cssi/SciSciGPT-SciSciNet huggingface dataset:
Attractive hydration forces in DNA-dendrimer interactions on the nanometer scale.

The energetic contribution of attractive hydration forces arising from water ordering is an interesting but often neglected aspect of macromolecular interactions. Ordering effects of water can bring about cooperativity in many intermolecular transactions, in both the short and long range. Given its high charge density, this is of particular importance for DNA. For instance, in nanotechnology, highly charged dendrimers are used for DNA compaction and transfection. Hypothesizing that water ordering and hydration forces should be maximal for DNA complexes that show charge complementarity (positive-negative), we present here analysis of water ordering from molecular dynamics simulations and free energy calculations of the interaction between DNA and a nanoparticle with a high positive charge density. Our results indicate not only that complexation of the dendrimer with DNA affects the local water structure, but also that ordered water molecules facilitate long range interactions between the molecules. This contributes significantly to the free energy of binding of dendrimers to DNA and extends the interaction well beyond the electrostatic range of the DNA. Such water effects are of potentially substantial importance in cases when molecules appear to recognize each other across sizable distances, or for which kinetic rates are too fast to be due to pure diffusion. Our results are in good agreement with experiments on the role of solvent in DNA condensation by multivalent cations and exemplify a microscopic realization of mean-field phenomenological theories for hydration forces between mesoscopic surfaces.
Student college choice sets: Toward an empirical characterization

This study investigates the nature of student college choice sets. Data on 599 students from several different communities in one suburban Philadelphia county are examined by a mode, cluster analytic procedure. The results indicate that students can be grouped according to their similarity in types of institutions to which they send their test scores. Specifically, there appear to be no more than eight stable choice sets, dominated primarily by larger institutions of moderate quality and cost approximately 150 miles from the students' homes
The Association of Obesity and Hyperandrogenemia during the Pubertal Transition in Girls: Obesity as a Potential Factor in the Genesis of Postpubertal Hyperandrogenism

Context: Adolescent hyperandrogenemia is considered a forerunner of adult polycystic ovary syndrome, but its etiology remains uncertain. Objective: Our objective was to explore the hypothesis that peripubertal obesity is associated with hyperandrogenemia. Design and Setting: We performed a cross-sectional analysis of data obtained at General Clinical Research Centers. Subjects: Subjects were 41 obese [body mass index (BMI) for age, ≥95%] and 35 normal-weight (BMI for age, <95%) peripubertal girls. Intervention: We used pooled blood samples (∼0500–0700 h; n = 64) while fasting or single morning (fasting) samples (n = 12). Main Outcome Measures: We assessed adiposity and androgen concentrations. Results: BMI correlated with total testosterone (T) (rs = 0.59), SHBG (rs = −0.69), and free T (rs = 0.69); free T was three times as great in obese girls compared with normal-weight girls (P < 0.0001 for all). BMI correlated with insulin (rs = 0.52); both insulin and LH correlated with free T (rs = 0.45 and 0.44, r...
On Wronskians of weight one Eisenstein series

Abstract We describe the span of Hecke eigenforms of weight four with nonzero central value of L -function in terms of Wronskians of certain weight one Eisenstein series.
Radiometric calibration system for IR cameras

This paper describes an automated calibration system that we developed to calibrate JR flight cameras for a series of sub-orbital experiments. Short schedules as well as concern over cryo-cooler lifetimes dictated a totally automated calibration system that obtained as much data as possible over a short period of time. The data must be as complete as possible since the cameras are not recovered. For this reason the system calibrates each pixel individually. The output of the calibration is a set of calibration coefficients which convert the gray level output of the camera into physical units of radiance (Watts/cm2-str-.tm). We have calibrated Hughes 256x256 pixels PtSi cameras and 128x128 pixels HgCd cameras and Amber 128x128 pixels JnSb cameras. These cameras put out 8 bit digital data and sync signal at a given camera setting. This paper describes the calibration acquisition system and shows the results for the Hughes 256x256 PtSi camera.
Theory of Proton-Coupled Electron Transfer in Energy Conversion Processes

Proton-coupled electron transfer (PCET) reactions play an essential role in a broad range of energy conversion processes, including photosynthesis and respiration. These reactions also form the basis of many types of solar fuel cells and electrochemical devices. Recent advances in the theory of PCET enable the prediction of the impact of system properties on the reaction rates. These predictions may guide the design of more efficient catalysts for energy production, including those based on artificial photosynthesis and solar energy conversion. This Account summarizes the theoretically predicted dependence of PCET rates on system properties and illustrates potential approaches for tuning the reaction rates in chemical systems. A general theoretical formulation for PCET reactions has been developed over the past decade. In this theory, PCET reactions are described in terms of nonadiabatic transitions between the reactant and product electron−proton vibronic states. A series of nonadiabatic rate constant ex...
Do You Mind if I Plug-in My Car? How etiquette shapes PEV drivers’ vehicle charging behavior

