cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of immune-matched hematopoietic transplantation in zebrafish

Evaluating hematopoietic stem cell (HSC) function in vivo requires a long-term transplantation assay. Although zebrafish are a powerful model for discovering the genetics of hematopoiesis, hematopoietic transplantation approaches have been underdeveloped. Here we established a long-term reconstitution assay in adult zebrafish. Primary and secondary recipients showed multilineage engraftment at 3 months after transplantation. Limiting dilution data suggest that at least 1 in 65 000 zebrafish marrow cells contain repopulating activity, consistent with mammalian HSC frequencies. We defined zebrafish haplotypes at the proposed major histocompatibility complex locus on chromosome 19 and tested functional significance through hematopoietic transplantation. Matching donors and recipients dramatically increased engraftment and percentage donor chimerism compared with unmatched fish. These data constitute the first functional test of zebrafish histocompatibility genes, enabling the development of matched hematopoietic transplantations. This lays the foundation for competitive transplantation experiments with mutant zebrafish HSCs and chemicals to test for effects on engraftment, thereby providing a model for human hematopoietic diseases and treatments not previously available.
Nifedipine solid dispersion in microparticles of ammonio methacrylate copolymer and ethylcellulose binary blend for controlled drug delivery Effect of drug loading on release kinetics

In order to elucidate the controlled-release mechanism of a poorly water-soluble drug from microparticles of ammonio methacrylate copolymer and ethylcellulose binary blend prepared by a phase-separation method, nifedipine-loaded microparticles with different levels of drug loading were evaluated by micromeritic properties, drug physical state, matrix internal structure, drug dissolution, and release modeling. Drug release study indicated that nifedipine release from the microparticles followed the Fickian diffusion mechanism, which supported the study hypothesis that as a result of formation of a nifedipine molecular dispersion, nifedipine dissolution inside the matrix was no longer the rate-limiting step for drug release, and the drug diffusion in matrix became the slowest step instead. Moreover, study results indicated that even though drug loading did not significantly affect the microparticle size distribution and morphology, nifedipine release rate from those microparticles was more or less influenced by the level of drug loading, depending on matrix formulation. At lower levels of drug loading, nifedipine release was well described by the Baker and Lonsdale's matrix diffusion model for microspheres containing dissolved drug and nifedipine had a plasticizing effect on the polymers that caused an increase in drug effective diffusion coefficient with increasing drug loading. However, at higher levels of drug loading, probably due to formation of solid nifedipine domains in microparticles, a change in the release kinetics was observed.
Towards an experiential analysis of shamanism

A comprehensive delineation of the ecstatic states of shamans is developed along the lines of cross-cultural psychiatry. Psychiatric concepts, such as dissociation, role playing and hypnosis, are integrated with the ethnographic literature on spirit possession, soul journey and other forms of shamanic ecstasy in order to shed light upon some old anthropological controversies regarding the psychopathology and authenticity of the shaman's trance. Forty-two cultures, from four different cultural areas, are compared in order to determine a set of experiential and psychological factors that collectively identify what is meant by shamanic ecstasy. Shamanic ecstasy is identified as a specific class of ASC involving: (a) voluntary control of entrance and duration of trance, (b) posttrance memory, and (c) transic communicative interplay with spectators. [shamanism, altered states of consciousness, spirit possession, ethnopsychiatry]
Measurement of dimeric inhibin in porcine serum: Evidence for low concentrations and existence of binding proteins

Abstract An immunoradiometric assay and serum extraction procedure were developed to measure dimeric inhibin in porcine serum with minimal interference by putative inhibin-binding proteins. Assay sensitivity was 50 pg/tube, and it incorporated antibodies against the N-terminal region of inhibin's α-subunit, α-(1–25)-Ab, and against the C-terminal region of inhibin's β A -subunit. To determine whether inhibin-binding proteins were present in porcine serum, serum was incubated with [ 125 I]-recombinant human (rh)-inhibin and then chromatographed by gel filtration. Radioiodinated rh-inhibin was associated with protein(s) >600 kDa. Radioiodinated rh-inhibin also was incubated with α 2 -macroglobulin, an inhibin-binding protein in human and rat serum. Elution profiles were similar for serum and α 2 -macroglobulin. Serum- and α2-macroglobulin-[125I]rh-inhibin complexes dissociated upon exposure to 8 M urea. Porcine serum was treated with urea, after which inhibin was isolated and concentrated. The recovery of rh-inhibin added to starting serum was 28%. Concentrations of endogenous dimeric inhibin were α 2 -macroglobulin, is present in porcine serum.
Length-Dry Weight Relationships of Some Freshwater Zooplanktona

Abstract Biomass of zooplankton can be estimated from the relation between length and weight by measuring the appropriate dimension of length on individual zooplankton. Length-dry weight relationships for 15 species of freshwater crustacean zooplankton collected from the Connecticut River were determined. Length-weight equations can be used to rapidly determine the biomass of zooplankton species when it is impractical to directly measure their weights.
Populations of spores and propagules of mycorrhizal Fungi in relation to the life cycles of tall fescue and tobacco

