cssi/SciSciGPT-SciSciNet huggingface dataset:
Dirac optical model analysis of p-/sup 40/Ca elastic scattering at 180 MeVand the wine-bottle-bottom shape

A Dirac equation optical model calculation with the real part of the optical potential constrained by relativistic model considerations is used to represent 180 MeV p-/sup 40/Ca elastic scattering data. The Dirac equation optical potential consists of a mixture of Lorentz scalar and Lorentz vector potentials. Features of an effective Schroedinger equation optical potential constructed from these two potentials are deduced and compared with results from the standard optical model.
Inferring Correlations of Asset Values and Distances-to-Default from CDS Spreads: A Structural Model Approach

Using structural credit risk models to estimate default dependence requires estimates of correlations of changes in distance-to-default. We present a structural model that yields simple relations between asset value, distance-to-default, and CDS spreads, allowing the correlations to be estimated from CDS spreads. We generalize the model to include a randomly varying default boundary; in this version the distance-to-default dynamics also depend on the movement of the default boundary. The CDS spread correlations we estimate exceed equity correlations, consistent with a randomly varying default boundary. We also present evidence that variations in funding liquidity affect the correlations, consistent with recent models.
Regional integration: an empirical assessment of Russia

Abstract Using a statistical model of commodity trade, we quantify the evolution of regional economic integration within Russia during 1995–1999, and explore potential determinants of this evolution. Our integration measure exhibits rich regional variation that, when aggregated to the national level, fluctuates substantially over time. In accounting for this behavior, we draw in part on theoretical models that emphasize the potential role of openness to international trade and regional disparities in income in threatening economic integration. Controlling for a host of additional regional- and national-level variables, we find a strong negative correspondence between openness to international trade and internal economic integration.
In Vitro Translation of the Upstream Open Reading Frame in the Mammalian mRNA EncodingS-Adenosylmethionine Decarboxylase

The upstream open reading frame (uORF) in the mRNA encoding S-adenosylmethionine decarboxylase is a polyamine-responsive element that suppresses translation of the associated downstream cistron in vivo. In this paper, we provide the first direct evidence of peptide synthesis from the S-adenosylmethionine decarboxylase uORF using an in vitro translation system. We examine both the influence of cation concentration on peptide synthesis and the effect of altering the uORF sequence on peptide synthesis. Synthesis of wild type and altered peptides was similar at all concentrations of magnesium tested. In contrast, synthesis of the wild type peptide was more sensitive than that of altered peptides to elevated concentrations of the naturally occurring polyamines, spermidine and spermine, as well as several polyamine analogs. The sensitivity of in vitro synthesis to spermidine was influenced by both the amino acid sequence and the length of the peptide product of the uORF. Findings from the present study correlate with the effects of the uORF and polyamines on translation of a downstream cistron in vivo and support the hypothesis that polyamines and the structure of the nascent peptide create a rate-limiting step in uORF translation, perhaps through a ribosome stalling mechanism.
A unifying hypothesis of temperature effects on egg development and diapause of the migratory grasshopper, Melanoplus sanguinipes (Orthoptera: Acrididae)

A conceptual model of diapause and egg development for Melanoplus sanguinipes (F) is presented. The processes regulating development are represented as non-linear functions of temperature. A diapause regulating process is hypothesized which is permitted to occur at any time during morphogenesis but must be completed before morphological development can progress beyond 80%. Under this hypothesis, the mean rates of the diapause regulating process and morphological development relative to each other determine whether or not morphogenesis is interrupted and the length of the resulting diapause. The model provides an excellent fit to an extensive data set collected for M. sanguinipes and can account for the observed occurrence of bivoltine southern populations, as well as of the more typical univoltine situation in the northern populations.
Effects of A-D conversion nonidealities on distributed sampling in dense sensor networks

We address the effect of the errors occurring at the analog-to-digital converter (ADC), from quantization noise, circuit noise, aperture uncertainty and comparator ambiguity, on the accuracy of sensor field reconstruction. We focus on the oversampling of bandlimited sensor fields in a distributed processing environment. It has previously been shown that pulse code modulation (PCM) style sampling fails to decrease the quantization error above some finite sampling rate. We show that the dither-based scheme, developed to decrease the quantization error, fails to decrease random errors associated with circuit noise, aperture uncertainty and comparator ambiguity. We propose an advanced dither-based sampling scheme with the goal of reducing both kinds of errors by increasing the density of the sensor nodes. It is based on distributing the task of improving the quantization error and random error among the nodes. The error of the scheme is shown to be O(1/r/sup 1/2 /) for oversampling rate r. The maximum energy consumption per node is O(log(r)). Finally, the bit rate of the scheme is O(1/r/sup 1/2 /log(r)) and it offers robustness to node failures in terms of a graceful degradation of reconstruction error.
Augmentation of carotid flow during cardiopulmonary resuscitation by ventilation at high airway pressure simultaneous with chest compression.

