as well as the linguistic context in which the new word was presented. We outline a general architecture for word learning, in which structural alignment coordinates this contextual information in order to restrict the possible interpretations of unknown words. We identify spatial relations as an applicable semantic domain, and describe a system-in-progress for implementing the general architecture using video sequences as our non-linguistic input. For example, when the complete system is presented with "The bird dove to the rock," with a video sequence of a bird flying from a tree to a rock, and with the meanings for all the words except the preposition "to," the system will register the unknown "to" with the corresponding aspect of the bird's trajectory.
Differential Gene Expression of E. coli O157:H7 in Ground Beef Extract Compared to Tryptic Soy Broth

E. coli O157:H7 is an important foodborne pathogen, and ground beef is a common vehicle of infection. DNA microarrays have been used for transcriptomic studies of E. coli O157:H7 using laboratory media; however, analysis of gene expression in complex matrices such as food are lacking. This study compared gene expression profiles of E. coli O157:H7 Sakai strain in raw ground beef extract (GBE) and tryptic soy broth (TSB). Total RNA was isolated from GBE and TSB after 2 h of incubation with E. coli O157:H7. Following reverse transcription (RT) of the RNA, labeled cDNA was hybridized to microarrays representing 9608 open reading frames (Operon; Genome Array-Ready Oligo Set) corresponding to 4 genomes of E. coli strains and 3 plasmids. There were 74 up-regulated (genes involved in protein and polysaccharide biosynthesis, transcription factors, membrane transport proteins, and acid shock proteins) and 54 down-regulated (encoding proteins for energy metabolism, biosynthesis of cofactors, transporters of small molecules, and transcription factors and enzymes responsible for protein degradation) genes in E. coli O157:H7 grown in GBE compared to TSB, respectively. Furthermore, compared to incubation in TSB, E. coli O157:H7 incubated in GBE for 2 h showed significantly increased survival when exposed to synthetic gastric fluid, pH 1.5. This study demonstrated that microarray analyses can be performed using complex food matrices, and gene expression of E. coli O157:H7 differs in TSB compared to GBE. The information will be useful for identification of genes that can be employed as potential targets for interventions to control E. coli O157:H7.
Precipitation Equilibria of the Chromium(VI)/Iron(III) System and Spectrospcopic Characterization of the Precipitates

Precipitation equilibria and spectroscopic studies of the Cr(VI)/Fe(III)/H2O system have been performed to identify the aqueous and solid speciation of the system in the pH range 1−9. The results suggest that three different precipitates FeOHCrO4, FeOHCrO4·2Fe(OH)3, and Fe(OH)3 exist depending on the pH range. The last two precipitates have been reported in the literature before, and they are confirmed in this study. The formation of a new precipitate, FeOHCrO4, that predominates in the pH range 1.5−2.5 is being suggested, and its thermodynamic solubility constant was estimated to be pKso = 22.50 ± 0.07. The mixed precipitate predominated in the 2.5−3.5 pH range and the pure ferric iron hydroxide predominated in the pH range grater than 3.5. All three precipitates were analyzed using X-ray photoelectron spectroscopy (XPS). The spectroscopic results suggest that the first and second precipitates contain one type of chromium species which corresponds to Cr(VI) type and one type of Fe species. The third prec...
Method and theory of monophasic action potential recording

MAP recordings have been at the cradle of cardiac electrophysiology but only recently, through safer and simpler technology, have gained wider access to clinical electrophysiology. In contrast to conventional electrode catheter recordings, MAP recording devices provide precise information not only of the local activation time but of the entire local repolarization time course as well. Although the MAP does not reflect the absolute amplitude or upstroke velocity of transmembrane action potentials, it delivers highly accurate information on the action potential duration and configuration, including early afterdepolarizations as well as relative changes in transmembrane diastolic and systolic potential changes. Based on available data, the MAP probably reflects the transmembrane voltage of cells within a few millimeters of the exploring electrode. MAPs can be recorded by catheter technique from the endocardial surface and by special probes from the epicardium in the operating room. The contact electrode technique is preferable over suction electrodes because it is safer and simpler to use in patients and because it produces more stable, longer-lasting signals. A modified contact MAP catheter incorporates pacing electrodes and permits simultaneous assessment of action potential duration and refractoriness. This not only facilitates the use of MAP catheters in routine electrophysiological studies but also is important for assessing the voltage-independent effects of antiarrhythmic drugs on refractoriness. MAP recordings offer the opportunity to study, in the in situ heart, a variety of pertinent electrophysiological phenomena including, for example, effects of cycle length changes and antiarrhythmic drugs on action potential duration or the role of afterdepolarizations in the genesis of triggered arrhythmias. Due to vigorous heart beating, movement artifacts may occur and need to be distinguished from true abnormalities in the action potential time course. With these limitations in mind, MAP recordings are a valuable addition to clinical electrophysiological studies.
Measurement of visual performance through scattering visors and aerospace transparencies

