cssi/SciSciGPT-SciSciNet huggingface dataset:
Spin densities of first-row atoms calculated from polarization wave functions with accurate numerical methods

Fermi contact spin densities of the first-row atoms B--F having open-shell p electrons are systematically calculated with simple, physically interpretable wave-function models that include only the dominant configurations together with relevant single excitations that describe polarization effects. All orbitals involved are optimized self-consistently by accurate numerical grid methods to obviate any questions about basis-set incompleteness. It is found that spin polarization of the 1s, 2s, and 2p shells (the latter for oxygen and fluorine only) together with orbital polarization of the 2s shell are the important effects. Core and valence contributions are separately large in magnitude, but nearly cancel one another leading to much smaller net spin densities. The results show good semiquantitative agreement with experiment, implying that true electron-correlation effects play a secondary role in determining the spin densities of these first-row atoms.
The spring bloom in the northwestern Sargasso Sea: spatial extent and relationship with winter mixing

Abstract The interannual variability of the spatial extent of the spring bloom in the central Sargasso Sea was quantified by remote-sensing approaches. Proxy measurements employing satellite-derived sea-surface temperature and chlorophyll a concentrations were used to estimate the amount of new production derived from inorganic nitrate supplied by convective winter mixing. Nitrate supply and new productivity were estimated from temperature–nitrate and chlorophyll a –euphotic-zone depth relationships derived from in situ measurements made at the US JGOFS Bermuda Atlantic Time-series Study (BATS) site near Bermuda (31°40′ N, 64°10′ W). Proxy estimates of springtime new production at the BATS latitude fall within the range of previous estimates from geochemical approaches, numerical modeling, and analysis of hydrographic measurements. However, estimates of new production made at BATS are poor predictors of the regional-scale new production due to large interannual differences in the spatial gradients of the controlling factors. Moreover, the BATS latitude is in a region of local maxima of meridional gradients in sea-surface temperature and thereby new production. The BATS site lies in a boundary region between the dynamic, spatially variable and productive northern Sargasso Sea and the spring-bloom-free region of the southern Sargasso. Hence, interpretations of spring bloom-forced regional scale biogeochemical processes from point observations made at BATS should be made with caution.
The design and analysis of a quantitative simulator for dynamic memory management

The use of object-oriented programming in software development allows software systems to be more robust and more maintainable. At the same time, the development time and expense are also reduced. To achieve these benefits, object-oriented applications use dynamic memory management (DMM) to create generic objects that can be reused. Consequently, these applications are often highly dynamic memory intensive. For the last three decades, several DMM schemes have been proposed. Such schemes include first fit, best fit. segregated fit, and buddy systems. Because the performance (e.g., speed, memory utilization, etc.) of each scheme differs, it becomes a difficult choice in selecting the most suitable approach for an application and what parameters (e.g., block size. etc.) should be adopted. In this paper, a DMM simulation tool and its usage are presented. This tool receives DMM traces of C/C++ or Java programs and performs simulation according to the scheme (first fit, best fit, buddy system, and segregated fit) defined by the user. Techniques required to obtain memory traces are presented. At the end of each simulation run, a variety of performance metrics are reported to the users. By using this tool, software engineers can evaluate system performance and decide which algorithm is the most suitable. Moreover, hardware engineers can perform a system analysis before hardware (e.g., modified buddy system, first fit, etc.) is fabricated.
THERMOCAPILLARY CAVITY CONVECTION IN WETTING AND NONWETTING LIQUIDS

A numerical study has been conducted to examine the influence of free surface curvature, due to the presence of various contact angles, on thermocapillary convection within a cavity. The results indicate that the system hydrodynamics are changed by a combination of surface temperature gradient modification due to the presence of the adiabatic meniscus and variation in the length of the free surface, as well as viscous force dependence on the wetting angle. Local and overall heat transfer rates are, in turn, altered. Wetting liquids exhibit decreased surface fluid velocities and convective heat transfer rates, while non-wetting liquids are characterized by more complicated behavior with local increases and decreases in surface fluid velocities and an increase in local heat transfer near the free surface.
Infants' Long-Term Memory for the Sound Patterns of Words and Voices

Infants' long-term memory for the phonological patterns of words versus the indexical properties of talkers' voices was examined in 3 experiments using the Headturn Preference Procedure (D. G. Kemler Nelson et al., 1995). Infants were familiarized with repetitions of 2 words and tested on the next day for their orientation times to 4 passages--2 of which included the familiarized words. At 7.5 months of age, infants oriented longer to passages containing familiarized words when these were produced by the original talker. At 7.5 and 10.5 months of age, infants did not recognize words in passages produced by a novel female talker. In contrast, 7.5-month-olds demonstrated word recognition in both talker conditions when presented with passages produced by both the original and the novel talker. The findings suggest that talker-specific information can prime infants' memory for words and facilitate word recognition across talkers.
Graphical Field-Plotting Methods in Engineering