Abstract Plug-in electric vehicles (PEVs) engage drivers in an essential new behavior—plugging the car into the electrical grid to charge the vehicles’ batteries. Broadly, it has been assumed that (1) away-from-home charging is necessary to grow the PEV market and (2) if away-from-home charging infrastructure is in place and PEV drivers know of it, they will perceive opportunities to charge. The experiences of early PEV drivers cause us to rethink at least the second of these assumptions. Drivers report a lack of what they call “etiquette,” i.e., rules to guide their behavior and their expectations of how they and other PEV drivers ought to behave in these new social interactions. PEV drivers want widely shared, understood, and practiced guidelines to feel comfortable and confident in charging their vehicles away from home. This study uses inductive thematic analysis of transcripts of interviews of 28 PEV driving households conducted in San Diego County, California in spring, 2012. Themes about etiquette emerged within two types of away from home charging. First, public chargers (available to any PEV driver) were the sites of situations in which drivers’ perceived a lack of rules or conflicts between different systems of rules; both were described as inhibiting use of public chargers. Second, workplace charging (typically available only to employees of the entity where the charger is located) adds an additional layer of rules and possibly resources that may either inhibit or encourage PEV charging by employees. As PEV markets and charger networks grow, charging will be shaped by additional systems of rules and regulations, e.g., those governing financial transactions. Our results suggest that absent efforts to help PEV drivers develop, learn, and practice the new rules, they may create as much uncertainty as guidance.
Chemical source of singlet oxygen, or its synthetic equivalent. Generation from resin-bound peroxomolybdate

Abstract Singlet oxygen, or its synthetic equivalent, is generated by the action of resin-bound molybdate on hydrogen peroxide. Resin-bound peroxomolybdate converts reactant olefins to their ene, [4+2] and [2+2] cycloaddition or secondary products.
Comparison of TCDD-elicited genome-wide hepatic gene expression in Sprague-Dawley rats and C57BL/6 mice.

Abstract Although the structure and function of the AhR are conserved, emerging evidence suggests that downstream effects are species-specific. In this study, rat hepatic gene expression data from the DrugMatrix database (National Toxicology Program) were compared to mouse hepatic whole-genome gene expression data following treatment with 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). For the DrugMatrix study, male Sprague–Dawley rats were gavaged daily with 20 μg/kg TCDD for 1, 3 and 5 days, while female C57BL/6 ovariectomized mice were examined 1, 3 and 7 days after a single oral gavage of 30 μg/kg TCDD. A total of 649 rat and 1386 mouse genes (|fold change| ≥ 1.5, P1( t ) ≥ 0.99) were differentially expressed following treatment. HomoloGene identified 11,708 orthologs represented across the rat Affymetrix 230 2.0 GeneChip (12,310 total orthologs), and the mouse 4 × 44K v.1 Agilent oligonucleotide array (17,578 total orthologs). Comparative analysis found 563 and 922 orthologs differentially expressed in response to TCDD in the rat and mouse, respectively, with 70 responses associated with immune function and lipid metabolism in common to both. Moreover, QRTPCR analysis of Ceacam1 , showed divergent expression (induced in rat; repressed in mouse) functionally consistent with TCDD-elicited hepatic steatosis in the mouse but not the rat. Functional analysis identified orthologs involved in nucleotide binding and acetyltransferase activity in rat, while mouse-specific responses were associated with steroid, phospholipid, fatty acid, and carbohydrate metabolism. These results provide further evidence that TCDD elicits species-specific regulation of distinct gene networks, and outlines considerations for future comparisons of publicly available microarray datasets.
Bounding minimum distances of cyclic codes using algebraic geometry

Abstract We introduce a new method for finding lower bounds on the minimum distance of cyclic codes by studying rational points on associated varieties.
Creativity and industrial cities: A case study of Baltimore

Creativity is changing the way in which cities approach economic development and formulate policy. Creative metropolises base their economic development strategies, at least partly, on building communities attractive to the creative class worker. While there are countless examples of high-tech regions transforming into creative economies, traditionally industrial cities have received much less attention in this regard. This research draws on Baltimore to assess the potential of transforming a traditionally industrial region into a creative economy. It analyses Baltimore's performance on dimensions of talent, tolerance, technology, and territory both as a stand-alone metropolitan area and in comparison to similar industrial metropolises. This case study concludes that Baltimore has the opportunity to capitalize on the creative economy because of its openness to diversity, established technology base, appealing territorial amenities, and access to the largest reservoir of creative talent in the USA: Washing...
Quality first. A model for TQM implementation and planning

Experience at Harris with managing change through Continuous Improvement (CI) has demonstrated it is a Socio-Technical process... that is, the human elements are crucial and must be addressed before pressing for structural, institutional or technological change. Harris utilizes a five-stage business improvement model. It is not a road map to problem solving, rather it is an analysis and direction-setting framework, which can be applied to virtually any business situation. We have used it to insert major technology advances, characterize multifunctional business processes, solve a problem, develop a new product, improve a service, etc. The model is easy to teach, easy to understand, and easy to follow. It guides the application of the correct set of Continuous Improvement tools at the correct time to achieve the goal. >
Squishy Non‐Spherical Hydrogel Microparticles

