cssi/SciSciGPT-SciSciNet huggingface dataset:
The stability of sunspot magnetic fields and the origin of solar flares

The steady motion in sunspot magnetic regions is considered for both current-free and force-free configurations. The sufficient condition for stability is obtained in the presence of both external current-free and force-free magnetic fields and a steady motion. It is shown that the pattern of such steady motion is most important in triggering an instability of sunspot magnetic fields, both for the current-free and force-free configuration. When there is no steady motion, the current-free configuration of sunspot magnetic fields is always stable, whereas the stability in the case of force-free magnetic fields is connected with the configuration. The onset of a solar flare seems to be associated with an instability connected to the steady motion within the sunspot magnetic regions.
Relating surface albedos in GCM to remotely sensed data

Abstract The albedo of land surfaces is an important parameter for climate models. Observations over large areas are determined by satellite-sensed radiation from a single direction. This bidirectional reflectance is related to albedo by integration over all view angles. In the absence of observations at all view angles, a model of the radiative transfer through the atmosphere and at the surface is required to carry out this integration and to relate observations at one or a limited number of angles to surface albedo. Ideally, the same surface radiative model would be used to represent albedos in climate models. Both remote sensing and climate models require simple expressions for surface radiative models that are computationally inexpensive. We develop an analytic solution for reflection from a homogeneous leaf canopy with statistically prescribed leaf orientations. Following the approach of Hapke for planetary surfaces, this solution is used with adjustable parameters to invert observations of canopy bidirectional reflectance and define values for the model parameters. We allow for the asymmetric scattering resulting from leaf geometry and leaf-scattering properties. The former results from the product of projections of the leaf normal in the source and view directions integrated over the leaf distribution. This integration is approximated by simple analytic functions. The analytic solution is exact in the single scattering limit for the model assumed but uses a simple two-stream solution to include multiple scattering contributions to the bidirectional reflectance. The accuracy of the procedure is bench-marked using the ray-tracing model of Kimes. The analytic bidirectional reflectances agree with the numerical solution with relative errors less than 10% for near-infrared and less than 1% for visible radiation. With the use of a more accurate two-stream approach available for total fluxes, analytic albedos agree with those computed numerically with even smaller relative error. Application to remote sensing is illustrated with two examples: Kimes' lawn and Kriebel's pasture land. The inferred parameters are physically plausible. The observations are fit with an r.m.s. error of the order of 5–10%.
Hypervelocity impacts and magnetization of small bodies in the Solar System

The observed magnetism of asteroids such as Gaspra and Ida (and other small bodies in the solar system including the Moon and meteorites) may have resulted from an impact-induced shock wave producing a thermodynamic state in which iron-nickel alloy, dispersed in a silicate matrix, is driven from the usual low-temperature, low-pressure, α, kaemacite, phase to the paramagnetic, epsilon (hcp), phase. The magnetization was acquired upon rarefaction and reentry into the ferromagnetic, α, structure. The degree of remagnetization depends on the strength of the ambient field, which may have been associated with a Solar-System-wide magnetic field. A transient held induced by the impact event itself may have resulted in a significant, or possibly, even a dominant contribution, as well. The scaling law of Housen et al. (Housen, K. R., R. M. Schmidt, and K. A. Holsapple 1991. Icarus 94, 180-190) for catastrophic asteroid impact disaggregation imposes a constraint on the degree to which small planetary bodies may be magnetized and yet survive fragmentation by the same event. Our modeling results show it is possible that Ida was magnetized when a large impact fractured a 125 +/- 22-km-radius protoasteroid to form the Koronis family. Similarly, we calculate that Gaspra could be a magnetized fragment of a 45 +/- 15 km-radius protoasteroid.
Larval morphology of the bryozoan Watersipora arcuata (Cheilostomata: Ascophora).

The larva of the ascophoran cheilstome Watersipora arcuata is described on the basis of serial 1-μ sections, light microscopy of whole mounts, and scanning electron microscopy. Using lightly osmicated specimens, it was possible to map almost every cell on the larval surface. Limited observations on hatching and larval behavior are provided in conjunction with the anatomical description. Tissues of the larva are partitioned between those that function exclusively during the larval period and are degraded at metamorphosis as transitory tissues and those that will have postmetamorphic fates in formation of the ancestrula. Significantly, W. arcuata has two possible anlagen for the ancestrular polypide, the infracoronal cells in the oral hemisphere and the epidermal blastemal cells in the aboral hemisphere, rather than only one or the other of these as reported in other species. Also detailed are the supracoronal flange and groove, which are unique to this genus and are involved in the transmission of mycoplasma-like organisms between successive generations of adults; two pairs of complex pigment cup ocelli; multiple intercoronal cells that are presumed to have varied sensory and mechanical functions; and the sensory, adhesive, and locomotory components of the pyriform organ. The larval anatomy of W. arcuata is compared with that of the larvae of the ctenostomes Alcyonidium gelatinosum (coronate), Bowerbankia imbricata (coronate), B. gracilis (coronate), and Flustrellidra hispida (shelled lecithotrophic) and of the cheilostomes Bugula neritina (coronate), Electra pilosa (cyphonautes), and Membranipora membranacea (cyphonautes). This study is the first detailed analysis of the larval structure of any ascophoran bryozoan and provides a necessary platform for subsequent analyses of embryology and metamorphosis.
Novel sequential copolymers by elucidating the mechanism of initiation and termination of carbocationic polymerizations