TO EXHIBIT the great range of problems that may be solved with comparative ease by graphical means, even though they may be very difficult to solve analytically, is the object of this paper.∗ The most familiar examples of field plotting are used for solving the Laplace equation δ2v/δx2 − δ2v/δy2 = 0, solutions of which are known as “harmonic” functions. This equation, as well as its three-dimensional analogue, has a wide range of application, and receives more comprehensive treatment than does any other type of equation.
Tracing wealth, cooperation and trust: A comparison of two great plains communities

Abstract This research examines the relationships between wealth, cooperation, and trust. Utilizing implications from the social capital literature and democratic theory, we found that trust directly affects patterns of socio-economic interactions, especially shopping. We also found that commuting was widespread and it created a rural sprawl deficit that affected trust. Specifically, the results indicated that trust of others in the community (generalized to a certain degree) tended to encourage people to shop more in town, thus contributing to the development of the community, even when controlling for commuting. Findings from this study suggest that further community level research will yield more specifics about how trust (and social capital) works to increase wealth in a community.
Adaptive plasticity in vestibular influences on cardiovascular control

Data collected in both human subjects and animal models indicate that the vestibular system influences the control of blood pressure. In animals, peripheral vestibular lesions diminish the capacity to rapidly and accurately make cardiovascular adjustments to changes in posture. Thus, one role of vestibulo-cardiovascular influences is to elicit changes in blood distribution in the body so that stable blood pressure is maintained during movement. However, deficits in correcting blood pressure following vestibular lesions diminish over time, and are less severe when non-labyrinthine sensory cues regarding body position in space are provided. These observations show that pathways that mediate vestibulo-sympathetic reflexes can be subject to plastic changes. This review considers the adaptive plasticity in cardiovascular responses elicited by the central vestibular system. Recent data indicate that the posterior cerebellar vermis may play an important role in adaptation of these responses, such that ablation of the posterior vermis impairs recovery of orthostatic tolerance following subsequent vestibular lesions. Furthermore, recent experiments suggest that non-labyrinthine inputs to the central vestibular system may be important in controlling blood pressure during movement, particularly following vestibular dysfunction. A number of sensory inputs appear to be integrated to produce cardiovascular adjustments during changes in posture. Although loss of any one of these inputs does not induce lability in blood pressure, it is likely that maximal blood pressure stability is achieved by the integration of a variety of sensory cues signaling body position in space.
Determination of amphetamine and methamphetamine enantiomers by chiral derivatization and gas chromatography–mass spectrometry as a test case for an automated sample preparation system

An automated sample preparation system has been applied to the chiral analysis of amphetamine and methamphetamine using derivatization with trifluoracetyl-L-prolyl chloride (L-TPC) and subsequent separation on a gas chromatography–mass spectrometry (GC-MS) system. Tasks automated were the dilution of standards and the off-line preparation of the diastereoisomer derivatives. Chromatographic performance, sensitivity, and reproducibility of the automated procedure were compared to the equivalent values obtained with two existing assays methods which employ manual derivatiation, either on-column or off-line. Chromatographic performance was unaffected by the derivatization procedure and sensitivity was better for both automated and manual off-line derivatization. Qualitative reproducibility as based on enantiomeric composition was equivalent for all three approaches, while quantitative reproducibility as based on peak areas was best for the automated procedure. Considering the fact that the diastereoisomer derivatives are unstable over time, automated sample preparation with “just-in-time” derivatization can increase the overall precision of the analytical method. The procedures described here are general enough in nature that they could be applied to other chiral or even achiral analytes. © 1994 Wiley-Liss, Inc.
GROWTH HORMONE HETEROGENEITY IN HUMAN PITUITARY AND PLASMA

Several isoforms of growth hormone (GH) have been identified in humans. There are many reasons for this heterogeneity. At the genetic level, two genes encode GH: GH-N, expressed in the pituitary, and
Crystal structure of quinolinic acid phosphoribosyltransferase from Mycobacterium tuberculosis: a potential TB drug target

Abstract Background: Mycobacterium tuberculosis is the single most deadly human pathogen and is responsible for nearly three million deaths every year. Recent elucidation of the mode of action of isoniazid, a frontline antimycobacterial drug, suggests that NAD metabolism is extremely critical for this microorganism. M. tuberculosis depends solely on the de novo pathway to meet its NAD demand. Quinolinic acid phosphoribosyltransferase (QAPRTase), a key enzyme in the de novo biosynthesis of NAD, provides an attractive target for designing novel antitubercular drugs. Results: The X-ray crystal structure of the M. tuberculosis QAPRTase apoenzyme has been determined by multiple isomorphous replacement at 2.4 a resolution. Structures of the enzyme have also been solved in complex with the substrate quinolinic acid (QA), the inhibitory QA analog phthalic acid (PA), the product nicotinate mononucleotide (NAMN), and as a ternary complex with PA and a substrate analog, 5-phosphoribosyl-1-( β -methylene)pyrophosphate (PRPCP). The structure of the nonproductive QAPRTase–PA–PRPCP Michaelis complex reveals a 5-phosphoribosyl-1-pyrophosphate-binding site that is different from the one observed in type I phosphoribosyltransferases (PRTases). The type II PRTase active site of QAPRTase undergoes conformational changes that appear to be important in determining substrate specificity and eliciting productive catalysis. Conclusions: QAPRTase is the only known representative of the type II PRTase fold, an unusual α / β barrel, and appears to represent convergent evolution for PRTase catalysis. The active site of type II PRTase bears little resemblance to the better known type I enzymes.
Novel LCMV-specific H-2k restricted CTL clones recognize internal viral gene products and cause CNS disease.

