cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of the developmental toxicity of aspirin in rabbits when administered throughout organogenesis or during sensitive windows of development.

BACKGROUND: A review of the nonsteroidal anti-inflammatory drug (NSAID) literature suggested occurrences of low-level incidences of cardiovascular and midline defects in rabbit fetuses exposed in utero. Aspirin (acetylsalicylic acid, ASA) is a widely used NSAID that irreversibly inhibits cyclooxygenases (COXs) 1 and 2. ASA has been studied extensively in rats and has consistently increased low-incidence cardiovascular malformations and defects in midline closure. The objectives of the current study were to comprehensively define the developmental toxicology profile of ASA in rabbits by using a dosing paradigm encompassing the period of organogenesis and to test the hypothesis that maternal gastrointestinal toxicity after repeated dose administrations hampers the detection of low-incidence malformations with ASA in rabbits by limiting ASA administration to sensitive windows for cardiovascular development and midline closure. METHODS: ASA was administered to pregnant New Zealand White rabbits from gestation days (GDs) 7 to 19 at dose levels of 125, 250, and 350 mg/kg per day and as single doses of 500, 750, or 1000 mg/kg on GD 9, 10, or 11. Cesarean sections were performed on GD 29, and the fetuses were examined for external, visceral, and skeletal development. RESULTS: In the repeated dose study, maternal toxicity was exhibited in the 250- and 350-mg/kg per day groups by mortality and decreased food consumption and body weight gain. In the single dose studies, maternal toxicity was exhibited at all doses by reductions in body weight gain and food consumption for 3 days after treatment. Fetal body weight was significantly reduced in the repeated dose study at 350 mg/kg per day. Fetal weights were not affected by single doses of ASA on GD 9, 10, or 11. There were no treatment-related external, visceral, or skeletal malformations associated with ASA administration throughout organogenesis or with single doses administered during critical developmental windows. CONCLUSION: These findings supported previous work demonstrating that ASA is not teratogenic in rabbits, as opposed to rats, even when large doses are administered on single days during specific windows of development. Birth Defects Research (Part B) 68:38–46, 2003. © 2003 Wiley-Liss, Inc.
Do Parties Make a Difference? The Role of Party Organizations in Congressional Elections

Political scientists have expressed concern over the decline of political parties in recent years. This study provides evidence that at least one element of the political party, the party organization, is experiencing a resurgence rather than a decline. Data collected from nearly 400 House candidates reveal that party organizations continue to play an important role in congressional elections. National party committees, particularly the parties' congressional campaign committees, are now providing candidates with valuable assistance in activities that require technical expertise, in-depth research, or connections with the Washington campaign community. Included among these activities are campaign advertising, issue development, and fund-raising. State and local party organizations continue to assist candidates with gauging public opinion and mobilizing the electorate. Republican party organizations, especially the Republican National Committee and the National Republican Congressional Committee, provide candidates with more assistance than do their Democratic counterparts. The RNC and the NRCC are more effective at targeting their assistance to candidates involved in competitive races. Party organizations are successfully adapting to the changing political environment. T he last few decades comprise an era of tremendous change for American political parties. Newly enacted campaign finance laws have served as a catalyst for the growth of vast numbers of political action committees (PACs), which now compete with parties for influence over candidates and voters. Party-initiated reforms in the nomination process have restructured the roles of party organizations in candidate recruitment and selection. The emergence of a more independent and more volatile electorate has helped to bring about changes in the tactics that candidates and parties use to garner support. Finally, technological innovations developed in the field of public relations have been adapted to the
Odontoid Fractures: Current Evaluation and Treatment Principles

Fractures of the odontoid process of the second cervical vertebra represent one of the most common and controversial injury types affecting the cervical spine. These fractures are observed in nearly all age groups but the incidence peaks in young adults and the elderly. The rate of associated spinal cord injury is considered relatively low but is not insignificant at approximately 20% of cases. Achieving osseous healing and long-term stability are principal concerns, although fibrous nonunion may provide adequate stability in certain patient populations such as low-demand elderly patients. Following careful scrutiny of radiological studies and thoughtful consideration of clinical factors, various treatment plans often remain viable options for any given patient. While nonsurgical management is always appealing when appropriate, early surgery frequently provides an ideal opportunity to achieve stable fracture healing without functional compromise. In most cases, early surgery also restores sufficient immediate stability to allow rapid patient mobilization without the need for external orthoses or halo vest immobilization, thereby reducing the risk of medical complications related to prolonged recumbency.
Studies with intra-arterial succinylcholine and its hydrolysis products.

