cssi/SciSciGPT-SciSciNet huggingface dataset:
An empirical study of hybrid genetic algorithms for the set covering problem

The purpose of this paper is to explore the computational performance of several hybrid algorithms that are extensions of a basic genetic algorithm (GA) approach for solving the set covering problem (SCP). We start by making several enhancements to a GA for the SCP that was proposed by Beasley and Chu. Next, several hybrid solution approaches are introduced that combine the GA with various local neighbourhood search approaches, with a form of the greedy randomized adaptive search procedure, and with an estimation of distribution algorithms approach. Using Beasley's library of SCPs extensive computational results are generated for the hybrid solution approaches defined in this paper. Statistical analyses of the results are performed.
Stereotyped and complex motor routines expressed during cocaine self-administration: results from a 24-h binge of unlimited cocaine access in rats.

Rationale Cocaine binges represent the most severe form of cocaine taking due to high levels of cocaine consumed and a potential loss of self-control over cocaine taking. Experimentally, regulation of intravenous cocaine self-administration is observed during binges as revealed by nearly constant sequential inter-infusion intervals, suggesting that pharmacological and unconditioned behavioral effects of cumulative cocaine leave intact its reinforcing effect.
Insight into the Selective Room-Temperature Platinum(II) Catalytic Hydration of Alkynes in Water

Three platinum complexes of water-soluble, bidentate phosphine ligands have been prepared and characterized. The complexes, PtCl2(P−P) (P−P = (m-NaSO3C6H4)2PCH2CH2P(m-C6H4SO3Na)2, DPPETS, (m-NaSO3C6H4)2PCH2CH2CH2P(m-C6H4SO3Na)2, DPPPTS, (m-NaSO3C6H4)2PCH2CH2CH2CH2P(m-C6H4SO3Na)2, DPPBTS), catalyze the hydration of 3-pentyn-1-ol and 4-pentyn-1-ol. 2-Pentyn-1-ol is slowly polymerized, allowing characterization of the intermediate η1-allenyl complexes. For PtCl2(DPPBTS) the η1-allenyl complex Pt(C(Et)CCH2)(X)(DPPBTS), where X is either OH-, OH2, or Cl-, is formed. However for PtCl2(DPPPTS) and PtCl2(DPPETS) the extent of formation of the coordinated complex is much less. The stability of the coordinated Pt(η1-allenyl)(X)(P−P) complexes shows a significant effect on chelate ring size, with DPPBTS > DPPPTS > DPPETS being the order of decreasing stability. Catalytic hydrations of 4-pentyn-1-ol with PtCl2(P−P) show a major effect of chelate ring size in the opposite direction, DPPETS > DPPPTS > DPPBTS. For 3-pen...
Movements during sleep correlate with impaired attention and verbal and memory skills in children with adenotonsillar hypertrophy suspected of having obstructive sleep disordered breathing.

Abstract Background Children with obstructive sleep disordered breathing (OSDB) have both impaired cognitive performance and frequent movements during sleep. It is not known whether movements during sleep are related to cognitive function. Methods We studied 56 children with adenotonsillar hypertrophy suspected of having OSDB with actigraphy for six consecutive days and nights, followed by cognitive and performance tests. Attended polysomnography was performed on the seventh night. Results Slower reaction time correlated with both higher sum of all movements during Time in Bed ( r 2 =0.19, p =0.001) and higher number of minutes with >5 movements/night ( r 2 =0.23, p =0.0003). Low Vocabulary, Similarities and General Memory Index scores correlated with more consolidation of movements (consecutive minutes with >5 movements) ( r 2 =0.16, p =0.002, r 2 =0.16, p =0.0026, respectively). Correlation with Vocabulary and Similarities scores improved when Time in Bed was added as an independently significant covariate ( r 2 =0.25, p =0.0006, r 2 =0.27, p =0.00028, respectively). Actigraphy correlated with Vocabulary and Similarities scores as well as polysomnography. Other cognitive or behavioral scores were not correlated with actigraphy or polysomnography. Children with more consolidation of movements had higher values for log10(OAHI+1) ( r 2 =0.38, p =0.000001). Conclusions (1) Frequency of movement during sleep correlated with impaired vigilance while consolidation of movements correlated with impaired verbal and memory skills. (2) OAHI was associated with more consolidation of movements.
An incomplete relevant modal logic

The relevant modal logic G is a simple extension of the logic RT, the relevant counterpart of the familiar classically based system T. Using the Routley–Meyer semantics for relevant modal logics, this paper proves three main results regarding G: (i) G is semantically complete, but only with a non-standard interpretation of necessity. From this, however, other nice properties follow. (ii) With a standard interpretation of necessity, G is semantically incomplete; there is no class of frames that characterizes G. (iii) The class of frames for G characterizes the classically based logic T.
On the existence and the coefficients of the implicit equation of rational surfaces