Abstract H-2 k (C3H/Hej) cytotoxic T lymphocytes (CTL) specific for lymphocytic choriomeningitis virus (LCMV) were cloned. Three clones recognizing internal viral antigens were studied. One such CTL clone recognized neither the glycoprotein nor nucleoprotein encoded by the viral short RNA segment, but reacted with a protein encoded by the long RNA segment, either the viral polymerase, or the Z protein. This one clone, in addition to primary CTL harvested from immunized C3H mice, failed to lyse target cells expressing the Z protein, suggesting recognition was to the viral polymerase. Two other clones recognized the viral nucleoprotein, amino acids 93–100, as determined by protein deletion and peptide mapping studies. When introduced directly into the central nervous systems of LCMV-infected histocompatible mice, all clones were active in vivo and capable of causing immunopathologically mediated death.
AN INVENTORY FOR MEASURING PLAYER-COACH INTERACTION

To develop the Medford Player-Coach Interaction Inventory for assessing positive interaction between players and coaches 23 adjectives of 81 were selected. Subjects were members of 9 women's teams and their coaches. To assess reliability subjects were 5 women's teams and their coaches. Data were collected through 3 forms of the inventory—player's form, coach's form, and validity form. Significant correlations were obtained among the adjectives, with few exceptions. Coefficients for the total score between Day 1 and Day 2 indicated stable scores (r = .87). Validity was studied by subjects rating each adjective on a 5-point scale as to its predictive value; each adjective received a rating above the mean of 3.0 on a 5-point scale.
Crocodilian evolution: Insights from immunological data

The quantitative immunological technique of microcomplement fixation was used to examine serum albumin evolution among members of the order Crocodylia. The cross-reactivity of the albumin antisera and antigens employed in this study had been examined previously using the qualitative technique of immunodiffusion. The phylogenetic conclusions derived from these two data sets are highly congruent, including support of the families Alligatoridae and Crocodylidae, with the placement of Gavialis as the sister taxon of Tomistoma. Both methods provide similar information on the relative amounts of amino acid sequence divergence between albumin molecules; however, the data obtained from microcomplement fixation comparisons are more discriminating than those derived from immunodiffusion. The estimated divergence times within the Crocodylia derived from the fossil record are examined in light of divergence times predicted by the microcomplement fixation-based albumin clock. The traditional phylogenetic placement of Gavialis outside the remaining extant crocodilians is inconsistent with all molecular data sets and we suggest that a careful reexamination of both the extant and the fossil morphological data is warranted.
The Sixth U.S.A. Mathematical Olympiad.

(1976). The Fourth U.S.A. Mathematical Olympiad. The American Mathematical Monthly: Vol. 83, No. 2, pp. 119-121.
Mattering: Empirical Validation of a Social-Psychological Concept

Mattering is the extent to which we make a difference in the world around us. People matter simply because: others attend to them (awareness), invest themselves in them (importance), or look to them for resources (reliance). We construct and validate a mattering index, using confirmatory factor analysis. We establish the discriminant validity of the mattering index, using self-consciousness, self-esteem, self-monitoring, alienation, and perceived social support. Finally, we discuss the potential importance of mattering as a dimension of the self-concept.
Stabilized CVD amorphous silicon for high temperature photothermal solar energy conversion

Abstract By pyrolytic decomposition of silane in the presence of dopant gases, a set of amorphous silicon films was prepared that contains various concentrations of carbon, nitrogen, boron or germanium. The effect of these dopants on the crystallization process and the optical properties is investigated. Films containing about 18 at % carbon show the properties most favorable for solar absorbers. The crystallization is retarded to temperatures near 1000°C, and the solar absorptance is greater than that of non-intentionally doped CVD amorphous silicon. From the experimentally determined activation energy of crystallization, the structural lifetime for such absorber films is extrapolated to be in excess of several decades for continuous operation at 700°C. For identical thicknesses of absorber layers, spectrally selective stacks of stabilized amorphous silicon deposited on top of a molybdenum reflector have higher solar absorptance than stacks composed of polycrystalline silicon on a silver reflector, amorphous silicon on molybdenum having been tested at temperatures in excess of 500°C.
Studies of αB crystallin subunit dynamics by surface plasmon resonance