Abstract Relations between spores and propagules of a mycorrhizal fungal community were studied in a tall fescue pasture which was plowed in late fall, then either reseeded in tall fescue or planted to tobacco the following spring. Soilborne populations of viable spores, isolated by wet-sieving, or propagules, determined by bioassay, were measured throughout a growing season and the following spring. Populations of spores of all species declined at least 7-fold from spring through mid-summer, then rose in the fall to densities not different from those in the spring. Populations of spores declined to some extent over-winter. Populations of propagules, however, were relatively constant. Spore and propagule population dynamics were similar for fescue and tobacco, although the phenologies of the two plants differ. Sporulation was not related to reproduction of fescue. These data suggest that from fall until early spring, propagules are primarily spores; whereas in spring, spores germinate, and propagules are primarily mycelia until sporulation occurs in the fall.
Working with symptoms of a respiratory infection: staff who care for high-risk individuals.

Background While many health care workers (HCWs) who have respiratory infections take sick leave, others work following illness onset. Little is known about attendance practices of HCWs caring for persons with spinal cord injuries (SCI), a group at high risk for respiratory complications. Methods Cross-sectional survey of HCWs. Logistic regression identified factors associated with having a respiratory infection and examined if awareness of facility level institutional control measures and/or individual level factors influenced working while symptomatic. Results Response rate was 53% (n = 820). Respiratory infections were reported by 36%; of those, 86% attended work while symptomatic. HCWs aged 50 and above were less likely (odds ratio [OR] 0.58, P = 0.003) and those with a chronic condition were more likely (OR 2.24, P P = 0.034), restricts staff movement between wards, (OR 0.26, P = 0.002), and restricts contact between patients (OR 0.32, P = 0.009) were significantly less likely to work while symptomatic. Conclusions It is alarming that 86% of HCWs attended work while symptomatic, given the consequences that respiratory infection can have on persons with SCI. HCW awareness of outbreak control measures within their facilities appeared to influence their attendance decisions, suggesting the importance of policy placement and information dissemination.
The emergence of molecular neurobiology

Abstract The field of molecular neurobiology has existed for several decades, but until the past few years the number of questions in neuroscience that could be addressed on a molecular level was quite limited. New methods in biophysics, molecular biology and immunology have increased dramatically the number of subjects amenable to molecular studies.
Malignant Hyperthermia. Considerations for the Ophthalmologist

Malignant hyperthermia, a relatively recently described entity, is a little-understood disease process usually manifesting as operative or postoperative hyperpyrexia in association with a hypermetabolic state. Specific therapy with procaine (Novocaine) and more recently with a muscle relaxant, dantrolene sodium (Dantrium), has shown itself to be life-saving, and currently diagnosis can be made by muscle biopsy in patients from affected pedigrees. Malignant hyperthermia is a risk in all general anesthetic procedures, particularly squint and ptosis repair, and may even be a consideration with local anesthesia.
Above the Law? A Comparative Study of National Prosecutions of Heads of State

Official polices on the appropriate government response to crimes committed by a head of state are seldom dictated by strict principles of justice. Deciding whether to bring an errant leader to justice is often influenced by political expediency. Given the number of documented cases of official abuse, there is a need to understand why some governments choose to prosecute a former or sitting head of state while others do not. Yet, few studies have been done on this subject. This study reviews 52 cases of heads of state accused of crimes and explores how their own national governments responded to such accusations. Using data culled from various documentary sources, it employs a grounded theory approach to focus on the process that drives the decision to prosecute. Analysis indicates that political legitimacy, perception of threat, political stability, and degree of politicization of the military influence the decision to prosecute. The article concludes with a discussion of the significance and implications of these findings and suggestions for future research.
Infrared spectra of the chromates of magnesium, nickel and cadmium

Abstract IR spectra have been determined for NiCrO 4 , α-MgCrO 4 , α-CdCrO 4 (all crystallizing with the CrVO 4 structure); β-MgCrO 4 , β-CdCrO 4 (both with the α-MnMoO 4 , structure); and Cd 2 CrO 5 . The number of bands does not exceed the predictions of factor group analysis. It is shown that a dichromate-like spectrum can arise from chromate anions if the CrO 4 tetrahedron is sufficiently distorted.
Techniques for intrasplenic hepatocyte transplantation in the large animal model

Background: The preferred therapy for acute and chronic liver insufficiency and severe heritable disorders of liver metabolism is whole-organ transplantation. However, due to the shortage of organ doproposed, including transplantation of normal allogeneic hepatocytes. Recently, it has been reported that many hepatocytes transplanted into the spleen migrated to the liver. We therefore carried out a series of large-animal experiments to reexamine the intrasplenic route and to develop a method for large-scale hepatocellular transplantation in pigs.
Computer simulation of image intensifier‐based computed tomography detector: Vascular application

