cssi/SciSciGPT-SciSciNet huggingface dataset:
Habitat partitioning in a community of darters in the Elk River, West Virginia

Microhabitat use and habitat partitioning for 10 darter species (Percidae: Etheostomatini) were studied by direct observation (snorkeling) at five sites in the Elk River drainage, West Virginia, U.S.A. We used canonical discriminant analysis and univariate tests to determine microhabitat variables that were important in segregating species. Darter species were segregated by depth, substrate size, and water velocity. In addition, Percina typically occurred in the water column, whereas species of Etheostoma were benthic and segregated by occurring under, between, and on top of rocks.
One skull does not a species make

Australopithecus(orParanthropus) boisei is a member of an extinct, early human branch, which separated from the lineage that led to today's humans some 3-2.5 million years ago. The discovery of the most complete skull from this species is now reported, and the features of the skull indicate that we may have to rethink where, and how, the boundaries between different species are drawn.
Considerations for Indirect Parameter Estimation in Nonlinear Reduced Order Models

Over the past few decades, there have been many developments in techniques that extract a reduced order model (ROM) from a geometrically nonlinear finite element model. The enforced displacement ROM strategy that is of interest in this work is known as an indirect approach because it does not require altering the finite element code. Instead, one uses a series of static displacement fields applied to the nonlinear finite element model to estimate the nonlinear stiffness coefficients in the reduced equations. Geometric nonlinearity causes the bending and membrane displacements to become coupled, and the enforced displacements method requires that the kinematics of the membrane motion be explicitly included in the basis using either axial vibration modes or dual modes. This work explores the accuracy of the enforced displacements ROM strategy by comparing the efficiency of these basis vectors, as well as the use of three different parameter estimation procedures and the effect of scaling factors on the static load cases used to generate the ROM. The different modeling decisions are shown to have a very significant effect on the accuracy of the ROMs, and the comparisons are used to suggest best practices that result in the most accurate ROMs. These issues are explored using finite element models of a flat geometrically nonlinear beam with fixed-fixed boundary conditions and a flat geometrically nonlinear exhaust cover plate. The effect of each of the modeling decisions on the resulting enforced displacement ROM is evaluated by computing the Nonlinear Normal Modes (NNMs) of the full finite element model and comparing them with the NNMs calculated from the ROMs. The NNMs offer a powerful metric that indicates whether or not the ROM captures a variety of important physics in the original model.
Nutrient and mineral retention and vitamin D absorption in low-birth-weight infants: effect of medium-chain triglycerides

A randomized prospective study of the effect of medium-chain triglycerides (MCT) upon the absorption and retention of major minerals and nutrients, as well as upon 25-hydroxy vitamin D levels, was performed in low-birth-weight infants. Ten infants received a high-calcium and vitamin D-containing formula, which contained 50% of its fat as MCT, while ten other infants received a similar formula in which all the fat was in long-chain triglycerides. There was a five-day delay in reaching full oral feeding volumes, and therefore there was a delay in the onset of the balance study in the MCT group, primarily due to gastrointestinal symptoms. There was a significant improvement in the percent of fat absorption (P less than .05) with MCT, but no difference in the percent of absorption or retention of calcium, phosphorus, sodium, or nitrogen. 25-Hydroxy vitamin D levels decreased in both groups after full oral feeding volumes had been established, but all values were within normal ranges. At the high intake levels of calcium and vitamin D given to the infants, MCT did not increase major mineral or nutrient absorption.
Dynamic localization of SPE-9 in sperm: a protein required for sperm-oocyte interactions in Caenorhabditis elegans

Background: Fertilization in Caenorhabditis elegans requires functional SPE-9 protein in sperm. SPE-9 is a transmembrane protein with a predicted extracellular domain that contains ten epidermal growth factor (EGF)-like motifs. The presence of these EGF-like motifs suggests that SPE-9 is likely to function in gamete adhesive and/or ligand-receptor interactions. Results: We obtained specific antisera directed against different regions of SPE-9 in order to determine its subcellular localization. SPE-9 is segregated to spermatids with a pattern that is consistent with localization to the plasma membrane. During spermiogenesis, SPE-9 becomes localized to spiky projections that coalesce to form a pseudopod. This leads to an accumulation of SPE-9 on the pseudopod of mature sperm. Conclusions: The wild type localization patterns of SPE-9 provide further evidence that like the sperm of other species, C. elegans sperm have molecularly mosaic and dynamic regions. SPE-9 is redistributed by what is likely to be a novel mechanism that is very fast (~5 minutes) and is coincident with dramatic rearrangements in the major sperm protein cytoskeleton. We conclude that SPE-9 ends up in a location on mature sperm where it can function during fertilization and this localization defines the sperm region required for these interactions.
Pulmonary Surfactant Protein A Activates a Phosphatidylinositol 3-Kinase/Calcium Signal Transduction Pathway in Human Macrophages: Participation in the Up-Regulation of Mannose Receptor Activity