Light scattered from helmet visors and aerospace transparencies is known to reduce visual performance. One popular measurement technique, maintained by the American Society for Testing and Materials, is ASTM D 1003. It is a standard procedure used to measure haze inherent in transparent materials, which is defined as the percent of the total transmitted light that is scattered. However, research has shown that visual acuity measured through several different types of helmet visors does not correlate well with visor haze. This is most likely due to the fact that the amount of light scattered from a transparent material depends heavily on the light illuminating the transparency and on the viewing geometry, behavior that ASTM D 1003 does not characterized. Scattered light causes transparent parts to appear luminescent and imparts a veiling luminance when superimposed over a target, reducing target contrast and inducing a visual performance loss. This paper describes an experiment in which threshold target background luminance, the luminance at which a target was barely visible, was measured for a number of observers viewing a Landolt C target through several levels of veiling luminance. Threshold luminance was examined for predictable behavior with respect to veiling luminance.
Phylogeny of the avian genus Pitohui and the evolution of toxicity in birds.

Bird species in the avian genus Pitohui contain potent neurotoxic alkaloids that may be used for defense. The genus comprises multiple species that are endemic to New Guinea and were presumed to belong to the family Pachycephalidae or Colluricinclidae, within the core corvoidea, an ancient Australasian radiation of crow-like birds. In order to understand the evolution of toxicity within the genus Pitohui, we sequenced three mitochondrial and two nuclear gene segments and reconstructed a phylogeny of the genus Pitohui and its putative relatives. We show that the genus Pitohui is polyphyletic, and consists of five different lineages. Using Bayesian ancestral state reconstruction, we estimate that toxicity likely evolved multiple times within this group. Furthermore, because the morphological and behavioral similarity among these poisonous birds appears to have evolved convergently, we hypothesize that this may be a possible example of Mullerian mimicry in birds. The Morningbird of Palau, Micronesia, that has often been included in the genus Pitohui, actually belongs in the genus Pachycephala and offers an intriguing case of pronounced evolution on a remote oceanic island.
The effects of virginity and ovariectomy on growth, food consumption, fat body mass and oxygen consumption in the house cricket, Acheta domesticus

Abstract Virgins have a low percentage blood volume and a small digestive tract containing almost no food. Still, the virgins are 150–200 mg heavier than mated females by day 18 because they retain all ovulated eggs while mated females quickly lay ovulated eggs. Food consumption in virgins decreases to very low levels because the mass of ovulated eggs compresses the gut. Virgins can remain in this state for months. Within 24 h of mating 75% of the eggs are fertilized and laid, oogenesis is resumed, the percentage blood volume increases, and food consumption triples. During oogenesis most of the fat body mass is used up, but the mass of eggs ovulated is about 5 times the fat body mass lost. Clearly eggs are primarily made from ingested material that is processed through the fat body. The availability of fat body reserves in young females allows maximized early high ovulation rates. Ovariectomized Acheta domesticus have a higher blood volume and a larger fat body mass than mated females, but by unknown mechanisms food consumption declines and the fat body mass and total body weight stabilize and remain unchanged. The pattern of oxygen consumption in adult females is determined by the number of eggs present in the oviducts. Unfertilized eggs consume negligible amounts of oxygen, therefore the total body oxygen consumption is depressed in direct proportion to the amount of contained eggs. By day 12 mated females have started laying eggs and retain few (consume 1.4 ml oxygen/g cricket/h), but virgins retain all ovulated eggs (consume 0.8 ml oxygen/g virgin/h).
Stimulation of β-Endorphin Secretion by Corticotropin-Releasing Factor in Primary Rat Leydig Cell Cultures*