Elucidation and understanding of the fundamentals of the initiation and termination of cationic olefin polymerization led to the control of these elementary events and in turn to the synthesis of novel sequential (block and graft) copolymers exhibiting unique physical properties. Most recent research concerns olefin polymerizations with BCl3 coinitiator. For example, the polymerization of isobutylene with the H2O/BCl3 initiator system produces macromolecules with tertiary chlorine termini. These end groups, in conjunction with certain alkylaluminum compounds, can be used to initiate the polymerization of a second olefin and thus can lead to new block copolymers. The synthesis of poly(isobutylene-b-styrene) by this technique will be discussed.
Nonequilibrium chemistry in shocked molecular clouds

The gas-phase chemistry is studied behind a 10-km/s shock propagating into a dense molecular cloud. The principal conclusions are that: the concentrations of certain molecules (CO, NH3, HCN, N2) are unperturbed by the shock; other molecules (H2CO, CN, HCO(+)) are greatly decreased in abundance; and substantial amounts of H2O, HCO, and CH4 are produced. Approximately 1 million yr (independent of the density) must elapse after shock passage before chemical equilibrium is attained.
Four Scenarios Concerning Fair Use and Copyright Costs: Electronic Reserves at the University of Colorado, Boulder

At the end of spring semester, 2001, the authors submitted to the University of Colorado, Boulder Libraries Cabinet a proposal for implementing electronic reserves. Four scenarios were proposed: (1...
Predicting discharge dynamics of wet cohesive particles from a rectangular hopper using the discrete element method (DEM)

Accurate prediction of the discharge rate from hoppers is important in many industrial processes involving the handling of granular materials. The present work investigates the parameters affecting the discharge rate of a wet cohesive system from a quasi-3-D, rectangular hopper using the discrete element method (DEM). The cohesion between the particles is described by a pendular liquid bridge force model and the strength of the cohesive bond is characterized by a Bond number. The Beverloo correlation is applied to cohesive systems by modifying the Beverloo constant as a function of Bond number. The predictions obtained from this modified correlation fit the simulation data reasonably well. In addition, the effect of hopper angle in cohesive systems is shown to follow a trend similar to cohesionless systems, where the discharge rate is insensitive to changes in hopper angle except below a critical angle (with respect to the vertical) where the discharge rate increases rapidly. This critical angle of flow decreases with increasing cohesion.
Direct stimulation by thyrotropin-releasing hormone (TRH) of polyphosphoinositide hydrolysis in GH3 cell membranes by a guanine nucleotide-modulated mechanism.

Abstract Polyphosphoinositide hydrolysis was examined in membranes from thyrotropin-releasing hormone (TRH)-responsive GH3 pituitary cells. [3H]Inositol phosphates (IP2 and IP3) were generated upon incubation of membranes from [3H]inositol-labeled cells indicating the presence of a membrane-associated polyphosphoinositide phosphodiesterase (PPI PDE). Membrane PPI PDE activity was found to be stimulated by TRH and by GTP-γ-S in Ca2+-modulated manner. In addition, TRH-stimulated PPI hydrolysis was potentiated by GTP. These results demonstrate direct in vitro effects of a hormone on PPI turnover and suggest the involvement of a GTP-binding component in transmembrane signalling by TRH.
Dough Strain Hardening Properties as Indicators of Baking Performance

Bread loaf volume is an important economic criterion. Breeders, millers, and bakers need measurements allowing them to evaluate dough performance during processing. Strain hardening is an important dough property. It describes the stability of the gas cell walls and the ability of cells to expand further; therefore, the higher the strain hardening index (n), the better the baking performance. Dough exhibits strain hardening during uniaxial extensibility tests. However, obtaining n from an extensibility test is time consuming. The objectives of this study were to identify the extensibility parameters that contribute to n. Three parameters were retained in the model (R2 = 0.90): dough strength (Rmax), extensional delay (EDiff), and initial slope of the curve (Ei). Rmax was the largest contributor and was proportional to the dough strain hardening properties. EDiff and Ei had a detrimental effect on n. The appropriateness of the model was validated with two sample sets (19 genotypes, 12 environments). Signif...
Agribusiness, Labor, and the Wetbacks; Truman's Commission On Migratory Labor

(1978). Agribusiness, Labor, and the Wetbacks; Truman's Commission On Migratory Labor. The Historian: Vol. 40, No. 4, pp. 650-667.
An evaluation of planning techniques for stereotactic body radiation therapy in lung tumors.