Surfactant protein A (SP-A), a major component of lung surfactant, binds to macrophages and has been shown to alter several macrophage biological functions, including up-regulation of macrophage mannose receptor (MR) activity. In the present study, we show that SP-A induces signal transduction pathway(s) that impact on MR expression. The addition of human, rat, or recombinant rat SP-A to human monocyte-derived macrophages significantly raised the level of cytosolic Ca2+ above baseline within 10 s of SP-A addition, as measured by spectrofluorometric analysis. SP-A induced a refractory state specific for SP-A consistent with homologous desensitization of a receptor(s) linked to calcium mobilization because a second application of SP-A did not induce a rise in cytosolic Ca2+ whereas the addition of platelet-activating factor did. Using site-directed mutations in SP-A, we determined that both the attached sugars and the collagen-like domain of SP-A are necessary to optimize Ca2+ mobilization. SP-A triggered the increase in cytosolic Ca2+ by inducing activation of phospholipase C, which leads to the hydrolysis of membrane phospholipids, yielding inositol 1,4,5-trisphosphate and mobilizing intracellularly stored Ca2+ by inositol triphosphate-sensitive channels. Finally, inhibition of PI3Ks, which appear to act upstream of phospholipase C in Ca2+ mobilization, decreased the SP-A-induced rise in MR expression, providing evidence that SP-A induction of MR activity involves the activation of a pathway in which PI3K is a component. These studies provide further evidence that SP-A produced in the lung plays a role in modulating macrophage biology, thereby contributing to the alternative activation state of the alveolar macrophage.
EGFR signaling modulates synaptic connectivity via Gurken

Synaptic target selection is critical for establishing functional neuronal circuits. The mechanisms regulating target selection remain incompletely understood. We describe a role for the EGF receptor and its ligand Gurken in target selection of octopaminergic Type II neurons in the Drosophila neuromuscular system. Mutants in happyhour, a regulator of EGFR signaling, form ectopic Type II neuromuscular junctions. These ectopic innervations are due to inappropriate target selection. We demonstrate that EGFR signaling is necessary and sufficient to inhibit synaptic target selection by these octopaminergic Type II neurons, and that the EGFR ligand Gurken is the postsynaptic, muscle-derived repulsive cue. These results identify a new pathway mediating cell-type and branch-specific synaptic repulsion, a novel role for EGFR signaling in synaptic target selection, and an unexpected role for Gurken as a muscle-secreted repulsive ligand. © 2011 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Effect of Cationic Surfactants on the Transdermal Permeation of Ionized Indomethacin

AbstractIn an attempt to enhance the skin permeation rate of ionized indomethacin by ion-pairiig, a group of cationic surfactants were evaluated to determine their potential as counter-ions. Permeation rates through hairless rat skin were measured in vitro. The ion-pairing agents used were all quaternary ammonium compounds. Most enhanced the skin permeation of indomethacin to varying magnitudes and through different mechanisms. Some involved increased drug solubilization in the aqueous vehicle while others demonstrated permeability increase as a function of partitioning. One surfactant did not exert an apparent effect on any of the permeation parameters. Of ArquadR 12, ArquadR 16, Cetylpyridinium chlorideR and Benzalkonium chlorideR, only the last surfactant clearly indicated its ability to pair with indomethacin.
Transitions to Ordered Phases in Systems Containing Rodlike Particles: I. A New Continuum Monte Carlo Approach

Abstract A new continuous-placement Monte Carlo (CMC) approach was developed that measures the entropy of rodlike particle configurations having pre-set global orientation distributions. Entropies are measured through a range of concentrations, independently of whether these configurations represent equilibrium conditions. Rod concentrations, orientation distribution shapes, and order parameters that are expected to be present at equilibrium can then be determined by comparing free energy curves. The method was applied to two-dimensional, monodisperse, athermal systems and the results demonstrated that choice of the shape of the global orientation distribution in the anisotropic phase can result in shifting from a first-order to a continuous isotropic-to-nematic phase transition.
A numerical model (MISER) for the simulation of coupled physical, chemical and biological processes in soil vapor extraction and bioventing systems