CRF, a hypothalamic peptide, is a potent stimulator of POMC synthesis and secretion in the pituitary. POMC biosynthesis has been documented in the testis, specifically in Leydig cells, and recent studies suggest that CRF is synthesized locally in the testis. A reverse hemolytic plaque assay and immunocytochemistry with Leydig cell-specific antibodies were used to study the effect of CRF on secretion of the POMC peptide β-endorphin (βEP) from normal rat primary Leydig cell cultures. In enriched Leydig cell preparations incubated with βEP antiserum (diluted 1:50) then with complement (diluted 1:25), approximately 15% of immunocytochemically identified Leydig cells formed plaques. Preabsorption of the antiserum with (βEP (2 μg/μl antiserum) overnight at 4 C abolished the formation of plaques. Increasing concentrations of CRF (from 10-1 to 10-7 M) resulted in an approximately 80% increase in both the percentage of plaque-forming cells and the mean plaque size. When the CRF antagonist CRF-(9-41) (10-6 M) was a...
Inactivation of microsomal NADPH-cytochrome c reductase by sulfhydryl-reactive derivatives of menadione☆☆☆

Abstract Five derivatives of menadione (2-methyl-1,4-naphthoquinone) having electronegative substituents on allylic carbons were prepared for study as sulfhydryl-reactive inactivators of mouse liver microsomal NADPH-cytochrome c reductase. Each of these naphthoquinones, incubated with dilute suspensions of microsomes, produced a loss of NADPH-cytochrome c reductase activity proportional to the initial naphthoquinone concentration. Each of the compounds also reacted with cysteine, as evidenced in the case of the haloggated compounds, by loss of reactive sulfhydryl groups and, in the case of 2- p -nitrophenoxymenadione, by the displacement of the leaving group, p -nitrophenol. Menadione, incubated under identical conditions, did not inactivate NADPH-cytochrome c reductase and was unreactive with cysteine. The requirement for a halogen or a nitrophenoxy substituent on at least one of the allylic carbons suggested that the mechanism of NADPH-cytochrome c reductase inactivation involves attack on critical microsomal nucleophiles, possibly sulhydryl groups. The possible significance of these findings is discussed in relation to the antitumor activity and bioactivation of the halomethyl naphthoquinones.
Lipoprotein in the normal and regenerating limb tissues of the adult newt, Diemictylus viridescens.

Lipids tightly bound to cell and tissue proteins (lipoproteins) were investigated with the acetone-sudan procedure in cryostat-cut sections of normal and regenerating limb tissues of the adult newt, Diemictylus viridescens. Nuclear and cytolplasmic membranes of all tissues stained moderately black; the nucleo- and cytoplasm stained less intensely than their membranes. Connective tissue fibers of the dermis, mysial and neural sheaths, and tunics of blood vessels yielded intense responses. In striated muscle of the limb, myofibrils and associated striations responded strongly. Nerve myelin responded weakly. In the preblastemic regenerate, the fibrous adepidermal basement membrane terminated abruptly at the surface of amputation. A distal fibrocellular residue was evident in continuity with the retrograde degeneration of amputation-injured muscle: observations suggest a possible contribution to the fibrocellular reticulum from myofibrils. The regeneration blastema appears isolated from proximal limb tissues by the intervening fibrocellular reticulum. The response of the blastema cell is relatively weaker than that of other cells and tissues. Regenerating muscle is recognized by the appearance of prominently stained myofibrils in myoblastic extensions off the limb stump musculature. The matrix and chondrocytes of regenerating cartilage stain for lipoprotein, with the osteoid of osteogenic centers responding strongly. Polychrome responses were obtained from hyalin-bodies within interphase nuclei, and from chromosomes in mitosis, suggesting that chromosomal lipid has been stained. Supporting the lipidic character of the observed responses is the negative reaction following long term lipid extraction in warm chloroform: methanol.
Transport of ozone in the middle stratosphere: evidence for planetary wave breaking

Data from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) for the period October 25, 1978-May 28, 1979 are used in a descriptive study of ozone variations in the middle stratosphere. It is shown that the ozone distribution is strongly influenced by irreversible deformation associated with large amplitude planetary-scale waves. This process, which has been described by McIntyre and Palmer as planetary wave breaking, takes place throughout the 3-30 mb layer, and poleward transport of ozone within this layer occurs in narrow tongues drawn on the tropics and subtropics in association with major and minor warming events. These events complement the zonal mean diabatic circulation in producing significant changes in the total column amount of ozone.
On the theory of plastic wave propagation in a bar