Abstract The existence of the implicit equation of rational surfaces can be proved by three techniques: elimination theory, undetermined coefficients, and the theory of field extensions. The methods of elimination theory and undetermined coefficients also reveal that the implicit equation can be written with coefficients from the coefficient field of the parametric polynomials. All three techniques can be implemented as implicitization algorithms. For each method, the theoretical limitations of the proof and the practical advantages and disadvantages of the algorithm are discussed. Our results are important for two reasons. First, we caution that elimination theory cannot be generalized in a straightforward manner from rational plane curves to rational surfaces to show the existence of the implicit equation; thus other rigorous methods are necessary to bypass the vanishing of the resultant in the presence of base points. Second, as an immediate consequence of the coefficient relationship, we see that the implicit representation involves only rational (or real) coefficients if a parametric representation involves only rational (or real) coefficients. The existence of the implicit equation means every rational surface is a subset of an irreducible algebraic surface. The subset relation can be proper and this may cause problems in certain applications in computer aided geometric design. This anomaly is illustrated by an example.
Factoring rational polynomials over the complexes

We give NC algorithms for determining the number and degrees of the absolute factors (factors irreducible over the complex numbers C) of a multi-variate polynomial with rational coefficients. NC is the class of functions computable by logspace-uniform Boolean circuits of polynomial size and polylogarithmic depth. The measures of size of the input polynomial are its degree d, coefficient length c, number of variables n, and for sparse polynomials, the number of non-zero coefficients s. For the general case, we give a random (Monte-Carlo) NC algorithm in these input measures. If n is fixed, or if the polynomial is dense, we give a deterministic NC algorithm. The algorithm also works in random NC for polynomials represented by straight-line programs, provided the polynomial can be evaluated at integer points in NC. Finally, we discuss a method for obtaining an approximation to the coefficients of each factor whose running time is polynomial in the size of the original (dense) polynomial. These methods rely on the fact that the connected components of a complex hypersurface P(z1…,zn) = 0 minus its singular points correspond to the absolute factors of P.
Comparison of Perioperative Outcomes Between Peroral Esophageal Myotomy (POEM) and Laparoscopic Heller Myotomy

Background Peroral esophageal myotomy (POEM) is a novel endoscopic operation for the treatment of achalasia. Few POEM outcome data exist, and no study has compared POEM with the surgical standard, laparoscopic Heller myotomy (LHM).
Specific 13C reductive methylation of glycophorin A. Possible relation of the N-terminal amino acid and the lysine residues to MN blood group specificities.

Abstract Heterozygous and homozygous glycophorin A were partially and fully reductively methylated with 13 C-enriched formaldehyde in the presence of sodium cyanoborohydride. Total reductive methylation modified the five lysine residues (to produce N ϵ ,N -[ 13 C]dimethyl ysine) and the N-terminal amino acid residues ( N α ,N -[ 13 C]dimethyl serine and leucine) of glycophorins A M and A N , respectively. 13 C-NMR spectra of these species indicated that the 13 C-enriched methyl carbons of the five lysyl derivatives all occur at 44.1 ppm downfield from Me 4 Si. Titration results indicate that the p K a of these methylated lysines is >;10. The chemical shift equivalent methyl resonances of the 13 C-enriched methylated N-terminal Leu derivative were found to occur at 42.8 ppm downfield from Me 4 Si and exhibited a normal pH titration behavior (p K a ~ 7.4). The methyl resonances of the N α ,N -[ 13 C]dimethyl Ser derivative, on the other hand, were found to exhibit chemical shift nonequivalence, indicating rotational constraints about the C α  N bond. The linewidths of the two methyl resonances were also found to be considerably different; this phenomenon could be eliminated by running spectra of the sample (pH ~ 5.0) at elevated temperatures (75 °C). This result suggested that for the N α ,N -[ 13 C]dimethyl Ser derivative of glycophorin A M , hindered rotation must occur about one of the N μα  13 CH 3 bonds. This structural difference at the N-terminal residue of glycophorins A M and A N may be related to the MN blood group determinants displayed by these related glycoproteins.
Analysis of wave propagation in dry granular soils using DEM simulations

In this paper, a three-dimensional particle-based technique utilizing the discrete element method (DEM) is proposed to study wave propagation in a dry granular soil column. Computational simulations were conducted to investigate the soil response to sinusoidal motions with different amplitudes and frequencies. Three types of soil deposits with different void ratios were employed in these simulations. Different boundary conditions at the base such as rigid bedrock, elastic bedrock, and infinite medium were also considered. Analysis is done in time domain while taking into account the effects of soil nonlinear behavior. The computational approach is able to capture a number of essential characteristics of wave propagation including motion amplification and resonance. Dynamic soil properties were then extracted from conducted simulations and used to predict the response of the soil using the widely used equivalent linear method program SHAKE and compare its predictions to DEM results. Generally, there was a good agreement between SHAKE and DEM results except when the exciting frequency was close to the resonance frequency of the deposit where significant discrepancy in computed shear strains between SHAKE predictions and DEM results was observed.
Optimal life insurance purchase and consumption/investment under uncertain lifetime

Abstract In this paper, we consider optimal insurance and consumption rules for a wage earner whose lifetime is random. The wage earner is endowed with an initial wealth, and he also receives an income continuously, but this may be terminated by the wage earner’s premature death. We use dynamic programming to analyze this problem and derive the optimal insurance and consumption rules. Explicit solutions are found for the family of CRRA utilities, and the demand for life insurance is studied by examining our solutions and doing numerical experiments.
Theoretical Prediction and Experimental Verification of Stability of Pt–3d–Pt Subsurface Bimetallic Structures: From Single Crystal Surfaces to Polycrystalline Films