In view of experimental work that has pointed to an effect of choline at the neuro-muscular junction, and in view of the release of this chemical in the circuTatory bed and tissue spaces upon hydrolysis of succinyldicholine, experiments have been conducted to investigate the possible interaction of choline with succinyldicholine. The experimental conditions obtained were not sufficiently accurate to warrant conclusions as regards the action of choline directly, and the reader is referred to the detailed and careful studies carried out by Hutter15 in England and Grob, Johns, and Harvey in Baltimore1416 on the action of choline. A marked interaction between choline and subsequently administered succinyldicholine was noted, however, and a hypothesis for the mechanism of action of choline under such circumstances has been presented. The release of choline by hydrolysis of succinyldicholine and succinylmono-choline is suggested as one cause for prolongation of neuriomusciilar block during clinical anaesthetic administration of succinylcholine.
Monte Carlo methods for estimating linear combinations of inverse matrix entries in lattice QCD

Abstract The lattice formulation of quantum chromodynamics (QCD) uses very large matrices (≈ 106×106 or larger). Certain linear combinations of inverse matrix elements have physical interest. Unfortunately, these matrices cannot be inverted exactly with current computers and algorithms. However, it is possible to estimate linear combinations of lattice QCD matrix elements, using Monte Carlo methods. In this paper we introduce these methods, give variances for the estimates obtained, and show how the method can be enhanced to reduce the variances of the estimates. Numerical results are given for randomly-generated matrices which simulate QCD matrices.
Failures of zidovudine postexposure prophylaxis

Since 1990, 11 cases of failure of zidovudine (ZDV) postexposure prophylaxis (PEP) for human immunodeficiency virus (HIV) exposure have been reported among healthcare workers (HCWs) around the world. In these cases, ZDV was begun 30 minutes to 8 days (median 1.5 hours) postexposure, at doses of 600-1,200 mg/day (median 1,000 mg/day) for 8-54 days (median 21 days). Five additional failures of ZDV PEP have been reported among non-HCWs exposed to an inoculum of HIV-infected blood larger than what would be expected from a needlestick. These non-HCW cases include one blood transfusion, one suicidal self-inoculation, one assault on a prison guard with a needle-syringe, and two instances of accidental intravenous infusion of HIV-infected blood or blood components during nuclear medicine procedures. One possible reason for these failures of ZDV PEP is that the transmitted strains of HIV may have had reduced sensitivity to ZDV. Collectively, these case reports indicate that if ZDV is protective as PEP, any protection afforded is not absolute.
Interferometric alignment and figure testing of large (0.5 m) off-axis parabolic mirrors in a challenging cleanroom environment

The Far Ultraviolet Spectroscopic Explorer (FUSE), successfully launched in June 1999, is an astrophysics satellite designed to provide high resolution spectra ((lambda) /(Delta) (lambda) equals 24,000 - 30,000) with large effective area (20 - 70 cm2) over the interval 90.5 - 118.7 nm. The FUSE instrument consists of four co-aligned, off-axis parabolic primary mirrors which focus light into separate spectrograph channels. The mirrors are rectangular (407 X 372 mm) and fabricated from lightweighted Zerodur blanks. We describe a straightforward method for aligning these off-axis parabolas in an autocollimation setup via qualitative and quantitative analysis of static interferograms. Initial alignment is achieved rapidly by visual inspection of the interferogram as adjustments are made in vertical and horizontal alignment. Fine alignment to the limit of the optical system then proceeds with small alignment steps and fringe analysis software to find the position which minimizes wavefront error. This method was used for figure testing the FUSE primary mirrors throughout build-up and qualification of the flight mirror assemblies. The far- ultraviolet reflectivity of the FUSE mirrors is very sensitive to molecular contamination. All mirror testing thus took place in a strictly controlled class 1000 clean room environment. In addition to the challenging vibration and turbulence problems this environment presented, two of the fight mirrors were coated with lithium fluoride over aluminum. This necessitated purging the setup with dry nitrogen, as the lithium fluoride coating degrades with exposure to water vapor. We discuss the difficulties these environmental constraints presented and summarize the mitigating action.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Ethical Care and Health Care Professionals' Involvement in Physician-Assisted Suicide

Due to growing public support for patient autonomy in end-of-life decision making, the notion of physician-assisted suicide has become less controversial among medical practitioners. Many hold that decisions regarding end-of-life care are properly made by patients, family members, and physicians directly involved with care. Given the realities of clinical practice, however, actual assistance in dying is frequently rendered by nurses, pharmacists, and respiratory technicians who are not included in the decision-making group. These health care providers are positioned between the language of professionalism which demands their active participation in all aspects of patient care, and the language of physician authority which discourages the critical questioning of physician orders, particularly concerning assistance in dying. This contradiction leads many health care providers to remain silent on the subject of assisted death, diminishing their professionalism and their contribution to public argument.
Tropism of Bunyaviruses: Evidence for a G1 Glycoprotein-Mediated Entry Pathway Common to the California Serogroup