Abstract A study is presented of the problem of plastic wave propagation in a semi-infinite bar subjected to an axially-applied impact stress. Malvern's theory is applied and it is shown on theoretical grounds that we should expect the strain plateau to appear always and that, for a given static stress-strain curve and magnitude of applied stress, the time needed for the appearance of a given length of plateau depends on a characteristic time τ char of the material. It is shown that the Karman-Taylor theory is the special case for which τ char = 0. Particular emphasis is placed on the influence of strain hardening on the instantaneous strain distribution along the bar. A bilinear static stress-strain curve is considered and the calculations are made by using Malvem's theory, the method of characteristics, and an IBM 7040–7094 digital computer. It is shown that a decrease in strain hardening increases the time needed for a given length of plateau to appear. It is therefore possible, when solving this problem numerically, to miss the plateau if calculations are not carried out for a sufficient duration of time.
An Ultrastructural Study of Vairimorpha necatrix (Microspora, Microsporida) with Particular Reference to Episporontal Inclusions During Octosporogony

ABSTRACT. The life cycle of Vairimorpha necatrix was studied by electron microscopy. Disporous development has two distinct stages: 1) diplokaryotic meronts which are actively mitotic, and 2) diplokaryotic sporonts which are distinguished by reduced ribosome density and a thickened plasmalemma. After final division of the sporont, sporoblasts form spores which are ovocylindrical and measure 4.4 ± 0.08 × 2.3 ± 0.05 μm (mean ± SE). Octosporous development results in eight haploid spores being formed in a sporophorous vesicle. The uninucleate octospores were smaller than the binucleate dispores and the exospore was thicker but less crenulate in outline. Early in octosporogony, tubules are produced from the sporont plasmalemma and electron‐dense material accumulates in the episporontal space. The latter may be amorphous, vesiculated, or vacuolated in appearance and in later stages may take a stacked, lamellar form. At sporoblast formation, exospore material coats the plasmalemma and attached tubules; all inclusions in the episporontal space gradually disappear as spores are formed. These secretory products may have application to taxonomic distinction at the species level.
The center-to-limb behavior of Ca i λ6573 and [Ca ii] λ7324

Center-to-limb measurements of the Ca i λ6573 intercombination line and the Ca ii λ7324 forbidden line are compared with synthetic profiles based on a simple representation of the non-LTE Ca-Ca+ ionization equilibrium. The effects of photoionizations from low lying excited states of neutral calcium are found to reduce the sensitivity of the λ6573 center-to-limb behavior as a thermal structure diagnostic. The synthetic center-to-limb behavior is also sensitive to uncertainties in the nonthermal broadening. Nevertheless, the measured center-to-limb behavior of λ6573 favors a ‘cool’ photospheric model similar to the Vernazza, Avrett, and Loeser model M over hotter models based on the Ca ii K wings. The non-LTE calcium abundance obtained from the disk center equivalent widths of λ6573 and λ7324 using the best fit model is ACa≅2.1±0.2 × 10-6 (by number relative to hydrogen). Applications of these lines as diagnostics of the Ca-Ca+ ionization equilibrium in other stars are briefly discussed.
Accounting for reactant consumption in the thermal explosion problem. Part I: Mathematical foundation

Abstract New definitions for the criticality conditions of the thermal explosion problem are founded on the mathematical behavior of the governing equations. The paper deals with uniform temperature and concentration (Semenov problem). It is well known that the results can be applied to the distributed temperature and concentration case by the use of correction factors. It is shown that criticality can be defined in the temperature-time plane as accepted by most authors. However, using our definitions of criticality in the temperature-concentration plane confirms the previous findings of Adler and Enig. They showed that the classically defined critical state in the temperature-time plane is always a subcritical state in the temperature-concentration plane. At the same time, the critical state in the temperature-concentration plane is always a supercritical state in the temperature-time plane. However, the critical state in the temperature-concentration plane is in agreement with that in the Semenov number (Ψ)-temperature plane. It is shown that the critical states in all planes coincide only when n = 0 or B = ∞ and agree with the well known results neglecting reactant consumption. The difference between the critical and ignition temperatures is discussed. It is shown that as B approaches infinity, the solution for Φ as a function of τ for any value of n approaches the solution for n = 0. Hence for B = ∞, substituting for n = 0 in Alder and Enig results produces the classical Semenov result. This resolves the objections expressed against these results before. At the same time the locus of the critical states for n = 0, with finite B is determined. The effect of the degree of reaction on the induction time for adiabatic systems is demonstrated. The conditions required for ignition of subcritical systems is demonstrated. The conditions required for ignition of subcritical systems are discussed as well as the effect of initial conditions on criticality.
The heuristic value of Werner's co-existence concept of development