In this paper we will provide a review of our recent studies on the general stability of the Pt–3d–Pt (3d = Ti, V, Cr, Mn, Fe, Co and Ni) subsurface structures, which are the desirable structural configurations in several applications in heterogeneous catalysis and electrocatalysis. We will first provide a review of density functional theory (DFT) predictions of the thermodynamic stability of Pt–3d–Pt(111) and Pt–3d–Pt(100) in vacuum and with adsorbed hydrogen and oxygen. The DFT results predict that the Pt–3d–Pt subsurface structures are stable in vacuum and with adsorbed hydrogen, while with adsorbed oxygen the 3d atoms should segregate to the surface to produce the 3d–Pt–Pt surface structures. The DFT predictions are verified experimentally on selected Pt–3d–Pt(111) systems. The experimental efforts are further expanded by bridging the materials gap form single crystal Pt(111) to polycrystalline Pt to incorporate multiple crystal facets and to determine their effects on the kinetic barriers for the segregation of the subsurface 3d atoms. In order to further correlate DFT calculations with experimental results, a Bronsted–Evans–Polanyi relationship is derived to correlate thermodynamic stability from DFT calculations with kinetic barriers from experimental measurements for the Pt–3d–Pt systems. Finally, empirical equations have been developed for predicting the thermodynamic stability of other bimetallic systems both in vacuum and with adsorbed hydrogen and oxygen.
Cavitation Bubble Collapse in Viscous, Compressible Liquids—Numerical Analysis

Numerical analysis of collapse of spherical bubble in compressible fluid, including surface tension, viscosity and adiabatic compression of gas within bubble
RST Flip-Flop Input Equations

There are several different usable combinations of the inputs of an RST flip-flop. It is shown how all of the possible combinations can be displayed simultaneously on three Karnaugh maps, facilitating the choice of the simplest input equations. The application equation for flip-flop Q characterized by a sequential problem is plotted on a map designated Qn+1. Additional maps, (Qn+1)* and (Qn+1)? are derived from Qn+1. Cells corresponding to prime implicants not containing the variable Q are identified on these maps, and are used to enter the properly designated arbitrary elements on the R, S, and T maps of flip-flop Q. The method is based on the following theorem: ``If Qn+1 = (g 1 Q + g 2 Q?)n, and if F is the set of all prime implicants that do not contain the literals Q or ?, then the Boolean function g 1 g 2 is the union of all the prime implicants of Qn+1 that belong to the set F.'' A simple illustrative example is included.
The incidence of mesh extrusion after vaginal incontinence and pelvic floor prolapse surgery

Purpose: The advantages of using synthetic mesh in vaginal reconstructive surgery are significant. However, the concern about extrusion has led many to question its use. We wished to learn the extrusion rates and time to extrusion in patients undergoing vaginal stress incontinence and prolapse surgeries using polypropylene mesh. Materials and methods: Five hundred and seventy six women underwent vaginal reconstructive surgery with synthetic mesh between August 2000 and October 2009 for the treatment of stress urinary incontinence, with or without pelvic organ prolapse repair. 367 patients had at least one year follow-up. Procedures were: pubo-vaginal sling (PVS), PVS and anterior repair, PVS with anterior and/or posterior repairs, and PVS with hysterectomy and anterior and posterior repairs. Time to mesh extrusion was estimated using a survival function curve. Results: Forty-two (11.4%) patients sustained a mesh extrusion. The rate of mesh extrusion was (6.3%) in the PVS group, (14.7%) in the PVS and anterior repair group, (11.1%) in the PVS with anterior and posterior repairs group and (5%) in the PVS with hysterectomy and anterior and posterior repair. Percent extrusion free at one to four years post-op was (91%) and (85%). Conclusion: Our study provides a large series of prolapse cases performed by a single surgeon with follow-up that extends at least one year, with the longest follow-up at eight years. The incidence of long term mesh extrusion needs to be considered with respect to the support advantages of synthetic mesh in planning vaginal reconstructive surgery.
Evaluating Physician Performance at Individualizing Care: A Pilot Study Tracking Contextual Errors in Medical Decision Making

contextual errors, and data were collected on information elicitation and error making. Results. The case validation process was successful in that, in the final iteration, the physicians who received the contextual variant of cases proposed an alternate plan of care to those who received the baseline variant 100% of the time. The subsequent piloting of these validated cases unmasked previously unmeasured differences in physician performance at contextualizing care. The findings, which reflect the performance characteristics of the study population, are presented. Conclusions. This pilot study demonstrates a methodology for measuring physician performance at contextualizing care and illustrates the contribution of such information to an overall assessment of physician practice.
On quantum solitons and their classical relatives: Bethe Ansatz states in soliton sectors of the sine-Gordon system