Recent advances in the synthesis of polymeric colloids have opened the doors to new advanced materials. There is strong interest in using these new techniques to produce particles that mimic and/or interact with biological systems. An important characteristic of biological systems that has not yet been exploited in synthetic polymeric colloids is their wide range of deformability. A canonical example of this is the human red blood cell (RBC) which exhibits extreme reversible deformability under flow. Here we report the synthesis of soft polymeric colloids with sizes and shapes that mimic those of the RBC. Additionally, we demonstrate that the mechanical flexibility of the colloids can be reproducibly varied over a large range resulting in RBC-like deformability under physiological flow conditions. These materials have the potential to impact the interaction between biological and synthetic systems.
The Entrepreneurial Society

This paper explains why and how entrepreneurship has emerged as an engine of economic growth, employment creation and competitiveness in global markets. The entrepreneurial society reflects the emergence as entrepreneurship as an important source of economic growth.
The first type ia supernovae: an empirical approach to taming evolutionary effects in dark energy surveys from sne ia at z>2

Future measurements of the nature of dark energy using Type Ia supernovae will require a precise characterization of systematic sources of error. Evolutionary effects remain the most uncertain contributor to the overall systematic error budget. Present plans to probe evolution with cosmology-independent explosion parameters could yield an absence of evidence for evolution without definitive evidence of its absence. Here we show that observations of Type Ia supernovae in the redshift interval 1.5 < z < 3.0, where dark-energy-dependent effects are relatively negligible, should provide direct evidence to discern evolutionary effects. As examples of our approach to constraining evolution, we examine the impact of changing progenitor metallicity and age on the degree of potential luminosity evolution. We show that the observations we propose can be carried out by existing space telescopes, or ones that are already under development.
String webs and 1/4 BPS monopoles

Abstract We argue for the existence of many new 1 4 BPS states in N = 4 SU(Nc) Super-Yang-Mills theory with Nc ⩾ 3, by constructing them from supersymmetric string webs whose external strings terminate on parallel D3-branes. The masses of the string webs are shown to agree with the BPS bound for the corresponding states in SYM. We identify the curves of marginal stability, at which these states decay into other BPS states. We find the bosonic and fermionic zero-modes of the string webs, and thereby the degeneracy and spin content of some of the BPS states. States of arbitrarily high spin are predicted in this manner, all of which become massless at the conformal point. For Nc ⩾ 4 we find BPS states which transform in long multiplets, and are therefore not protected against becoming stable non-BPS states as moduli are varied. The mass of these extremal non-BPS states is constrained as they are connected to BPS states. Analogous geometric phenomena are anticipated.
Two Palladium-Catalyzed Domino Reactions from One Set of Substrates/Reagents: Efficient Synthesis of Substituted Indenes and cis-Stilbenoid Hydrocarbons from the Same Internal Alkynes and Hindered Grignard Reagents

Two types of domino reactions from the same internal alkynes and hindered Grignard reagents based on carbopalladation, Pd-catalyzed cross-coupling reaction, and a C−H activation strategy are described. The realization of these domino reactions relied on the control of the use of the ligand and the reaction temperature. Our study provides efficient access to useful polysubstituted indenes and cis-substituted stilbenes and may offer a new means of development of tandem/domino reactions in a more efficient way.
A stereoselective synthesis of (–)-tetrahydrolipstatin

A stereoselective synthesis of (–)-tetrahydrolipstatin has been accomplished utilizing olefin metathesis of an acrylate ester as the key step.
A complexity question in justification logic

Abstract Bounds for the computational complexity of major justification logics were found in papers by Buss, N. Krupski, Kuznets, and Milnikel: logics J , J4 , JT , LP and JD were established to be Σ 2 p -complete. A corresponding lower bound is also known for JD4 , the system that includes the consistency axiom and positive introspection. However, no upper bound has been established so far for this logic. Here, the missing upper bound for the complexity of JD4 is established through an alternating algorithm. It is shown that using Fitting models of only two worlds is adequate to describe JD4 ; this helps to design an effective tableau procedure and essentially is what distinguishes the new algorithm from existing ones.
On the cohomology groups of holomorphic Banach bundles

We consider a compact complex manifold M and introduce the notion of two holomorphic Banach bundles E, F over M being compact perturbations of one another. Given two such bundles we show that if the cohomology groups H q (M, E) are finite dimensional, then so are the cohomology groups H q (M, F); as well as a more precise result in the same spirit.
A new method for the phosphorylation of nucleosides

A new phosphorylating reagent, 2-O-(4,4′-dimethoxytrityl)ethylsulfonylethan-2′-yl-phosphate (1), was developed for the phosphorylation of primary and secondary alcohols of nucleosides. In the many examples studied, yields in the phosphorylation step were excellent (∼80 to 95%). There is potential for wide applicability of this procedure, not only in nucleoside and nucleotide chemistry, but also in the phosphorylation of biomolecules such as carbohydrates and amino acids.
Catalytic synthesis of tricyclic quinoline derivatives from the regioselective hydroamination and C-H bond activation reaction of benzocyclic amines and alkynes.