Werner's co-existence concept of development accounts for expectable and consistent between group differences in ontogenesis. A co-existence concept of development, rather than a replacement concept of development, also addresses variabilities within individual children and adults in the same domain. This study examined both “replacement” and “co-existence” concepts of development in the domain of illness. Both concepts of development accounted for the fact that no child exhibited abstract concepts of illness. However, only a co-existence concept of development can account for the fact that most college students demonstrated magical and concrete concepts of illness.
Exchangeability and rate of flip-flop of phosphatidylcholine in large unilamellar vesicles, cholate dialysis vesicles, and cytochrome oxidase vesicles.

Abstract Three model membrane systems have been characterized in terms of their interaction with phospholipid exchange proteins. Large unilamellar vesicles of phosphatidylcholine prepared by ether vaporization are shown to be homogeneous by gel filtration. Phospholipid exchange proteins from three sources are capable of catalyzing the rapid exchange of approximately half of the phospholipid from these vesicles. The remaining pool of radioactive phospholipid is virtually nonexchangeable ( t 1 2 of several days). Small unilamellar vesicles of phosphatidylcholine prepared by cholate dialysis also exhibit two pools of phospholipid (65% rapidly exchangable, 35% very slowly exchangeable) when incubated with beef liver phospholipid exchange protein. Cytochrome oxidase vesicles prepared both by a cholate dialysis method and by a direct incorporation method have been fractionated on a Ficoll discontinuous gradient, and tested for interaction with beef heart exchange protein. Two pools of phospholipid are once again observed (70% rapidly exchangable, 30% nonexchangeable), even for vesicles which have incorporated the transmembranous enzyme at a phospholipid to protein weight ratio of 2. The size of the rapidly exchangeable pool of phosphatidylcholine for each of the vesicle systems is consistent with the calculated fraction of phospholipid in the outer monolayer. The extremely slow rate of exchange of the second pool of phospholipid reflects the virtual nonexistence of phospholipid flip-flop in any of these model membranes.
Tandem Transplantation for Follicular Lymphoma: The Best of Both Worlds?

Follicular lymphoma (FL) is the second most common type of non-Hodgkin’s lymphoma with an incidence of 15,000 new cases/year in the United States. The definite management of patients with FL remains under considerable debate due to the numerous treatment options available today. Such options include observation, chemotherapy, external beam radiation therapy, monoclonal antibodies, and radioimmunoconjugates [1]. Hematopoietic cell transplant (HCT) historically has been offered to younger patients and/or patients with fairly advanced disease. Autologous HCT (autoHCT) has unequivocally shown improved disease-free survival in patients with relapsed chemosensitive disease with 1 trial showing an overall survival benefit [2,3]. For patients with FL with relapsed disease, retrospective analyses have shown that autoHCT can provide benefit for patients who are not heavily pretreated before autoHCT [4]. There is no role for autoHCT as consolidation therapy in first remission as 3 randomized trials failed to demonstrate a survival advantage for autoHCT compared to conventional therapy [5-7].
Variable cost of prey defense and coevolution in predator–prey systems

Predation acts as a selective pressure, driving prey adaptation. Predators can also evolve counter-defenses to increase the likelihood of successful attack. Investment in either trait can be costly, leading to a trade-off between the traits and other fitness components. Costs for defense have been shown experimentally to depend on environmental factors such as resource availability. This suggests that costs can increase with population size, rather than remaining constant as models often assume. Using a quantitative trait model with predator–prey coevolution, we investigate how both population and trait dynamics are affected by density-dependent prey defense cost (“variable cost”) vs. density-independent cost (“fixed cost”). We assume predator counter-defense cost is always density independent. We also investigate the effect of relative speeds of prey and predator evolution on population and trait dynamics, by varying a parameter that determines each population's additive genetic variance. For both models...
The Insurgency Environment in Northeast India