Abstract Prior studies in dogs indicate that (1) blood flow during cardiopulmonary resuscitation results from the induced rise in intrathoracic pressure rather than from direct cardiac compression, and (2) maneuvers that increase intrathoracic pressure lead to increased carotid blood flow. Therefore, a system was devised for administering cyclical increases in intrathoracic pressure without lung overinflation for use during cardiac arrest. Ventilation at high airway pressure (60 to 100 mm Hg) was performed simultaneously with chest compression at a rate of 40/min in seven dogs with cardiac arrest. Airway pressure returned to the atmospheric level between compression-ventilation periods to allow venous return. This new technique was compared with conventional cardiopulmonary resuscitation both with and without sustained abdominal compression by binding. Peak chest compression force was held constant during all forms of resuscitation. Carotid blood flow was higher during simultaneous compression-ventilation resuscitation than with conventional resuscitation both without abdominal binding (mean ± standard error of the mean 18.7 ± 4.7 versus 5.1 ± 1.08 ml/min, p
Sumo15A: a lambda phasmid that permits easy selection for and against cloned inserts

We report the construction of a phasmid vector, Sumo15A, designed for recombination-based screening of recombinant DNA libraries [Seed, Nucleic Acids Res. 11 (1983) 2427-2445]. This vector permits rapid selection in Escherichia coli for homology-mediated integration and excision between homologous DNA inserts cloned in a supF-carrying plasmid and in Sumo15A. The region available for recombination spans the homologous sequence shared by the plasmid and the phasmid. SupF is the selection tool that we used. Efficient selection for supF expression by Sumo15A requires recombination mediated by the lambda phage red gene, which promotes homologous recombination between phage and plasmid DNAs. Counterselection against supF expression by Sumo15A occurs because the presence of a pSC101-derived plasmid replicon in this phasmid permits the growth of Sumo15A as a plasmid in a specialized host, E. coli strain DK37. In strain DK37, Sumo15A cannot replicate as a phage, and the presence of a plasmid-carrying supF is lethal to cells plated on galactose plates. This scheme was developed to select for sequences that are transcribed from chromosomes of interest.
Quantification of a silver contrast agent in dual-energy breast x-ray imaging

Dual-energy (DE) breast x-ray imaging involves acquiring images using a low- and high-energy x-ray spectral pair. These images are then subtracted with a weighting factor that eliminates the soft-tissue signal variation present in the breast leaving only contrast that is attributed to an exogenous imaging agent. We have previously demonstrated the potential for silver (Ag) as a contrast material for DE breast imaging. Theoretical analysis shows that silver can provide better contrast to clinically-used iodine. Here, we present the subtraction method developed to eliminate the contrast between adipose and glandular tissue; the two major component materials in the breast. The weighting factor is calculated from the attenuation coefficients of the two tissue types and varies between values of 0 and 1 for the energy combinations studied. A spectral search was performed to identify the set of clinically-feasible imaging parameters that will optimize the contrast of silver using our subtraction technique. The subtraction methodology was tested experimentally using step-phantoms and demonstrated that we are able to a) nullify the soft-tissue contrast that arises from differences in glandularity, and b) preserve an image contrast for silver that is independent of the underlying soft-tissue composition. By applying the DE subtraction proposed, a silver-based agent will outperform an iodinated contrast agent on a commercially-available CEDE breast x-ray imaging system.
38th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) San Diego, USA, 24–27 September 1998

Summary The renaissance in infections diseases, stimulated by well-documented and publicized microbial resistance, continues. The field is benefiting from the infusion of new technologies, aimed at accelerating the discovery process: genomics, combinatorial chemistry and high throughput screening. At this year's ICAAC, there were numerous reports on drug resistance and drug discovery though no surprises on either front. Microbial resistance to established agents is still edging upwards. Most agents (oxazolidinones, everninomycins, glycopeptides, ketolides, quinolones, β-lactams, azoles, echinocandins, sordarins) introduced in previous years are still in development. Combination antiretroviral chemotherapy (protease inhibitors, NRTIs and NNRTIs) is now the mainstream therapy for AIDS, at least in the developed world. A few antimicrobial agents (augmentin, ciprofloxacin, clarithromycin, fluconazole) are near or past the billion dollar mark, underscoring the healthy state of the market. In conclusion, convergence of medical needs and commercial opportunities has brought microbes and antimicrobials into center stage.
Self-administration of nalbuphine, butorphanol and pentazocine by morphine post-addict rats

The purpose of the study was to define possible self-administration of nalbuphine, butorphanol and pentazocine by morphine post-addict rats. Rats were prepared with permanent EEG and EMG electrodes and indwelling IV cannulae, made tolerant to and physically dependent on morphine, then trained to lever press for morphine IV self-injections on a fixed ratio (FR) 20 schedule of reinforcement. Rats were then spontaneously withdrawn from morphine. When these morphine post-addict rats were returned to the experimental cages three to four weeks later, they were found to reestablish self-administration of morphine as well as to establish self-administration of nalbuphine, butorphanol and pentazocine. Suppression of REM sleep for at least 30 min was apparent following self-injections of these agents. After the stabilization of self-injection patterns, withdrawal from nalbuphine and pentazocine was found to be associated with intense abstinence symptoms. However, withdrawal from morphine and butorphanol was not. It can be concluded that while drug-seeking behavior for the above narcotics in morphine post-addict rats was analogous as measured by self-administration, nalbuphine and butorphanol appeared to produce lower levels of physical dependence.
A model of lasing axion clusters

