cssi/SciSciGPT-SciSciNet huggingface dataset:
Congenital hyperinsulinism: localization of a focal lesion with 18F-FDOPA positron emission tomography

Hyperinsulinemic hypoglycemia of infancy, also known as congenital hyperinsulinism, is a group of disorders characterized by dysregulated insulin release. Neonates with severe, persistent hyperinsulinemic hypoglycemia who are unresponsive to medical therapy require pancreatectomy to prevent brain damage from hypoglycemia. To date, multiple genetic mutations and syndromes and several unique histopathological entities have been identified in children with hyperinsulinism. Histopathology is characterized as diffuse, focal or atypical. Surgical resection of a focal lesion results in a cure in up to 97% of these children. Imaging with 6-fluoro-(18F)-L-3,4-dihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET) is the test of choice for identifying and localizing a focal lesion and has proved to be an invaluable guide for surgical resection. Genetic evaluation is essential for determining who will benefit from PET imaging. This article provides an approach to determine who should be imaged, how to set up a protocol and how to interpret the imaging findings. The diagnosis and management of this disorder require a multidisciplinary approach to prevent brain damage from hypoglycemia.
Perinatal infections and cerebral palsy.

There are many causes of cerebral palsy (CP) apart from hypoxic events during the perinatal period. Perinatal infections and systemic inflammatory response syndrome of the mother and infant can affect the development of CP significantly. The majority of premature infants are vulnerable to CP and the association between intraamniotic infections, preterm rupture of fetal membranes and the effect of preterm birth predispose the infant to CP. Incidence of intraventricular hemorrhage, white matter disease and periventricular leukomalacia has increased after preterm labor resulting from intraamniotic infections. Bacterial vaginosis, fever, periodontal disease of the mother, as well as bacterial, viral, protozoan and fungal infections of the newborn infant are effective during the development of CP. The balance between proinflammatory and anti-inflammatory cytokines and the combined effects of genetic predisposition, hypoxia, cytokines and bacterial products may initiate the unfavorable process. Treatments directed towards cytokines and bacterial products have not been effective until now. Fetuses and neonates should be protected from perinatal infections as much as possible and all infections should be treated promptly in order to prevent short-term and long-term adverse outcomes.
Amino Acid Sequence Studies with the Tryptophan Synthetase α Chain of Salmonella typhimurium

Abstract The isolation, composition, and amino acid sequences of tryptic peptides of the tryptophan synthetase α chain of Salmonella typhimurium are described. The probable over-all sequence of the 268 residues in this polypeptide are compared with that of Escherichia coli, and 44 residue differences are apparent.
Uterine fibroids and women's right to choose. Hysterectomies and informed consent.

Ellen, a woman aged 50 having constant pelvic discomfort and ovulatory pain, was diagnosed with two uterine fibroids. 1 When her nurse practitioner suggested she undergo a hysterectomy, she discuss...
A course on software engineering for concurrent systems

This paper describes a graduate level course that covers concepts, techniques and tools for the specification, design, coding, and validation of concurrent software. This course is intended to transfer practical software engineering technology for the production of reliable concurrent software systems. One unique aspect of this course is the use of a collection of tools developed at NCSU for testing and debugging concurrent software.
Partisanship and Preference Formation: Competing Motivations, Elite Polarization, and Issue Importance

An enduring and increasingly acute concern—in an age of polarized parties—is that people’s partisan attachments distort preference formation at the expense of relevant information. For example, research suggests that a Democrat may support a policy proposed by Democrats, but oppose the same policy if proposed by Republicans. However, a related body of literature suggests that how people respond to information and form preferences is distorted by their prior issue attitudes. In neither instance is information even-handedly evaluated, rather, it is interpreted in light of partisanship or existing issue opinions. Both effects are well documented in isolation, but in most political scenarios individuals consider both partisanship and prior opinions—yet, these dynamics may or may not pull toward the same preference. Using nationally representative experiments focused on tax and education policies, I introduce and test a theory that isolates when: partisanship dominates preference formation, partisanship and issue opinions reinforce or offset each other, and issue attitudes trump partisanship. The findings make clear that the public does not blindly follow party elites. Depending on elite positions, the level of partisan polarization, and personal importance of issues, the public can be attentive to information and shirk the influence of party elites. The results have broad implications for political parties and citizen competence in contemporary democratic politics.
Analysis of photochemical and dark glyoxal uptake: Implications for SOA formation

The dependence of glyoxal uptake onto deliquesced ammonium sulfate seed aerosol was studied under photochemical (light + hydroxyl radical (OH)) and dark conditions. In this study, the chemical composition of aerosol formed from glyoxal is identical in the presence or absence of OH. In addition, there was no observed OH dependence on either glyoxal uptake or glyoxal-driven aerosol growth for this study. These findings demonstrate that, for the system used here, glyoxal uptake is not affected by the presence of OH. In combination with previous studies, this shows that the exact nature of the type of seed aerosol, in particular the presence of a coating, has a large influence on fast photochemical uptake of glyoxal. Due to the challenge of relating this seed aerosol dependence to ambient conditions, this work highlights the resulting difficulty in quantitatively including SOA formation from glyoxal in models.
A graphical microcomputer simulator for classroom use