Abstract The California serogroup is composed of antigenically and biologically related viruses within the Bunyavirus genus of the Bunyaviridae. We used a large panel of murine cells to study their tissue tropisms and found virtually identical patterns of viral replication among all of the members of this serogroup, in contrast to other members of the family (Bunyamwera, Cache Valley, and Punta Toro viruses). By analyzing the nonpermissive infections with both an RNA dot-blot and a virus binding assay, we determined that tropism for cultured cells was determined at the level of entry. A truncated soluble form of the La Crosse G1 glycoprotein (sG1) was expressed in a baculovirus system and, despite slight differences in glycosylation, was shown to resemble native G1 by immunoprecipitation with six monoclonal antibodies. sG1 bound to permissive but not to nonpermissive cell lines, as demonstrated by flow cytometry. The sG1 effectively blocked infection of permissive cell lines with all of the California serogroup viruses, but did not block infection of two other bunyaviruses. These results indicate that the California serogroup bunyaviruses share a common receptor on vertebrate cells which may differ from the receptor used by other Bunyaviridae and demonstrate that the G1 glycoprotein is the virus attachment protein. sG1 will be a useful reagent in the search for a putative receptor molecule.
Thiophene Hydrodesulfurization over Alumina-Supported Molybdenum Carbide and Nitride Catalysts: Adsorption Sites, Catalytic Activities, and Nature of the Active Surface

Mo2C/Al2O3and Mo2N/Al2O3catalysts have been synthesized and characterized by X-ray diffraction, pulsed chemisorption (CO and O2) and infrared (IR) spectroscopy, and temperature programmed desorption (TPD) measurements. Thiophene hydrodesulfurization (HDS) activities were measured for alumina-supported Mo carbide and nitride catalysts as well as a sulfided Mo/Al2O3catalyst, all with a 10 wt% Mo loading. The HDS activities (μmol Th/mol Mo/s) of the catalysts after 24 h at 693 K were found to increase according to the trend sulfided Mo < γ-Mo2N < β-Mo2C, and provide further evidence that carbide and nitride catalysts have the potential to replace sulfided Mo catalysts in commercial HDS reactors. X-ray diffraction analysis of fresh and tested 30 wt% Mo2C/Al2O3and Mo2N/Al2O3catalysts indicates that the bulk structure of the carbide (β-Mo2C) and nitride (γ-Mo2N) particles is retained, while IR spectroscopy of adsorbed CO indicates that the surface of the carbide and nitride particles becomes sulfided under reaction conditions. A model is proposed for the structure of the active catalytic surface of the alumina-supported Mo carbide and nitride catalysts in which a thin layer of highly dispersed sulfided Mo is present on the surfaces of the carbide and nitride particles.
Analytic measurement of mirror surfaces by a single shot with united modeling of incident rays

In this study, an analytic measurement system is developed to reconstruct the 3D shapes of mirror surfaces. Its principle is to compute the interception points of the incident rays and the corresponding emergent rays reflected by the mirror surface. The laser rays are produced by projecting a dot pattern using a pico laser projector and each bright dot corresponds to one single laser ray. To obtain more laser rays and a more detailed reconstruction, the distance between adjacent dots needs to be as small as possible. During the practical implementation, it is found that its sensitivity to noise increases abruptly when the adjacent distances between rays are relatively small. To reduce the noise and improve the reconstruction accuracy, a united modeling method is proposed properly. After each laser ray has been modeled separately and their equations are known, they are modeled as a whole based on the working scheme of the laser projector. The united modeling restricts the freedom of the ray distribution as a whole and thus reduces the noise greatly. In addition, the proposed united modeling method can rectify the optical distortion introduced by the projector and thus the additional projector calibration is avoided. Experimental results verified both the effectiveness of the proposed united modeling method and the effectiveness of the developed analytic measurement system.
Characterization of surfaces of laser-annealed samples by ellipsometry

Abstract It is shown that ellipsometry can be used for the nondestructive characterization of surface layers of laser-annealed semiconductors as well as of transparent materials such as glasses. The structural imperfections introduced during their preparatory history of the surface layers of single crystal silicon, vitreous silica, and pyrex samples, can be laser annealed and characterized. The “polish layers” on the surface of glasses can also be annealed out by this process.
The role of biologic mesh in abdominal wall reconstruction: a systematic review of the current literature

Abstract Background Biologic mesh in the form of allograft or xenograft products have been used in complicated abdominal hernia repair, but few comparative studies exist. Methods A systematic review of original incisional hernia studies was conducted to include 2 primary end points: hernia recurrence and surgical site occurrence. Analysis of variance and a Satterthwaite t test compared the devices. Results Twenty-nine studies were included in this analysis, which included 1,257 patients. The total number of studies and the total subjects for each device include the following: Permacol (Tissue Science Laboratories, Hampshire, UK) (4/64), Surgisis (Cook Medical, Bloomington, IN) (3/87), and Alloderm (LifeCell, Corp, Branchburg, NJ) (23/1,106). Device-specific recurrence rates and surgical site occurrence rates, respectively, were as follows: Alloderm (20.8%, 31.4%), Permacol (10.9%, 25%), and Surgisis (8.0%, 40.2%). A Satterthwaite t test comparison revealed significantly higher numbers of hernia recurrence ( P = .006) and surgical site occurrence ( P = .04) when comparing Alloderm with Permacol. Conclusions Biologic mesh does play a beneficial role in abdominal wall reconstruction although allograft acellular dermal matrix does have a higher recurrence rate as compared with xenograft products, which limits its current role in hernia repair.
Generation of up-converted or down-converted photon echoes in three-level resonant medium