Abstract If axions make up the majority of the dark matter, then most are nonthermal and likely to be clustered in gravitational potential wells. For a range of cluster mass M, cluster radius R, and axion mass ma, photons from spontaneous axion decay can trigger exponential growth of photon number via stimulated decay. We derive (i) constraints on these parameters for lasing to occur, and (ii) the lasing rate equations for a general axion distribution. A simple axion cluster model with a flat momentum distribution is studied in analytical and numerical detail.
MANAGING RAPE: EXPLORATORY RESEARCH ON THE BEHAVIOR OF RAPE STATISTICS*

This article explores interpretations of the UCR-NCS disparity in rape rates within the context of recent debates and research about the UCR-NCS relationship. Analysis of a variety of survey, organizational, and employee data together with UCR and NCS crime data yields a pattern of findings that makes sense if two assumptions are made: Downward trends in NCS data are an approximation of trends in the real rate of rape, and upward trends in UCR data are primarily a product of changes in the management of rape cases. The common attribution of disparities between UCR and NCS rape data to changes in public or victim reporting receives little support when compared with explanations stressing organizational change. Upward movement in official attention to rape could, in fact, account for downward movement in NCS rape rates. The implications of recent NCS efforts to improve the official measurement of rape for the future behavior of rape statistics are also considered.
Determination of midazolam and its metabolites in serum microsamples by high-performance liquid chromatography and its application to pharmacokinetics in rats.

A single-solvent extraction step high-performance liquid chromatographic method is described for quantitating midazolam and its two hydroxy metabolites in rat serum microsamples (50 μl). The separation used a 2 mm I.D. reversed-phase Symmetry C18 column with an isocratic mobile phase consisting of methanol-acetonitrile-14.9 mM sodium acetate in water at pH 3.0 (10:23:67, v/v). The detection limit was 10 ng/ml for all the compounds using an ultraviolet detector operated at 230 nm. The method was used to study the pharmacokinetics of midazolam after an intravenous bolus dose (0.75 mg/kg).
The relationship between the MOCVD parameters and the crystallinity, epitaxy, and domain structure of PbTiO3 films

Lead- and titanium-based oxide thin films were prepared by the metal-organic chemical vapor deposition technique (MOCVD) and the relationship between the film structures and the processing parameters, such as the ratio of Pb/Ti precursors in the gas phase, substrate materials, substrate surface orientation, and growth temperature, was systematically studied. It was found that whether a single-phase stoichiometric PbTiO3 film could be obtained depended on both the Pb/Ti precursor ratio in the gas phase and the deposition temperature. Under appropriate conditions, stoichiometric PbTiO3, films could be obtained on all the substrates including silicon, MgO, α-Al2O3, SrTiO3, and LaAlO3. The PbTiO3 films grown on silicon substrates were always polycrystalline, whereas epitaxial PbTiO3 films were obtainable on all the other substrates. For epitaxial PbTiO3 films, the epitaxial relationship, crystallinity, and domain structures were found to be a function of both the substrate materials and surface orientation as well as the deposition temperature. X-ray rocking curves (ω scan) of the (100) and (001) planes of PbTiO3 epitaxial film and PbTiO3 single crystal revealed the inherent nature of the domain structures in PbTiO3.
Identification and Biochemical Characterization of Small-Molecule Inhibitors of Clostridium botulinum Neurotoxin Serotype A

An integrated strategy that combined in silico screening and tiered biochemical assays (enzymatic, in vitro, and ex vivo) was used to identify and characterize effective small-molecule inhibitors of Clostridium botulinum neurotoxin serotype A (BoNT/A). Virtual screening was initially performed by computationally docking compounds of the National Cancer Institute (NCI) database into the active site of BoNT/A light chain (LC). A total of 100 high-scoring compounds were evaluated in a high-performance liquid chromatography (HPLC)-based protease assay using recombinant full-length BoNT/A LC. Seven compounds that significantly inhibited the BoNT/A protease activity were selected. Database search queries of the best candidate hit [7-((4-nitro-anilino)(phenyl)methyl)-8-quinolinol (NSC 1010)] were performed to mine its nontoxic analogs. Fifty-five analogs of NSC 1010 were synthesized and examined by the HPLC-based assay. Of these, five quinolinol derivatives that potently inhibited both full-length BoNT/A LC and truncated BoNT/A LC (residues 1 to 425) were selected for further inhibition studies in neuroblastoma (N2a) cell-based and tissue-based mouse phrenic nerve hemidiaphragm assays. Consistent with enzymatic assays, in vitro and ex vivo studies revealed that these five quinolinol-based analogs effectively neutralized BoNT/A toxicity, with CB 7969312 exhibiting ex vivo protection at 0.5 microM. To date, this is the most potent BoNT/A small-molecule inhibitor that showed activity in an ex vivo assay. The reduced toxicity and high potency demonstrated by these five compounds at the biochemical, cellular, and tissue levels are distinctive among the BoNT/A small-molecule inhibitors reported thus far. This study demonstrates the utility of a multidisciplinary approach (in silico screening coupled with biochemical testing) for identifying promising small-molecule BoNT/A inhibitors.
Time for a Quiz! [AP-S Turnstile]