Abstract The molecular chaperone activity of αB crystallin, an important stress protein in humans, is regulated by physiological factors, including temperature, pH, Ca2+, and ATP. In this study, the role of these factors in regulating the subunit dynamics of human αB crystallin was investigated using surface plasmon resonance (SPR). SPR experiments indicate that at temperatures above 37 °C, where αB crystallin has been reported to have higher chaperone activity, the subunit dynamics of αB crystallin were increased with faster association and dissociation rates. SPR experiments also indicate that interactions between αB crystallin subunits were enhanced with much faster association and slower dissociation rates at pH values below 7.0, where αB crystallin has been reported to have lower chaperone activity. The results suggest that the dynamic and rapid subunit exchange rate may regulate the chaperone activity of αB crystallin. The effect of Ca2+ and ATP on the subunit dynamics of αB crystallin was minimal, suggesting that Ca2+ and ATP modulate the chaperone activity of αB crystallin without altering the subunit dynamics. Based on the SPR results and previously reported biochemical data for the chaperone activity of αB crystallin under different conditions of temperature and pH, a model for the relationship between the subunit dynamics and chaperone activity of αB crystallin is established. The model is consistent with previous biochemical data for the chaperone activity and subunit dynamics of small heat shock proteins (sHSPs) and establishes a working hypothesis for the relationship between complex assembly and chaperone activity for sHSPs.
L-Type Ca(2+) channel charge movement and intracellular Ca(2+) in skeletal muscle fibers from aging mice.

Abstract In this work we tested the hypothesis that skeletal muscle fibers from aging mice exhibit a significant decline in myoplasmic Ca 2+ concentration resulting from a reduction in L-type Ca 2+ channel (dihydropyridine receptor, DHPR) charge movement. Skeletal muscle fibers from the flexor digitorum brevis (FDB) muscle were obtained from 5–7-, 14–18-, or 21–24-month-old FVB mice and voltage-clamped in the whole-cell configuration of the patch-clamp technique according to described procedures (Wang, Z.-M., M. L. Messi, and O. Delbono. 1999. Biophys. J. 77:2709–2716). Total charge movement or the DHPR charge movement was measured simultaneously with intracellular Ca 2+ concentration. The maximum charge movement ( Q max ) recorded (mean±SEM, in nC μ F −1 ) was 53±3.2 ( n =47), 51±3.2 ( n =35) (non-significant, ns), and 33±1.9 ( n =32) ( p Q max corresponding to the DHPR was 43±3.3, 38±4.1 (ns), and 25±3.4 ( p 2+ ] recorded at 40mV (in μ M) was 15.7±0.12, 16.7±0.18 (ns), and 8.2±0.07 ( p Q - V or [Ca 2+ ]- V relationship were found. These data support the concept that the reduction in the peak intracellular [Ca 2+ ] results from a larger number of ryanodine receptors uncoupled to DHPRs in skeletal muscle fibers from aging mammals.
The flow of information through social networks: diagonal-free measures of inefficiency and the structural determinants of inefficiency

Abstract The aim of this paper is to (1) propose specific diagonal-free measures of the inefficiency of information flow through social networks and (2) present an analysis of the structural determinants of inefficiency. We employ a formal model of collective action developed by Coleman (1973, 1990); link it to the Markov model of interpersonal influence developed by among others French (1956), Harary (1959), and Friedkin (1991; Friedkin and Johnsen 1990); and extend it to measure inefficiency in information flow based on the concept of mean first passage times. It is shown that structural characteristics of social networks — such as global density, local density, diameter, number of bridges, and inequality in centrality, and certain interactions among these variables — strongly affect inefficiency. Theoretical implications of the results are discussed.
Shell-model Monte Carlo studies of fp-shell nuclei.

We study the gross properties of even-even and N=Z nuclei with A=48–64 using shell-model Monte Carlo methods. Our calculations account for all 0ħω configurations in the fp shell and employ the modified Kuo-Brown interaction KB3. We find good agreement with data for masses and total B(E2) strengths, the latter employing effective charges ep=1.35e and en=0.35e. The calculated total Gamow-Teller strengths agree consistently with the B(GT+) values deduced from (n,p) data if the shell-model results are renormalized by 0.64, as has already been established for sd-shell nuclei. The present calculations therefore suggest that this renormalization (i.e., gA=1 in the nuclear medium) is universal.
SOLUBLE PHOSPHOLIPIDS ENHANCE FACTOR XA-CATALYZED PROTHROMBIN ACTIVATION IN SOLUTION

Acidic phospholipids play an important but incompletely understood role in prothrombin activation. Here we report the effect of short-chain phosphatidylserine (dicaproylphosphatidylserine, C6PS) and the corresponding phosphatidylglycerol (C6PG) and phosphatidylcholine (C6PC) derivatives on the rate of prothrombin activation by factor Xa. The critical micellar concentrations of these short-chained phospholipids have been determined under a variety of conditions that we used for kinetic and structural studies. Under conditions for which these lipids exist in a soluble form, the results demonstrate that: (i) the rate of human prothrombin activation by human factor Xa was enhanced in a calcium-dependent fashion up to 60-fold by addition of C6PS, roughly 20% of the optimal enhancement seen with bovine phosphatidylserine/palmitoyloleoylphosphatidylcholine (25/75 PS/POPC) membranes; (ii) C6PS inhibited the rate of hydrolysis of synthetic factor Xa substrate (S-2765), an effect that was mimicked, but at much lower lipid concentrations, by PS/POPC membranes; (iii) there was no enhancement of prothrombin activation and much less inhibition of hydrolysis of S-2765 by factor Xa in the presence of C6PG or C6PC; and (iv) the thermal denaturation of prothrombin was altered in a calcium-independent but dose-dependent fashion by either C6PS or C6PG. These results have been interpreted in terms of the existence of (a) specific PS binding site(s) on factor Xa (Kd approximately 73 microM) that regulate(s) the activity of this serine protease. Our results do not rule out the possibility that the rate of prothrombin activation is also influenced by a weaker, calcium-independent, and less specific acidic lipid binding site on prothrombin, the occupancy of which results in conformational changes in this protein. The results clearly suggest that PS binding regulates the rate of prothrombin activation.
Pathogenesis of the rubella exanthem. Isolation of rubella virus from the skin.