Educational aids for microprocessor courses are typically either hardware trainers or software simulators. The former enable the student to observe the details of I/O interfacing, but tend to be costly, at least to duplicate for many students, and provide only a limited view of the internal operations of the microprocessor. While more cost-effective, the latter are usually limited to displaying hexadecimal values written to I/O addresses with regard to peripheral interfacing. This paper describes a software simulator which illustrates microprocessor operation utilizing a graphical format designed for a PC-DOS platform. The simulator displays the registers and buses of a Motorola 6800 microprocessor. Instructions can be executed on a per-cycle or per-instruction (single-step) basis, with the bus logic values and register contents graphically changing at each step. A one-line assembler is available for writing programs into the 8 kByte RAM. In addition, an R6522 Versatile Interface Adapter (VIA) is also displayed. User-selectable peripherals include a hex keypad, 7-segment displays and an A/D converter. Online help screens are easily accessed. We have employed this simulator in our classes for two semesters and have found that students are able to learn it very quickly. It is an excellent tool for observing the details of microprocessor operation and interfacing to common peripherals.
Structural Database of Allergenic Proteins (SDAP)

The Structural Database of Allergenic Proteins (SDAP) brings together data from diverse sources on over 800 allergen sequences and their epitopes in a cross-referenced format. Special methods developed for SDAP, such as the property distance (PD) scale, automatically detect peptides in the ensemble of allergen sequences that have physicochemical properties similar to known immunoglobulin E (IgE) epitopes. Comparing the structure of food allergens with allergenic proteins from exposure to pollens, insect dust, or other aeroallergens can give valuable information about the sensitization process. Any novel protein introduced into a food crop should have a low potential to be an allergen. This chapter deals with database approaches to determine the allergenic potential of a test protein, based on similarity to known allergens. It outlines basic methodology to identify cross-reacting proteins in food sources and predict the potential allergenicity of novel proteins. The chapter concentrates on the SDAP, which has been specifically designed to allow combined analysis of the sequence, structure, and epitopes of allergens. It also shows how SDAP and the methods for sequence and peptide comparison incorporated therein can be used to predict cross-reactive allergens in foods and determine common properties of their IgE epitopes. The second half of the chapter demonstrates how SDAP has allowed one to rapidly collect data pertinent to very basic questions about allergens, such as whether enzymatic activity is related to allergenicity. The chapter provides an overview of the information and methods incorporated into the cross-referenced (MySQL-Linux) lists of data.
A theoretical study of 31P NMR chemical shielding models for concentrated phosphoric acid solution.

Calculations on the hydrates, dimer, and trimer of phosphoric acid were carried out in an effort to obtain a viable model of the phosphorus NMR chemical shielding in 85% phosphoric acid solution. The theoretical approaches used the gauge-including-atomic-orbital (GIAO) 6-311+G(nd,p) basis set at both scaled density functional theory (sB3LYP) and estimated infinite order Moller-Plesset (EMPI) approaches and with the aug-cc-pvtz basis in the sB3LYP approach. Shieldings and hydrogen bonding stabilization energies are similar in the three approaches and indicate that the faster sB3LYP/6-31 +G(nd,p) approach can be used with larger systems. The changes in shielding compared to the isolated species are small and suggest that the undissociated acid dihydrate could serve as a model entity for modeling the phosphorus shielding in concentrated phosphoric acid solution.
B4-4: Genome-Wide Association Study of Macular Degeneration: Early Results from the Kaiser Permanente Research Program on Genes, Environment, and Health (RPGEH)

Background/Aims Age-related macular degeneration (AMD) is the most common cause of vision loss in individuals over the age of 50 in the United States. Genetic factors explain a large portion of the risk of developing AMD, and genetic variants at the CFH, HTRA1/ARMS2, C2/CFB, and C3 gene loci have previously been associated with the disease.
Emerging Technologies for Metals Production

The present annual world production of iron and steel, aluminum, copper, zinc, lead, nickel, magnesium and titanium is close to 1 billion tonnes. Based on current trends, metals are likely to remain one of the primary materials of choice for several decades to come. Most metals and their alloys are synthesized from oxide, sulfide, and halide sources. The energy required for metals production is obtained in one way or another from carbon, hydrocarbons, and oxygen. The reactants and energy sources often contain many additional elements, such as sulfur, phosphorous, nitrogen, halogens, and other metals. During processing, these elements sometimes combine with each other and other elements to form many toxic compounds. The major processing routes for metals production are electosynthesis, pyrosynthesis, and aqueous synthesis, all of which are very energy intensive and generate an order of magnitude more wastes and byproducts than the desired metal product. Metals are generally considered to be commodity materials. However, the metals industries, with their matured technologies, are among the top industrial polluters (1999 Toxic Release Inventory available at www.epa. gov/tri/tri99/press/press.htm) and energy consumers (Figure 1)1 in the United States; it is true globally as well. The impact of the metals industry on pollution and energy consumption is likely to worsen—as the grade of the raw materials declines in the future, energy required for processing will increase greatly.2 In addition, an increasing global population will demand a higher standard of living, driving industrialization and, in turn, depleting energy sources and compounding the effects of the associated pollution. It is, therefore, important to reevaluate processing alternatives and to develop new energy and environmentally efficient technologies in light of the changing external constraints and an expanding dependence on metals for industrial growth. The choice of the processing technology is always based on economic viability, which is subject to many constantly Figure 1. Total energy consumption of the U.S. Manufacturing Industries.2 Emerging Technologies for Metals Production
Improving the accuracy of prolapse and incontinence procedure epidemiology by utilizing both inpatient and outpatient data