The efficiency and effectiveness of soil vapor extraction (SVE) and bioventing (BV) systems for remediation of unsaturated zone soils is controlled by a complex combination of physical, chemical and biological factors. The Michigan soil vapor extraction remediation (MISER) model, a two-dimensional numerical simulator, is developed to advance our ability to investigate the performance of field scale SVE and BV systems by integrating processes of multiphase flow, multicomponent compositional transport with nonequilibrium interphase mass transfer, and aerobic biodegradation. Subsequent to the model presentation, example simulations of single well SVE and BV systems are used to illustrate the interplay between physical, chemical and biological processes and their potential influence on remediation efficiency and the pathways of contaminant removal. Simulations of SVE reveal that removal efficiency is controlled primarily by the ability to engineer gas flow through regions of organic liquid contaminated soil and by interphase mass transfer limitations. Biodegradation is found to play a minor role in mass removal for the examined SVE scenarios. Simulations of BV systems suggest that the effective supply of oxygen may not be the sole criterion for efficient BV performance. The efficiency and contaminant removal pathways in these systems can be significantly influenced by interdependent dynamics involving biological growth factors, interphase mass transfer rates, and air injection rates. Simulation results emphasize the need for the continued refinement and validation of predictive interphase mass transfer models applicable under a variety of conditions and for the continued elucidation and quantification of microbial processes under unsaturated field conditions.
Early development and progression of lymphocyte-stimulatory cross-reactive idiotypes expressed on antibodies to soluble egg antigens during Schistosoma mansoni infection of mice

Idiotypes (Id) that stimulate immunoregulatory anti-Id T lymphocyte proliferation are expressed on murine and human antibodies (Ab) to soluble egg antigens (SEA) of Schistosoma mansoni. Kinetics of early expression of these stimulatory Id have now been studied using immunoaffinity-purified serum anti-SEA Ab from mice infected with S. mansoni for 6, 7, 8, 12, or 16 weeks. Rabbit anti-Id Ab specific for mouse anti-SEA Id expressed at 8 weeks post-infection (anti-8WkId) demonstrated the strongest interactions with Id present at 7 and 8 weeks post-infection by competitive enzyme-linked immunosorbent assay. Anti-8WkId Ab reacted progressively less well with 12 WkId, 6WkId, and 16WkId. Splenocytes from mice infected for 8 weeks demonstrated the highest blast transformation responses in vitro to anti-SEA Id from mice infected for 6 weeks, while 7, 8, 12, and 16 weeks post-infection Id preparations stimulated progressively less proliferation. These data indicate that although eventual Id-associated immunoregulatory events contribute to chronicity in this disease, production of anti-SEA Ab that express stimulatory cross-reactive immunoregulatory Id comprises a substantial portion of the initial, acute anti-SEA response in mice infected with Schistosoma mansoni. Furthermore, either this particular Id-expressing response is not maintained, or its proportional presence is greatly diminished by the cumulative production of other multiple anti-SEA Ab during the establishment of chronicity, perhaps in response to its immunoregulatory influence very early in infection.
Toxicity of Three-Dimensional Conformal Radiotherapy for Accelerated Partial Breast Irradiation

Purpose To assess the incidence and severity of late normal tissue toxicity using three-dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Methods and Materials A total of 60 patients were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation. Treatment planning and delivery were in strict accordance with the technique and specified dose–volume constraints of the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 protocol. Late toxicity was evaluated according to the Radiation Therapy Oncology Group grading schema. The cosmetic outcome was scored using the Harvard criteria. Univariate logistic regression analysis was performed to evaluate the correlation of dosimetric variables with outcome. Results At a median follow-up of 15 months, moderate-to-severe late toxicity developed in 10% of patients. The most pronounced late toxicity was subcutaneous fibrosis: 25% Grade 2-4 and 8.3% Grade 3-4. The modified planning tumor volume/whole breast volume ratio, ratio of the volume of breast tissue receiving 5%, 20%, 50%, and 80% of the prescription dose to the whole breast volume, and maximal dose within the breast correlated with the development of fibrosis ( p = .10, p = .03, p = .04, p = .06, p = .09, and p = .046, respectively). The overall cosmetic outcome was good to excellent in 81.7%, fair in 11.7%, and poor in 6.7%. The presence of subcutaneous fibrosis, modified planning tumor volume/whole breast volume ratio, ratio of the volume of breast tissue receiving 5% and 20% of the prescription dose to the whole breast volume, and pathologic specimen volume correlated with the risk of a fair/poor cosmetic outcome ( p p = .02, p = .05, p = .04, p = .01, respectively). Conclusion The three-dimensional conformal radiotherapy technique for accelerated partial breast irradiation as specified in the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 protocol resulted in a remarkably high rate of moderate-to-severe late normal tissue effects, despite the relatively brief follow-up period. The toxic events correlated clearly with several dose–volume parameters.
CONGRUENCES FOR DYSON'S RANKS