MANY of the viruses associated with vesiculopapular exanthems such as vaccinia, varicella and herpes simplex have been recovered from the skin lesions that characterize these infections. It is thought, therefore, that dermal injury in these diseases results from replication of virus in skill cells, perhaps in combination with an immunologic reaction against viral antigen deposited in this tissue.1 2 3 In rubella, however, except in its congenital form, recovery of virus from the skin has not been reported, and the role of virus in the pathogenesis of this nonvesicular, maculopapular exanthem is unknown. The purpose of this study was to determine whether . . .
Acute and subchronic toxicity of 2,4-dichlorophenol in CD-1 mice.

Abstract The acute oral LD50 of 2,4-dichlorophenol (2,4-DCP) employing corn oil as vehicle was determined to be 1352 mg/kg for female and 1276 mg/kg for male CD-1 mice. CD-1 mice of both sexes were exposed to 2,4-DCP in drinking water containing 10% Emulphor for 90 days at concentrations of 0.2, 0.6, and 2.0 mg/ml providing theoretical daily doses of 50, 150, and 500 mg/kg. These concentrations resulted in mean daily doses of 50, 143, and 491 mg/kg for females and 40, 114, and 383 mg/kg for males. In both sexes, fluid consumption was lower in the vehicle control group (10% Emulphor) and in the 2,4-DCP treated groups than in the naive controls (deionized water). There were no biologically significant differences in body weight gain between females or males in the vehicle control and experimental groups. No differences were found in terminal organ weights or organ weight ratios in either sex. Hematological differences were observed in males only and included an increase in leukocytes (high dose) and an increase in polymorphonuclears (low dose). Clinical chemistry parameters were altered in females only and included a decrease in creatinine (low dose), an increase in BUN/creatinine ratio (mid dose), and an increase in ALP (high dose). In an assessment of the hepatic microsomal mixed function oxidase system, no significant differences were found in the components of the system, component activity, the kinetics of ethylmorphine N -demethylase, or the metabolism of testosterone. Administration of 2,4-DCP to CD-1 mice of both sexes for 90 days at mean doses of 40 to 491 mg/kg/day in drinking water did not elicit either consistent compound-related or dose-dependent significant toxicological effects.
A quadratically constrained minimization problem arising from PDE of Monge–Ampère type

This note develops theory and a solution technique for a quadratically constrained eigenvalue minimization problem. This class of problems arises in the numerical solution of fully-nonlinear boundary value problems of Monge–Ampere type. Though it is most important in the three dimensional case, the solution method is directly applicable to systems of arbitrary dimension. The focus here is on solving the minimization subproblem which is part of a method to numerically solve a Monge–Ampere type equation. These subproblems must be evaluated many times in this numerical solution technique and thus efficiency is of utmost importance. A novelty of this minimization algorithm is that it is finite, of complexity \(\mathcal{O}(n^3)\), with the exception of solving a very simple rational function of one variable. This function is essentially the same for any dimension. This result is quite surprising given the nature of the constrained minimization problem.
Utilizing imaging tools in lipidology: examining the potential of MRI for monitoring cholesterol therapy

Lipid abnormalities play important roles in the development of atherosclerosis. Lipid therapies result in alterations in atherosclerotic plaques including halting of progression of the plaque, lipid transport out of the plaque and reducing inflammatory activity, which lead to plaque morphologies that are less prone to disruption, the main cause of clinical events. In order to investigate and monitor plaque morphological changes during lipid therapy in vivo we need an imaging method that can provide accurate assessment of plaque tissue components and activity. MRI of atherosclerosis has been validated as a reliable assessment of the size of the vessel lumen, but also the size of the plaque, its tissue composition and plaque activity, including inflammation. The purpose of this review is to summarize the state of evidence for the direct assessment of atherosclerotic plaque and its change by MRI, and to establish the proven role of MRI of atherosclerosis in pharmaceutical trials with lipid therapy.
Geometric selection in two-dimensional crystal aggregates

The simultaneous growth of randomly oriented crystals nucleated at a surface rapidly produces a coarsely crystalline radial or columnar aggregate possessing a strong preferred shape and lattice orientation. Such textures are common in natural crystalline aggregates and are considered to arise because those crystals having their fastest growth direction normal to the initial substrate outdistance and eventually eliminate their less favorably oriented neighbors. In its simplest form the process of elimination is a purely geometric phenomenon. Detailed analysis and computer simulation of textural changes accompanying geometric selection in random two dimensional needlelike crystal aggregates demonstrate that selection initially proceeds exceedingly rapidly but slows drastically once roughly 90 percent of the crystals originally present are eliminated. Subsequent decrease in crystal density is inversely proportional to the square root of the distance from the initial substrate. Increases in crystal size larger than one or two orders of magnitude are thus unlikely to arise in natural crystalline aggregates in which only simple geometric selection is involved.
Development and dispensing of a nickel nanoparticle ink for the diffusion brazing of a microchannel array