Purpose To evaluate four planning techniques for stereotactic body radiation therapy (SBRT) in lung tumors.
Anaerobic tanks for cucumber fermentation and storage

Fermentation in sodium chloride (NaCl) brine by naturally occurring micro-organisms is an established procedure for temporary preservation of cucumbers in open-top tanks. The physical attributes and accessory supporting equipment of an anaerobic, closed-top tanking system with the potential to reduce environmental problems and facilitate the use of new fermentation technology is reviewed and updated. Prototype tanks of 30 to 35 m 3 capacity and fibreglass construction having a food-grade liner were selected for introductory stage testing and semi-commercial evaluation. Anaerobic conditions were achieved by sealing the manhole port located at the tank top and purging the brine with nitrogen (N 2 ) gas to remove oxygen. The purging (at rates up to 1·0 m 3 /h) served to remove carbon dioxide (CO 2 ) generated during fermentation and also operated as a gas lift pump to circulate the cover brine. During fermentation, N 2 and CO 2 gases were vented from the tank top through a 50 mm diameter vent tube at atmospheric pressure. During storage, anaerobic conditions were maintained by a slight (approximately 250 mm water column) positive pressure of N 2 in the headspace above the liquid level; a U-tube manometer served as a means of isolation, a pressure indicator and a safety device against excessive positive or negative tank pressures. Field trials to the system under commercial conditions have demonstrated that anaerobic tanks can alleviate many of the objectional features of open-top tanks. Implications of projected modifications of the system are briefly examined.
Dynamics of aerosol agglomerate formation

Abstract The dynamics of the formation of metal oxide agglomerates was studied by introducing metal containing salts of magnesium and zinc into a flat flame. Distributions of the mobility equivalent diameter of the agglomerates formed downstream from the flat flame were self-preserving and in good agreement with the theory for the agglomerating of power law (fractal-like) agglomerates in the free molecule regime. Theory indicates that after sufficiently long times, the average size of the agglomerates varies inversely with the size of the primary particles composing the agglomerates, for a given volumetric concentration of aerosol material. The effect of primary particle size is significant, and supported by experimental evidence.
Thermal contact resistance measurements at ambient pressures of one atmosphere to 3 x 10 super minus super 12 mm Hg and comparison with theoretical predictions.

Thermal contact resistance measurement at various ambient pressures compared with theoretical predictions with each parameter analyzed over interface by computer program
Comparison of anterior cerebral artery blood flow velocity and cerebral blood flow during hypoxia.

ABSTRACT: Measurement of anterior cerebral artery blood flow velocity with a continuous wave bidirectional Doppler was compared with cerebral blood flow (CBF) measured with radioactive microspheres in 11 paralyzed newborn lambs during hypoxic hypoxia. The Doppler probe was maintained in a fixed position during each experiment. The objectives of the study were to validate this noninvasive technique that is being used widely in the clinical setting to qualitatively assess changes in CBF, and to evaluate which of the velocity parameters measured provide the most information. Diastolic velocity (DV), peak systolic velocity (PSV), area under the velocity curve (AUC), and pulsatility index (PI) were examined under conditions of varied arterial oxygen content and compared to microsphere CBF. DV (r = 0.72, p < 0.001), AUC (r = 0.72, p < 0.001), and PSV (r = 0.63,p < 0.001) demonstrated stronger correlations with changes in CBF than did the PI (r = -0.41, p < 0.05). DV (r = 0.81, p < 0.001), AUC (r = 0.80, p < 0.001), and PSV (r = 0.75, p < 0.001) also exhibited stronger relationships with changes in arterial oxygen content than did the PI (r = –036, p < 0.05). These data demonstrate that changes in cerebral blood flow velocity are useful qualitative measures of changes in cerebral blood flow. However, the utility of this technique is dependent upon a stable probe position, and assessment of the actual velocity measurements (DV, PSV, AUC) rather than simply the pulsatility index.
Using symbolic math to evaluate saddlepoint approximations for the difference of order statistics

We show how symbolic math can be used to calculate saddlepoint approximations for the difference of order statistics from any continuous parent distribution. The difference of order statistics is commonly used as a test statistic in nonparametric tests for constancy of a process. The usefulness of the program is shown by examining the steps required to obtain saddlepoint approximations for a single distribution. A sample session of the a program is presented for the interquartile range of a sample of size 100 from an exponential distribution with mean 2. The results are graphically compared to the true density.
Improving joints between composites and steel using perforations

The elastic mismatch between fiber reinforced composites and steel makes joining them difficult. One way to reduce this mismatch is to decrease the average stiffness of the steel by introducing perforations. Further, this has the possible advantage of mechanical interlocking. In the present study, stainless steel strips were perforated with circular or triangular holes. The hole sizes were smaller near the edge of the composite, and increased with increasing depth in the composite, thus creating a graded steel component. Various surface preparations, perforation fillers, and degrees of perforations were investigated. The steel strips were joined to the composite by inserting them between glass fiber fabrics before vacuum assisted resin transfer molding the composite. Tensile experiments were performed, and the quasi-static strength was used as the measure by which the different joints were compared.
Transit pricing research