In this paper, we prove infinite families of congruences for coefficients of harmonic Maass forms whose coefficients encode Dyson's rank. This generalizes the earlier joint work of the author with Ken Ono.
On optimising taboo criteria in Markov decision processes

The standard approach when using a Markov decision process to find an optimal policy is to assume a fixed profit or cost structure. However, in many applied problems it may be not possible to determine profits or costs associated with all states or actions. In such cases we propose the use of taboo first passage reward and taboo first passage time as objectives. In this paper, we investigate problems related to optimising aforementioned taboo measures and we provide two examples.
Analysis of protein interaction and function with a 3-dimensional MALDI-MS protein array

Protein profiling and characterization of protein interactions in biological samples ultimately require indicator-free methods of signal detection, which likewise offer an opportunity to distinguish specific interactions from nonspecific protein binding. Here we describe a new 3-dimensional protein microchip for detecting biomolecular interactions with matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS); the microchip comprises a high-density array of methacrylate polymer elements containing immobilized proteins as capture molecules and directly interfaces with a commercially available mass spectrometer. We demonstrated the performance of the chip in three types of experiments by detecting antibody-antigen interactions, enzymatic activity, and enzyme-inhibitor interactions. MALDI-MS biochip-based tumor necrosis factor α (TNF-α) immunoassays demonstrated the feasibility of detecting antigens in complex biological samples by identifying molecular masses of bound proteins even at high nonspecific protein binding. By detecting model interactions of trypsin with trypsin inhibitors, we showed that the protein binding capacity of methacrylate polymer elements and the sensitivity of MALDI-MS detection of proteins bound to these elements surpassed that of other 2- and 3-dimensional substrates tested. Immobilized trypsin retained functional (enzymatic) activity within the protein microchip and the specificity of macromolecular interactions even in complex biological samples. We believe that the underlying technology should therefore be extensible to whole-proteome protein expression profiling and interaction mapping.
Understanding the mechanism of cytochrome P450 3A4: recent advances and remaining problems

Cytochromes P450 (CYPs) represent a diverse group of heme-thiolate proteins found in almost all organisms. CYPs share a common protein fold but differ in substrate selectivity and catalyze a wide variety of monooxygenation reactions via activation of molecular oxygen. Among 57 human P450s, the 3A4 isoform (CYP3A4) is the most abundant and the most important because it metabolizes the majority of administered drugs. A remarkable feature of CYP3A4 is its extreme promiscuity in substrate specificity and cooperative substrate binding, which often leads to undesirable drug-drug interactions and toxic side effects. Owing to its importance in drug development and therapy, CYP3A4 has been the most extensively studied mammalian P450. In this review we provide an overview on recent progress and remaining problems in the CYP3A4 research.
Animating vernaculars, wired: critical discourse analysis on an awkward scale

In recent years critical discourse analysts have increasingly pointed to the World Wide Web as a distinctive site of discursive practice, and have urged that more research work be conducted with specifically web-based corpora. While the conduct of ‘wired CDA’ presents new possibilities for CDA, it also entails apparent dilemmas that stem from the scale of web-specific corpora and CDA's disciplinary remit to conduct close qualitative readings of relatively small sample texts. Social anthropology has grappled with similar dilemmas as the relevance of trans-local ethnography in the contemporary world has become increasingly apparent, and in this process has developed productive analytical resources that might fruitfully inform wired CDA. This article explores a range of associated methodological issues, with particular emphasis on the identification and use of ‘keywords’ as a moment in the conduct of wired CDA. The paper looks at methodological precedents that frame the use of ‘keywords’ as an analytical cat...
Thymine - A possible prebiotic synthesis

A possible prebiotic synthesis of thymine has been achieved via the methylation of uracil with formaldehyde and hydrazine.
Proposal for a probabilistic dial-up generator of Fock states in a traveling-wave optical field