The cationic ruthenium−hydride complex [(PCy3)2(CO)(CH3CN)2RuH]+BF4- (1) was found to be an effective catalyst for the regioselective coupling reaction of benzocyclic amines and terminal alkynes to form the tricyclic quinoline derivatives. The scope of the reaction was explored by using the catalytic system Ru3(CO)12/NH4PF6. The catalytically active cationic ruthenium−acetylide complex [(PCy3)2(CO)(CH3CN)2RuC⋮CPh]+BF4- was isolated from the reaction of 1 with phenylacetylene.
Multicomponent Polymerization. I. Integration of the Rate Equations

Abstract The equation describing instantaneous copolymer composition in free radical vinyl copolymerization has been known and verified for many years. Although this equation has been integrated to give composition as a function of conversion, no analytical expression has been presented which gives conversion as a simple function of time. In this paper a derivation and experimental verification of such an equation is presented. Applications to problems in copolymerization kinetics are also considered. Extension of the equation to systems of more than two monomers is postulated.
Beyond the Bottom Line: the Theoretical Aims of Moral Theorizing

Moral theory is no substitute for virtue, but virtue is no substitute for moral theory. Many critics of moral theory, with Richard Posner being one prominent recent example, complain that moral theory is too abstract, that it cannot generally be used to derive particular rights and wrongs, and that it does not improve people's characters. Posner complains that it is thus of no use to legal theorists. This article defends moral theory, and to some degree, philosophical inquiry in general, against such pragmatic complaints. I argue that the primary goal of moral theorizing is not pragmatic, but theoretical. Moral theory aims at explanation, at answering certain kinds of questions about morality. Moral theory is meant to deepen our insight into morality but, to count as deepening our insight, it need not provide a formula for calculating what to do in a particular circumstance, nor must it make us more virtuous. I provide an account of the scope and nature of explanation provided by moral theory as well as an account of why such explanations can be worth having, even if they were to have few pragmatic consequences.
Likely Values of the Cosmological Constant

In theories in which the cosmological constant takes a variety of values in different "subuniverses," the probability distribution of its observed values is conditioned by the requirement that there be someone to measure it. This probability is proportional to the fraction of matter that is destined to condense out of the background into mass concentrations large enough to form observers. We calculate this "collapsed fraction" with a simple, pressure-free, spherically symmetric, nonlinear model for the growth of density fluctuations in a flat universe with arbitrary value of the cosmological constant, applied in a statistical way to the observed spectrum of density fluctuations at recombination. From this the probability distribution for the vacuum energy density ρV for Gaussian random density fluctuations is derived analytically. (The conventional quantity λ0 is the vacuum energy density in units of the critical density at present, λ0 = ρV/ρcrit,0, where ρcrit,0 = 3H20/8πG.) It is shown that the results depend on only one quantity, σ3, where σ2 and are the variance and mean value of the fluctuating matter density field at recombination, respectively. To calculate σ, we adopt the flat, cold dark matter model with a nonzero cosmological constant and fix the amplitude and shape of the primordial power spectrum in accordance with data on cosmic microwave background anisotropy from the COBE satellite DMR experiment. A comparison of the results of this calculation of the likely values of ρV with present observational bounds on the cosmological constant indicates that the small, positive values of ρV (from 1 to 3 times greater than the present cosmic mass density) suggested recently by several lines of evidence are not very unlikely values to observe, even if there is nothing in the a priori probability distribution that favors such relatively small values.
Diversity-oriented synthesis for novel, selective and drug-like inhibitors for a phosphatase from Mycobacterium tuberculosis

Mycobacterium protein tyrosine phosphatase B (mPTPB) is a potential drug target of tuberculosis (TB). Using small molecule inhibitors of mPTPB could be a treatment to overcome emerging TB drug resistance. Using a Diversity-Oriented Synthesis (DOS) strategy, we successfully developed a salicylic acid based and drug-like mPTPB inhibitor with an IC50 of 2 μM and >20-fold specificity over many human PTPs, making it an excellent lead molecule for anti-TB drug discovery. In addition, DOS generated bicyclic salicylic acids are also promising starting points for acquiring inhibitors targeting other PTPs.
Hog Cycles and Countercyclical Production Response

The cycle in prices and output is not a permanent fixture of the pork industry. Exogenous shocks occasionally give rise to predictable cycles in pork prices, but these are eventually eliminated in a manner that is consistent with the existence of countercyclical producers. It normally takes several revolutions of the cycle before a sufficient number of countercyclical producers notice that a cycle has begun and are able to alter their production patterns sufficiently to eliminate it. Consequently, the more compelling the evidence is in favor of a cycle the less likely it is to continue.
Quantum electrodynamics and light rays

Light is a quantum electrodynamic entity and hence bundles of rays must be describable in this framework. We demonstrate the duality in the description of elementary optical phenomena in terms of two-point correlation functions and in terms of collections of light rays. The generalizations necessary to deal with two-slit interference and diffraction by a rectangular slit are worked out and the usefulness of the notion of rays of darkness is illustrated.
Generation of bases and anions from inorganic and organometallic photoinitiators