The northeast states of India have faced a series of insurgencies almost since independence. Most insurgent groups have been based on the competing demands of various ethnic groups, with conflicts not only between the insurgents and the government, but also between groups. The combination of anti-government and intercommunal violence shows little sign of ending. Although the Indian government has made progress in dealing with the largest groups, the continued existence of several dozen insurgent movements represents a significant security threat to internal stability in India.
Identification of seismic stratigraphic traps using statistical pattern recognition

Abstract Stratigraphic hydrocarbon traps commonly result in very subtle changes in seismic reflection waveforms, making their detection difficult using ordinary processing techniques. This paper describes the implementation of a Bayes classifier using a multimodal estimate of the conditional class probability density function. Also, a relaxation labeling procedure is presented which is used to reclassify the initial Bayes results using a priori contextual information extracted from the training data. Processing synthetic data with 20% additive noise resulted in 84.8% correct using only 3 features.
Plutonium disproportionation : What did Sherman Rabideau measure?

Sherman Rabideau’s classic study of the disproportionation of Pu(IV) is reviewed and its results are questioned. Rabideau used mixed potentials and incorrect statements of mass and charge conservation to establish his conclusions.
SEARCHING FOR ENDOGENOUS BUSINESS CYCLES IN THE U.S. POSTWAR ECONOMY

This paper explores the possibility that booms and busts are endogenous with an econometric examination of the U.S. economy. Although existing empirical results suggest the contrary, a theoretical literature discounts the stability verdict on the grounds that it is based on linear econometric evidence which is unreliable when the underlying phenomenon is non-linear. We study a simple Keynesian cycle model which is theoretically general enough to include convergence to equilibrium or endogenous cycles as special cases. We find one particular nonlinear econometric specification which exhibits a limit cycle when estimated on postwar data, while the estimate of its global linear approximation converges to a fixed equilibrium. Our results are an empirical investigation of the boundary between stability and instability.
Isolation and characterization of osteogenic cells derived from first bone of the embryonic tibia

Osteogenesis in the embryonic long bone rudiment occurs initially within an outer periosteal membrane and subsequently inside the cartilaginous core as a consequence of the endochondral ossification process. In order to investigate the development of these two different mechanisms of bone formation, embryonic chick tibial cell isolates were prepared from sites of first periosteal bone formation and from the immediately underlying hypertrophic cartilaginous core region. Mid-diaphyseal periosteal collars and the corresponding cartilage core were microdissected free from Hamburger-Hamilton stage 35 (Day 9) chick tibias and separately digested with a trypsin-collagenase enzyme mixture. The released cell populations were cultivated in vitro and characterized by morphological analysis, histochemical localization of alkaline phosphatase, alizarin red S staining for mineral deposition, growth rate ([3H]thymidine uptake), and proteoglycan content. Results of these studies showed that periosteal collar cell cultures form nodule-like structures that stain positive with alkaline phosphatase and alizarin red S. Light and electron microscopic observation revealed cell and matrix morphologies similar to that of intact periosteum. The nodules were composed of plump cell types embedded within a mineralized matrix surrounded by a fibroblastic cell layer. Core cartilage cell cultures displayed typical characteristics of the hypertrophic state in their visual appearance and proteoglycan composition. The formation of osseous-like structures in periosteal collar cell cultures but not in core chondrocyte cell cultures demonstrates the relatively autonomous nature of intramembranous ossification while emphasizing the dependence of the endochondral ossification process upon an intact vascularized environment present in the developing tibia.
User-Driven Collaboration for NASA Mission Control

NASA Ames, in conjunction with the Johnson Space Center (JSC), is building a platform to enable mission control operations software to be assembled from flexible collections of components and services. MCT is designed to support rapid creation, composition, visualization, and certification of user objects, while using social media techniques to help communicate, categorize, and analyze the massive amount of data and complex processes required for space flight operations. Since its initial deployment, MCT has helped spur collaboration within and across NASA centers, allowing different teams to work together on the shared goal of safe space flight. Flight controllers at JSC are assembling, tagging, searching, and visualizing telemetry. Software developers are extending the platform by integrating new data sources and analysis capabilities while reusing high-level functionality, such as scalable real-time plotting. Finally, the process of adopting MCT across NASA centers has opened communication channels through shared software development, feature design, and work practices.
Probing the microelastic properties of nanobiological particles with tapping mode atomic force microscopy

We have studied untreated photosystem II (PSII) membrane using tapping mode atomic force microscopy (AFM). The individual PSII particles distribute randomly in the membrane. Near the center of each particle, our AFM reveals an intramolecular cavity which confirms the previous electron microscopy of stained samples. The cavity can be reversibly enlarged from a few nm to as many as 40 nm in diameter by increasing the force on the AFM tip. A study of the particle's apparent height and cavity size under various forces provides unique information about the microelastic properties of single PSII particles.
Behavioral interventions to increase HPV vaccination acceptability among mothers of young girls.