We discuss a method for generating Fock (number) states in a single-mode traveling-wave optical field, based on a method we recently proposed for performing a quantum nondemolition measurement of parity and for the generation of parity eigenstates [C. C. Gerry, A. Benmoussa, and R. A. Campos, Phys. Rev. A 72, 053818 (2005)]. The approach is a kind of 'dial-up' scheme that is probabilistic but also depends partially on directed state reductive measurements.
Fixed point iterations using infinite matrices

ABSTRACT Let E be a closed, bounded, convex subset of a Banach space X, f: E → E. Consider the iteration scheme defined by , where A is a regular weighted mean matrix. For particular spaces X and functions f this iterative scheme converges to a fixed point of f. [5] extends or generalizes related work of Browder and Petryshyn, Dotson, Franks and Marzec, Johnson, Kannan, Mann, and Reinermann. This paper continues investigations begun in [6].
Spectrum of anorectal anomalies in pygopagus twins.

Abstract Background/Purpose: The literature lacks a concise description of the anorectal anomalies encountered in pygopagus twins. Methods: This is a retrospective literature review of 34 pygopagus twins highlighting their anorectal malformations. Results: Overall pygopagus twins represent 17% of all conjoined twins. Live-birth pygopagus twins are more commonly female (86%), whereas stillborns are commonly male (80%). Half of the twins had nonfused rectums, and half had fused rectums. The nonfused had 2 rectums (80%) or one rectum and one rectovaginal fistula (20%). The fused had high (46%) or low (54%) rectal junctions. All reported living male pygopagus twins have had nonfused rectums. All can be managed applying the principles of posterior sagittal anorectoplasty. Conclusions: In general, live-born male pygopagus twins are likely to survive with a nonfused rectum and good bowel function, whereas live-born female pygopagus twins have a good chance of surviving with a fused rectum (high or low), which requires appropriate operative reconstruction. J Pediatr Surg 38:608-612. Copyright 2003, Elsevier Science (USA). All rights reserved.
Alexithymia and Somatic Amplification in Chronic Pain

A controlled study was undertaken to assess alexithymia and somatic amplification among 50 medical outpatients with chronic pain referred for psychiatric consultation. Data were collected on demographics; DSM-IV diagnoses; and measures of anxiety, depression, and alexithymia, assessed with the Toronto Alexithymia Scale (TAS–20), as well as somatic amplification, assessed with the Somatosensory Amplificiation Scale (SAS). Data analysis revealed low scores on the TAS–20 and SAS for the pain patients, compared with a control group without pain. In this sample, depression and anxiety were the primary determinants of alexithymia and somatic amplification, rather than pain. These findings suggest that psychological markers for chronic pain may be different from those for other somatoform disorders.
Low-density lipoprotein activates Jun N-terminal kinase (JNK) in human endothelial cells

We have reported previously that native low-density lipoprotein (LDL) activates c-Jun and transcription factor AP-1 in human umbilical vein endothelial cells (HUVEC). The aim of this study was to elucidate the upstream signaling mechanisms mediating LDL activation of c-Jun/AP-1. Using a c-Jun NH2-terminal kinase (JNK) activity assay, we have detected an increase in JNK activity in LDL-exposed HUVEC, which started at 15 min and reached maximum activity after 1-2 h. This JNK activity, increased by LDL, occurred in a dose-dependent fashion starting at a concentration of 80 mg/dl of LDL and reaching maximum activation at a concentration of 160-240 mg/dl. Following cotransfection, the increase of AP-1 driven luciferase activity by LDL was attenuated 54% by a kinase-deficient JNK1. Furthermore, a specific trans-reporting system was utilized to confirm c-Jun activation by upstream signal mechanisms. The results show c-Jun activity increased by 3-fold after LDL exposure when compared with respective controls. In contrast, LDL exposure did not affect the activation of extracellular signal regulated kinase 1 and 2 (ERK1/2), even though phorbol 12-myristate 13-acetate treatment remarkably increased the activity of these kinases. Thus, this study demonstrates, for the first time, that JNK mediates LDL-induced endothelial cell activation.
Silver methenamine stain for electron microscopy