This present study reports the results of a computer simulation whose aim was to predict the low-contrast imaging performance of which a conventional x-ray image intensifier with charge coupled device (CCD) camera would be capable if incorporated into a computed tomography (CT) volume imager. A vascular imaging task was modeled in our simulation. The effects of detector noise, x-ray exposure levels, analog-to-digital conversion (ADC) precision and residual levels of detected x-ray scatter were considered. The results of this simulation indicate that the low-contrast imaging performance of an image intensifier-based CT system was most limited by the CCD detector readout noise. Given this limitation the detection of greater than about 100,000 detected photons/pixel/projection gave marginal improvement in low-contrast resolution. At these exposures 12 bit ADC precision resulted in little additional image noise. The effects of detecting scattered x rays are twofold; decreasing the signal-to-noise ratio associated with our modeled artery and introducing a cupping artifact. Based on the results from the simulation, it appears that an image intensifier-based CT system is a feasible concept from a noise viewpoint, if the anticipated imaging task is intravenous angiography.
The nature of the helium flow in Fermilab's Tevatron dipole magnets

Recent attempts to lower the temperature of the superconducting magnets in Fermilab's high energy particle accelerator, the Tevatron, and push Fermilab's accelerator complex to somewhat higher energy have motivated investigations into the temperature profiles of the flow around the Tevatron dipole magnet coil. A specially instrumented magnet with thermometry in the single-phase and two-phase helium passages has been tested at the Magnet Test Facility at Fermilab. Measurements show that two-phase flow is separated with a low liquid level in the two-phase shell; heat transfer to the two-phase is poor. Single-phase flow is dramatically stratified. Values of AT of more than 100 mK are typical across the magnet coil, and the top of the coil is more than 300 mK warmer than the two-phase helium. A ramp of current produces a heat pulse which reaches the end of the magnet about 30 s later, and could account for some 'flattop quenches' Published by Elsevier Science Ltd.
Evaluation of outpatient hysteroscopy, saline infusion hysterosonography, and hysterosalpingography in infertile women: a prospective, randomized study ☆

Abstract Objective: To compare the diagnostic accuracy, pain scores, and procedure length of outpatient hysteroscopy (OHS), hysterosalpingography (HSG), and saline infusion hysterosonography (SIS) for evaluation of the uterine cavity of infertile women. Design: Prospective, randomized, investigator-blind study. Setting: Tertiary infertility clinic. Patient(s): Forty-six consecutive infertile women. Intervention(s): Outpatient HSG, OHS, and SIS, followed by operative hysteroscopy (HS). Main Outcome Measure(s): Uterine abnormalities, procedure length, and subjective pain. Result(s): Fifty-nine percent of infertile subjects were found to have an abnormality on at least one of three outpatient uterine evaluations. When compared with the case of definitive operative HS, 60% of abnormalities were correctly classified by HSG, 72% by OHS, and 52% by SIS ( P : NS). When comparing all combinations of 2 outpatient screening tests to operative hysteroscopy, 68% were correctly classified by HSG/OHS, 58% by HSG/SIS, and 64% by OHS/SIS ( P : NS). The average time length for the OHS was 9.1 min., which was significantly greater than for both HSG (average, 5.3 min) and SIS (average, 6.1 min.) ( P Conclusion(s): OHS, SIS, and HSG were statistically equivalent regarding evaluation of uterine cavity pathology in infertile women.
Should transcranial magnetic stimulation research in children be considered minimal risk

Abstract Objective : Transcranial magnetic stimulation (TMS) is a neurophysiologic technique with research applications. Institutional Review Boards (IRBs) must carefully consider potential risks and possible benefits in research involving children. The purpose of this study is to provide concise information for investigators and IRBs about the safety of single and paired pulse TMS research in children. Methods : This paper has 4 sections: (I) Regulations governing research in children are reviewed and applied to the use of TMS. (II) Energy imparted by TMS is assessed in terms of theoretical biological risks to human subjects. (III) Through MEDLINE review, the empirical evidence of risk from TMS is assessed. Reported adverse events, including issues related to risk of seizures and of hearing loss, are summarized. (IV) Safety data are presented from a study of TMS in children with Tourette Syndrome. Results : No published or empirical evidence was found to suggest that single or paired pulse TMS is associated with more than minimal risk in children. Conclusions : IRBs may consider well-designed studies using single and paired pulse TMS protocols similar to those described in this study as bearing minimal risk to children. Significance : This manuscript may be useful as a reference to IRBs and TMS investigators.
SU-E-CAMPUS-J-06: The Impact of CT-Scan Energy On Range Uncertainty in Proton Therapy Planning