Abstract Photosensitive materials composed of a substrate (monomer, oligomer or polymer) and a photoinitiator play a central role in numerous commercial processes. Most photoinitiators in common use are organic compounds that, upon irradiation, produce radicals and/or acids. The desire to expand the scope of photoinitiated chemistry has led to the recent discovery of several classes of inorganic and organometallic photoinitiators that photochemically release neutral Lewis bases and/or anions. This article provides an overview of the author's research program to develop novel photobase and photoanion generators. Fundamental studies of these systems and examples of their potential applications are described.
Fine-spectral interface effects of resonance scattering upon multigroup cross section averaging

Abstract Fine-energy neutron spectra are utilized to obtain spatially-dependent coarse-energy multigroup cross sections for simulated core-reflector slab-geometry systems in the energy range containing scattering resonances in many of the diluents of fast reactor materials. Comparisons of both pointwise and subregion fine-group to coarse-group cross section sets are shown. Spatially-dependent coarse-group cross section sets enable accurate interface neutron-leakages to be obtained in the energy range containing resonance scattering.
Active Versus Passive Index Management: A Performance Comparison of the S&P and the Russell Indexes

The S&P and the Russell indexes often serve as proxies for passive portfolios in the debate over the merits of active versus passive portfolio management. However, the S&P indexes, are, in effect, actively constructed portfolios, since S&P index managers exercise discretion in selecting firms for the indexes from a pool of eligible firms. In contrast, Russell index managers use a passive, nondiscretionary approach and select firms solely based on market capitalization. I assess the relative merits of these approaches by comparing their performance over the last 11 years. I find that the S&P indexes dominate the Russell indexes, particularly in the small-cap sector, where the S&P 600 index consistently outperforms the Russell 2000 index. The results suggest that index investors would benefit by choosing actively constructed index portfolios over passively constructed index portfolios, particularly in the small-cap sector.
Lensing Constraints on the Cores of Massive Dark Matter Halos

The statistics of wide-separation (6'' < θ < 15'') gravitational lenses constrain the amount of mass in the cores of dark matter halos on group and cluster mass scales. For a family of halo models with a central cusp ρ ∝ r-α (1.0 ≤ α ≤ 1.9), the lack of wide-separation lenses in the large Cosmic Lens All-Sky Survey yields an upper limit on the fraction of the halo mass that is contained within ~4% of the virial radius, fcore < 0.023 (95% confidence level, Λ cold dark matter). This limit offers an important test of the cold dark matter paradigm. While the halo profiles derived from numerical simulations appear to be consistent with this upper limit, larger surveys currently underway such as the Two-degree Field and Sloan Digital Sky Survey should detect wide-separation lenses and thus provide a measurement of the core mass fraction in massive dark matter halos.
Quantum algorithms for Simon's problem over general groups

Daniel Simon's 1994 discovery of an efficient quantum algorithm for solving the hidden subgroup problem (HSP) over Zn2 provided one of the first algebraic problems for which quantum computers are exponentially faster than their classical counterparts. In this paper, we study the generalization of Simon's problem to arbitrary groups. Fixing a finite group G, this is the problem of recovering an involution m = (m1,...,mn) e Gn from an oracle f with the property that f(x) = f(x · y) ⇔ y e {1, m}. In the current parlance, this is the hidden subgroup problem (HSP) over groups of the form Gn, where G is a nonabelian group of constant size, and where the hidden subgroup is either trivial or has order two.Although groups of the form Gn have a simple product structure, they share important representation-theoretic properties with the symmetric groups Sn, where a solution to the HSP would yield a quantum algorithm for Graph Isomorphism. In particular, solving their HSP with the so-called "standard method" requires highly entangled measurements on the tensor product of many coset states.Here we give quantum algorithms with time complexity 2O(√n log n) that recover hidden involutions m = (m1,..., mn) e Gn where, as in Simon's problem, each mi is either the identity or the conjugate of a known element m and there is a character X of G for which X(m) = - X(1). Our approach combines the general idea behind Kuperberg's sieve for dihedral groups with the "missing harmonic" approach of Moore and Russell. These are the first nontrivial hidden subgroup algorithms for group families that require highly entangled multiregister Fourier sampling.
Preparation and properties in vitro and in vivo of antitubercular pyrroles

The title compounds (III) are conveniently prepared by Paal—Knorr reaction of hydrazides (II) with hexane-2,5-dione without an acid catalyst.
Diffusion of a reptating polymer interacting with a random matrix

The diffusion of a long polymer chain in a random matrix is investigated using a discrete Ising-like reptation model which has been modified to include a weak random chain-matrix interaction. While reptation's usual inverse-length dependence of the diffusion constant is not changed, the interaction engenders a long-lived transient with a characteristic time proportional to the square of the chain length
Quantitative resonance Raman spectroscopy of N-acetylpyrrolidine in aqueous solution