Previously we have found that the semiclassical sine-Gordon/Thirring spectrum can be received in the absence of quantum solitons via the spin 12 approximation of the quantized sine-Gordon system on a lattice. Later on, we have recovered the Hilbert space of quantum soliton states for the sine-Gordon system. In the present paper we present a derivation of the Bethe Ansatz eigenstates for the generalized ice model in this soliton Hilbert space. We demonstrate that via “Wick rotation” of a fundamental parameter of the ice model one arrives at the Bethe Ansatz eigenstates of the quantum sine-Gordon system. The latter is a “local transition matrix” ancestor of the conventional sine-Gordon /Thirring model, as derived by Faddeev et al. within the quantum inverse-scattering method. Our result is essentially based on the N < ∞, Δ = 1, m ⪡ 1 regime. Consequently, the spectrum received, though resembling the semiclassical one, does not coincide with it at all.
Determination of Flow Stress Data for Practical Metal Forming Analysis

The analysis of metal forming processes requires (a) a mathematical model of plastic deformation, (b) values of friction at the tool-material interface and (c) flow stress data at temperatures and strain rates of interest. This paper describes the experimental techniques and the evaluation of experimental data used for obtaining the flow stress of various alloys under hot forming conditions. The discussion covers the variations in flow stress with (a) the equipment used for flow stress measurements, (b) the starting microstructure of the test material, (c) heat generation and heat loss during the tests, (d) the Imposed strain, and (e) the temperature and strain-rate conditions present in practical forming operations.
A Compact, Easily Assembled Micromirror With Liquid Metal Pivot

We have developed a new approach to achieve a high-speed micromirror, which can rapidly tilt large angles with a low voltage and a compact footprint. In our approach we use a liquid metal drop with a low vapor pressure as the pivot, and the micromirror is tilted by an electrostatic torque. Micromirrors (1 mm x 1 mm) and the actuating circuit are microfabricated with a centralized wetting area surrounded by a non-wetting Parylene area to confine the drop. The frequency response curve shows that the mirror has 78V snap-down voltage and resonant frequency at 165Hz, and has a potential resonant frequency more than 3k Hz if the size of the mirror and liquid metal pivot is reduced. A micromirror with a liquid metal pivot is expected to have significantly higher reliability since a liquid drop does not suffer from mechanical fatigue. Due to the single point support, the micromirror can be tilted in an arbitrary direction, and the fabrication process is simpler than those required to create solid torsional weak links.Copyright © 2003 by ASME
ABSENCE OF RADIATION-INDUCED G1 ARREST IN TWO CLOSELY RELATED HUMAN LYMPHOBLAST CELL LINES THAT DIFFER IN P53 STATUS

In order to examine more precisely the role of p53 in the activation of the G1/S checkpoint by ionizing radiation, we examined two human lymphoblast cell lines derived from the same donor. The TK6 line had a doubling time of 12.2 h and expressed wild type p53, while the WTK1 line had a doubling time of 12.7 h and expressed mutant p53. The two lines differ significantly in their susceptibility to radiation-induced cell killing and apoptosis. Cells were examined by flow cytometry at regular intervals from 0 to 12 h after irradiation with two different doses designed to yield equivalent survival levels in both cell lines. In some experiments, cells were incubated with colcemid to block them in the first postirradiation mitosis and prevent contamination of the flow cytometric profiles with second cycle cells. There was no significant difference between the two cell lines in the progression of irradiated cells out of G1 and into the S and G2 phases of the cell cycle. In particular, there was no evidence for a prolonged arrest in G1 in the TK6 cell line expressing wild type p53. Furthermore, expression of the p53 downstream genes WAF1/CIP1 and RB appeared normal in TK6 cells. These results suggest that factors other than those in the p53 signal transduction pathway alone may be required to activate the G1/S checkpoint in irradiated human cells and that apoptosis and G1 arrest may utilize different pathways.
CULTURALLY SENSITIVE ASSESSMENT OF NARRATIVE SKILLS IN CHILDREN

The clinical legacy of William Labov's narrative analysis framework is explored. In recent years, the importance of narration for children's developing literacy and discourse skills has been widely recognized. This article describes a three-step process for assessing children's narrative discourse: elicitation, coding, and scoring. The influences of cultural differences on narration are also presented, with implications and suggestions for culturally sensitive assessment.
Is epidemiology the key to cumulative risk assessment

Although cumulative risk assessment by definition evaluates the joint effects of chemical and nonchemical stressors, studies to date have not considered both dimensions, in part because toxicological studies cannot capture many stressors of interest. Epidemiology can potentially include all relevant stressors, but developing and extracting the necessary information is challenging given some of the inherent limitations of epidemiology. In this article, I propose a conceptual framework within which epidemiological studies could be evaluated for their inclusion into cumulative risk assessment, including a problem formulation/planning and scoping step that focuses on stressors meaningful for risk management decisions, extension of the chemical mixtures framework to include nonchemical stressors, and formal consideration of vulnerability characteristics of the population. In the long term, broadening the applicability and informativeness of cumulative risk assessment will require enhanced communication and collaboration between epidemiologists and risk assessors, in which the structure of social and environmental epidemiological analyses may be informed in part by the needs of cumulative risk assessment.
Development and germination of the Azotobacter cyst.