Every year, there are many items that I clip from magazines and newspapers, download from the Web, or receive from others that, for one reason or another, do not find their way into a column. Some of the juicier tidbits are featured in this short quiz. So, take out a pen and start marking your choices. The answers appear elsewhere in this issue. I hope you find the quiz both amusing and instructive. Good luck!
Listening to Hyphenated Americans: Hybrid Identities of Youth From Immigrant Families

The author argues that educators need to move beyond stereotypic representations of diverse youth, including youth from immigrant families, to recognize and engage their hybrid identities. To that end, the author draws on postcolonial perspectives as well as critiques of the model minority stereotype applied to Asian Americans to analyze the narratives of 10 high school students from Indian immigrant families in New York City. The article discusses how these students negotiate a range of identities as hyphenated Americans who encounter differences and contradictions at the dynamic intersections of race, culture, class, and gender at both home and school. In concluding, the author discusses implications for educational theory, research, and practice.
Earthquake risk prediction as a stochastic process

Abstract The extrapolation in time of an earthquake sequence considered as a multidimensional stochastic point process is discussed. Estimates of seismic risk for both long- and short-term predictions are considered and an algorithm for the calculations is proposed. Several examples of short-term extrapolations are carried out by means of Monte Carlo simulations of the process. An assessment of the predictability of the seismic process shows that the catalog of strong earthquakes (M ⩾ 7.0) contains about 0.4 bits of information per earthquake for the particular model of the process applied here.
Learning Applications in the Architectural Engineering Educational Setting

Reception and processing of information is essential to learning. How the information is presented is a critical element in student comprehension. In most engineering institutions, theory and fundamental concepts are taught with passive lectures and “recipe” laboratories. A balance between engineering science and engineering practice must be provided to prepare students for the real world. A relationship, described in this paper, is developed between the academic community and the design and construction industries to help bridge the gap between fundamental engineering principles and practical installation experience. Building this alliance helps to provide an additional element of proficiency essential to architectural engineering students’ practical understanding of systems in the built environment. A series of workshops consisting of demonstrations, lectures, and hands-on activities is developed and conducted, bringing professionals from 13 companies, two universities, and an apprenticeship program tog...
Rotational levels of double-minimum potentials: The linear BAB molecule with unequal bond lengths

Abstract The rotational constants and energy levels for the linear BAB system are studied under the assumption of unequal AB bond lengths. The quantum mechanical Hamiltonians is derived according to a formalism which allows for a large-amplitude antisymmetric stretching motion. A numberical integration technique is used to obtain solutions of the one-dimensional Schroedinger equation corresponding to a zeroth-order approximation of the Hamiltonian. The behavior of the resulting rotational constants for various heights of the barrier in the double-minimum potential is discussed.
Distance education students speak to the library: here's how you can help even more

Distance education students have unique needs from library services. This paper reports on a study of 17 distance learning students and describes what they say they need and want from the library. In talking to these distance students over time, we learned what general kinds of factors help them in their learning experience. Some of these are specifically related to library services, while some are more general but can be applied to the library. They range from changes in the provision of library materials and interpersonal services to large‐scale integration of the library with distance learning infrastructure and the governing institution as a whole.
Spread of branching diffusion: Sharp asymptotics

A one-dimensional branching diffusion with a stable drift is considered. Let Rt denote the position of the rightmost particle at time t. It is shown that Rt , properly normalized, has a limiting distribution.
Structural analysis of a bovine arginine tRNACCG gene

A bovine genomic clone containing a 17.4-kb DNA fragment was isolated and found to contain a solitary arginine tRNA gene with an anticodon of CCG that has a 100% identity to its cognate tRNA. This arginine tRNA gene, symbolized as TRR4, has a characteristic internal split promoter and a typical termination site for RNA polymerase III. The tRNA gene was transcribed in vitro by RNA polymerase III using a HeLa cell-free extract to yield a mature-sized tRNA product. The gene was mapped to bovine chromosome 19 using a panel of bovine-rodent somatic cell hybrid DNAs.
Current update on cellular and molecular mechanisms of hereditary angioedema.