A process was developed for producing nickel nanoparticle (NiNP) films for use in diffusion-brazing stainless steel 316L microchannel laminae at 800 °C and 1 MPa of bonding pressure. NiNPs were synthesized in 45 s at 80 °C using a NiCl2·6H2O salt solution, a combination of NaBH4 and N2H5OH as reducing agents and PVP-40K as a stabilizing agent. A minimum molar ratio of 8:1 [NaOH]:[NaBH4] was required to obtain pure fcc-Ni with an average particle size of 4.2 ± 0.6 nm. Using TGA and DSC, phase change behavior was observed at temperatures as low as 720 °C. A continuous and uniform NiNP film with a thickness of 18.1 ± 2.3 μm and a roughness of 3.1 ± 0.5 μm was dispensed using a fluid pressure of 0.6 psi, a dispense gap of 1.5 mm, and a head speed of 0.5 mm/s. A microchannel array was bonded and hermetically tested up to a pressure of 120 psi with no leakage. The ultimate lap shear strength of the joint was found to be 341 ± 29 MPa. Migration of Ni into the stainless steel 316L laminae was confirmed using SEM and EDS.
Immobilized Phosphate Ligands with Enhanced Ionic Affinity through Supported Ligand Synergistic Interaction

Abstract The ability of a secondary group to influence the metal ion affinities of a primary ligand immobilized on crosslinked polystyrene beads is reported. The secondary groups were glycol units, ‐(CH2CH2O)1‐4‐, and their effect on phosphate ligands was studied. The affinities of Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Fe(III), Y(III), La(III), Eu(III), Lu(III), and U(VI) were quantified from HNO3, HCl, and H2SO4 solutions in concentrations up to 4 N. Affinities were highest for U(VI) and the trivalent ions. The glycol units enhanced the extent of metal ion complexation by the phosphate ligands through coordination of the metal ion and not through an auxiliary group effect (where there would be a direct interaction between the glycol units and the phosphate ligand) as indicated by the similarity in the FTIR spectra of the four phosphorylated glycol resins. At least two glycol units are needed for synergistic cooperation between the glycol and phosphate in binding metal ions.
Auditory Detectability of Hybrid Electric Vehicles by Blind Pedestrians

Hybrid electric vehicles (HEVs) in low-speed operation may introduce a safety issue for pedestrians. This study compares the auditory detectability of HEVs and internal combustion engine vehicles among pedestrians who are legally blind. Independent travelers, with self-reported normal hearing, listened to binaural audio recordings of two HEVs and two internal combustion engine vehicles in three operating conditions and two different ambient sound levels. The operating conditions include approaching at a constant speed (6 mph), backing out at 5 mph, and slowing from 20 to 10 mph (as if to turn right). The ambient sound levels simulated a quiet rural [31.2 dB(A)] environment and a moderately noisy suburban [49.8 dB(A)] environment. Overall, participants took longer to detect HEVs (operated in electric mode). Vehicle type, ambient level, and operating condition had a significant effect on response time. Candidate countermeasures are discussed in terms of types of information provided (direction, rate of speed change), useful range of detection of vehicles by pedestrians, warning time, acceptability, and barriers to implementation.
Providential Partners? Tocqueville’s Take on Equality and Centralization

In Democracy in America, Alexis de Tocqueville predicted that America’s love of equality would lead it to centralize administrative power. In The Old Regime and the Revolution, Tocqueville argues that centralization of administrative power began prior to the French Revolution—a revolution largely aimed at instituting equality. In fact, he argues that centralization led to greater equality in France and was therefore a major cause of the Revolution itself. This apparent contradiction is resolved, and the logics of the two books are made coherent, if equality and centralization constitute a circular causal relationship. Whether the point of departure is equality (America) or centralization (France), the other ultimately follows. This circular relationship exemplifies Tocquevillian “equilibrium analysis,” as each phenomenon reinforces the other to stabilize democratic society. Yet such equilibrium was anathema to Tocqueville, who through his writings sought to protect the political freedom he called “this fi...
Free‐radical identification by ESR in polyethylene and nylon

Identification of the free radicals in polyethylene and nylon produced by irradiation, grinding, and pulling to fracture was carried out by comparing the experimentally observed spectra with the spectra constructed from theoretical consideration with the aid of a computer. It was demonstrated that the various primary and secondary radicals are produced and formed in the materials depending upon means of degradation, degradation processes, orientation of materials, and conditions of ESR measurement.
The crystalline morphology of poly(vinylidene fluoride)/poly(methylmethacrylate) blends