The fine structure of Azotobacter vinelandii has been studied by means of electron microscopy of ultrathin sections made of the encysting and germinating cells. The organisms were fixed with KMnO4 and embedded in epoxy resin. On an encystment medium the rod-shaped bacteria begin to assume an almost spherical form and then bark-like exine appears in 1½ to 2 days. The exine thickens and an electron permeable intine forms between it and the shrinking cell body. In 5 days the intine makes up more than half of the cyst volume and begins to show a definite two-layered structure. Meanwhile the peripheral bodies, which may be extensions of the cell membrane of the vegetative cell, disappear as the encystment progresses. The cell wall and membrane of the vegetative cell remain demonstrable as the confining structure of the shrinking central body of the mature cyst. In this central body lipoidal globules appear together with aggregations of nuclear material. Cyst germination begins with an increase in the size of the central body at the expense of the intine. The nuclear aggregations become more diffuse and the lipoidal globules disappear. The exine may be pushed outward and the bark-like fragments separate as the emerging vegetative cell develops. Invagination of the cell wall and membrane may occur at this stage leading to cell division. Empty exines remain as horseshoe-shaped structures.
Intraspecific variation in the response to CO2 enrichment in seeds and seedlings of Plantago lanceolata L

Four genotypes of P. lanceolata were grown to maturity at combinations of two levels of atmospheric CO2 concentrations and two temperature conditions. Seed weight was determined, and seed germination and seedling growth were measured for the progeny of each genotype under the same environmental conditions. Overall, high CO2 levels decreased seed weight, increased germination percentage and rate, and increased seedling size. Families differed in their response to CO2 enrichment, and to combinations of CO2 and temperature levels for several characters. These results suggest the existence of genetic variability in P. lanceolata in response to CO2 enrichment.
Slip of the Keyboard: How Unintentional Cues Convey Email-Sender Emotions

Email has become ubiquitous in the workplace. However, there is limited research exploring the expression and perception of emotion using this pervasive mode of communication, with most researchers...
Got image? Examining organizational image in web recruitment

Purpose – This study aims to investigate whether organizational image: mediates the relationship between web site attributes and organizational attraction and moderates the relationship between person‐job (P‐J) fit and organizational attraction.Design/methodology/approach – A total of 320 observations were collected from 80 senior‐level undergraduates, each half navigating a different set of four actual organizational web sites.Findings – Organizational image was found to fully mediate the relationship between a web site's aesthetic features and organizational attraction; and moderate the relationship between P‐J fit perceptions and organizational attraction such that the change in organizational attraction was more sensitive to perceptions of P‐J fit when organizational image perceptions were more unfavorable rather than favorable. In addition, intercept differences revealed that individuals with below average P‐J fit were more attracted to organizations having a favorable image than an unfavorable image...
Advance reservations: a theoretical and practical comparison of GUR & HARC

Grid computing has provided new capabilities for connecting distributed computing nodes, experimental instruments, visualization facilities, data storage and people across high speed networks. Emerging communities of "e-Scientists" are now building cyber-infrastructures for inter-disciplinary scientists to exploit Grids for new modes of problem solving in science, engineering and the humanities.One new need, that these cyber-infrastructures require, is to be able to co-allocate these varied resources. For example, multiple machines can be reserved at the same time for meta-computing with large scale tightly coupled simulations; visualization equipment and networks can be co-allocated for real time visualization and interaction; data management tools and high speed networks can be immediately reserved as soon as an experimental device, such as a particle detector, starts recording terabytes of data. As scientists start developing complex workflows for their work, the needs for sophisticated and flexible co-allocation will increase.Traditionally, scientists submit their supercomputing tasks using batch scheduler, typically running in a backfill mode. Jobs are added to queues, and will run at some unknown time which may be in days or weeks time. Networks, visualization equipment, and data archives are typically scheduled through human reservations.In this poster we examine two new tools which have the ability for advance reservations and co-allocation. HARC (Highly-Available Resource Co-allocator), developed at CCT LSU through the NSF EnLIGHTened Computing project, was motivated by the need to dynamically provision 10Gbps Ethernet connections for applications. GUR (Generic Universal Remote), deployed on the IA-64 clusters at NCSA (Mercury) and SDSC, is a metascheduler developed to automatically manage and create overlapping reservations at multiple sites. Both tools have been deployed on the NSF TeraGrid. And HARC is also deployed on subsets of LONI, UK NGS and NorthWest Grid. These two modern toolkits will be analyzed from both theoretical and practical points of view. For the theoretical comparison, we analyze them in terms of their software engineering and architecture based on their design philosophies. For the practical part, they are compared from the end user point of view. In total, the poster covers seven aspects of comparison: architecture; installation; usability; portability; reliability; security, and functionality. The analysis shows interesting differences between the service-based HARC and more intuitive designed GUR, which may shed some light on grid software design and applicability for real world applications. Advantages, disadvantages and problem-oriented nature of GUR and HARC are studied and exemplified.
New quantitative trait loci that regulate wound healing in an intercross progeny from DBA/1J and 129×1/SvJ inbred strains of mice