Several decades of research on transit pricing have provided clear insights into how riders respond to price changes in both the transit and automobile sectors. For the most part, riders are insensitive to changes in either fare levels, structures, or forms of payments, though this varies considerably among user groups and operating environments. Since riders are approximately twice as sensitive to changes in travel time as they are to changes in fares, a compelling argument can be made for operating more premium quality transit services at higher prices. Such programs could be supplemented by vouchers and concessionary programs to reduce the burden of higher fares on low-income users. Also, cross-elasticity research suggests that higher automobile prices would have a significantly greater affect on ridership than lower fares. Most research on transit fare structures shows that the common practice of flat fares is highly inequitable, penalizing short-distance and off-peak users. Free fare programs have proven quite costly for each new transit user attracted and have rarely lured motorists to transit. Free fares limited to downtowns have been more successful than systemwide free fare programs. While prepayment schemes have met with success in the U.S. and Europe, honor fares have suffered from excessive revenue losses in at least one case in the U.S. Some of the more noteworthy fare policy successes in North America have been Bridgeport's combined pass-fare program, Allentown's deep discounts, Ottawa's major fare reduction and differentiation, and Columbus's substantial midday discount. As paratransit and other new transit alternatives to conventional bus continue to emerge, new, more differentiated fare practices can be expected in the future.
[PPN][Fe3(CO)9(C⋮CH)] and [Fe3(CO)9(C⋮COTi(THF)4Cl)] from the Reaction of Low-Valent Titanium with [Fe3(CO)9(CCO)]2-

TiCl3(DME)1.5 (DME = 1,2-dimethoxyethane) and a Zn−Cu couple react with [PPN]2[Fe3(CO)9(CCO)] to give the new compound [PPN][Fe3(CO)9(C⋮CH)] (I) (70% yield), a known compound [Fe3(CO)10(CCH2)] (II) (9% yield), and another new compound [Fe3(CO)9(CCOTi(THF)4Cl)] (III). Compound I was characterized by 1H and 13C NMR, IR, mass spectrometry, and X-ray crystallography. Compound III was characterized by IR, mass spectrometry, 13C NMR, and X-ray crystallography.
Optical-radar imaging of scale models for studies in asteroid astronomy

During the past five years, delay-Doppler radar has become the primary technique for studying the structure of Earth-crossing asteroids. None of these objects has yet been visited by spacecraft, so ground-truth test cases are lacking. A laboratory system is described that provides optical-radar images at 0.1-mm resolution. These data are analogous to the highest-resolution asteroid radar images currently available and provided realistic test cases for developing signal-processing techniques. The system can be thought of as a 1/188,000 scale model of the Arecibo radar, or a 1/52,800 scale model of the Goldstone radar.
Lithium-selective alteration of the function of brain versus cardiac Gs protein.

Abstract Lithium was recently demonstrated to inhibit the coupling of both muscarinic cholinergic receptors and β-adrenergic receptors to pertussis toxin-sensitive and cholera toxin-sensitive G proteins, respectively, thus suggesting alteration of the function of G protein by lithium, as the single site for both the antimanic and antidepressant effects of this drug. One of the most puzzling aspects of the ability of lithium to ameliorate the manic-depressive condition, is its relatively selective action upon the central nervous system (CNS). In the present study, it was shown that lithium selectively attenuated the function of Gs proteins in the CNS, assessed through isoproterenol-induced increases in the binding of guanosine triphosphate (GTP) to these proteins. Therapeutic concentrations of lithium (1–1.5 M in vitro) inhibited the function of Gs protein in the cerebral cortex of the rat, while 4- to 6-fold larger concentrations of lithium were required to alter the function of Gs protein equivalently in the cardiac ventricles of the rat. Chronic administration of lithium via rat chow, containing lithium carbonate, to rats totally abolished the effect of isoproterenol on the binding of GTP in the CNS but did not affect the function of peripheral cardiac Gs protein. The lithium-selective action on the function of Gs protein in the CNS may stem from the heterogeneity of the αs subunit proteins: in the heart, the major species is a 45 kDa molecule, while in the brain, a 52 kDa molecular weight species predominates. The heterogeneity in αs subunits may thus be the biochemical basis for the selective action of lithium on the CNS and for the scarcity of peripheral side effects.
Liver X receptor is a regulator of orphan nuclear receptor NOR-1 gene transcription in adipocytes

Liver X receptor is a regulator of orphan nuclear receptor NOR-1 gene transcription in adipocytes
Induction of stress proteins by electromagnetic fields in cultured HL-60 cells.