The epidemiologic description of pelvic organ prolapse (POP) and stress urinary incontinence (SUI) procedures is documented in several large studies using national database cohorts. These studies, however, may underestimate the number of procedures performed because they only capture procedures performed in either the inpatient or outpatient settings alone. We present a complete annual description of all inpatient and outpatient surgeries for POP and SUI in California. We reviewed a record of all inpatient and outpatient POP and SUI surgeries performed in California in 2008 using data from the Office of Statewide Health Planning (OSHPD). In 2008, 20,004 and 20,330 women in California underwent POP and SUI procedures, respectively. Of these, 3,134 (15.6 %) and 9,016 (44.3 %) were performed in an outpatient setting. The age-adjusted rates of POP and SUI were 1.20 and 1.20 per 1,000 US females, respectively. This correlates to 186,000 POP and 186,000 SUI procedures per year nationally. Vaginal apical suspensions were more common in those undergoing surgery as an inpatient (45.1 vs 19.4 %). The use of mesh to augment prolapse repairs was similar (22.3 % inpatient vs 19.3 % outpatient). SUI procedures performed in the outpatient setting were more likely to be performed as stand-alone procedures (82.9 vs 18.8 %, respectively). In California, 16 % of POP and 44 % of SUI procedures were performed in an outpatient surgical setting in 2008. Epidemiologic studies of POP and SUI should account for the fact that a substantial number of repairs are performed in the outpatient setting in order to achieve accuracy.
Three-dimensional integration of silicon-on-insulator RF amplifier

An RF amplifier implemented by wafer-scale three-dimensional integration of three completely fabricated silicon-on-insulator wafers is demonstrated. The MOSFETs are on the top and bottom tier with middle-tier matching circuits. Measured amplifier performance agrees well with simulation and the footprint is approximately 40% smaller than the conventional 2D layout.
Effect of Sequential Planting, Plant Replacement, and Planting Date on Marketable Yield of Bell Pepper, Capsicum annuum var. annuum L.

Earliest plantings of the bell pepper cv. Pip were on 16 May 1990 and 15 April 1991 at Lane, Okla. Additional plantings were at monthly intervals through July. Peppers were harvested weekly. Plants of the earliest plantings had marketable yields of approximately 21 Mg. ha-'. Marketable yields of later plantings were no higher than 8.6 Mg, ha-'. Combined marketable yields of sequential monthly lantings increased marketable yield to approximately 36 Mg.ha-(I a 1.7 fold increase over the earliest planting alone. W~th the earliest planting removed and peppers immediately replanted in June or July 1990 or May through July 1991, the marketable yield from subsequent plantings did not equal the marketable yield lost with the earliest planting maintained. Results showed sequential planting, with the earliest planting being no later than early May in the South Central United States, to be a viable method to increase marketable yield of bell pepper.
Magnetic properties of the pseudo-binary Heusler alloy (Fe1−xVx)3Al

Abstract The magnetization of the D 0 3 type Heusler alloy (Fe 1− x V x ) 3 Al with compositions 0.18≤ x ≤0.33, has been measured at temperatures from 2 to 600 K. The Curie temperature decreases to zero as the composition approaches the x =1/3 value. The effective moment calculated from both the high temperature portion of the data utilizing a Curie–Weiss fit and from the saturation moment decreases to very near zero as the x =1/3 composition is approached. This behavior is explained by the existence of magnetic clusters of Fe atoms. Fe atoms on the V site in Fe 2 VAl cause the eight neighboring Fe atoms to become magnetically active thereby forming clusters of nine magnetic Fe atoms.
Segmental shrinkage and argentophilia of dendrons after fixation by perfusion with dimethyl sulfoxide (DMSO)-containing solutions.