Wound healing/regeneration mouse models are few, and studies performed have mainly utilized crosses between MRL/MPJ (a good healer) and SJL/J (a poor healer) or MRL/lpr (a good healer) and C57BL/6J (a poor healer). Wound healing is a complex trait with many genes involved in the expression of the phenotype. Based on data from previous studies that common and additional quantitative trait loci (QTL) were identified using different crosses of inbred strains of mice for various complex traits, we hypothesized that a new cross would identify common and additional QTL, unique modes of inheritance, and interacting loci, which are responsible for variation in susceptibility to fast wound healing. In this study, we crossed DBA/1J (DBA, a good healer) and 129/SvJ (129, a poor healer) and performed a genome-wide scan using 492 (DBA×129) F2 mice and 98 markers to identify QTL that regulate wound healing/regeneration. Four QTL on chromosomes 1, 4, 12, and 18 were identified which contributed toward wound healing in F2 mice and accounted for 17.1% of the phenotypic variation in ear punch healing. Surprisingly, locus interactions contributed to 55.7% of the phenotype variation in ear punch healing. In conclusion, we have identified novel QTL and shown that minor interacting loci contribute significantly to wound healing in DBA×129 mice cross.
Optimal distributed control of a flexible spacecraft during a large-angle maneuver

This paper discusses the solution of the necessary conditions obtained from Pontryagin's principle, for the problem of optimal large-angle single-axis maneuvers of a flexible spacecraft possessing a distributed control system. A single-stage continuation method is presented for the solution of the resulting two-point boundaryvalue problem. Starting iteratives for the initial costate variables are obtained by neglecting the kinematic nonlinearity in the state equation which leads to a closed form solution algorithm. The continuation process then increases the participation of the kinematic nonlinearity in a sequence of neighboring optimal solutions (in essence a method of successive linearizations), converging finally to the nonlinear problem of interest.
Design and fabrication of a micro Alvarez lens array with a variable focal length

A 5 × 5 micro Alvarez lens array mold was fabricated using a 5-axis ultraprecision diamond machine and an Alvarez lens array was manufactured by injection molding process. Unlike conventional processes for asymmetrical element fabrication such as small tool grinding, this research demonstrates slow tool servo broaching process that allows the entire Alvarez lens array to be accurately machined on a metal mold in a single operation. To further reduce manufacturing cost, injection molding was used to fabricate the Alvarez lens arrays. The mold and molded lenses were both measured using an optical profiler. All measured profiles showed a good agreement with design and surface roughness also indicated an optical surface finish. The functionality of the molded polymeric lens arrays was achieved when the focal lengths were varied by laterally translating the molded Alvarez lens array pair. This research is a demonstration of the capability of fabricating complex optics using the same approach.
Second-order finite difference approximation for inverse determination of thermal conductivity

A second-order finite difference procedure is presented for the inverse determination of the thermal conductivity in a one-dimensional heat conduction domain. In this approach, the thermal conductivity of the material is reconstructed by using the available temperature data at discrete grid points. The accuracy of the computational algorithm is investigated. To confirm the validity of the numerical procedure, various comparative examples are presented. The close agreement between the current results and the exact solutions confirms that the proposed finite difference procedure is an effective technique for the inverse determination of thermal conductivity. The method is applicable for linear and nonlinear spatially dependent, as well as temperature dependent, thermal conductivities. In addition, a key feature of the present technique is that a priori knowledge of the functional form for the thermal conductivity is not required.
The use of potassium iodide equilibrium density gradient centrifugation in the purification of RNA for hybridization with nonreiterated DNA sequences

Abstract RNA should be essentially free of DNA contamination to avoid error in molecular hybridization studies where RNA is used at high RNA-to-DNA ratios to saturate nonreiterated DNA sequences. To achieve this purity the banding of RNA on KI equilibrium density gradients is an alternative to repeated DNase treatment of preparations of nuclear and cytoplasmic RNA. A one-step procedure for purification of polysome RNA is described in which RNA is recovered directly from polysomes suitable for hybridization studies. In control hybridization studies rat DNA nonreiterated sequences were annealed with either Escherichia coli RNA or rat liver RNA purified on KI gradients which had been alkali or RNase treated. No differences were noted between the degraded RNA and the E. coli RNA, indicating an absence of significant DNA contamination in the purified rat RNA. Hybridization of free polysome RNA of the 5123 minimal deviation hepatoma containing 0.63% contaminating DNA resulted in a markedly increased percentage of hybridization when compared with DNase-treated and KI gradient-purified hepatoma free polysome RNA. The use of KI, a relatively inexpensive salt, instead of more expensive salts such as Cs 2 SO 4 , makes preparative RNA purification by equilibrium density gradient centrifugation economically feasible.
Coordination Chemistry of Tripyridinedimethane

The ligand tripyridinedimethane (tpdm), consisting of three pyridine residues linked at their ortho carbons by two CH(2) groups, is shown to be a sterically flexible ligand capable of binding in a meridional arrangement in trigonal bipyramidal (tpdm) Cu(II)Cl(2) but binding in a facial arrangement in tetrahedral (tpdm) Cu(I)Cl. Nucleophilic substitution of chloride by (t)BuO(-) and PhC[triple bond]C(-) is possible, and deprotonation of the acidic benzylic protons does not take place because the resulting carbanion cannot achieve coplanarity with the aryl rings. RhCl(3) forms, with tpdm in boiling methanol, a 1:1 kinetic mixture of fac- and mer-isomers RhCl(3)(tpdm). The former isomerizes slowly at RT (room temperature) in DMSO solution into the latter with Rh-N bond dissociation as the rate-determining step.
Effect of lectins on the cobalamin-protein binding reactions: implications for the tissue uptake of cobalamin.