Abstract Objective To provide an update on the molecular mechanisms of hereditary angioedema (HAE). Data Sources MEDLINE and PubMed databases were searched to identify pertinent articles using the following key terms: hereditary angioedema , angioedema , C1 inhibitor , bradykinin , contact system , factor XII , mechanism , pathophysiology , severity , permeability , and estrogen . Study Selections Articles were selected based on their relevance to the subject matter. Results Although the biochemical basis of "classic" HAE is known to result from C1 esterase inhibitor (C1INH) deficiency, a new form, HAE with normal C1INH, has been identified. HAE types I and II are caused by mutations in the SERPING1 gene that result in decreased plasma levels of functional C1INH. In HAE with normal C1INH, mutations in the F12 gene have been identified in a subset of individuals, but the genetic defect remains unknown in most patients. The primary mediator of swelling in HAE is bradykinin, a product of the plasma contact system that increases vascular permeability. HAE disease severity is highly variable and may be influenced by polymorphisms in other genes and other factors, such as hormones, trauma, stress, and infection. Conclusion Hereditary angioedema is a heterogeneous disorder with a complex pathophysiology. Implicated genes include SERPING1 and FXII in patients with HAE from C1INH deficiency and HAE with normal C1INH levels, respectively. Disease severity is highly variable.
Suppression of inhomogeneous broadening in optically addressed solids for quantum computing applications (Invited Paper)

Inhomogeneous broadening in optically addressed solids provides a convenient technique for individually addressing a large number of optically active defects in a crystal. Such a capability is important for quantum computer development. However, the random nature of inhomogeneous broadening can limit scalability. Here, techniques that can be used to suppress inhomogeneous broadening will be reviewed including a recently proposed VLSI quantum computer design based on nitrogen-vacancy (NV) color centers in diamond.
The Role of Significant Policy Issues in the 2000 Presidential Primaries

This study examines candidate discourse across four media types: television spots, radio spots, debates, and Web sites in the 2000 presidential primaries. The purpose of the analysis was to determine whether there is a relationship between candidate discourse on certain issues and the level of importance assigned to those issues by voters. The analysis indicates that some candidates are more effective than are others at addressing the issues most important to voters. The analysis also indicates that two message forms—debates and television spots—were modestly successful at adapting to audience preferences and two forms—radio spots and Web sites—were somewhat less successful at adapting to audience preferences.
Trade-Offs in Defensive Metabolite Production But Not Ecological Function in Healthy and Diseased Sponges

Diseases of marine organisms, and sponges in particular, are increasingly reported worldwide. Prior research indicates that the survival of sponges on reefs is due largely to their production of biologically active secondary metabolites that provide protection from a diversity of stressors. Aplysina Red Band Syndrome (ARBS) is an emerging disease affecting Caribbean rope sponges (Aplysina spp.), but it is not known whether secondary metabolites play a role in disease susceptibility and resistance. To investigate whether differences in secondary metabolites may explain variability in susceptibility to ARBS in Aplysina cauliformis, we used high performance liquid chromatography (HPLC) to generate chemical profiles from healthy tissue in both healthy and diseased sponges, and quantified peak areas for 15 metabolites. Analyses of healthy and diseased sponges revealed qualitative and quantitative differences in their chemical profiles. Aplysamine-1 and fistularin-3 were produced in significantly higher concentrations by healthy sponges, whereas aerothionin and 11-oxoaerothionin were found only in diseased sponges. At natural concentrations, extracts from both healthy and diseased sponges deterred feeding by an omnivorous reef fish. Fistularin-3 deterred feeding at concentrations found in healthy sponges, but not at concentrations found in diseased sponges. Aerothionin deterred feeding at concentrations found in diseased sponges, and may at least partially replace the loss of fistularin-3 as a feeding deterrent compound following pathogenesis, suggesting a trade-off in the production of feeding deterrent compounds. Extracts from healthy and diseased sponges inhibited bacterial growth, and both aplysamine-1 and fistularin-3 displayed selective antibacterial activity. Despite differences in secondary metabolite production between healthy and diseased sponges, the stress associated with ARBS does not appear to compromise the ability of A. cauliformis to maintain defenses against some of its natural enemies.
Taxonomically restricted genes are associated with the evolution of sociality in the honey bee

Studies have shown that taxonomically restricted genes are significant in number and important for the evolution of lineage specific traits. Social insects have gained many novel morphological and behavioral traits relative to their solitary ancestors. The task repertoire of an advanced social insect, for example, can be 40-50 tasks, about twice that of a solitary wasp or bee. The genetic basis of this expansion in behavioral repertoire is still poorly understood, and a role for taxonomically restricted genes has not been explored at the whole genome level. Here we present comparative genomics results suggesting that taxonomically restricted genes may have played an important role in generating the expansion of behavioral repertoire associated with the evolution of eusociality. First, we show that the current honey bee official gene set contains about 700 taxonomically restricted genes. These are split between orphans, genes found only in the Hymenoptera, and genes found only in insects. Few of the orphans or genes restricted to the Hymenoptera have been the focus of experimental work, but several of those that have are associated with novel eusocial traits or traits thought to have changed radically as a consequence of eusociality. Second, we predicted that if taxonomically restricted genes are important for generating novel eusocial traits, then they should be expressed with greater frequency in workers relative to the queen, as the workers exhibit most of the novel behavior of the honey bee relative to their solitary ancestors. We found support for this prediction. Twice as many taxonomically restricted genes were found amongst the genes with higher expression in workers compared to those with higher expression in queens. Finally, we compiled an extensive list of candidate taxonomically restricted genes involved in eusocial evolution by analyzing several caste specific gene expression data sets. This work identifies a large number of candidate taxonomically restricted genes that may have played a role in eusocial evolution. This work thus lays the foundation for future functional genomics work on the evolution of novelty in the context of social behavior. We also present preliminary evidence, based on biased patterns of gene expression, that taxonomically restricted genes may have played a role in the evolution of caste systems, a characteristic lineage specific social trait.
Energy gap in the phonon dispersion of the linear mercury chains in Hg3−σAsF6