Purpose: To investigate the impact of tube potential (kVp) on the CTnumber (HU) to proton stopping power ratio (PSPR) conversion table; the range uncertainty and the dosimetric change introduced by a mismatch in kVp between the CT and the HU to PSPR table used to calculate dose are analyzed. Methods: A CIRS CT-ED phantom was scanned with a Philips Brilliance 64-slice scanner under 90kVp and 120kVp tube potentials. Two HU to PSPR curves were then created. Using Eclipse (Varian) a treatment plan was created for a single beam in a water phantom (HU=0) passing through a wedge-shaped heterogeneity (HU=1488). The dose was recalculated by changing only the HU to PSPR table used in the dose calculation. The change in range (the distal 90% isodose line) relative to a distal structure was recorded as a function of heterogeneity thickness in the beam. To show the dosimetric impact of a mismatch in kVp between the CT and the HU to PSPR table, we repeated this procedure using a clinical plan comparing DVH data. Results: The HU to PSPR tables diverge for low-density bone and higher density structures. In the phantom plan, the divergence of the tables results in a change in range of ~1mm per cm of bone in the beam path for the HU used. For the clinical plan, a mismatch in kVp showed a 28% increase in mean dose to the brainstem along with a 10% increase in maximum dose to the brainstem center. Conclusion: A mismatch in kVp between the CT and the HU to PSPR table can introduce significant uncertainty in the proton beam range. For dense bone, the measured range uncertainty is about 1mm per cm of bone in the beam. CT-scan energy verification should be employed, particularly when high-density media is in the proton beam path.
Effects of morphine and two enzyme resistant enkephalins on schedule-controlled responding in the rat ☆

Water-deprived rats to respond for access to a water-filled dipper under a 20 response fixed-ratio schedule. After training, the rats were each implanted with a lateral ventricle cannula and the effects of intraventricular injection of morphine, (N-methyl-tyrosly)1 -des COOH-Norleucyl5-Enkephalin, and (D-Ala)2 - (des COOH-Norleucy)5-Enkephalin were determined. All three compounds produced dose-related decreases in FR20 responding. Morphine was about 5 times more potent than either of the two peptides. Naloxone (1.0 mg/kg, SC) antagonized the response-rate decreasing effects of intraventricular morphine and the two opiate peptides.
PTPN22: the archetypal non-HLA autoimmunity gene.

SNPs ofPTPN22, a 'shared autoimmunity gene', are important risk factors for rheumatoid arthritis, juvenile idiopathic arthritis and other autoimmune diseases. In this article, Stanford and Bottini review the function of mouse and human PTPN22 in Toll-like receptor and lymphocyte antigen-receptor signalling pathways, and suggest functional models for the involvement of PTPN22 variants in the pathogenesis of autoimmune diseases. PTPN22 encodes a tyrosine phosphatase that is expressed by haematopoietic cells and functions as a key regulator of immune homeostasis by inhibiting T-cell receptor signalling and by selectively promoting type I interferon responses after activation of myeloid-cell pattern-recognition receptors. A single nucleotide polymorphism of PTPN22, 1858C>T (rs2476601), disrupts an interaction motif in the protein, and is the most important non-HLA genetic risk factor for rheumatoid arthritis and the second most important for juvenile idiopathic arthritis. PTPN22 exemplifies a shared autoimmunity gene, affecting the pathogenesis of systemic lupus erythematosus, vasculitis and other autoimmune diseases. In this Review, we explore the role of PTPN22 in autoimmune connective tissue disease, with particular emphasis on candidate-gene and genome-wide association studies and clinical variability of disease. We also propose a number of PTPN22-dependent functional models of the pathogenesis of autoimmune diseases.
Abstract 5298: Human enhancer of filamentation 1 induction by Prostaglandin E2 enhances the cell motility of colorectal cancer cells

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Prostaglandin (PG) E2 promotes cell motility during colorectal carcinogenesis. The mechanism by which PGE2 signaling regulates cell motility is not completely understood. Here, we demonstrated that PGE2 treatment induces HEF1 expression that links with cell motility in colorectal cancer cells. PGE2 rapidly stimulated HEF1 expression in colorectal cancer cells. Both PGE2 treatment and HEF1 overexpression activated Rac 1 and resulted in similar effects on cell spreading. Moreover, knockdown of HEF1 using shRNA suppressed PGE2-driven cell spreading. PKA activator forskolin induced HEF1 expression and cell spreading in a similar manner as PGE2. Inhibition of PKA activity by H-89 attenuated HEF1 expression induced by PGE2. Furthermore, PKA knockdown by siRNA blocked the HEF1 expression and cell spreading induced by PGE2. These data suggest that PGE2 induces HEF1 expression to promote cell motility through a PKA-involved pathway. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5298.
Opportunities and challenges in application-tuned circuits and architectures based on nanodevices