Poly(vinylidene fluoride), PVF2, as well as blends of PVF2 with poly(methyl methacrylate), PMMA, develop a variety of crystalline morphologies at low undercoolings. Both the α and γ crystal forms grow from the melt and the former undergoes a solid-solid phase transition to the latter, though its morphology remains unaltered. Three melting temperatures which decrease with increasing PMMA content are observed. Hoffman-Weeks analysis shows the equilibrium melting points of the blends to be depressed. Using these equilibrium values, the thermodynamic interaction energy density is calculated to go from −5.40 × 106 to −2.96 × 107 j/m3 as the blend composition goes from 40.1 volume percent to pure PVF2. The band periodicity in the α form spherulites increases with crystallization temperature and PMMA content and it appears to be from a lamellar reorientation process with an apparent activation energy of 322 cal/mole. Electron diffraction patterns taken along the radial direction in a given spherulite reveal lamellar twisting which causes the banded appearance. Light scattering results suggest that the lamellar are formed into rod-like structures on a local scale but that on a larger scale they develop a disoriented spherulitic morphology.
The fate of carbon during the assimilation of carbamoyl phosphate in white spruce seedlings as revealed by [14C]-carbamoyl phosphate, [14C]-cyanate, and [14C] -bicarbonate labeling patterns

The fate of carbamoyl phosphate in white spruce seedlings revolves around the production of spontaneous degradation products, cyanate, bicarbonate, and carba-mate. When [14C]-carbamoyl phosphate and [14C]-cyanate are assimilated, urea is a common early metabolic intermediate that appears in the alcohol soluble N. By contrast, urea is not detected among the products of [14C]-bicarbonate. Carbamoyl phosphate and glutamic acid are implicated as having pivotal roles in the production of amides, arginine, and biotin. Within 2-h exposures to radioactive substrates considerably more carbon from bicarbonate was diverted into amino acids Incorporated into proteins than with carbon-nitrogen substrates. Specific activities of bound amino acid residues support the view that proteins formed from these [14C]-substrates have different rates of metabolic turnover.
Substitution of Soybean Protein for Fish Protein in Formulated Diets for Red Swamp Crawfish Procambarus clarkii1

A 10 week laboratory growth trial was conducted with red swamp crawfish Procambarus clarkii to determine the amount of soybean protein that could be substituted for fish protein in formulated crawfish diets without reducing growth. Crawfish received 32% crude protein, isocaloric diets in which protein was supplied by soybean (soy) meal, menhaden fish meal or an isonitrogenous mixture of soybean and fish meal calculated to provide graded levels of each protein source. Dietary protein was provided as: 1) 100% soy protein; 2) 75% soy protein: 25% fish protein; 3) 50% soy protein: 50% fish protein; 4) 25% soy protein: 75% fish protein; and 5) 100% fish protein. Crawfish fed soy protein: fish protein (SP:FP) mixtures or fish protein alone exhibited better (P 0.05) among diets with SP:FP ratios of 1:3, 1:1 and 3:1. However, maximum (P < 0.05) weight gain occurred in crawfish fed the 1:3 SP:FP ratio. Although crawfish fed SP:FP ratios of 1:1 and 3:1 had lower weight gains in the laboratory than crawfish fed a 1:3 SP:FP ratio, SP:FP ratios of 1:1 and 3:1 might be adequate for supplemental diets fed to pond-reared crawfish that have access to natural sources of food.
Spatial gradients of protein-level time delays set the pace of the traveling segmentation clock waves

The vertebrate segmentation clock is a gene expression oscillator controlling rhythmic segmentation of the vertebral column during embryonic development. The period of oscillations becomes longer as cells are displaced along the posterior to anterior axis, which results in traveling waves of clock gene expression sweeping in the unsegmented tissue. Although various hypotheses necessitating the inclusion of additional regulatory genes into the core clock network at different spatial locations have been proposed, the mechanism underlying traveling waves has remained elusive. Here, we combined molecular-level computational modeling and quantitative experimentation to solve this puzzle. Our model predicts the existence of an increasing gradient of gene expression time delays along the posterior to anterior direction to recapitulate spatiotemporal profiles of the traveling segmentation clock waves in different genetic backgrounds in zebrafish. We validated this prediction by measuring an increased time delay of oscillatory Her1 protein production along the unsegmented tissue. Our results refuted the need for spatial expansion of the core feedback loop to explain the occurrence of traveling waves. Spatial regulation of gene expression time delays is a novel way of creating dynamic patterns; this is the first report demonstrating such a control mechanism in any tissue and future investigations will explore the presence of analogous examples in other biological systems.
Regulation of Weibel-Palade body exocytosis.

Weibel–Palade bodies (WPBs) are endothelial granules that store von Willebrand factor (VWF), P-selectin, and other vascular modulators. Endothelial cells secrete WPBs in response to vascular injury, releasing VWF, which triggers platelet rolling, and externalizing P-selectin, which activates leukocyte trafficking. Endothelial exocytosis is one of the earliest responses to vascular damage and plays a pivotal role in thrombosis and inflammation. This review examines the regulation of WPB exocytosis—the exocytic machinery, activators, and inhibitors of exocytosis—and speculates about the development of novel anti-exocytic drugs.
Modular configuration design for a controlled fall