Abstract The equations describing the interaction of optical pulses with three-level resonant media are considered. It is shown that the resonant medium, if excited by suitable sequences of ultrashort optical pulses, can generate up-converted or down-converted photon echoes.
Resistance to American foulbrood in honey bees IX. Effects of honey-bee larval food on the growth and viability of Bacillus larvae☆

Abstract Experiments were designed to learn whether there are any differences between honey-bee (Apis mellifera) larval food from American-foulbrood-resistant and American-foulbrood-susceptible lines of bees in regard to antimicrobial action on Bacillus larvae, the pathogenic agent of American foulbrood, cultured in vitro. To test for inhibition of germination, spores were exposed to various concentrations of brood food from both genetic lines in culture medium, heat-shocked to kill vegetable cells, and then plated for germination of those spores which were inhibited from germinating. Results indicated that brood food, from an American-foulbrood-resistant line (Brown) of bees was more effective in inhibiting spore germination than brood food from a disease-susceptible line (Van Scoy). Tests for effects of brood food on vegetable cells involved their exposure for different periods of time to various concentrations of the food in an aqueous medium. It was found that brood food from the resistant line was more effective in reducing the number of viable vegetable cells than brood food from the susceptible line.
Regulation of actin gene expression during spore germination in Dictyostelium discoideum.

Abstract The regulation of actin synthesis was examined in synchronously germinating spores of Dictyostelium discoideum. Actin cDNA complementary RNA sequences were quantitiated by hybridization kinetics and compared to the relative change in total poly(A)+ mRNA and the incorporation of [35S]methionine into actin protein in vivo and in vitro. RNA excess hybridization experiments demonstrate that actin cDNA complementary RNA increases approximately 300-fold during the course of germination, whereas the relative level of total poly(A)+ RNA increases less than twofold. No actin protein synthesis can be detected during the first hour of germination in vivo. RNA isolated from activated spores, however, is capable of directing the synthesis of actin in vitro. Two hours after activation, synthesis of all actin isoelectric forms present in vegetative cells can be detected in vivo. Preferential transcription of actin messages appears to account for most of the parallel increase in in vivo synthesis of actin protein. Furthermore, the comparison of the in vivo and in vitro actin translation suggests there is some early translational regulation of actin synthesis. Isoelectric focusing and DNase-I agarose binding were used to identify four forms of actin protein synthesized during germination. These four actin forms appear to commence synthesis at approximately the same time during the second hour of germination.
Pulse dynamics in mode-locked lasers: relaxation oscillations and frequency pulling.

A theoretical description of the pulse dynamics in a mode-locked laser including gain dynamics is developed. Relaxation oscillations and frequency pulling are predicted that influence the pulse parameters. Experimental observations of the response of a mode-locked Ti:sapphire laser to an abrupt change in the pump power confirm that the predicted behavior occurs. These results provide a framework for understanding the effects of noise on the spectrum of the laser.
The Issue of Isopower in Power Analysis for Tests of Structural Equation Models

Two general frameworks have been proposed for evaluating statistical power of tests of model fit in structural equation modeling (SEM). Under the Satorra–Saris (1985) approach, to evaluate the power of the test of fit of Model A, a Model B, within which A is nested, is specified as the alternative hypothesis and considered as the true model. We then determine the power of the test of fit of A when B is true. Under the MacCallum–Browne–Sugawara (1996) approach, power is evaluated with respect to the test of fit of Model A against an alternative hypothesis specifying a true degree of model misfit. We then determine the power of the test of fit of A when a specified degree of misfit is assumed to exist as the alternative hypothesis. In both approaches the phenomenon of isopower is present, which means that different alternative hypotheses (in the Satorra–Saris approach) or combinations of alternative hypotheses and other factors (in the MacCallum–Browne–Sugawara approach) yield the same level of power. We sh...
On sojourn times in the finite capacity M/M/1 queue with processor sharing

We consider a processor shared M/M/1 queue that can accommodate at most a finite number K of customers. We give an exact expression for the sojourn time distribution in this finite capacity model, in terms of a Laplace transform. We then give the tail behavior, for the limit K->~.
Behavioral medicine: treatment and organizational issues.