Nanoelectronics research has primarily focused on devices. By contrast, not much has been published on innovations at higher layers: we know little about how to construct circuits or architectures out of such devices. In this paper, we focus on the currently most promising nanodevice technologies, such as arrays of semiconductor nanowires (NWs) and arrays of crossed carbon nanotubes (CNTs). In contrast to general-purpose programmable fabrics (such as PLAs), we investigate nano-fabrics that, while also programmable and hierarchical, are more tuned towards an application domain (in this sense they resemble ASIC). Our goal is to achieve denser designs with better fabric utilization, efficient cascading of circuits, and routing of signals. We demonstrate detailed designs of several circuits and processor data-paths, and highlight associated challenges and opportunities for optimization.
The impact of motivation and socioeconomic background on earnings

Abstract In an effort to examine the effect of achievement motivation and socioeconomic background on the earnings of young men, a path model has been specified and estimated using OLS. Using a richer data set than others have had available, we find that motivation and socioeconomic differences are significant in explaining earnings differences.
Radiocarbon Dating: Implications for Establishing a Forensic Context

ABSTRACTThough radiocarbon dating has been common practice in archaeology, it has yet to be regularly and consistently applied in forensic anthropology. Rather, forensic anthropologists analyze human remains using methods established on the basis of skeletal biology, such as estimating ancestry using characteristics that vary between breeding populations and estimating time-since-death based on the degree and pattern of weathering on the bones. Time since death is an essential question because this is what will determine whether the remains have forensic or historical significance. However, these methods are dependent on many extrinsic factors that include preservation and available contextual information regarding how and where the individual was placed or buried, as well as any personal effects included within the burial. In addition, the postmortem interval based on weathering is inaccurate and very difficult if not impossible to assess with any accuracy. Therefore, traditional methods such as skeletal...
Incretin hormones and insulin sensitivity.

Incretin hormones such as glucagon-like peptide-1 (GLP-1) and the longer lasting analog exendin-4 show clinical promise for the treatment of diabetes because of glucoregulatory activities that enhance β-cell function and growth, and actions in the central nervous system that induce satiety and decrease caloric intake. The actions of these peptides on insulin-responsive tissues is less clear, but recent advances indicate that chronic treatment with exendin-4 increases insulin sensitivity via two distinct mechanisms: one is attributable to changes in food intake and the subsequent improvements in glycemia; the second is largely independent of reductions in blood glucose. In addition, exendin-4 might also have direct effects on β-cell neogenesis that are independent of insulin demand.
Determination of ratios of photoelectron mean free paths from orbital ionization cross-sections

Abstract Ratios of inelastic-scattering mean free paths of photoelectrons in carbonaceous overlayers and in pure condensates of fluorides have been determined through the use of two procedures, respectively: (1) the variation of two intensities of orbital electrons from the substrate as the carbon overlayer is removed successively by argon-ion bombardment; and (2) the ratio of two intensities and the corresponding theoretical cross-sections. The results show that the dependence of the mean free path on kinetic energy agrees with that predicted by the asymptotic form aE/lnαE for energies in the range 400—120OeV; the value of α obtained, however, is near unity rather than the theoretical value of 0.1. The derived variation of the mean free path agrees with published measurements for NaF. The relation among intensity, cross-section and mean free path applies only when the spectra considered are symmetrical.
The use of tensor fascia lata interposition grafts for the treatment of posttraumatic radioulnar synostosis.

Purpose There is no agreement on the ideal treatment of traumatic radioulnar synostosis, especially the type of interposition material to be used. The purpose of this study is to report our experience with synostosis resection and interposition of tensor fascia lata grafts. Methods A chart review was conducted for all patients treated for posttraumatic radioulnar synostosis between 2000 and 2004. Demographic data, mechanism of injury, length of time to synostosis resection, range-of-motion, patient satisfaction, and postoperative complications were analyzed. Results Thirteen patients were identified for this study. The mean preoperative pronation was 14° and the mean postoperative pronation was 62°. The mean preoperative supination was 4° and the mean postoperative supination was 62°. The mean follow-up time was 30 months. Conclusions These results indicate that synostosis resection with tensor fascia lata graft interposition is an effective technique for the treatment of posttraumatic radioulnar synostosis. Type of study/level of evidence Therapeutic, Level IV.
PERTURBATIONS OF SPHERICAL STELLAR SYSTEMS DURING FLYBY ENCOUNTERS