Abstract Plant lectins have been thought to impair nutrient absorption, both by specific and nonspecific interference in the absorptive process. The main objective of this investigation was to study the effect of lectins on the various binding reactions involving cobalamin (cbl)-protein complexes and their receptors, and to identify the rate-limiting step important in maintaining tissue levels of cobalamin. Among the lectins tested in vivo, only concanavalin A (ConA) was able to inhibit the transport of cobalamin to the tissues and caused a 70% to 75% inhibition of [ 57 Co] cobalamin transported to the liver and kidney. The inhibition of transport to the tissues was independent of route of administration of cobalamin, whether intragastric or systemic, and was not due to decreased gastrointestinal uptake. When tested in vitro, concanavalin A inhibited the binding of transcobalamin II-cbl to its receptor, but not the binding of cobalamin to intrinsic factor or intrinsic factor-cobalamin complex to the ileal receptor. These results suggest that late events during transcellular transport of cobalamin through the enterocytes is the rate-limiting step determining tissue levels of cobalamin and that ConA inhibits these latter events.
t-Matrix perturbation theory of solid helium

Abstract A detailed t-matrix theory is developed for the ground state of solid helium, based on partial summations of the Brueckner-Goldstone expansion. Self-consistent Wannier orbitals are used to define the single-particle basis. This raises some theoretical and practical questions which are carefully examined. (The suitability of this type of basis for Mott insulators is also pointed out.) We draw attention to the existence of a degenerate version of the Goldstone linked-cluster expansion. This can be used (1) to handle the degeneracy problem arising from the possibility of multiply occupied sites in the unperturbed wavefunction, and (2) to justify and derive a model Hamiltonian of the Heisenberg form, in order to describe the spin interactions in solid 3He. A specific partial-summation scheme is then developed. Detailed arguments show that this should provide very rapid convergence, for both the long-range attractive and the short-range repulsive aspects of v. By carefully including the ladders of particle-hole and hole-hole interactions, we obtain a wave equation for the two-body correlations (Bethe-Goldstone equation) which differs from those of previous t-matrix theories. Perturbative comparisons are made with these earlier theories, and some discrepancies between the previous calculations and experiment are qualitatively resolved. The problem of the exchange energy of solid 3He is carefully examined, and several corrections to previous theories are found. Our formula for the exchange energy is manifestly antiferromagnetic, no matter how strong the short-range repulsion may be. The previous t-matrix calculations have all approximated the normally occupied orbitals by Gaussian functions. Our theory satisfies a many-body variational principle, and this is shown to provide a useful criterion for optimizing the size parameter α2 in such Gaussian-orbital calculations. A linked-cluster expansion is developed for the boson system of solid 4He, and we demonstrate that all to the foregoing results can be readily adapted to this Bose system. Wherever possible, comparisons are made with the results obtained from the Jastrow variational approach. The problems of phonon correlations (real and virtual) are briefly discussed.
Dwarf Novae with Newly Determined Parallaxes: Model Analyses of VY Aquarii, RU Pegasi, and T Leonis

ABSTRACT Using newly determined parallaxes for dwarf novae, we have derived outburst accretion rates for VY Aqr, RU Peg, and T Leo, and for T Leo during quiescence. The two short‐period dwarf novae, VY Aqr and T Leo, show good agreement with optically thick steady‐state accretion disks in outburst, whereas RU Peg shows a significant departure from a steady‐state disk. We have determined that the white dwarf in T Leo has \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $T_{\mathrm{eff}\,}=16,000\pm 1000$ \end{document} K, a value c...
497: The outcomes of prenatally diagnosed gastroschisis after comparing two delivery management protocols: Elective cesarean section vs. term vaginal delivery