Behavioral medicine is a newly emerging field dating back to the early 1970s. In this short time, a great deal of controversy and confusion has arisen as to even the definition of the term. Similarly, there are now a variety of different operational applications of this concept in patient care, research, and health care system organizations. It is proposed that the title "behavioral medicine" be used in the most general way, consistent with the definition developed by the Institute of Medicine meeting in 1978. In it, behavioral medicine is a term designating a very large field and is not analogous to a profession, medical specialty, or discipline. This term denotes a body of psychologic and social knowledge and a set of techniques applied to research, prevention, and treatment of medical illness, including psychiatric illness. By this definition, behavioral medicine treatment techniques would include psychotherapy, hypnosis, relaxation, behavior therapy, behavior modification, biofeedback, and pharmacotherapy. One of the cardinal principles of behavioral medicine as a field is that well-defined treatment techniques are used for specific target symptoms or signs of illness. It is proposed that individual behavioral medicine treatment programs be called by the name of either the specific treatment utilized or of the target(s) of the intervention. It is important to ensure collaboration between the variety of treatment and research programs that would fall under this general definition of behavioral medicine, which includes consultation-liaison psychiatry. An organizational model is proposed that would combine all such programs within a multidisciplinary division of a department of psychiatry. This division might be entitled with one or both names, e.g., "consultation-liaison psychiatry and behavioral medicine." Perhaps most importantly, this new field should not promise more than it may be able to provide, particularly in trying to achieve the biopsychosocial model of medicine. Many factors have contributed to the rise of biomedicine and to the decline of personal medicine, most of them far beyond the scope and control of behavioral medicine.
Evaluation of a retention model for high-performance ion-exchange chromatography using two different displacing salts

Abstract A model proposed for the retention of proteins on high-performance ion-exchange chromatographic supports was further investigated via the use of NaCl vs. MgCl2 as the chromatographic displacing salt. Evaluations of the Z term generated by this model were carried out using selected proteins on a strong anion-exchange support in an effort to define its meaning more clearly. A positive correlation between Z and protein retention was found. Higher values for ZMgCl2 were attributed to enhanced ionization of protein functional groups by Mg2+. Findings suggest that Z could be more precisely defined as the number of electrostatic interactions between the protein and the ion-exchange support.
Resistance to Antiviral Inhibitors Caused by the Mutation S889A in the Highly-Conserved 885-GDTDS Motif of the Herpes Simplex Virus Type 1 DNA Polymerase

Most point substitutions in the highly-conserved 885-GDTDS motif of the HSV-1 DNA polymerase inactivate polymerase elongation activity. However, in an assay system based on expression by in vitro transcription-translation, the mutant GDTDA (S889A) possessed wild-type elongation activity which was highly resistant to phosphonoacetic acid and acyclovir triphosphate, but retained sensitivity to aphidicolin.
The Essence and Efficiency Limits of Bulk-Heterostructure Organic Solar Cells

Since its introduction in early 1990s, bulk-heterojunction organic photovoltaic solar cell (BHJ-OPV) has promised high-efficiency at ultra-low cost and weight, with potential for nontraditional applications such as building-integrated PV. There is a widespread presumption, however, that the complexity of morphology makes carrier transport in OPV irreducibly complicated, and possibly, beyond predictive modeling. In this paper, we use elementary and intuitive arguments to derive the fundamental thermodynamic as well as morphology-specific practical limits of BHJ-OPV efficiency. We find that constraints of the percolation threshold and trade-off among short-circuit current, open circuit voltage, and fill factor make substantial improvement in OPV efficiency difficult. We posit that future improvement in OPV will rely not on morphology engineering, or reducing the polymer bandgap, but on increasing both the effective product and the cross-gap between donor/acceptors. Even if the OPV fails to achieve the highest efficiency anticipated by the thermodynamic limit, its novel form factor, lightweight, and transparency can make it a commercially viable option for many applications.
Individualized hybrid models for conjoint analysis

Increasingly, conjoint analysts are being asked to design and analyze studies involving large numbers of attributes and/or attribute levels. Various types of approaches, including attribute bridging, Adaptive Conjoint Analysis, and hybrid models have been proposed to deal with the problem. This paper describes recent developments in hybrid modeling. Four hybrid models are described and compared in terms of their performance in an industry-based study entailing 15 product attributes. Comparisons are made in terms of internal cross-validation, market share estimates, attribute importances clustering, and its relationship to exogenous background variables. The proposed models are also compared to selected models from the transportation science literature. The authors emphasize the point that comparative model performance may strongly depend on the ways in which the models are to be used.
Subunit Rules Governing the Sorting of Internalized AMPA Receptors in Hippocampal Neurons

Removal of synaptic AMPA receptors is important for synaptic depression. Here, we characterize the roles of individual subunits in the inducible redistribution of AMPA receptors from the cell surface to intracellular compartments in cultured hippocampal neurons. The intracellular accumulation of GluR2 and GluR3 but not GluR1 is enhanced by AMPA, NMDA, or synaptic activity. After AMPA-induced internalization, homomeric GluR2 enters the recycling pathway, but following NMDA, GluR2 is diverted to late endosomes/lysosomes. In contrast, GluR1 remains in the recycling pathway, and GluR3 is targeted to lysosomes regardless of NMDA receptor activation. Interaction with NSF plays a role in regulated lysosomal targeting of GluR2. GluR1/GluR2 heteromeric receptors behave like GluR2 homomers, and endogenous AMPA receptors show differential activity-dependent sorting similar to homomeric GluR2. Thus, GluR2 is a key subunit that controls recycling and degradation of AMPA receptors after internalization.
Type-Curve Matching Techniques With Error Sensitivity Numbers