We study the internal response of a galaxy to an unbound encounter and present a survey of orbital parameters covering typical encounters in diUerent galactic environments. Overall, we conclude that rela- tively weak encounters by low-mass interloping galaxies can cause observable distortions in the pri- maries. The resulting asymmetries may persist long after the interloper is evident. We focus our attention on the production of structure in dark halos and in cluster elliptical galaxies. Any distortion produced in a dark halo can distort the embedded stellar disk, possibly leading to the formation of lopsided and warped disks. We show that distant encounters with pericenters in the outer regions of a halo can excite strong and persistent features in the inner regions. Features excited in an elliptical galaxy are directly observable, and we predict that asymmetries in the morphologies of these systems can be produced by relatively small perturbers. For example, a —yby on an orbit with pericenter equal to the half-mass radius of the primary system and velocity of 200 km s~1 (a value typical for groups) can result in a signi—cant dipole distortion for perturbers with mass as small as 5% of the primarys mass. We use these detailed results to predict the distribution of the A parameter de—ned by Abraham et al. (sensitive to lopsidedness) and the shift between the center of mass of the primary system and the posi- tion of the peak of density for a range of environments. We —nd that high-density, low velocity disper- sion environments are more likely to host galaxies with signi—cant asymmetries. Our distribution for the A parameter is in good agreement with the range spanned by the observed values for local galaxy clus- ters and for distant galaxies in the Medium Deep Survey and in the Hubble Deep Field. Assuming that primordial galaxies were located in dense environments with previrialized low velocity dispersions, our conclusions are consistent with the observational results showing a systematic trend for galaxies at larger redshifts to be more asymmetric than local galaxies. Finally, we propose a generalized asymmetry parameter A(r) which provides detailed information on the radial structure of the asymmetry produced by the mechanism explored in our work. Subject headings: celestial mechanics, stellar dynamicsgalaxies: clusters: generalgalaxies: halos ¨ galaxies: interactionsgalaxies: kinematics and dynamicsgalaxies: structure
Sequence divergence in a family of variant surface glycoprotein genes from trypanosomes: coding region hypervariability and downstream recombinogenic repeats.

The surface of the parasitic protozoanTrypanosoma brucei spp. is covered with a dense coat consisting of a single type of glycoprotein molecule, the variant surface glycoprotein (VSG). There may be as many as 1,000 genes for VSG within the genome ofT. brucei, and the switch of expression from one to another is the phenomenon of antigenic variation. As an approach to understanding the evolution of VSG genes we have determined the genomic DNA sequences of the eight genes encoding the variant surface glycoprotein 117 (VSG) family. From these data we have observed a number of features concerning the relationships between these genes: (1) there is a region of high variability confined to the N-terminus of the coding sequence, and comparison of the sequences with the available X-ray diffraction crystal structures suggests that two of the most variable stretches within the N-terminal domain are present on surface-exposed loops, indicating a role for epitope selection in evolution of these genes; (2) the 29 nucleotides surrounding the splice acceptor site are absolutely conserved in all eight 117 VSG genes; (3) numerous insertion/deletion mutations are located within or immediately downstream of the C-terminal protein-coding sequences: (4) within 500 by downstream of the insertion/deletion mutations are one or two copies of a repeat motif highly homologous to the recombinogenic 76-bp repeat sequences present upstream of many VSG basic copy genes and the expression-linked copy.
An in situ mechanical-radiation effects test capsule for simulating fusion material environments

Abstract Conditions of radiation and simultaneous cyclic stress on materials are inherent in advanced energy source designs such as inertially and magnetically confined controlled thermonuclear reactors. A test capsule capable of applying a cyclic stress to test specimens while they are being irradiated in the 800-MeV proton beam at the Clinton P. Anderson Los Alamos Meson Physics Facility has been developed. The design and performance of this device are discussed in this report. This machine has facilities for seven pairs of differential samples; one sample of a pair receives an applied cyclic stress and its companion in an identical flux will be the unstressed control. Control of the sample temperature and in situ monitoring of sample elongation and load are provided in the design. Results of an earlier experiment will be discussed, along with those of preliminary bench tests of the redesigned capsule.
Torsion of undescended testis.

Abstract Torsion of an undescended testis is uncommon. When encountered, this entity represents a surgical emergency and must be dealt with immediately. A report of 2 cases, one in a five-mouth-old child and the other in a twelve-year-old mentally retarded child, is made and the pertinent literature is reviewed.
Potential Bacterial Contamination of Eyedrops Used for Tonometry

We compared the potential for bacterial contamination of a proparacaine hydrochloride solution preserved with benzalkonium chloride, which is used with fluorescein paper for tonometry, to that of a fluorescein-benoxinate hydrochloride combination solution preserved with chlorobutanol. We contaminated bottles of each solution with Pseudomonas aeruginosa or Staphylococcus aureus (10 7 organisms per milliliter of eyedrop solution). From the fluorescein-benoxinate hydrochloride solution, Staphylococcus organisms were cultured in declining numbers over time, with a half-life of nine seconds, and no Staphylococcus organisms were recovered after five minutes. Pseudomonas organisms disappeared from this solution within 15 seconds. Neither species was viable after 15 seconds in the proparacaine hydrochloride solution. Additionally, we cultured 12 bottles of fluorescein-benoxinate hydrochloride and 15 bottles of proparacaine hydrochloride that had been in use in the clinic for one month. No organisms were recovered from a drop dispensed from any bottle or from the tips, caps, rims, or solution from within any bottle, except that five colonies of Staphylococcus grew from the external rim of one bottle. We conclude that both solutions sterilize themselves rapidly and effectively. Either may be used safely for tonometry.
Religious Poverty, Mendicancy, and Reform in the Late Middle Ages