MEDICINE ANDREW DEONARINE, GREG RYAN, LINDSAY POLLARD, NINDU KARU, RORY WINDRIM, DAVID CHITAYAT, PETER KIM, HANA SROKA, SULOCHANA SHANMUGATHASAN, University of Toronto, Toronto, Ontario, Canada, Mount Sinai Hospital, Fetal Medicine Unit, Toronto, Ontario, Canada, Fetal Alert Network, Toronto, Ontario, Canada, Mount Sinai Hospital, Toronto, Ontario, Canada, Mount Sinai Hospital, Prenatal Diagnosis & Medical Genetics, Toronto, Ontario, Canada, Hospital for Sick Children, Paediatric Surgery, Toronto, Ontario, Canada, Fetal Alert Network, Ontario, Canada OBJECTIVE: Terminology and coding systems vary widely in fetal medicine. This lack of uniformity hampers effective communication & comparison of results between different units, specialties and countries. We aimed to develop a lexicon of terminology and definitions (a biomedical ontology) that could be used by all MFM’s in Canada. This would be maintained through a web server allowing clinicians to obtain standardized, transferable, accurate results for clinical and research purposes. STUDY DESIGN: FOX-DB was developed in Visual Studio.Net 2005 to crossreference some of the most respected and widely used international coding systems: 1) ICD-10, 2) London Database, 3) American Cardiac Association, 4) OMIM, 5) British Pediatric Association COD, 6) Orpha.Net. Other appropriate systems can be included in the future. A mutidisciplinary group used FOX-DB to develop and evaluate a unified ontology by x-referencing terminologies and codes across various coding systems. Variables were compared at several levels: i) clinical systems, ii) sub-components, iii) antenatal findings, iv) postnatal diagnoses, v) frequency of occurence. RESULTS: Preliminary analyses show marked differences and overlap in terminology and coding between systems. We created a unified ontology in XML format of several thousand entries. These data can be converted into a variety of formats for different computer systems & epidemiological databases. Entries were divided into findings and diagnoses, each being associated with various ontological properties and x-referenced with various coding systems. We are developing an online web server to facilitate maintenance, distribution and analysis in a variety of data formats. CONCLUSION: Standardized terminology is essential for effective clinical and research communication between specialties, databases, units & countries. It would allow data sharing between institutions and would improve record accuracy. We suggest that FOX-DB may have widespread application and appeal for many clinicians internationally.
Linear DNA introduced into carrot protoplasts by electroporation undergoes ligation and recircularization.

The integrated DNA in stable transformants formed by direct gene transfer often shows complex restriction patterns. One cause of these complex restriction patterns could be the ligation of plasmid fragments prior to their integration. This paper provides evidence for the ligation of plasmid fragments by plant cells. Carrot protoplasts were electroporated in the presence of pCaMVCATM and assayed for chloramphenicol actyltransferase (CAT) activity 24h later. Linear and supercoiled forms of pCaMVCATM supported similar levels of CAT expression. Surprisingly, digestion of the plasmid at a site between the CaMV 35S promoter and the CAT coding region reduced expression by only 40–50%. Electroporation carried out in the presence of isolated plasmid fragments suggested that this result was due to ligation of the linearized plasmid by the protoplasts. CAT expression was obtained with a mixture of isolated CaMV 35S promoter and the CAT coding region; neither fragment alone supported expression. Further evidence of ligation was provided by electroporation of protoplasts in the presence of a mixture of linearized pGEM and the 1.5-kbHind III fragment of pCaMVCATM. DNA isolated from nuclei of the protoplasts was used to transform competent cells ofEscherichia coli, and colonies were recovered that carried pGEM withHind III-CaMVCAT inserts. Electroporation of protoplasts in the presence of linear and supercoiled pGEM and use of DNA isolated from nuclei to transformE. coli yielded an estimate of the frequency of plasmid ligation. A maximum of only 4% of the input linear DNA was recovered as circular molecules. This result suggests the frequency of ligation is low, but examination of the plasmid DNA in the plant nuclei by electrophoresis indicates extensive degradation of the plasmid and preferential loss of the circular forms. Thus, the ligated plasmids may be converted to the linear form and hence rendered unrecoverable by cloning intoE. coli.
Prenyltransferase from Gossypium hirsutum

Abstract A protein fraction has been purified from Gossypium hirsutum var. Coker 413 which synthesized all four geometrical isomers of farnesyl pyrophosphate from isopentenyl pyrophosphate alone, from isopentenyl pyrophosphate and geranyl or neryl pyrophosphate. Electrophoretic analysis showed that this protein fraction consisted of three proteins. One of these proteins contained isopentenyl pyrophosphate /ag dimethylallyl pyrophosphate isomerase activity. The other two proteins were insufficiently pure to characterize. Estimation of molecular weights by electrophoresis of the three proteins revealed values in the order of 3 × 10 4 to 1.3 × 10 5 . However the same protein fraction eluted as one peak from Sepharose 6B molecular sieve columns, indicative of a larger protein component as could be accounted for by the electrophoretic molecular weight estimation. From these results and from the different products synthesized it is proposed that isopentenyl pyrophosphate /ag dimethylallyl pyrophosphate isomerase and prenyltransferase (farnesyl pyrophosphate synthetase) exists as a multiprotein complex in G. hirsutum .
Computational model of the bat auditory periphery

This paper presents an auditory processing model of the bat auditory periphery. The influence of model parameters on the dynamic range, time encoding and noise-suppression are examined. The study focuses on the operating conditions of the echolocating bat, Myotis lucifugus.
Comparative respiratory physiology of a desert snail Rabdotus schiedeanus, and a garden snail, Helix aspersa

Abstract 1. 1. Active snails of both species displayed regulation of oxygen consumption at high temperatures. 2. 2. Humidity modified oxygen consumption of dormant snails of both species. 3. 3. Oxygen consumption during activity and dormancy was consistently lower among desert snails. 4. 4. Thermal acclimation of active snails did not alter respiration: temperature relations in either species. 5. 5. Light-to-dark changes in illumination elevated metabolic rates in active desert snails.