The resonance Raman spectra of aqueous solutions of N-acetylpyrrolidine are determined at seven excitation frequencies from 40 660 to 53 130 cm[sup [minus]1] spanning the first strong absorption band which is broad and diffuse The resonance Raman spectra are dominated by the single amide II[prime]-like vibration at 1485 cm[sup [minus]1] and its overtones of up to five quanta. Absolute resonance Raman cross sections are determined for these fundamental and overtone transitions at each excitation wavelength by reference to an internal standard of sodium perchlorate. A quantitative analysis of these data and the broad absorption spectrum is made on the basis of a model for the electronic excitation that includes the effects of inhomogeneous broadening. The observation of only a single enhanced vibrational normal mode, with the assumption that there is no Duschinsky rotation upon electronic excitation, makes this a particularly simple case for detailed analysis. A reasonably good fit to the experimental data is obtained using standard assumptions of Lorentzian inhomogeneous broadening and A-term (Condom) Raman scattering. In this fitting procedure, the integrated absorption spectrum determines the transition dipole length. 43 refs., 4 figs., 2 tabs.
Mercury, cadmium, and arsenite enhance heat shock protein synthesis in chick embryos prior to embryotoxicity.

BACKGROUND: Cells respond to adverse environmental stimuli by enhancing the expression of specific genes, the products of which include a suite of proteins known as heat shock proteins (hsps), a response often attributed to cellular protection. METHODS:In this study, we characterized alterations in hsp expression in chick embryos (Hamburger-Hamilton stage 17, 72 h) exposed in ovo to arsenite (As), mercury (Hg), and cadmium (Cd), known developmental toxicants. Embryos were incubated for 2 h following exposure to 3, 10, 30, or 100 nmol metal, or for 2, 4, 12, or 24 h following treatment with 10 nmol metal. RESULTS: An enhanced de novo synthesis of 24-, 70-, and 90-kD, 70- and 90-kD, and 70-kD proteins was observed with As, Hg, and Cd treatments, respectively. These responses were transient; apparent rates of protein synthesis were maximal 2–4 h after exposure and returned to control rates by 24 h. Actinomycin D experiments demonstrated that arsenite-induced expression of these proteins is transcriptionally regulated. Immunoblotting experiments identified the 24-, 70-, and 90-kD proteins as the heat shock proteins hsp24, hsp70, and hsp90, respectively. Exposure duration-related abnormalities were noted in the neural tube with all metals and in the ganglia and somites with Cd and As. Retina, allantois, and limb defects were specific to Cd-treated embryos, and branchial arch defects were specific to As-treated embryos. CONCLUSIONS: The data support metal-induced developmental abnormalities, which are preceded by synthesis of stress proteins. Birth Defects Res B 68:456–464, 2003. Published 2003 Wiley-Liss, Inc.
A numerical tool for the design/analysis of dual-cavitating propellers

The motivation of this work is to develop a numerical tool to explore a new propeller design with dual-cavitating characteristics, i.e., one that is capable of operating efficiently at low speeds in subcavitating (fully wetted) mode and at high speeds in the supercavitating mode. To compute the hydrodynamic performance, a three-dimensional (3D) potential-based boundary element method (BEM) is presented. The BEM is able to predict complex cavitation patterns and blade forces on fully submerged and partially submerged propellers in subcavitating, partially cavitating, fully cavitating, and ventilated conditions. To study the hydroelastic characteristic of potential designs, the 3D BEM is coupled with a 3D finite element method (FEM) to compute the blade stresses, deflections, and dynamic characteristics. An overview of the formulation for both the BEM and FEM is presented. The numerical predictions are compared to experimental measurements for the well-known Newton Rader (NR) three-bladed propeller series with varying pitch and blade area ratios. Comparison of the performance of the Newton Rader blade section to conventional blade sections is presented.
Fabrication and characterization of replicated and lacquer-coated grazing incidence optics for x-ray astronomy

In this paper we discuss the fabrication and testing of electroformed replica Wolter I optics made from gold-coated lacquered mandrels. We also discuss testing of gold- and palladium- coated lacquered test flats. X ray and (5 keV for Wolter I mirror and 8 - 40 keV for test flats) and optical (Wyko NCP-1000 profiler measurements were used to evaluate the mirrors.
X-ray imaging with ultra-small-angle X-ray scattering as a contrast mechanism

A new transmission X-ray imaging technique using ultra-small-angle X-ray scattering (USAXS) as a contrast mechanism is described. USAXS imaging can sometimes provide contrast in cases where radiography and phase-contrast imaging are unsuccessful. Images produced at different scattering vectors highlight different microstructural features within the same sample volume. When used in conjunction with USAXS scans, USAXS imaging provides substantial quantitative and qualitative three-dimensional information on the sizes, shapes and spatial arrangements of the scattering objects. The imaging technique is demonstrated on metal and biological samples.
A volume-preserving counterexample to the Seifert conjecture

We prove that every 3-manifold possesses aC1, volume-preserving flow with no fixed points and no closed trajectories. The main construction is a volume-preserving version of the Schweitzer plug. We also prove that every 3-manifold possesses a volume-preserving,C∞ flow with discrete closed trajectories and no fixed points (as well as a PL flow with the same geometry), which is needed for the first result. The proof uses a Dehn-twisted Wilson-type plug which also preserves volume.
The crystal structure of HfZrP