Abstract Inelastic neutron scattering measurements of Hg-chain excitations in Hg3−σAsF6 are presented. Below Tc = 120 K, where the Hg-ions develop an ordered sublattice, a small but well-defined gap in the Hg-chain dispersion develops at finite q. The response of the Hg-chains does not involve an elastic component indicating the absence of defect or impurity-interactions along the chains.
The Healthy Worker Effect in Major League Baseball Revisited

We investigated the “healthy worker effect” (HWE) in major league baseball. Ages of death of major league baseball players who debuted between 1900 and 1939 were obtained and differences between those ages and age-adjusted life expectancies were examined to determine if longevity increased with career length, controlling for decade in which a player debuted, player position, and handedness. Major league baseball players (N = 4,492) lived an average of 4.8 (±15.0 Standard deviation [SD]) years longer than age-matched controls from the general public. Career length significantly and incrementally increased longevity of players from an average of 4.1 years for players playing one season to 7.4 years for players playing 11 or more years. None of the other factors, nor any of the interactions, was statistically significant. These data provide strong support for the HWE in professional baseball.
Deletion of the Basigin gene results in reduced mitochondria in the neural retina.

Basigin-null mice are characterized as blind from the time of eye opening, with degeneration of the retina beginning at 8weeks of age, and progressing until the entire photoreceptor cell layer is destroyed. It is likely that a metabolic deficiency underlies the blindness and degeneration phenotypes, as it has been determined that Basigin-null mice do not express the transporter protein monocarboxylate transporter one on the membrane of photoreceptor cells and inner segments, nor Muller cells of the neural retina, as is observed in normal mice. The purpose of the present study was to assess the health of mitochondria in normal and Basigin-null mice, specifically to determine if mitochondria within the Basigin-null mouse neural retina are metabolically active. This was achieved via a measurement of cytochrome C concentration and the expression of autophagy-specific proteins via ELISA analyses. Additionally, Mitotracker dyes were used to assess the number and relative activity of mitochondria. It was determined that cytochrome C concentrations and expression of autophagy-specific proteins were not increased in Basigin-null animals, as compared to control animals. Also, while Basigin-null mice do have metabolically active mitochondria, the amount of mitochondria was greatly reduced, when compared to control animals. The results suggest that a reduction in mitochondria is a result, rather than the cause, of the metabolic deficiency observed in Basigin-null mice, and likely occurs because of reduced metabolic activity in the absence of MCT1 expression.
Investigating the binding specificity of U1A-RNA by computational mutagenesis.

The mammalian spliceosomal protein U1A binds a hairpin RNA with picomolar affinity. To examine the origin of this binding specificity, we carried out computational mutagenesis on protein and RNA residues in the U1A-RNA binding interface. Our computational mutagenesis methods calculate the relative binding affinity between mutant and wild-type as the sum of molecular mechanical energies and solvation free energies estimated with a continuum solvent model. We obtained good agreement with experimental studies and we verified mutations that abolish and improve binding. Therefore, we offer these methods as computationally inexpensive tools for investigating and predicting the effects of site-specific mutagenesis.
Molecular properties of matrilin-3 isolated from human growth cartilage.

Abstract Matrilin-3 is a recently identified matrix protein of cartilage that shows sequence homology to matrilin-1 (cartilage matrix protein or CMP). Here we identify and characterize the molecular properties of matrilin-3 from human growth cartilage by immunochemical and mass spectrometry methods. Extracts of fetal skeletal cartilage were resolved by SDS–PAGE and candidate matrilin subunits were identified by electrospray mass spectrometry of tryptic peptides. Matrilin-3 and matrilin-1 were both present in disulfide-bonded tetrameric components. Polyclonal antisera to synthetic peptides specific to each subunit confirmed the identities by Western blotting and further demonstrated the existence of several forms of tetramer. A homotetramer (matrilin-3) 4 and more than one species of heterotetramer containing matrilin-3 and matrilin-1 chains were resolved. Immunohistochemistry of tissue sections confirmed that both matrilin-1 and matrilin-3 are widely codistributed throughout human skeletal growth cartilage.
Population transfer and pulse propagation in certain closed-loop systems☆

Abstract Analytic results for efficient population transfer in and shape-preserving pulse propagation through four-level atomic or molecular systems that are connected in closed loop are presented. Four lasers with frequencies at resonance with atomic or molecular transition frequencies are used. Generalizations to certain N -level systems are presented.
Energy transfer in complexes of E. coli single-stranded DNA-binding protein with single-stranded poly-(2-thiouridylic acid).