HL-60 cells in culture were exposed for 2 h to a sinusoidal 0.1 or 1 mT (1 or 10 Gauss) magnetic field at 60 Hz and pulse labeled after exposure with radioactive isotopes by incubation by using either [35S]methionine, [3H]leucine, or [33P]phosphate. The radioactive labels were incorporated into cellular proteins through synthesis or phosphorylation. Proteins were extracted from electrostatically sorted nuclei, and the heat shock/stress proteins (sp) were analyzed for synthesis and phosphorylation by two-dimensional polyacrylamide gel electrophoresis. In the control cultures (no exposure to the magnetic field), sp 72c (cognate form) was faintly observed. A 0.1 mT exposure did not show sp metabolism to be different from that of the controls; however, after a 1 mT exposure of the HL-60 cells, sp 70i (inducible form) was synthesized ([35S]methionine incorporation). Sp 90 was not synthesized at either field level, but was phosphorylated ([33P]phosphate incorporation) in the 1 mT exposure. Sp 27 (isoforms a and b) was induced after a 1 mT exposure as reflected by labeling with [3H]leucine. These sps were not detected after a 0.1 mT exposure. After a 1 mT exposure and labeling with [33P], sp 27 isoforms b and c were phosphorylated whereas isoform ‘a‘ was not observed. Sps 70i, 72c, and 90 were identified by commercial sp antibodies. Likewise, polypeptides a, b, and c were verified as sp 27 isoforms by Western blotting. Statistical evaluation of sp areas and densities, determined from fluorographs by Western-blot analysis, revealed a significant increase in sps 90 and 27a after a 1 mT magnetic field exposure. The 1 mT magnetic field interacts at the cellular level to induce a variety of sp species. Bioelectromagnetics 20:347–357, 1999. Published 1999 Wiley-Liss, Inc.
Teaching Science Through Pictorial Models During Read-Alouds

This study examines how three elementary teachers refer to pictorial models (photographs, drawings, and cartoons) during science read-alouds. While one teacher used realistic photographs for the purpose of visually verifying facts about crystals, another employed analytical diagrams as heuristic tools to help students visualize complex target systems (rainbow formation and human eye functioning). Another teacher used fictional cartoons to engage students in analogical storytelling, communicating animal camouflage as analogous to human “blending in.” However, teachers did not always explicitly convey the representational nature of pictorial models (analog and target as separate entities). It is argued that teachers need to become more aware of how they refer to pictorial models in children’s science books and how to promote student visual literacy.
Buflomedil in peripheral arterial disease: trials and tribulations.

Peripheral arterial disease (PAD) is a distinct clinical manifestation of atherosclerosis, with an associated long-term risk of coronary and cerebrovascular events that is equivalent to that of a primary diagnosis of myocardial infarction or ischemic stroke.1,2 The prevalence of PAD, as estimated by an abnormal ankle-to-brachial systolic pressure index (ABI 55 years of age in Western societies.3–5 The majority of patients with PAD are asymptomatic, but recognition of the disease is clinically important because it may be the primary manifestation of systemic atherosclerosis. Indeed, numerous studies have demonstrated a correlation between the global risk of cardiovascular events and ABI, which portends a more dire outcome for those with increasing degrees of hemodynamic compromise in the limb.6,7 The major risk factors for PAD, aside from age, are cigarette smoking, diabetes mellitus, dyslipidemia, hyperhomocysteinemia, and hypertension. Among these, the recent explosion in the worldwide prevalence of diabetes mellitus is of particular concern, particularly because the risk of both mortality and limb loss in diabetic PAD patients is increased several-fold. Thus, a major focus of clinical management in PAD is on secondary prevention, including the aggressive treatment of these risk factors by dietary and behavioral modification, combined with medical therapies. Present evidence suggests that PAD patients should receive lifelong antiplatelet therapy, treatment with a hydroxymethylglutaryl coenzyme A reductase inhibitor (statin), and appropriate antihypertensive therapy, which should probably include an angiotensin-converting enzyme inhibitor.8 Article p 816 Symptomatic PAD, which affects approximately one third of all PAD patients, is most commonly manifested as intermittent claudication (IC), a walking impairment that results at least in part from a classic mismatch between blood supply and metabolic demand of the leg muscle groups. Critical limb ischemia, the most severe form …
Chaos in the heart: the interaction between body and mind

A number of factors influence the chaotic dynamics of heart function. Genetics, age, sex, disease, the environment, experience, and of course the mind, play roles in influencing cardiovascular dynamics. The mind is of particular interest because it is an emergent phenomenon of the body admittedly seated and co-occurrent in the brain. The brain serves as the body's controller, and commands the heart through complex multipathway feedback loops. Structures deep within the brain, the hypothalamus and other centers in the brainstem, modulate heart function, partially as a result of afferent input from the body but also a result of higher mental processes. What can chaos in the body, i.e., the nonlinear dynamics of the heart, tell of the mind? This paper presents a brief overview of the spectral structure of heart rate activity followed by a summary of experimental results based on phase space analysis of data from semi-structured interviews. This paper then describes preliminary quantification of cardiovascular dynamics during different stressor conditions in an effort to apply more quantitative methods to clinical data.
Fiber order of the normal and regenerated optic tract of the frog (Rana pipiens).