Objective To determine the most effective ways to present human papillomavirus (HPV) vaccine risk and benefit information to mothers in Hispanic, African American, and White communities, to increase mothers' intentions to vaccinate their daughters against HPV. Design The study used a 3 x 2 between-subjects factorial design, involving 3 different risk presentation formats (graphical HPV statistics, nongraphical HPV statistics, or no-statistics control) and the presence or absence of rhetorical questions (RQ). Data were collected from a national sample of 471 mothers of girls ages 11-16. Main outcome variables The primary outcome variable was mothers' intention to vaccinate their daughters against HPV. Secondary outcomes included mothers' self-reported message comprehension and perceptions of daughters' vulnerability to HPV infection, infection severity, vaccine efficacy, and obstacles to immunization. Results and conclusion Results showed that both risk presentation format and RQs had an overall positive effect on mothers' intention to vaccinate their daughters. However, the interventions appear to be more effective when used separately than when used in combination. Each of these interventions is brief and could easily be implemented by health care providers as well as in patient health communication literature.
Identification and assessment of effective services and interventions: the nursing home perspective.

In the past decade, researchers across the world have published a great number of studies on the care of nursing home residents with dementia. Investigations have concentrated on such important subjects as special care units, staff training, functional performance, and problem behaviors. However, most of the studies have lacked the rigor needed to establish the treatments that they tested as standards of care, according to criteria from the American Academy of Neurology. Without a solid scientific foundation, researchers in the USA have found it difficult to offer authoritative advice to policy makers and advocacy groups. This article will discuss some theoretical and methodological issues of research that require attention to fortify the scientific foundation. Topics include theoretical and definitional inconsistencies, sampling issues, limitations related to data collectors, the need for greater specificity of interventions, and outcome measures. The article will continue with an overview of areas that ...
Determination of the Deuteron D Wave from Coherent π 0 Photoproduction

The differential cross section for the elastic photoproduction of mesons( pi /sup 0/) in deuterium was measured for an incident gamma energy of 500 Mev to determine the deuteron D wave function. It is found that the D wave in the deuteron ground state is (7.5 plus or minus 0.6)%. (C.E.S.)
Adherence to dietary guidelines and mortality: a report from prospective cohort studies of 134,000 Chinese adults in urban Shanghai

Background: A higher adherence to dietary recommendations, such as the Dietary Approaches to Stop Hypertension (DASH) and the Alternative Healthy Eating Index (AHEI), has been associated with lower morbidity and mortality from chronic diseases in Western populations. However, the health benefits of following the Dietary Guidelines for Chinese remain unknown. Objective: We examined adherence to the Chinese Food Pagoda (CHFP) in association with total and cause-specific mortality and compared associations with those of the DASH and AHEI. Design: Participants included 61,239 men and 73,216 women (aged 40–74 y) from 2 population-based prospective studies in Shanghai, China. Habitual dietary intakes were assessed at baseline in-person interviews by using validated food-frequency questionnaires. Deaths and underlying causes were identified through the Shanghai Vital Statistics Registry and follow-up home visits. Results: We documented 2954 deaths in men and 4348 deaths in women during mean follow-ups of 6.5 and 12.0 y, respectively. A higher CHFP score was associated with lower total mortality with multivariable-adjusted HRs of 0.67 (95% CI: 0.60, 0.75) in men and 0.87 (95% CI: 0.80, 0.95) in women when extreme quartiles were compared (both P-trend < 0.005). Decreased risks associated with a higher CHFP score were observed for cardiovascular disease, cancer, and diabetes mortality, particularly in men. A significantly lower total mortality was shown for adherence to specific recommendations on vegetables, fruit, legumes, fish, and eggs but not grains, dairy, meat, fat, and salt. A higher DASH score and AHEI also predicted lower mortality from all causes, cardiovascular disease, and diabetes but not cancer. Conclusions: A greater compliance with Chinese or US dietary guidelines is associated with lower total mortality in Chinese adults. Favorable associations are more evident in men than women and more consistent for cardiometabolic mortality than cancer mortality.