The complexes of point-mutated Escherichia coli single-stranded DNA-binding protein (Eco SSB) with poly-(2-thiouridylic acid) (poly S2U) have been studied by optical detection of magnetic resonance spectroscopy (ODMR). Previous work has determined that two of four tryptophan (Trp) residues in Eco SSB undergo stacking interactions with nucleic acid bases. Selective photoexcitation of S2U bases was performed and subsequent triplet → triplet energy transfer from S2U to nearby Trp residues in the protein took place. The zero-field splitting (ZFS) parameters and sublevel kinetics were determined for each Trp residue sensitized by S2U. The sublevel lifetimes of the two sensitized residues are similar to those of normal Trp. The ZFS parameters, on the other hand, show a dramatic reduction relative to those of the uncomplexed protein, implying a more polarizable environment for the sensitized Trp residues and/or charge transfer interactions with the S2U bases.
Semiconductor final test logistics and product dispositioning systems

As product lines at the IBM East Fishkill plant have expanded in the last few years, and as the number of technologies and semiconductor wafer and module volumes have increased, more sophisticated software systems were introduced which not only drove test times downward, but also reduced the development time previously required to accommodate testing new technologies. This paper discusses two such systems developedf or the bipolar semiconductor line. They are a final test logistics system which provides for computerized tracking of each device in the production line through both testing and diagnostic analysis, and an automatic product dispositioning system which immediately identifies shippable product batches after flow through the test sector or schedules the batchesf or additional diagnostic analysis.
DNA signals for G2 checkpoint response in diploid human fibroblasts

Abstract DNA (deoxyribonucleic acid) signals that induce the G2 checkpoint response were examined using proliferative secondary cultures of diploid human fibroblasts. Treatments that generated DNA double-strand breaks (DSBs) directly were effective inducers of checkpoint response, generally producing >80% inhibition of mitosis (G2 delay) and the kinase activity of M-phase-promoting factor within 2 h of treatment. Effective inducers of G2 checkpoint response included γ-irradiation and the cancer chemotherapeutic drugs, bleomycin and etoposide. Treatments that produced DNA single-strand breaks, directly or indirectly through nucleotide excision repair, were not effective inducers of G2 delay. Ineffective treatments included incubation with camptothecin, an inhibitor of topoisomerase I (topo I), and irradiation with sublethal fluences of UVC, followed by incubation with aphidicolin. Transient severe inhibition of DNA synthesis with aphidicolin did not affect mitosis substantially, suggesting that the replication arrest input to the G2 checkpoint required more than brief inhibition of DNA synthesis. In contrast, moderate camptothecin-induced inhibition of DNA synthesis was associated with a strong inhibition of mitosis that developed 4–12 h after drug treatment. This result suggested that G2 delay was not expressed until the cells that were in S-phase at the time of treatment with camptothecin proceeded into G2. DNA damage was not necessary for induction of mitotic delay. An inhibitor of topoisomerase II (topo II), ICRF-193, which inhibits chromatid decatenation in G2 cells without damaging DNA, induced a severe inhibition of mitosis and M-phase-promoting factor kinase activity. The results suggest that DNA double-strand breaks and insufficiency of chromatid decatenation effectively induce the G2 checkpoint response, but DNA single-strand breaks do not.
PATHOGENETIC VARIABILITY OF NEPHROPATHY (N) IN JUVENILE DIABETES MELLITUS (JDM)

Clinicopathologic studies of 4 patients with JDM and N demonstrated the pathogenetic variability of the nephropathy. Only 1 patient had the typical diabetic N in form of proteinuria (P), hypertension (H), decreased glomerular filtration rate (GFR) and diffuse and nodular diabetic glomerulosclerosis (DG). In another patient the N had the features of steroid responsive nephrotic syndrome (SRNS) of childhood superimposed on a very mild DG. This patient had HLA-B12 antigen associated with SRNS. The third patient also had a nephrotic syndrome (NS) which, unlike the other, responded only partially to treatment. In addition, she had Grave's disease (GD). Kidney biopsy 9 years after appearance of the NS showed only mild DG. The presence of HLA-B8 antigen, shown to be associated with SRNS, JDM and GD could be suggestive of a common pathogenesis of all 3 disorders in this patient. In the fourth patient, the N in form of H, P and rapidly declining GFR could have been related more to the severe tubulointerstitial disease of unknown etiology than to the moderate DO. The presence of renal tubular epithelial antigen in the mesangium in this case, may have had some pathogenetic significance. The poor prognosis of diabetic N warrants a careful search for other potentially treatable, causes of N in patients with JDM.
Developmental capacity of equine oocytes matured and cultured in equine trophoblast-conditioned media