Abstract The crystal structure of HfZrP has been determined using single crystal X-ray diffraction data. This compound crystallizes in the orthorhombic space group Cmmm (No.65), with a =19.004(3), b =29.372(4), c =3.565(1) A and the Zr 2 P structure type. The Hf and Zr atoms are disordered on one site with total occupancy of 1.0. X-ray powder patterns indicate that (Hf x Zr 1− x ) 2 P alloys consist of single phase (Zr 2 P-type),two phases and single phase (Hf 2 P-type) corresponding to 0≤ x ≤0.5, 0.5 x x ≤1.0, respectively.
Conceptual Model Development for Holistic Building Fire Safety Performance Analysis

The evaluation of building performance during fires is a critical step in designing appropriate strategies. Inappropriate or incomplete performance evaluations can mislead fire safety design solutions, which may in turn result in unacceptable loss of life or building damage from fire. While various building fire safety performance evaluation models have been developed, they focus primarily on ‘hard’ characteristics, such as building construction type and fire protection measures. However, ‘soft’ characteristics, such as building design (architectural) features and occupant characteristics, which also significantly influence building fire safety performance, have not been comprehensively taken into account. In the current study, two conceptual performance models: a generic fire response model and an integrated characteristic interaction model, have been developed to represent the holistic building fire safety performance considering the effects of both hard and soft characteristics. In these models, various cause-effect relationships among building, people, and fire characteristics are identified at the different levels of detail. Based on the conceptual models, a quantitative model utilizing the parameter ranking method and weighted sum method, which are commonly used in analytical hierarchy process, is proposed as a tool to help evaluate building fire safety performance and to assist decision making process of developing fire safety design solutions.
Brain Mechanisms for Offense, Defense and Submission

A preliminary attempt is made to analyze the intraspecific aggressive behavior of mammals in terms of specific neural circuitry. The results of stimulation, lesion, and recording studies of aggressive behavior in cats and rats are reviewed and analyzed in terms of three hypothetical motivational systems: offense, defense, and submission. A critical distinction, derived from ethological theory, is made between motivating stimuli that simultaneously activate functional groupings of motor patterning mechanisms, and releasing and directing stimuli that are necessary for the activation of discrete motor patterning mechanisms. It is suggested that motivating stimuli activate pathways that converge upon sets of homogeneous neurons, called motivational mechanisms, whose activity determines the motivational state of the animal.A defense motivational mechanism is hypothesized to be located in the midbrain central gray. In addition to tactile, auditory, and visual inputs from the paleospinothalamic tract, lateral lemniscus, and (perhaps) from the pretectum, it may receive inputs from a major forebrain pathway whose functional significance is not yet understood.A submission motivational mechanism is also thought to be located in the central gray. In addition to inputs for defense, it is thought to receive a necessary input from a “consociate (social familiarity cue) modulator” located in the ventromedial hypothalamus, which can switch behavior from defense to submission. The location of the hypothetical offense motivational mechanism is not known, although the pathways by which it is activated are traced in some detail.Brain mechanisms of aggression in primitive mammals and in primates are apparently similar to those in rats and cats.
Fundamental Mechanisms of Aeroelastic Control with Control Surface and Strain Actuation

A typical section analysis is employed to provide an understanding of the fundamental mechanisms and limitations involved in performing aeroelastic control. The effects of both articulated aerodynamic control surfaces and induced strain actuators are included in the model. The ability of these actuators to effect aeroelastic control is studied for each actuator individually as well as in various combinations. The control options available are examined for single-input, single-output (SISO) and multiple-input, multiple-output (MIMO) classical and optimal control laws. A state-cost-vs-control-cost analysis is performed to assess the effectiveness of optimal linear quadratic regulator (LQR) control laws for different actuators and actuator combinations. The cost comparisons show that strain actuation is an effective means of achieving aeroelastic control and a viable alternative to articulated control surface methods. In addition, the advantages of using multiple actuators to avoid limitations associated with single-actuator systems are demonstrated.
Palliative Medicine in the Surgical Intensive Care Unit and Trauma

The purpose of palliative medicine is to prevent and relieve suffering and to help patients and their families set informed goals of care and treatment. Palliative medicine can be provided along with life-prolonging treatment or as the main focus of treatment. Increasingly, palliative medicine has a role in the surgical intensive care unit (SICU) and trauma. Data show involving palliative medicine in the SICU results in decreased length of stay, improved communication with families and patients, and earlier setting of goals of care, without increasing mortality. The use of triggers for palliative medicine consultation improves patient-centered care in the SICU.
Hypersphere mapper: a nonlinear programming approach to the hypercube embedding problem