This paper presents several error sensitivity numbers suitable to general type-matching curves given as log-log graphs with dimensionless parameters. Also, the utility and application of type-curves with tables of error sensitivity numbers are illustrated with an example type curve proposed by Wattenbarger and Ramey. The reliability of each parameter obtained by this type curve is discussed, as well as its appropriate use in terms of proper number cycles to be used and proper data points.
Kinetics and mechanisms of creep in hot isostatically pressed niobium carbide

Constant compressive stress creep experiments in the temperature and stress ranges of 1730K to 2100K and 16 MN/m/sup 2/ to 70 MN/m/sup 2/ on HIPed NbC/sub 0.74/ have revealed stress exponents of 2.0 under stress levels of 16 to 54 MN/m/sup 2/ at all temperatures investigated and 3.2 under stress levels of 54 to 70 MN/m/sup 2/ at 1830K. The activation energy of steady state creep is approximately 230 kJ/mol in the temperature range of 1730K to 1930K under 48 to 54 MN/m/sup 2/ and 470 kJ/mol in the temperature range of 1900K to 2100K under 64 MN/m/sup 2/. TEM of the annealed but uncrept material reveals grown-in dislocation subboundaries. At 1730K and under 34 to 54 MN/m/sup 2/ the subboundaries evolve into simple tilt boundaries which are occasionally knitted, indicating more glide activity at higher stresses. At 1930K and under 34 to 54 MN/m/sup 2/, hexagonal subboundaries form, but are not as well defined as in the annealed material. At 2100K and under 16 to 30 MN/m/sup 2/, the subboundaries are well-defined hexagonal networks which become polygonized under higher stresses on 64 MN/m/sup 2/. The experimental and TEM results indicate that at low temperatures (below 0.5 T/sub m/ =more » 2073K) and at all stresses, creep occurs by dislocation glide which is accompanied by subgrain and high angle boundary interaction. At high temperature (above 0.5 T/sub m/), strain occurs by glide and subboundary movement; recovery occurs by climb in the subboundary.« less
Children’s Learning Groups: A Study of Emergent Leadership, Dominance, and Group Effectiveness

This study explores the importance of the group context in the emergence of leadership, dominance, and group effectiveness in children’s cooperative learning groups. Using achievement goal orientat...
A SOLUBLE PROTEIN‐CHLOROPHYLL COMPLEX FROM SPINACH CHLOROPLASTS—III DETERMINATION OF MOLECULAR WEIGHT AND COMPARTSON OF COMPLEX ISOLATED FROM DIFFERENT SOURCES*

Abstract— Work on the purification and characterization of the soluble protein-chlorophyll complex isolated from spinach chloroplasts has led to these results: (a) The sedimentation constant Sw,20 of the complex bound to the Triton micelle is 2.28. With excessive dialysis however, it aggregates and sediments with varied Sw,20 values that are multiples of 2.28. (b) The micelle has a partial specific volume V= 0.920 and a diffusion coefficient D= 5.53 ± 10-7 cm2/sec. A molecular weight of 120,200 for the micelk was calculated from these data. From the ratio of Triton to protein and chlorophyll in the preparation, the molecular weight for the complex alone was calculated as 17,200. (c) The complexes isolated from different species have similar physical and photochemical characteristics. (d) The percent of the chloroplast-chlorophyll extractable as the protein-chlorophyll complex is low in young, expanding leaves, reaches a peak in mature leaves and drops off with senescence. (e) Under strictly anaerobic conditions the complex will reduce cytochromes at rates similar to those of ferricyanide reduction.
Writing style for architectural synthesis

An encapsulated writing style of Verilog is described together with models for a corresponding scheduler and synthesizer. The method provides a middle ground between synthesis from behavioral specifications, which implies decisions too difficult for architectural synthesis, and synthesis from pure structural specifications, which necessitates providing full details of the controller and netlist. The input writing style is designed to be as concise as possible. This is done by the encapsulation of the functionality of major submodules, and implicit (inferred) control. In this way it is possible to describe complex functional architectures in an economical and transparent manner. This description can be transformed semi-automatically by steps through intermediate styles and eventually to a pure structural specification containing fall details of timing invocations and interconnections to appropriate controllers. At each stage after the first, the writing styles can be fully accessible to native Verilog simulators. The efficiency and economy of this style is demonstrated by a simulation of the well known DLX processor benchmark with full pipeline bypasses.
Prospective Patterns and Correlates of Quality of Life among Women in Substance Abuse Treatment

Background Quality of life (QOL) is increasingly recognized as central to the broad construct of recovery in substance abuse services. QOL measures can supplement more objective symptom measures, identify specific service needs and document changes in functioning that are associated with substance use patterns. To date however, QOL remains an under investigated area in the addictions field, especially in the United States.
Forces on immersed tubes in fluidized beds