The objective was to compare culture media for in vitro maturation of equine oocytes and for in vitro culture of zygotes produced from IVF of partially zona-removed oocytes. Cumulus-oocyte complexes from slaughterhouse-derived ovaries were washed in m-Dulbecco's PBS and cultured in TCM-199, F10-DMEM or c-F10-DMEM (50% F10-DMEM + 50% F10-DMEM conditioned medium from culture of an equine trophoblast monolayer for 3 or 4 days). All media included FSH, LH, E2, and 10% FCS. After 28 to 30 h maturation, cumulus expansion was scored from 0 (no expansion) to 4 (fully expanded). Oocytes with a 1st polar body were selected for manipulation after removing cumulus cells using hyaluronidase. About one-third of the zona pellucida was cut using a fragment of a razor blade. For fertilization, fresh stallion semen was washed twice in BGM3 (a modified Tyrode's medium) and capacitated with 0.5 mM c-AMP for 3.5 h and 100 microM ionomycin for 15 min and added to oocytes in fert-TALP at 10(6) spermatozoa/mL. After 20 h, some presumptive zygotes were stained, and the rest were cultured in 100% TCM-DMEM conditioned medium. Cumulus expansion in F10-DMEM and c-F10-DMEM was higher (P 0.1) between TCM-DMEM and 100% conditioned TCM-DMEM for culturing embryos. Six embryos (2 morulae and 4 blastocysts) were nonsurgically transferred to 4 recipient mares, but no pregnancy continued.
A proposed voltage dependence of the ionic strength of a confined electrolyte based on a grand canonical ensemble model

Electrodes with highly porous morphologies are of great technological interest, as their exceptionally high specific surface areas make them ideal for use in capacitors, battery electrodes and electrochemical sensors. There is a large body of research focusing on the structure of confined electrolytes in these systems, but the majority of these studies focus on cases where the length scale of the porous domain is equal to or less than the Debye screening length of the electrolyte. In this work, we use a thermodynamic model to consider the structure of electrolytes in mesoscale domains, where the pore dimensions are significantly larger than the Debye screening length. In this limit, the interface is screened by the electrochemical double layer and the enclosed volume primarily consists of an electroneutral ‘bulk liquid’ domain. Despite the absence of direct interactions between ions in the bulk domain and the charged interface, we show that minimization of the free energy of the system leads to a reduction in the ionic strength of the electrolyte within the bulk liquid domain of the pore. Based on our model studies, we anticipate that this depletion will apply for porous domains with widths of the order of 50–200 nm even under mild experimental conditions and low applied voltages. The results imply relationships between electrolyte strength, surface morphology and applied voltage that may be important in device design.
Production of a biomimetic Fe(I)-S phase on pyrite by atomic hydrogen beam surface reactive scattering.

Molecular beam-surface scattering and X-ray absorption spectroscopic experiments were employed to study the reaction of deuterium atoms with a pyrite, FeS2 (100), surface and to investigate the electronic and geometric structures of the resulting Fe-S phases. Incident D atoms, produced by a radio frequency plasma and expanded in an effusive beam, were directed at a pyrite surface held at various temperatures from ambient up to 200 °C. During exposure to the D-atom beam, D2S products were released with a thermal distribution of molecular speeds, indicating that the D atoms likely reacted in thermal equilibrium with the surface. The yield of D2S from the surface decreased approximately exponentially with exposure duration, suggesting that the surface accessible sulfur atoms were depleted, thus leaving an iron-rich surface. This conclusion is consistent with X-ray absorption measurements of the exposed surfaces, which indicated the formation of a layered structure, with elemental iron as the outermost layer on top of a formally Fe(I)-S phase as an intermediate layer and a formally Fe(II)-S2 bulk pyrite layer at lower depths. The reduced Fe(I)-S phase is particularly remarkable because of its similarity to the catalytically active sites of small molecule metalloenzymes, such as FeFe-hydrogenases and MoFe-nitrogenases.
Thermal hydrolysis as a means of opening supercoiled circles of DNA.

Abstract Thermal hydrolysis has been shown to be a useful method for converting supercoiled DNA molecules to open circles.
Analysis of an anisotropic coastal aquifer system using variable-density flow and solute transport simulation

Abstract The groundwater system in southern Oahu, Hawaii consists of a thick, areally extensive freshwater lens overlying a zone of transition to a thick saltwater body. This system is analyzed in cross section with a variable-density groundwater flow and solute transport model on a regional scale. The simulation is difficult, because the coastal aquifer system has a saltwater transition zone that is broadly dispersed near the discharge area, but is very sharply defined inland. Steady-state simulation analysis of the transition zone in the layered basalt aquifer of southern Oahu indicates that a small transverse dispersivity is characteristic of horizontal regional flow. Further, in this system flow is generally parallel to isochlors and steady-state behavior is insensitive to the longitudinal dispersivity. Parameter analysis identifies that only six parameters control the complex hydraulics of the system: horizontal and vertical hydraulic conductivity of the basalt aquifer; hydraulic conductivity of the confining “caprock” layer; leakance below the caprock; specific yield; and aquifer matrix compressibility. The best-fitting models indicate the horizontal hydraulic conductivity is significantly greater than the vertical hydraulic conductivity. These models give values for specific yield and aquifer compressibility which imply a considerable degree of compressive storage in the water table aquifer.