Abstract Dimethyl sulfoxide (DMSO) was added in concentrations of 1, 5, or 10% to the fixative alone or to the solutions used in a three-step perfusion procedure with (i) 0.9% sodium chloride solution, (ii) Bouin's solution or a modified Bouin's solution, and (iii) 100% ethyl alcohol used for preparation of Netherlands dwarf rabbits, New Zealand white rabbits, guinea pigs, and cats (experimental systemic oil embolism for 90 min). Myriads of small pericapillary foci of acute tissue necrosis were formed. The foci contained neurons with perikarya which had concave sides, basophil cytoplasm, and argentophil neurofibrils and with dendrons which displayed an unusual segmental shrinkage and argentophilia. The segmental dendritic changes are regarded as specific for brains fixed by perfusion with DMSO-containing solutions because they are not reproducible in normal or experimental brains perfused with solutions free of DMSO or in brains fixed by immersion several hours or days after death. The mechanism inducing the pericapillary foci with the unusual dendritic changes has not been determined.
Syringomycin stimulation of potassium efflux by yeast cells

Abstract The phytotoxin, syringomycin, produced by Pseudomonas syringae pv. syringae caused the cellular efflux of K+ in cell suspensions of Rhodotorula pilimanae and Saccharomyces cerevisiae. K+ levels in the suspension media increased 3–10-fold within 2 min after adding syringomycin (1.5 μg/ml). As shown previously, syringomycin also stimulated the uptake of tetraphenylphosphonium (TPP) ions 10-fold. Although valinomycin (10 μM) and nigericin (10 μM) inhibited and N,N′-dicyclohexylcarbodiimide (DCCD) (50 μg/ml) stimulated TPP uptake, these ienophores had no effect on K+ efflux. However, carbonylcyanide m-chlorophenylhydrazone (CCCP) induced K+ efflux and inhibited TPP uptake. We conclude that syringomycin causes K+ efflux and that this effect is independent of the toxin's action on the DCCD-sensitive H+-ATPase. Also syringomycin is not acting as a K+ ionophore such as valinomycin or nigericin, nor does its action resemble that of the protonophore CCCP.
Many-Body Problem in Quantum Statistical Mechanics. IV. Formulation in Terms of Average Occupation Number in Momentum Space

Starting from Rules A and B of a previous paper (I), it is shown that the grand partition function can be evaluated in terms of the statistical averages of the occupation number in momentum space. The final formulation is in terms of a simple variational principle. The procedure represents a concise and complete separation of the effect of the BoseEinstein or Fermi-Dirac statistical character of the particles from the dynamical problem. In the case of Bose statistics, this formulation makes possible a systematic computation of all thermodynannic functions near the BoseEinstein transition point in the gaseous phase. Applications to a system of hard spheres are discussed. (auth)
Presidents as Commenders in Chief: Recognitions of Citizen Heroes from Ronald Reagan through George W. Bush

Presidents have long referred in their speeches to heroes of previous times. In 1982, President Reagan inaugurated the practice of inviting contemporary citizen heroes to attend his televised speeches to Congress and of recognizing them by name. Since then, Reagan and each of his three successors have continued this practice, which has evolved over time to include individuals who exemplify potential benefits of government programs and some foreign guests. In honoring citizen heroes, presidents point to the ideals that fellow Americans value, and inspire faith that Americans can meet modern crises. In addition, presidents seek to profit from the popularity of the individuals that they recognize. Despite these benefits, the practice also presents some potential pitfalls. Presidents must avoid seeming scripted or exploitative of others. Also, they can neither guarantee how honorees will respond nor guarantee their future behavior. Bill Clinton and George W. Bush have generally used the mechanism ably, but Ge...
A role for highly conserved carboxylate, aspartate-140, in oxygen activation and heme degradation by heme oxygenase-1.

Heme oxygenase (HO) catalyzes the oxygen-dependent degradation of heme to biliverdinIXα, CO, and free iron ion via three sequential monooxygenase reactions. Although the distinct active-site structure of HO from cytochrome P450 families suggests unique distal protein machinery to activate molecular oxygen, the mechanism and the key amino acid for the oxygen activation have not been clear. To investigate the functionality of highly conserved polar amino acids in the distal helix of HO-1, we have prepared alanine mutants: T135A, R136A, D140A, and S142A, and found drastic changes in the heme degradation reactions of D140A. In this paper, we report the first evidence that D140 is involved in the oxygen activation mechanism in HO-1. The heme complexes of HO mutants examined in this study fold and bind heme normally. The pKa values of the iron-bound water and autoxidation rates of the oxy-form are increased with R136A, D140A, and S142A mutations, but are not changed with T135A mutation. As the wild-type, T135A...
Modeling aggregation and growth processes in an algal population model: analysis and computations

Aggregation, the formation of large particles through multiple collision of smaller ones is a highly visible phenomena in oceanic waters which can control material flux to the deep sea. Oceanic aggregates more than 1 cm in diameter have been observed and are frequently described to consist of phytoplankton cells as well as other organic matter such as fecel pellets and mucus nets from pteropods. Division of live phytoplankton cells within an aggregate can also increase the size of aggregate (assuming some daughter cells stay in the aggregate) and hence could be a significant factor in speeding up the formation process of larger aggregate. Due to the difficulty of modeling cell division within aggregates, few efforts have been made in this direction. In this paper, we propose a size structured approach that includes growth of aggregate size due to both cell division and aggregation. We first examine some basic mathematical issues associated with the development of a numerical simulation of the resulting algal aggregation model. The numerical algorithm is then used to examine the basic model behavior and present a comparison between aggregate distribution with and without division in aggregates. Results indicate that the inclusion of a growth term in aggregates, due to cell division, results in higher densities of larger aggregates; hence it has the impact to speed clearance of organic matter from the surface layer of the ocean.
On source association of DOA estimation under multipath propagation