The external forces imparted by the bed material on tubes in a fluidized bed contribute to failure of the tubes and their support systems. The objective of this investigation was to provide data on tube forces to be used in structural design. Forces on tubes of various lengths were measured in fluidized beds operating at room temperature. The parameters varied in the experiments were superficial gas velocity and tube array height above the gas distributor. The force-time histories consisted of a series of pulses, whose magnitudes were approximately linearly proportional to tube length. Spectral analyses of the time series indicated that the primary frequency composition of the load was below 25 Hz.
Embodied knowledge: The experience of meaning and the struggle towards proficiency in glassblowing

Becoming a proficient glassblower involves an indispensable shift away from cognitive readings of practice towards corporeal readings. In learning glassblowing myself in the course of an ethnograph...
Development of the gonads in the female Japanese quail.

The germ cells in the Japanese quail, appear in the gonadal area between two to two and one half days incubation with a preferential distribution favoring the left gonad. Proliferation of the primary or medullary cords from the germinal epithelium was observed between four and five and one half days. The secondary or cortical cords were found to proliferate in the left gonad on the sixth day. The right gonad revealed neither cortical cords nor cortex in any of the cases studied. It began to involute around eighth day and reached its minimum size by seven to ten days after hatching. In the adult it was composed of loose, or occasionally cord-like, epithelial cells, sparsely scattered “fat laden” cells, masses of lymphocytes and fibrous connective tissue, the latter predominating in older stages. Germ cells either disappeared or could no longer be recognized in the right gonad by four days after hatching. In the left ovary oogonia began to show meiotic changes by the eleventh day and primary follicles were present on the day of hatching. Ovulation was observed as early as 45 days after hatching. In female embryos the right Mullerian duct underwent atrophy and became a rudimentary cloacal remnant between eight and 14 days. In males complete atrophy of both left and right Mullerian ducts occurred between seven and 13 days. The mesonephric ducts persisted in females and were demonstrable throughout post-hatch period as thread-like structures.
A note on a production control model for a facility with limited storage capacity in a random environment

Abstract This note presents an extension of our earlier paper on a production–inventory system with limited storage capacity in a multi-state random environment [i.e., E. Mohebbi, A production–inventory model with randomly changing environmental conditions, Eur. J Res. 174 (2006) 539–552]. More specifically, it assumes that the production rate as well as the occurrence rate and batch sizes of a compound Poisson demand stream are influenced by the state of a continuous-time homogeneous Markov chain representing the random environment. We present an adaptation of the system-point method of level crossings which yields the limiting distribution of inventory level (stock-on-hand) for a two-parameter production control policy when stockouts are lost.
Small- and moderate-size right-to-left shunts identified by saline contrast echocardiography are normal and unrelated to migraine headache.

Background We suspected, based on clinical experience, that the prevalence of both intracardiac and pulmonary arteriovenous malformations (PAVMs) is higher than previously reported in a healthy population when using modern ultrasound technology combined with a rigorous saline contrast echocardiogram (SCE) protocol. We hypothesized the prevalence of right-to-left shunts (RLSs) would be so high when using this sensitive technique that there would be no significant association of RLS with migraine headache. Methods We recruited 104 healthy volunteers to undergo an SCE followed by completion of a migraine questionnaire. The SCEs were meticulously graded for shunt size and location based on left-sided heart contrast quantity and timing. The migraine headache questionnaire was graded by a neurologist blinded to SCE results. Results One hundred four subjects underwent the study protocol. We found 71% of subjects exhibited evidence of RLS. Patent foramen ovale (PFO) was identified in 40 (38%), PAVM was identified in 29 (28%), and five subjects had evidence of both (5%). Based on questionnaires, 42 (40%) of the subjects had migraine headache (29% with aura). There was no significant association of migraine headache with PFO (OR, 0.59; 95% CI, 0.16-2.12; P = .54) or PAVM (OR, 0.8; 95% CI, 0.34-1.9; P = .67), although only 13 (13%) of the subjects had evidence of large RLS. Conclusions When using modern ultrasound technology combined with a rigorous SCE technique, the majority of healthy subjects demonstrate some degree of RLS. PAVM in an otherwise healthy population is common. Small- and moderate-size RLSs do not appear to be significantly associated with migraine headache.
Immunostaining for peroxisome proliferator gamma distinguishes dedifferentiated liposarcoma from other retroperitoneal sarcomas