Abstract A nonlinear programming approach is introduced for solving the hypercube embedding problem. The basic idea of the proposed approach is to approximate the discrete space of an n-dimensional hypercube, i.e., {z: z ∈ {0, 1}n}, with the continuous space of an n-dimensional hypersphere, i.e., {x: x ∈ Rn & ||x||2 = 1}. The mapping problem is initially solved in the continuous domain by employing the gradient projection technique to a continuously differentiable objective function. The optimal process "locations" from the solution of the continuous hypersphere mapping problem are then discretized onto the n-dimensional hypercube. The proposed approach can solve, directly, the problem of mapping P processes onto N nodes for the general case where P > N. In contrast, competing embedding heuristics from the literature can produce only one-to-one mappings and cannot, therefore, be directly applied when P > N.
Effect of Solvent−Co-solvent Mixtures on Lipase-Catalyzed Transesterification of Canola Oil†

In this work, various solvent−co-solvent mixtures were established to enhance both enzyme activity and mass transfer of substrates in the enzymatic transesterification of canola oil catalyzed by Candida antarctica lipase. The solvent−co-solvent mixture comprised a hydrophobic solvent and a hydrophilic co-solvent. Dependent upon the co-solvent, at low co-solvent concentrations, the yield of biodiesel was enhanced because of the improvement in the dispersion of methanol in the co-solvent media. However, at higher co-solvent concentrations, the biodiesel yield was reduced because of the inactivation of lipase. The polarity of solvent−co-solvent mixtures was correlated with the yield of biodiesel to assess the potential relationship between the polarity of reaction media and lipase activity. The effect of the water content on lipase activity in the transesterification reaction was also ascertained.
Discovery of a Transient X-Ray Source in the Compact Stellar Nucleus of NGC 2403

We report the discovery of an X-ray source coincident with the nuclear star cluster at the dynamical center of the nearby late-type spiral galaxy NGC 2403. The X-ray luminosity of this source varies from below detection levels, ~1035 erg s-1 in the 0.5-8.0 keV band to 7 × 1038 erg s-1 on timescales between observations of <2 months. The X-ray spectrum is well fit by an accretion disk model consisting of multiple blackbody components and corresponding physically to a compact object mass of 5 M☉. No pulsations nor aperiodic behavior is evident in its X-ray light curve on the short timescales of the individual observations. The X-ray properties of the source are more similar to those of the nuclear source X-8 in M33, believed to be a low-mass X-ray binary, then to those of the low-luminosity active galactic nucleus (AGN) in NGC 4395. The brightness of the nuclear star cluster, MI ~ -11.8 mag, is typical of clusters in late-type spirals but its effective radius, re ~ 12 pc, is several times larger than average indicating a relatively relaxed cluster and a low probability of a central massive object. Estimating from its observed colors and brightness, the cluster has a mass of 106.5 M☉ and an age of ~1.4 Gyr.
Strangers and friends: collaborative play in world of warcraft

We analyze collaborative play in an online video game, World of Warcraft, the most popular personal computer game in the United States, with significant markets in Asia and Europe. Based on an immersive ethnographic study, we describe how the social organization of the game and player culture affect players' enjoyment and learning of the game. We discovered that play is characterized by a multiplicity of collaborations from brief informal encounters to highly organized play in structured groups. The variety of collaborations makes the game more fun and provides rich learning opportunities. We contrast these varied collaborations, including those with strangers, to the "gold standard" of Gemeinschaft-like communities of close relations in tightknit groups. We suggest populations for whom similar games could be designed.
The effect of human chorionic gonadotropin (HCG) on functional recovery of spinal cord sectioned rats.

The effect of human chorionic gonadotropin (HCG) on functional recovery after complete spinal cord transection in the rat was studied. Twelve rats (6 male and 6 female) received HCG daily for the first week and then every alternate day for three weeks. Ten rats (5 male and 5 female) served as controls. Return of bladder function, Tarlov's grading and measuring the maximum angle at which the rats were able to climb up an inclined plane were used as criteria in assessing the functional recovery. Improvement was noted in the HCG-treated rats by the end of two weeks. At six weeks the recovery of HCG-treated rats as compared to the control group was very significant (p < 0.001). No recovery whatsoever was noted in the control group even after six weeks. Histological evidence of bridging of the gap between the cut ends of the spinal cord by nerve fibres containing tissue was noted in the HCG-treated rats only. The possible mode of action of HCG on spinal cord injury is briefly discussed.
Friction, Wear, Transfer and Wear Surface Morphology of Ultra-High-Molecular-Weight Polyethylene.

Tribological studies at 25 C in a 50-percent-relative-humidity air atmosphere were conducted using hemispherically tipped 440 C HT (high temperature) stainless steel pins sliding against ultra-high-molecular-weight polyethylene (UHMWPE) disks. The results indicate that sliding speed, sliding distance, contact stress and specimen geometry can markedly affect friction, UHMWPE wear, UHMWPE transfer and the type of wear mechanisms that occur. Adhesion appears to be the predominant wear mechanism; but after long sliding distances at slow speeds, heavy ridges of transfer result which can induce fatigue-like wear on the UHMWPE disk wear track. In one instance, abrasive wear to the metallic pin was observed. This was caused by a hard particle embedded in the UHMWPE disk wear track.