The idea and the ideal of religious poverty exerted a powerful force throughout the Middle Ages. “Take no gold, or silver, or copper in your belts, no bag for your journey, or two tunics, or sandals, or a staff,” Christ had commanded his apostles. He had sternly warned, “it is easier for a camel to go through the eye of a needle, than for someone who is rich to enter into the kingdom of God.” And he had instructed one of the faithful, who had asked what he needed to do to live the most holy sort of life, “if you wish to be perfect, go, sell your possessions and give your money to the poor, and you will have treasure in heaven.” Beginning with these biblical injunctions, voluntary poverty, the casting off of wealth and worldly goods for the sake of Christ, dominated much of medieval religious thought. The desire for a more perfect poverty impelled devout men and women to new heights of piety, while disgust with the material wealth of the church fueled reform movements and more radical heresies alike. Often, as so clearly illustrated by the case of the Spiritual Franciscans and fraticelli in the later thirteenth and fourteenth centuries, the lines separating devout believer from condemned heretic shifted and even reversed themselves entirely depending on how one understood the religious call to poverty. Moreover, the Christian ideal of poverty interacted powerfully with and helped to shape many major economic, social, and cultural trends in medieval Europe. As Lester Little demonstrated over two decades ago, for example, developing ideals of religious poverty were deeply intermeshed with the revitalizing European economy of the eleventh, twelfth, and thirteenth centuries and did much to shape the emerging urban spirituality of that period.
Influence of the autonomic nervous system on coronary blood flow during partial stenosis.

Partial coronary stenosis produces cyclical changes in coronary blood flow (CBF) which are the result of spontaneous aggregation and disaggregation of platelet plugs at the site of occlusion. The possible influence of the autonomic nervous system on this phenomenon has not been hitherto determined. The present study was performed in 20 chloralose-anesthetized dogs in which the effects of bilateral vagotomy and stellectomy were examined during partial stenosis of the left circumflex coronary artery. Vagotomy reduced the frequency of CBF oscillations from 11.5 ± 2.1 to 5.0 ± 2.1 cycles/hr (p < 0.05). The magnitude of the flow changes was reduced from 13.8 ± 4.0 to 9.7 ± 3.0 ml/min (NS). Bilateral cervical stellectomy reduced the frequency of CBF changes from 7.8 ± 2.7 to 3.7 ± 1.3 cycles/hr (p < 0.025) and their magnitude from 10.6 ± 2.5 to 5.6 ± 1.8 ml/min (p < 0.05). In five dogs in which cyclical CBF changes were reduced or abolished by decentralizing the stellate ganglia, electrical stimulation of the main body of the left ganglion evoked or enhanced the oscillations in two dogs, had no distinct effect in two dogs, and elicited no response in one dog. A 5-minute infusion of 0.5 μg/kg/min and 0.75 μg/kg/min epinephrine (four dogs) provoked the CBF changes in all animals for a period of 5 to 10 minutes. Blockade of muscarinic receptors by 0.2 mg/kg atropine resulted in a significant attenuation of flow changes, which may at least in part have been due to a direct effect of atropine on platelets. We conclude that cardiac sympathetic tone significantly influences the CBF pattern during critical coronary stenosis. While the afferent limb of the vagus may in part mediate this effect via a reflex increase of adrenal medullary catecholamines, the role of the efferent vagus awaits further clarification.
Measurement of differential carrier lifetime in vertical-cavity surface-emitting lasers

Measurements of differential carrier lifetimes on gain-guided proton-implanted vertical-cavity surface-emitting lasers with device size as a parameter are reported. The lifetimes were obtained from laser impedance measurements and from small-signal modulation optical response at subthreshold currents. A simple small-signal equivalent circuit was used to correct the optical data and to extract the carrier lifetimes from the impedance data. Carrier lifetimes ranged from 4.2 ns at 0.04 mA, to about 0.6 ns at a bias close to threshold. The measured carrier lifetimes were used to calculate the corresponding threshold carrier density (n/sub th//spl sim/6/spl times/10/sup 18/ cm/sup -3/) and recombination parameters.
Sensor networks for the detection and tracking of radiation and other threats in cities

This paper presents results from experiments, mathematical analysis, and simulations of a network of static and mobile sensors for detecting threats on city streets and in open areas such as parks. The paper focuses on the detection of nuclear radiation threats and shows how the analysis can be extended to other classes of threat. The paper evaluates algorithms that integrate methods of parametric and Bayesian statistics. A pure Bayesian approach is difficult because obtaining prior distributions on the large number of parameters is challenging. The results of analyses and simulations are compared against measurements made on a reduced scale testbed. A survey of background radiation in the city of Sacramento is used to quantify the efficacy of police patrols to detect threats. The paper also presents algorithms that optimize network parameters such as sensor placement.
Constant spread of feature-based attention across the visual field