For direction of arrival (DOA) estimation under a multipath environment, algorithms exist to estimate the DOAs of all paths associated with different sources, by employing various schemes to cope with coherent signals induced by multipath. Most of these methods do not provide any information on which source a detected path belongs to, i.e., source association. However, information on source association is useful for identifying, locating, and tracking the sources. In this letter, we propose a novel method to associate all paths to each source based on the assumption that the DOAs of all paths have been detected by an existing method. The description of our source association algorithm and the simulation are based on wideband cyclostationary signals. However, our algorithm can be easily modified to work for both stationary signals and narrowband cyclostationary signals.
Direct correlation of phonon anomalies in NbC with fermi-surface-induced maxima in generalized susceptibilities

The generalized susceptibility of NbC, determined from its augmented plane wave energy band structure (with constant matrix elements), shows large maxima, arising in large part from Fermi surface "nesting," to occur at precisely those $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ values at which soft modes have been found in the phonon acoustic branches by Smith. These maxima can be represented by a warped cube of dimension $\ensuremath{\sim}1.2(\frac{2\ensuremath{\pi}}{a})$ in momentum space, in striking agreement with the soft mode surface proposed by Weber.
Stiff Mutant Genes of Phycomyces Affect Turgor Pressure and Wall Mechanical Properties to Regulate Elongation Growth Rate

Regulation of cell growth is paramount to all living organisms. In plants, algae and fungi, regulation of expansive growth of cells is required for development and morphogenesis. Also, many sensory responses of stage IVb sporangiophores of Phycomyces blakesleeanus are produced by regulating elongation growth rate (growth responses) and differential elongation growth rate (tropic responses). “Stiff” mutant sporangiophores exhibit diminished tropic responses and are found to be defective in at least four genes; madD, madE, madF and madG. Prior experimental research suggests that the defective genes affect growth regulation, but this was not verified. All the growth of the single-celled stalk of the stage IVb sporangiophore occurs in a short region termed the “growth zone”. Prior experimental and theoretical research indicates that elongation growth rate of the stage IVb sporangiophore can be regulated by controlling the cell wall mechanical properties within the growth zone and the magnitude of the turgor pressure. A quantitative biophysical model for elongation growth rate is required to elucidate the relationship between wall mechanical properties and turgor pressure during growth regulation. In this study, it is hypothesized that the mechanical properties of the wall within the growth zone of stiff mutant sporangiophores are different compared to wild type. A biophysical equation for elongation growth rate is derived for fungal and plant cells with a “growth zone”. Two strains of stiff mutants are studied, C149 madD120 (-) and C216 geo- (-). Experimental results demonstrate that turgor pressure is larger but irreversible deformation rates of the wall within the growth zone and growth zone length are smaller for stiff mutant sporangiophores compared to wild type. These findings explain the diminished tropic responses of the stiff mutant sporangiophores and suggest that the defective genes affect the amount of wall-building material delivered to the inner cell wall.
Estrogen receptor binding to a DNA response element in vitro is not dependent upon estradiol

Gel shift assays were employed to distinguish between the contribution of 17{beta}-estradiol (E{sub 2}) and a short heating step to the ability of the rat uterine cytosolic estrogen receptor (ER) to bind to the estrogen response element (ERE) from the vitellogenin A2 gene (vitERE). Despite the popularity of models in which the ER is a ligand-activated DNA-binding protein, these studies find that estrogen does not significantly contribute to receptor-DNA complex formation. An avidin-biotin complex with DNA (ABCD) assay was utilized to obtain quantitative measurement of the affinities of the ER for the vitERE and a mutant sequence. Scatchard analysis give a dissociation constant of 390 {plus minus} 40 pM for the E{sub 2}-occupied, heated ER to the vitERE. The data fit a one-site model and evidence for cooperativity was not observed. A dissociation constant of 450 {plus minus} 170 pM was obtained for the unoccupied, heated ER, leading to the conclusion that estrogen was not necessary for specific binding to DNA. The percentage of ER capable of binding vitERE varied with each cytosol preparation, ranging from 60 to 100% and estrogen did not appear to affect this variation. Competition against the vitERE with a 2-bp mutant sequence showed a 250-foldmore » lower relative binding affinity of the receptor for the mutant over the vitERE sequence. This ability of the ER to discriminate between target and nonspecific DNA sequences was also not dependent on the presence of estrogen.« less
The growth hormone content of human plasma.