Much like a falling cat can reorient itself to land on its feet, a climbing robot should also reorient itself to minimize damage during a fall. This paper presents and analyzes the dynamic motion of a modular robot, called CKbot righting itself during a fall. It presents a mathematical model of the falling system that correlates well with experimental reorientation results about one axis. The model also explains why the the process of flipping around is practical only about the long axis of the robot. For more robust orientation correction, a different configuration of CKbot and a new motion plan is presented that corrects for all forms of posture error.
Addictive Economies and Coal Dependency: Methods of Extraction and Socioeconomic Outcomes in West Virginia, 1997-2009

Policy makers generally see resource extraction as a boon for local economies and citizens. Numerous studies, however, have shown negative socioeconomic outcomes in extractive com- munities, supporting the notion that resources can be more of a curse than a blessing. One aspect of this debate that requires further clarification is the role played by method of extrac- tion. In this article, we use the case of West Virginia coal mining and a fixed effects model to test whether extraction methods affect socioeconomic outcomes. We observe little difference in these outcomes between surface and underground mining; rather, it is the presence or absence of mining that matters most. We find that nonmining counties have lower poverty and unem- ployment rates than mining counties. These results lead us to conclude that leaving remaining coal stores in the ground will likely prove most beneficial to the state’s people and economy in the long run.
THE INCIDENCE AND REGULATION OF PLANT SHUTDOWNS

This paper analyzes the proposed plant closing legislation, together with other complementary approaches to the orderly regulation of private capital disinvestment, especially as it occurs in the form of large-scale plant or store shutdowns. The authors also provide a review of the recent data on the incidence and employment impact of shutdowns during the 1970's, in particular industries, by region and by form of ownership.
Improving Web performance in broadcast-unicast networks

Satellite operators have recently begun offering Internet access over their networks. Typically, users connect to the network using a modem for uplink, and a satellite dish for downlink. We investigate how the performance of these networks might be improved by two simple techniques: caching and use of the return path on the modem link. We examine the problem from a theoretical perspective and via simulation. We show that the general problem is NP-hard, as are several special cases, and we give approximation algorithms for them. We then use insights from these cases to design practical heuristic schedulers which leverage caching and the modem downlinks. Via simulation, we show that caching alone can simultaneously reduce bandwidth requirements by 33% and improve response times by 62%. We further show that the proposed schedulers, combined with caching, yield a system that performs far better under high loads than existing systems.
A high-level analytical model for application specific CMP design exploration

We present a high-level analytical model for chip-multiprocessors (CMPs) that encompasses processors, memory, and communication in an area-constrained, global optimization process. Applying this analytical model to the design of a symmetric CMP for speech recognition, we demonstrate a methodology for estimating model parameters prior to design exploration. Then we present an automated approach for finding the optimal high-level CMP architecture. The result is the ability to find the allocation of silicon resources for each architectural element that maximizes overall system performance. This balances the performance gains from parallelism, processor microarchitecture, and cache memory with the energy-delay costs of computation and communication.
Multiple Pathways of Duplication Formation With and Without Recombination (RecA) in Salmonella enterica

Duplications are often attributed to “unequal recombination” between separated, directly repeated sequence elements (>100 bp), events that leave a recombinant element at the duplication junction. However, in the bacterial chromosome, duplications form at high rates (10−3–10−5/cell/division) even without recombination (RecA). Here we describe 1800 spontaneous lac duplications trapped nonselectively on the low-copy F′128 plasmid, where lac is flanked by direct repeats of the transposable element IS3 (1258 bp) and by numerous quasipalindromic REP elements (30 bp). Duplications form at a high rate (10−4/cell/division) that is reduced only about 11-fold in the absence of RecA. With and without RecA, most duplications arise by recombination between IS3 elements (97%). Formation of these duplications is stimulated by IS3 transposase (Tnp) and plasmid transfer functions (TraI). Three duplication pathways are proposed. First, plasmid dimers form at a high rate stimulated by RecA and are then modified by deletions between IS3 elements (resolution) that leave a monomeric plasmid with an IS3-flanked lac duplication. Second, without RecA, duplications occur by single-strand annealing of DNA ends generated in different sister chromosomes after transposase nicks DNA near participating IS3 elements. The absence of RecA may stimulate annealing by allowing chromosome breaks to persist. Third, a minority of lac duplications (3%) have short (0–36 bp) junction sequences (SJ), some of which are located within REP elements. These duplication types form without RecA, Tnp, or Tra by a pathway in which the palindromic junctions of a tandem inversion duplication (TID) may stimulate deletions that leave the final duplication.
Integrating Ethics with Symbolic Interactionism: The Case of Oncology

Social scientists often relegate ethics to ex post facto considerations and dissociate theory from experientially moral phenomena because it lacks the requisite epistemological tools for an ethic-centered discourse. Research linking individual attributes and access to privilege perpetuates the politics of status-contingent voice and perspective. Therefore, our work has inherently [un]ethical dimensions—more powerful because they remain unarticulated. Drawing from feminist scholarship highlighting the unavoidability of "standpoint" and "perspective" in research, and from data from a 39-month ethnography of ovarian cancer patients, I reveal ethical principles embedded within the Chicago school of symbolic interactionism. This articulation of embodied ethics creates a context wherein ethnographic data reveal themselves as sociopolitical. The vulnerability of respondents emerges; however, they use research participation to identify the multiple layers of their [dis]empowerment. Integrating an ethical mandate ...