Attending to a feature in one location can produce feature-specific modulation in a different location. This global feature-based attention effect has been demonstrated using two stimulus locations. Although the spread of feature-based attention is presumed to be constant across spatial locations, it has not been tested empirically. We examined the spread of feature-based attention by measuring attentional modulation of the motion aftereffect (MAE) at remote locations. Observers attended to one of two directions in a compound motion stimulus (adapter) and performed a speed-increment task. MAE was measured via a speed nulling procedure for a test stimulus at different distances from the adapter. In Experiment 1, the adapter was at fixation, while the test stimulus was located at different eccentricities. We also measured the magnitude of baseline MAE for each location in two control conditions that did not require feature-based selection necessitated by a compound stimulus. In Experiment 2, the adapter and test stimuli were all located in the periphery at the same eccentricity. Our results showed that attention induced MAE spread completely across the visual field, indicating a genuine global effect. These results add to our understanding of the deployment of feature-based attention and provide empirical constraints on theories of visual attention.
Costs of broad-based stock option plans

Abstract We generate estimates of the costs of broad-based stock option programs under varying assumptions about why firms use these pay schemes. We show that, if accounting considerations alone drive option grants, a typical firm in our sample incurs between 50 cents and one dollar of real costs in order to increase reported pre-tax net income by one dollar. This cost is reduced, but is still quite substantial, if accounting leads firms to grant options rather than restricted stock. We also show that, if option grants are efficient, the patterns in our data are consistent with firms using these grants to attract and retain employees.
CITY SIZE, RACIAL COMPOSITION, AND ELECTION OF BLACK MAYORS INSIDE AND OUTSIDE THE SOUTH

: This article examines the linkage between racial composition and likelihood of electing a black mayor in cities of a particular size and location. Special attention is given to cities with a black majority population in 1980 or with a black mayor in 1985. Most black mayors come from cities with black majority populations, but most cities with such a majority do not have black mayors. After controlling for city size and percentage of blacks, it is shown that being located in the South has a continuing negative impact on the likelihood of electing black mayors in black majority cities. The need for the 1982 extention of the Voting Rights Act is discussed.
The Business Case for Using Compressed Natural Gas Fuel in Concrete Mixer Trucks

Contractors are working towards defining their role in the movement towards sustainability in the built environment. Amongst all of the uncertainty surrounding this quest, one thing is certain: solutions must be based upon sound financial principles. Transportation during the construction process has been identified as one area where the environmental impacts of construction may be reduced. Compressed natural gas is an alternative fuel that could be used in concrete mixer trucks to increase the environmental performance of the construction process. The question is: will switching from diesel fuel to compressed natural gas save money while providing increased value during the construction process? This research examines the various costs, impacts, and savings involved in such a transition. Results of the study indicate the cost is a function of numerous operational parameters, government policies, and cost and availability of compressed natural gas. A general multi-variant financial model was developed to aid in the analysis. The model may be used by companies who wish to determine if switching to natural gas would be feasible for their operation.
The function of call alternation in the African reed frog (Hyperolius marmoratus): precise call timing prevents auditory masking

The function of call alternation in the African painted reed frog, Hyperolius marmoratus was studied. Males actively avoided call overlap with neighboring males in their natural habitat. Advertisement calls produced by groups of two or three males showed less overlap than expected if they called at random. In addition, isolated males significantly reduced their calling rate to match the periodicity of a playback of periodic tone pulses, with vocalizations given during the silent intervals between tones. Gap-detection experiments showed that males suppressed vocalizations during playbacks of constant-frequency tone bursts and gave more calls during silent periods than expected by chance. Females discriminated against conspecific advertisement calls with many pulses in favor of calls with few or no pulses. This suggests that there would be little selection pressure on males to alternate calls so that pulses are not obscured. To test if call alternation functions to make calls more conspicuous, females were presented with identical conspecific advertisement calls from two speakers in four different temporal patterns: simultaneous, overlapping, abutting, and alternating. Females did not discriminate when calls were presented in a simultaneous, abutting, or alternating time pattern. When calls overlapped with the trailing call delayed from 0.5 to 70 ms females discriminated in favor of the leading call. When the intensity of the leading call was reduced by 6 dB the preference for the leading call was maintained when calls overlapped by 2 and 40 ms but was abolished or reversed at 0.5 and 70 ms, respectively. These results support the notion that the second of two partially overlapping calls was acoustically masked, rendering female painted reed frogs unwilling to approach or unable to locate such calls. It is suggested that either simultaneous masking or the precedence effect are responsible for the observed behavior. Acoustic masking of the second call by the first when calls overlapped was maintained even when the frequency of the first call was altered by 150 Hz above and below the more preferred frequency of the second call.