The present investigation was undertaken in an effort to assay the growth hormone content of body fluids. Reports to date show a successful assay in only one acromegalic patient (Kinsell, 1950). The thickness of the tibial epiphyseal cartilage in the immature hypophysectomized rat is the most sensitive of the currently available methods and, therefore, this method was employed. It was not considered worthwhile to attempt to set up a model for fractionation of plasma based on ability to recover hypophyseal growth hormone added to plasma before fractionation because of the different solubility characteristics of growth hormone prepared by various methods from pituitaries of different species. Instead it was thought advisable to attempt first the measurement of the growth hormone content of whole plasma. After preliminary trials the following standardized procedure was employed. Immature rats of the Sprague-Dawley strain (75 to 85 gm. in weight) were hypophysectomized, permitted to rest for two weeks,
Crystallization of rapidly heated amorphous solids

Abstract Traditional theoretical approaches to the description of a non-isothermal phase transformation view its initial stage-nucleation - as a quasi-steady-state (QSS) process. These approaches are approximate, however, and may fail completely even for quite moderate heating (cooling) rates due to very large internal relaxation times of the amorphous state. A simple way to adjust the QSS approximation to account for strong time-dependent nucleation effects during rapid heating of amorphous solids with no quenched in nuclei is proposed. In combination with the approximate expression for the growth of nucleated particles, this leads to explicit closed formulas for the rate of phase transformation and the volume fraction transformed. Results are tested by comparison with numerical solutions of the time-dependent Becker-Doring nucleation equation, and it is demonstrated that the present method provides highly accurate corrections to the QSS approximation.
SRA- and SET-domain-containing proteins link RNA polymerase V occupancy to DNA methylation

RNA-directed DNA methylation in Arabidopsis thaliana depends on the upstream synthesis of 24-nucleotide small interfering RNAs (siRNAs) by RNA POLYMERASE IV (Pol IV) and downstream synthesis of non-coding transcripts by Pol V. Pol V transcripts are thought to interact with siRNAs which then recruit DOMAINS REARRANGED METHYLTRANSFERASE 2 (DRM2) to methylate DNA. The SU(VAR)3-9 homologues SUVH2 and SUVH9 act in this downstream step but the mechanism of their action is unknown. Here we show that genome-wide Pol V association with chromatin redundantly requires SUVH2 and SUVH9. Although SUVH2 and SUVH9 resemble histone methyltransferases, a crystal structure reveals that SUVH9 lacks a peptide-substrate binding cleft and lacks a properly formed S-adenosyl methionine (SAM)-binding pocket necessary for normal catalysis, consistent with a lack of methyltransferase activity for these proteins. SUVH2 and SUVH9 both contain SRA (SET- and RING-ASSOCIATED) domains capable of binding methylated DNA, suggesting that they function to recruit Pol V through DNA methylation. Consistent with this model, mutation of DNA METHYLTRANSFERASE 1 (MET1) causes loss of DNA methylation, a nearly complete loss of Pol V at its normal locations, and redistribution of Pol V to sites that become hypermethylated. Furthermore, tethering SUVH9 [corrected] with a zinc finger to an unmethylated site is sufficient to recruit Pol V and establish DNA methylation and gene silencing. These results indicate that Pol V is recruited to DNA methylation through the methyl-DNA binding SUVH2 and SUVH9 proteins, and our mechanistic findings suggest a means for selectively targeting regions of plant genomes for epigenetic silencing.
Modification of alloy surface composition by segregation processes as a means of impurity control in fusion devices

Abstract The bulk properties required of materials to be used in fusion devices: tensile strength, swelling resistance, thermal conductivity, low induced activity, and high melting point, are not generally compatible with the required surface properties of low Z and low chemical reactivity with hydrogen. Coatings have been suggested as a means of providing the necessary surface properties, while preserving the requisite substrate properties. The coatings, however, introduce new problems in terms of maintenance, thermal conductivity and mechanical integrity. We are investigating the use of surface segregation in alloys as a means of producing low Z coatings which are self-sustaining in a reactor environment, present no thermal barrier to the substrate, and avoid mechanical problems associated with the interface region. Several candidate materials have emerged from our calculations, including alloys of copper, vanadium and tungsten. The segregation calculations, light and heavy ion sputtering properties and thermodynamic properties of these materials are presented. Calculations indicate that as little as one atomic layer of low Z material significantly reduces the substrate erosion for both light and heavy ion sputtering. Experimental data on the degree of surface segregation and the rate at which the low Z component migrates to the surface are presented using dilute alloys of lithium in copper as a reference system. The long term stability of the overlayer is limited primarily by the rate at which radiation-enhanced diffusion can replace the eroded surface material. The radiation-enhanced process proceeds much more quickly than the purely thermodynamic process and depends on the damage profile, which in turn depends on the mass and energy spectrum of the incident radiation.
Analysis of Eccentrically Loaded Adjacent Box Girders

Research has shown that exterior girders of adjacent box (AB) beam bridges act compositely with their barrier wall and curb slab assemblies, resulting in a highly asymmetric cross section. Additionally, impact damage from vehicle collision often severs or exposes strands in the exterior soffit corner of exterior girders. These effects individually (and more so in combination) have the effect of rotating the neutral axis of the girder, resulting in significant, unaccounted for biaxial flexure. Common structural rating practices analyze the member about its horizontal axis, neglecting the effects of neutral axis rotation, and thus overestimate the actual capacity of the member. A parametric study that analyzed the effects of varying levels of damage to eight prototype AB girders was conducted. In all, 106 analyses were carried out. From this study, a relationship is proposed to determine the capacity of an AB beam subject to asymmetric loading, which includes the composite behavior of the barrier wall assembly and the effect of prestressing strands lost as a result of damage to the girder. This relationship is based on easily obtained capacity predictions and is shown to result in predictions of capacity having an average absolute error of less than 6%. This study also examines, in the context of complete AB bridges, the potential for in-service loading to exceed assumed design loads.
Laser-induced thermal desorption with Fourier transform mass spectrometry for the time resolved analysis of catalyst and biomedical implant model surface molecular composition