Dedifferentiated liposarcoma can be readily diagnosed by the juxtaposition of a well-differentiated liposarcoma to a nonlipogenic sarcoma. However, if the lipogenic component is not abundant due to surgical sampling or small biopsy, dedifferentiated liposarcoma can be difficult to distinguish from other poorly different sarcomas. Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a nuclear hormone receptor that plays a critical role in adipocyte differentiation. Prior studies have not only demonstrated PPAR-gamma mRNA in various subtypes of liposarcoma but have also shown that adipocyte differentiation can be induced in some liposarcomas by a PPAR-gamma agonist. In the present study, we investigated whether immunostaining for PPAR-gamma can be used to distinguish dedifferentiated liposarcoma from other retroperitoneal sarcomas. We examined a series of 40 dedifferentiated liposarcoma and compared the staining for PPAR-gamma to a series of 24 retroperitoneal sarcomas that lacked lipogenic differentiation. A monoclonal antibody against PPAR-gamma was used to stain formalin-fixed paraffin-embedded tissue. Specific nuclear immunostaining was present in 37/40 (93%) of the dedifferentiated liposarcoma and 6/24 (25%) of the other sarcomas (two leiomyosarcomas and four undifferentiated sarcomas). Interestingly, immunostaining for CDK4 and/or MDM2 was identified in three of the four PPAR-gamma-positive undifferentiated sarcomas, raising the possibility that these may represent dedifferentiated liposarcoma. This is the first study demonstrating the utility of PPAR-gamma immunohistochemistry in the diagnosis of dedifferentiated liposarcoma in tissue sections. Although not completely specific, the presence of PPAR-gamma staining, in combination with histologic findings and other markers, can aid in the diagnosis of dedifferentiated liposarcoma, particularly on small biopsies that may not sample the well-differentiated component.
Shell neurons of the master circadian clock coordinate the phase of tissue clocks throughout the brain and body

Daily rhythms in mammals are programmed by a master clock in the suprachiasmatic nucleus (SCN). The SCN contains two main compartments (shell and core), but the role of each region in system-level coordination remains ill defined. Herein, we use a functional assay to investigate how downstream tissues interpret region-specific outputs by using in vivo exposure to long day photoperiods to temporally dissociate the SCN. We then analyze resulting changes in the rhythms of clocks located throughout the brain and body to examine whether they maintain phase synchrony with the SCN shell or core. Nearly all of the 17 tissues examined in the brain and body maintain phase synchrony with the SCN shell, but not the SCN core, which indicates that downstream oscillators are set by cues controlled specifically by the SCN shell. Interestingly, we also found that SCN dissociation diminished the amplitude of rhythms in core clock gene and protein expression in brain tissues by 50–75 %, which suggests that light-driven changes in the functional organization of the SCN markedly influence the strength of rhythms in downstream tissues. Overall, our results reveal that body clocks receive time-of-day cues specifically from the SCN shell, which may be an adaptive design principle that serves to maintain system-level phase relationships in a changing environment. Further, we demonstrate that lighting conditions alter the amplitude of the molecular clock in downstream tissues, which uncovers a new form of plasticity that may contribute to seasonal changes in physiology and behavior.
Redesign of Choline Acetyltransferase Specificity by Protein Engineering

Abstract Since the development of site-directed mutagenesis techniques over 15 years ago (Zoller, M. J., and Smith, M. (1982) Nucleic Acids Res. 10, 6487–6500), it has been a goal of protein engineering to utilize the procedure to redesign existing enzyme structures to produce proteins with altered or novel catalytic properties. To date, however, the more successful achievements have relied exclusively on the availability of three-dimensional protein structure maps to direct the redesign strategies. Presently, such maps are unavailable for choline acetyltransferase and carnitine acetyltransferase, enzymes that catalyze the reversible transfer of an acetyl group from acetyl-CoA to choline and l-carnitine, respectively. A more empirical approach, based on cross-referencing substrate structure comparisons with protein alignment data, was used to redesign choline acetyltransferase to accommodate l-carnitine as an acceptor of the acetyl group. A mutant choline acetyltransferase that incorporates four amino acid substitutions from wild type, shows a substantial increase in catalytic efficiency (k cat/K m) towardl-carnitine (1,620-fold) and shifts the catalytic discrimination between choline and l-carnitine by >390,000 in favor of the latter substrate. These dramatic alterations in catalytic function demonstrate that significant success in protein redesign can be achieved in the absence of three-dimensional protein structure data.
Nonlinear Normal Modes in a System with Nonholonomic Constraints

We investigate the dynamics of a system involving the planar motion of a rigid body which is restrained by linear springs and which possesses a skate-like nonholonomic constraint known as Caplygin’s sleigh. It is shown that the system can be reduced to one with 2 1/2 degrees of freedom. The resulting phase flow is shown to involve a curve of nonisolated equilibria. Using second-order averaging, the system is shown to possess two families of nonlinear normal modes (NNMs). Each NNM involves two amplitude parameters. The structure of the NNMs is shown to depart from the generic form in the neighborhood of a 1:1 internal resonance.
Ultramicro Automated Screening Method for Uric Acid

An automated colorimetric microprocedure, suitable for screening purposes, has been developed for the determination of blood uric acid levels. The method uses 2O-µl. whole-blood (capillary) samples and is based on the AutoAnalyzer measurement of the absorbance of the colored uric acid-phosphotungstic acid complex. The dilution inherent in the sampling procedure necessitated a modification of the existing AutoAnalyzer method to increase the sensitivity. The proposed method is evaluated for precision and accuracy by comparison with the standard AutoAnalyzer macro-method.