In the normal frog, axons from the peripheral retina arising at the temporal pole course superficially in the middle stream of the diencephalic optic tract. Axons from the nasal pole course in two streams running in the opposite margins of the tract, dorsonasal axons ventrally, ventronasal axons dorsally. Axons from the dorsal and ventral poles of the retina occupy the intervals between the aforementioned middle and marginal streams. Axons from more central regions of the retina tend to occupy deeper levels of the optic tract. The regenerated optic tract does not regain its normal organization, e.g., axons of peripheral nasal origin are spread out widely over the entire width of the tract. However, axons from the temporal pole of the retina do return approximately to their original location in the middle stream. The concentration of temporal axons in the middle stream of the optic tract after regeneration may now be understood in terms of the expression pattern of the ephrin-A class of receptor tyrosine kinase ligands in the cellular matrix of the optic tract. The ephrin-As, which have a repellent effect on growing temporal retinal axons, are concentrated in and along the margins of the diencephalic optic tract and essentially absent from its middle stream. It is proposed here that peripheral temporal axons may be forced into this middle region by their avoidance of the higher levels of ephrin-A expression in the tract margins. In contrast, the growth pattern of regenerating peripheral nasal axons would not be affected by the ephrin-A gradient in the optic tract. J. Comp. Neurol. 477:43–54, 2004. © 2004 Wiley-Liss, Inc.
Lunar polymict breccia 14321 - A petrographic study

A detailed description is given of the petrology and mineralogy of lunar polymict breccia 14321, which was returned from the Fra Mauro formation on the Apollo 14 mission. Electron probe microanalysis and microscopic studies were made of seven petrographic thin sections of the rock. Three broad genetic classes were found in the thin sections: (1) rounded fragments of pre-existing microbreccia with microscopically recognizable crystal and lithic fragments incorporated in a dark matrix; (2) igneous rock fragments of basaltic composition; and (3) a light colored, somewhat friable matrix which cements the other two classes. The components are classified according to chemical, mineralogical textural, and chronological criteria.
Comparison of the luteolytic action of LH and estrogen in the hamster.

Luteal morphology and maintenance of decidual cell response (DCR) or pregnancy were used as end-points in evaluating the effects of bovine luteinizing hormone (NIH-LH-B3) on the corpora lutea (CL) of the hamster. Daily treatment for 5 days with 20 to 100 μg of LH induced luteal regression in pseudopregnant and pregnant animals. However, 50 μg of LH also caused hyperplasia and hypertrophy of the ovarian interstitium which resulted in a positive DCR in pseudopregnant animals despite the involution of the CL. One hundred μg of LH consistently induced ovulation in pseudopregnant and occasionally in pregnant animals. The CL resulting from new ovulations were nonfunctional. FSH, prolactin or a combination of FSH and prolactin did not induce luteolysis. The luteoly-tic effect of 100 μg of LH was counteracted by prolactin, but not FSH. The ratio of exogenous prolactin and LH was critical for the preservation of the CL. Treatment with combinations of prolactin and LH in ratios of 2.5, 10 and 20 preserved CL in 37....
Mutations Affecting the Oligomerization Interface of G-Protein-Coupled Receptors Revealed by a Novel De Novo Protein Design Framework

Specific functional and pharmacological properties have recently been ascribed to G-protein-coupled receptor (GPCR) dimers/oligomers. Because the association of two identical or two distinct GPCR monomers seems to be required to elicit receptor function, it is necessary to understand the exact nature of this interaction. We present here a novel method for de novo protein design and its application to the prediction of mutations that can stabilize or destabilize a GPCR dimer while maintaining the monomer's native fold. To test the efficacy of this new method, the dimer of the single-spanned transmembrane domain of glycophorin A was used as a model system. Experimental data from mutagenesis of the helix-helix interface are compared with computational predictions at that interface, and the model's results are found to be consistent with the experimental findings. A flexible template was developed for the rhodopsin homodimer at atomic resolution and used to predict sets of three and five mutations. The results are found to be consistent across eight case studies, with favored mutations at each position. Mutation sets predicted to be the most disruptive at the dimerization interface are found to be less specific to the flexible template than sets predicted to be less disruptive.
Theoretical investigation of an integrated all-optical controller-modulator device using QCSE in a multiquantum well phototransistor

Theoretical investigation of an all-optical controller-modulator device based on excitonic transitions for the purpose of a general logic implementation are discussed. The device is based on the quantum confined Stark effect of the heavy-hole excitonic transition in a multiquantum well. The device consists of three basic elements: modulator, controller, and load. The controller is a heterojunction phototransistor with multiquantum wells in the base-collector depletion region. This allows an amplified photocurrent-controlled voltage feedback with low light levels, allowing one to change the state of the modulator. A detailed analysis of the sensitivity of this device in various modes of operation (i.e. floating base and contacted base) is presented. Studies on the cascadability of the device as well as its integrating-threshold properties are also presented. Switching of the resistive load and optically active load with less than 10 mu W total power is demonstrated to be feasible. >
A new technique for analyzing soft real-time self-suspending task systems

We consider the problem of globally scheduling soft real-time sporadic self-suspending task systems on multiprocessors. Existing analysis methods are pessimistic, yielding O(n) utilization loss where n is the number of tasks in the system. Unless the number of tasks is small and suspension delays are short, such methods entail significant capacity loss. We identify the fundamental sources that cause pessimism in existing methods, and propose a new analysis technique that entails only O(m) suspension-related utilization loss, where m is the number of processors.
Stability of liposome encapsulated hemoglobin dispersions