Laser-induced thermal desorption with Fourier transform mass spectrometry is used to analyze the surface molecular composition of several samples containing complex mixtures of adsorbates. Data are presented for the formation of benzene and thiophene from acetylene on a sulfur-treated Pd(111) surface showing the utility of this technique for monitoring changes in surface composition on catalyst models. Also, time dependent data are shown for the formation of benzene from acetylene on clean Pd(111). The data are first order, lending insight into the mechanism. Finally, a new technique for deflection of laser-formed ions to allow analysis of the coadsorbed organics is described and used to analyze the surface composition of oxidized Ti foils used as biomedical implant models.
The Ethnography of Landscape: GIS and Remote Sensing in the Study of Forest Change in West African Guinea Savanna

In this paper we explore the application of Amazonian forest change models to the Guinea savanna environment of western Africa. In particular, we examine recent research documenting the growth of peri-village forest islands in the area of Kissidougou, Guinea, which purports to challenge the pervasive view of Guinea savanna deforestation brought about by human activity. As a more systematic approach to the analysis of human/environmental interactions, we propose an "ethnography of landscape," in which the findings of detailed, local ethnographic and ecological case studies are combined with remotely sensed information on what the wider region looks like as it changes over time. In pursuing this research, we employ aerial photography and Geographic Information Systems (GIS) techniques to examine our study area of Kilimi in northwestern Sierra Leone. We show that a Kissidougou-type model of peri-village forest island growth is not applicable to this region, where other environmental change processes are underway. In future work, we propose to employ Landsat satellite image archives to examine, monitor, and compare processes of ecological change throughout the Guinea savanna. [deforestation, ecological anthropology, remote sensing, Sierra Leone, West Africa]
Shining Armor: Structural Colors in Insects

The wings and cuticles of insects have much to teach us in areas such as thin films, lattice structures, iridescence, and polarization.
An abdominal receptor of the American cockroach, Periplaneta americana (L.) and its response to airborne sound

Abstract A receptor sensitive to substratum vibration and high-intensity airborne sound has been found in the lateral folds of abdominal segments 2 to 6 of Periplaneta americana . The electrophysiological results reveal the presence of two sensory units that differ in the amplitude of their output and the degree of sensitivity to airborne sound. The histological study revealed the presence of rigid spines in the lateral fold. These spines are probably an integral part of the entire sensory structure.
The secretary problem with a call option

In addition to accepting or rejecting a candidate arriving at time r, we may consider purchasing an option at a cost cx to recall the candidate at time r + x, but this privilege may be invoked only once. For large sample size, using the best-choice criterion and deducting option costs, the optimal strategy and return are obtained.
Reciprocity for Jacobi Sums

Abstract Let l be an odd prime number and p, q be two prime numbers ≡ 1 (mod l). If χ, χ′ (resp. ψ, ψ′) are multiplicative characters of order l on the finite field Fp (resp. Fq), then the corresponding Jacobi sums J(χ, χ′) and J(ψ, ψ′) satisfy the reciprocity relation [formula] where (−) denotes the lth power residue symbol over the cyclotomic field of lth roots of unity.
Pathology of the choroid plexus in spontaneous immune complex disease and chronic viral infections

Using immunofluorescence and electron microscopy, deposits of immunoglobulin G (IgG) and the third complement component (C3) are found in the choroid plexus of mice with spontaneous immune complex disease, in mice chronically infected with lymphocytic choriomeningitis (LCM) virus and in patients with systemic lupus erythematosus (SLE). (NZB × W) F1 mice develop antibodies to nuclear antigen (ANA) and DNA (ADNA) and are an animal model of human SLE. Enhancement of ANA and ADNA responses by immunization with DNA leads to accelerated and more severe involvement of the choroid plexus accompanied by leukocytic infiltrates. Mice infected in utero or at birth with LCM virus harbor the virus throughout life and continuously produce antibodies. Virus and antiviral antibody(s) combine in the serum and form immune complexes that are trapped in renal glomeruli and choroid plexus. In contrast, mice chronically infected with scrapie fail to show immunoglobulin deposits in choroid plexus and brain despite clinical and pathological evidence of severe scrapie encephalopathy. The findings indicate that the choroid plexus is a favored site for the trapping of immune complexes and may be damaged during immune complex disease. Choroid plexus injury could lead to spinal fluid changes that may be responsible in part for neurologic and psychiatric disturbances seen in patients with systemic lupus erythematosus, chronic and acute viral infections and other disorders associated with circulating antigen-antibody complexes.
A primer-dependent polymerase function of pseudomonas aeruginosa ATP-dependent DNA ligase (LigD).

Pseudomonas aeruginosa encodes two putative DNA ligases: a classical NAD+-dependent DNA ligase (LigA) plus an ATP-dependent DNA ligase (LigD). LigD exemplifies a family of bacterial proteins that consist of a ligase domain fused to flanking domains that resemble nucleases and/or polymerases. Here we purify LigD and show that it possesses an intrinsic polymerase function resident within an autonomous C-terminal polymerase domain, LigD-(533–840), that flanks an autonomous DNA ligase domain, LigD-(188–527). Native LigD and the polymerase domain are both monomeric proteins. The polymerase activity is manifest in three ways: (i) non-templated nucleotide addition to a blunt-ended duplex DNA primer; (ii) non-templated addition to a single-stranded DNA primer; and (iii) templated extension of a 5′-tailed duplex DNA primer-template. The divalent cation cofactor requirement for non-templated and templated polymerase activity is satisfied by manganese or cobalt. rNTPs are preferred over dNTPs as substrates for non-templated blunt-end addition, which typically entails the incorporation of only 1 or 2 nucleotides at the primer terminus. Templated dNMP addition to a 5′-tailed substrate is efficient with respect to dNTP utilization; the primer is elongated to the end of the template strand and is then further extended with a non-templated nucleotide. The polymerase activity is abolished by alanine substitution for two aspartates (Asp-669 and Asp-671) within the putative metal-binding site. We speculate that polymerase activity is relevant to LigD function in nonhomologous end-joining.
Chromatographic chemical characterization of solvent refined coal I and II liquids for toxicological testing

High resolution gas chromatography and gas chromatography/mass spectrometry were employed to determine the components in samples of solvent refined coal (SRC) II naphtha, middle distillate, heavy distillate, and fuel oil blend and SRC-I light oil, wash solvent, and process solvent in concentrations higher than approximately 0.5%. Quantitation was based on the addition of n-alkane internal standards and peak area response of a flame ionization detector with the use of fused silica and glass capillary columns coated with SE-52 and SF-96. The major differences in the SRC-I and II materials were the molecular weight ranges and sizes of the chemical components found in the products, an effect of the differences in the nominal boiling ranges of the materials. Alkanes, alkenes, hydroxylated aromatics, hydrogenated and polycyclic aromatic hydrocarbon ring systems, and alkylated derivatives of the above were found in greatest concentration in the unfractionated materials. Sulfur and nitrogen heteroatomic species were in greates concentration in the higher nominal boiling range materials. A major purpose of these investigations was to develop a method to obtain data on the composition of these complex sample matrices for use in designing studies for toxicological evaluation of these materials.
How the CO in myoglobin acquired its bend: lessons in interpretation of crystallographic data.

Contrary to the expectation of chemists, the first X-ray structures of carbon monoxide bound to myoglobin (Mb) showed a highly distorted Fe—C—O bond system. These results appeared to support the idea of a largely steric mechanism for discrimination by the protein against CO binding, a lethal act for the protein in terms of its physiological function. The most recent independently determined high-resolution structures of Mb–CO have allowed the 25 year old controversy concerning the mode of CO binding to be resolved. The CO is now seen to bind in a roughly linear fashion without substantial bending, consistent with chemical expectations and spectroscopic measurements. Access to deposited diffraction data prompted a reevaluation of the sources of the original misinterpretation. A series of careful refinements of models against the data at high (1.1 A) and modest resolutions (1.5 A) have been performed in anisotropic versus isotropic modes. The results suggest that the original artifact was a result of lower quality crystals combined with anisotropic motion and limited resolution of the diffraction data sets. This retrospective analysis should serve as a caution for all researchers using structural tools to draw far-reaching biochemical conclusions.
On Identifying Authors with Style

Stylometry is the quantified (often statistical) analysis of author style as a set of (usually morphosyntactic) features expressed in several documents by the author. The focus of this paper is a task to which stylometry is often applied: authorship attribution, the question of identifying or confirming the author of a text based on the known body of work. We analyze a feature set previously introduced in the field, using a tool and corpus already available. Decomposing the set, we identify the features that seem to have contributed the most to accurate performance. In re-composing the set under different objectives - first, for English-only document sets, and then for possible multi-language use - we identify smaller sets of feature combinations that work well together in accurate performance. We then outline our continuing work based on the results we obtain.
Identification of CYP21 mutations, one novel, by single strand conformational polymorphism (SSCP) analysis. Mutations in brief no. 218. Online.

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is a common autosomal recessive disorder (MIM# 201910) due to mutations in the 21-hydroxylase (CYP21) gene (GDB Accession # M12792). Using our protocol for single strand conformational polymorphism (SSCP) analysis, we have identified two mutations not known to exist in the 21-hydroxylase pseudogene (CYP21P). One mutation involving codon 169, TGC to AC appears to be novel. The 46,XX patient carried the codon 169 mutation on her paternal allele and a large gene deletion/conversion event on her maternal allele. This patient had been referred in the immediate neonatal period for the evaluation of genital ambiguity and had developed hyponatremia and hyperkalemia. The second patient presented with premature pubic hair. She carried R356Q on her maternal allele and V281L on her paternal allele. © 1998 Wiley-Liss, Inc.