The demand for artificial blood substitutes in cases of elective surgeries, trauma, and civilian mass catastrophes increases every day. However, few studies have been done to characterize the mechanical stability of blood substitutes, especially liposome encapsulated hemoglobin (LEHb) dispersions. In this work, the stability of LEHb dispersions was investigated by fitting Jung et al.'s liposome size distribution model to experimentally measured LEHb size distributions [6] (produced via extrusion) using asymmetric flow field-flow fractionation coupled with multi-angle static light scattering. The effective bending constant (KB) and radius of curvature (R0) of each liposome dispersion were regressed from the size distribution fits. The model was found to be in agreement with the size distributions of LEHbs extruded through 400, 200 and 100 nm pore diameter membranes, but not in agreement with LEHbs extruded through 80 and 50 nm pore diameter membranes. Although the magnitude of KB fluctuated, we deduced a general trend for KB to decrease with decreasing pore diameter, and increasing initial Hb concentration. LEHbs extruded through 400nm pore diameter membranes were stabilized by the spontaneous curvature effect, while those extruded through 80 and 50 nm pore diameter membranes were mostly stabilized by thermal undulations, regardless of the initial Hb concentration. For LEHb dispersions extruded through 200 and 100 nm pore diameter membranes, there was a transition of stabilization mechanism from spontaneous curvature to thermal undulations with increasing initial Hb concentration. Taken together, these results suggest that moderate Hb encapsulation might actually impart better mechanical stability to LEHb dispersions extruded through 200 and 100 nm pore diameter membranes.
Nuclear Data Sheets for A = 202☆

Abstract Evaluated nuclear structure and decay data for all nuclei within the A = 202 mass chain are presented. This work supersedes the earlier evaluation by M.R. Schmorak (1997Sc07), published in Nuclear Data Sheets 80 , 647 (1997).
Selective absorption of sulphur-35 by fungus-infected leaves.

IT has been shown that fungi and higher plants absorb and accumulate fungicidal substances to a high degree1–3; but, so far as we are aware, no quantitative demonstration of selective absorption of therapeutic chemicals by parasitized tissues of plants or animals has been reported. The successful therapeutic use of sulphur vapours against external powdery mildews and internal rusts4 suggested that these infections would be suitable for the study of selective absorption of a fungicide.
Transmission loss of damped asymmetric sandwich panels with orthotropic cores

Abstract A theoretical model of the acoustic performance of asymmetric sandwich panels is developed and verified by comparison with experimental data. The panel models consist of unequal elastic isotropic skins sandwiching an elastic orthotropic core. Damping is incorporated in both the skins and the core. The roles of various structural and material properties are determined via a parametric study. The importance of phase wave speeds and panel impedances for physically symmetric panels is discussed, as are implications for transmission loss characterization. For asymmetric panels it is seen that a relatively thick skin on one side produces some change in the transmission loss.
Reactivity and equilibrium thermodynamic studies of rhodium tetrakis(3,5-disulfonatomesityl)porphyrin species with H2, CO, and olefins in water.

Aqueous (D2O) solutions of tetrakis(3,5-disulfonatomesityl)porphyrin rhodium(III) aquo/hydroxo complexes ([(TMPS)RhIII(D2O)2]-7 (1), [(TMPS)RhIII(OD)(D2O)]-8 (2), and [(TMPS)RhIII(OD)2]-9 (3)) react with hydrogen (D2) to form an equilibrium distribution with a rhodium hydride ([(TMPS)Rh−D(D2O)]-8 (4)) and a rhodium(I) complex ([(TMPS)RhI(D2O)]-9 (5)). Equilibrium constants (298 K) are measured that define the distribution for all five of these (TMPS)Rh species in this system as a function of the dihydrogen (D2) and hydrogen ion (D+) concentrations. The hydride complex [(TMPS)Rh−D(D2O)]-8 is a weak acid in D2O (Ka(298 K) = 4.3 × 10-8). Steric demands of the TMPS porphyrin ligand prohibit formation of a Rh(II)−Rh(II)-bonded complex, related rhodium(I)−rhodium(III) adducts, and intermolecular association of alkyl complexes which are prominent features of the rhodium tetra(p-sulfonatophenyl)porphyrin ((TSPP)Rh) system. The rhodium(II) complex ([(TMPS)RhII(D2O)]-8) reacts with water to form hydride and hydroxi...
Altered brain sodium channel transcript levels in human epilepsy

Normal, and perhaps pathological, characteristics of neuronal excitability are related to the distribution and density of voltage-gated ion channels such as the sodium channel. We studied normal and epileptic human brain using the ligase detection reaction to measure the relative quantities of mRNAs encoding sodium channel subtypes 1 and 2. Normal brains exhibited characteristic 1:2 ratios which varied by brain region, but the ratios were invariate among individuals. These normal values were altered as much as threefold in anatomically corresponding regions of epileptic brain tissues. Changes of this magnitude in such a highly conserved value support a potential role for sodium channels in the pathophysiology of epilepsy.
FEMA and the Prospects for Reputation-Based Autonomy

Following its 1992 reorganization, the once scandal-ridden and sclerotic Federal Emergency Management Agency (FEMA) experienced a dramatic turnaround. The agency morphed from a caricature of the ills of bureaucracy into a model of effective federal administration. Politicians who previously blamed the agency for its slow and inefficient response to disasters came to depend on the agency to lend credibility to their own efforts. After the agency’s reorganization, politicians at all levels of government purposefully appeared beside FEMA workers. As recently as 2002, FEMA’s reputation was so strong that the designers of the Department of Homeland Security (DHS) included FEMA in it to lend prestige to the nascent department. Unlike other agencies so included, FEMA was allowed to keep its name, confirming the cachet of its brand.
The CDRH Helix-I: a physical evaluation

The use of a resonant helical coil with predominantly axial electric fields for regional hyperthermia in the abdomen and pelvis is addressed. The Helix-I applicator, which consists of a three-turn, 36-cm-long, oval-wound helical coil measuring 60 and 43 cm along its major and minor axes, respectively, is described, and specific absorption rate (SAR) measurements for the device are reported. Measurements of the E-field are also described. Specific absorption patterns for the Helix, determined by transient temperature measurements using a gel phantom, and by E/sup 2/-field scans using a liquid phantom, are in general agreement. The general agreement of electric power intensity distribution, inside and outside the phantom, with corresponding SAR distributions obtained from transient temperature data, ensures reliability of the distribution patterns. The E/sup 2/ contours provide a clear picture of hot and cold spots as well as the nature of the general distribution. >
Towards grid-based O ( N ) density-functional theory methods: Optimized nonorthogonal orbitals and multigrid acceleration

We have formulated and implemented a real-space ab initio method for electronic structure calculations in terms of nonorthogonal orbitals defined on a grid. A multigrid preconditioner is used to improve the steepest descent directions used in the iterative minimization of the energy functional. Unoccupied or partially occupied states are included using a density matrix formalism in the subspace spanned by the nonorthogonal orbitals. The freedom introduced by the nonorthogonal real-space description of the orbitals allows for localization constraints that linearize the cost of the most expensive parts of the calculations, while keeping a fast convergence rate for the iterative minimization with multigrid acceleration. Numerical tests for carbon nanotubes show that very accurate results can be obtained for localization regions with radii of 8 bohr. This approach, which substantially reduces the computational cost for very large systems, has been implemented on the massively parallel Cray T3E computer and tested on carbon nanotubes containing more than 1000 atoms.
A theoretical approach to the re-suspension factor

The atmospheric re-suspension of radionuclides is a well-known phenomenon that consists in the re-injection into the atmosphere of previously deposited radioactivity. The process is driven by the action of wind on surfaces and can act as an additional source of radiation exposure by inhalation, after the deposition has finished. It is thus defined as the re-suspension factor, a parameter K generally considered as a time depending function and defined as the ratio of Ca ,t he volumetric air activity concentration (Bq m −3 )a ndI0 (Bq m −2 ), the radioactivity deposition at time zero. The re-suspension factor concept is very useful in radioprotection in order to estimate the inhalation of radionuclides re-suspended from contaminated surfaces when direct atmospheric measurements are lacking or difficult to perform. However, the choice of the proper values of K is usually not a simple task, being quite site-specific and related to the meteorological, geomorphologic and environmental characteristics of the area to be studied. Moreover, several investigations showed clearly that the values of K are a decreasing function of time. For that reason, K values span several orders of magnitude: typical values in the range 10 −5 –10 −10 m −1 are reported in literature for different environmental conditions and time elapsed since the deposition event. The current available models for the re-suspension factor are based on empirical formulas whose parameters are highly site dependent and cannot easily be related to some physical quantity. In this paper a simple physical model for the re-suspension factor is proposed and tested with available environmental radioactivity
Sparse Coding of Natural Images Using an Overcomplete Set of Limited Capacity Units

It has been suggested that the primary goal of the sensory system is to represent input in such a way as to reduce the high degree of redundancy. Given a noisy neural representation, however, solely reducing redundancy is not desirable, since redundancy is the only clue to reduce the effects of noise. Here we propose a model that best balances redundancy reduction and redundant representation. Like previous models, our model accounts for the localized and oriented structure of simple cells, but it also predicts a different organization for the population. With noisy, limited-capacity units, the optimal representation becomes an overcomplete, multi-scale representation, which, compared to previous models, is in closer agreement with physiological data. These results offer a new perspective on the expansion of the number of neurons from retina to V1 and provide a theoretical model of incorporating useful redundancy into efficient neural representations.
Exploring Prescription Drug Coverage and Drug Use for Older Americans

OBJECTIVE:To describe existing prescription drug insurance coverage for older Americans, to describe out-of-pocket payment levels per prescription associated with service benefit prescription drug plans used by older persons, and to examine the association of prescription drug coverage types with the reported use of prescription drugs by older persons.PATIENTS AND METHODS:Data were obtained from a national survey of 1570 community-dwelling older persons (≥65 y) conducted in June 1998. A 2-part utilization model was estimated using logistic regression and ordinary least-squares regression.RESULTS:Data from 310 respondents were used for analysis. Overall, 66.1% of respondents reported having prescription drug insurance coverage. A majority (76.6%) of respondents having private drug coverage reported having a service benefit plan (requiring copayment or coinsurance amount to be paid for each prescription). The median copayment per brand name and generic prescription for persons reporting having coverage by s...