The results obtained by the application of five different methods to stain with silver methenamine thin sections of tissue for electron microscopy are described and evaluated in this article. Three of these methods lend themselves to wide applications in that they enhance vividly the argentophilic structures without inducing excessive graininess of the staining. The latter appears to be due mainly to prolonged and unnecessary exposure of the sections to the staining solution. The graininess observed in specimens prepared under the most favorable conditions, however, is still too coarse to allow the application of this technique for high resolution electron microscopy.
On the Homology of Distributive Lattices

This paper gives a method for computing the reduced poset homology of the rank-selected subposet of a distributive lattice. As an example of the method, letLbe the lattice a+1 × ···× a+1 (b-times).Sbacts onLby permuting coordinates. ForS? ab, we give a description of the decomposition of the reduced homology ofLSas anSb-module. This generalizes L. Solomon's result for decomposition of the reduced homology of the Boolean algebra (Bb)Sas anSb-module.
Plasmonics in strained monolayer black phosphorus

Monolayer black phosphorus (BP) has high band anisotropy which can be modulated with strain. We show that the plasmonic dispersions in monolayer BPs not only strongly depend on the crystalline direction but also strain. Application of strain can alter the optimum direction for plasmon transport and engineer the anisotropic plasmonic dispersion relations. Furthermore, we evaluate the plasmon losses and wave localization via the random-phase approximation framework. It is found that although the BP monolayer is inferior to graphene in terms of loss at the same wave localization, it outperforms monolayer MoS2. The dependence of plasmon properties on the applied strain in BP makes it an interesting nanophotonic material, as well as a potential medium for piezo-optic applications.
Global optima results for the Kauffman NK model

The Kauffman NK model has been used in theoretical biology, physics and business organizations to model complex systems with interacting components. Recent NK model results have focused on local optima. This paper analyzes global optima of the NK model. The resulting global optimization problem is transformed into a stochastic network model that is closely related to two well-studied problems in operations research. This leads to applicable strategies for explicit computation of bounds on the global optima particularly with K either small or close to N. A general lower bound, which is sharp for K = 0, is obtained for the expected value of the global optimum of the NK model. A detailed analysis is provided for the expectation and variance of the global optimum when K = N−1. The lower and upper bounds on the expectation obtained for this case show that there is a wide gap between the values of the local and the global optima. They also indicate that the complexity catastrophe that occurs with the local optima does not arise for the global optima.
Combining Novel Biomolecules and Stimuli‐Sensitive Biomaterials into New Recognition‐Response Biomaterial Systems

An important present and emerging trend in biomaterials development is the synthesis of polymers which combine capabilities of biologic recognition ("biomimetic") with sensitivity to small environmental changes ("stimuli-responsive"). This short article highlights some of the many opportunities and challenges in this exciting area.
Some Demonstrations of the Effects of Structural Descriptions in Mental Imagery

A visual imagery task is presented which is beyond the limits of normal human ability, and some of the factors contributing to its difficulty are isolated by comparing the difficulty of related tasks. It is argued that complex objects are assigned hierarchical structural descriptions by being parsed into parts, each of which has its own local system of significant directions. Two quite different schemas for a wire-frame cube are used to illustrate this theory, and some striking perceptual differences to which they give rise are described. The difficulty of certain mental imagery tasks is shown to depend on which of the alternative structural descriptions of an object is used, and this is interpreted as evidence that structural descriptions are an important component of mental images. Finally, it is argued that analog transformations like mental folding involve changing the values of continuous variables in a structural description.
Drugs and chemicals that produce diabetes

Abstract Many pharmacologists and toxicologists are aware that chemicals can produce diabetes in animals, but Lawrence Fischer believes that the important implications of our present insufficient knowledge in this area may not be widely appreciated. Insulin-secreting cells appear to be more sensitive to chemical insult than other hormone-secreting cells of the pancreas and the diverse nature of the chemical structures of the substances known to produce deleterious changes indicates that there may be a number of different mechanisms by which s-cells are damaged. Until these mechanisms are elucidated, we may unknowingly remain at risk of exposure to diabetogenic agents.
The role of the prostacyclin receptor antagonist RO3244019 in treating neurogenic detrusor overactivity after spinal cord injury in rats.

OBJECTIVE To determine the effects of the prostacyclin receptor (IP) antagonist RO3244019 on neurogenic detrusor overactivity (NDO) in spinal cord-injured (SCI) neurogenic bladder of the rat. MATERIALS AND METHODS Female Sprague-Dawley rats with SCI were divided into four treatment groups of eight each: vehicle (200 mm Tris base), indomethacin (3 mg/kg), RO3244019 (at 1 and 5 mg/kg). The conscious rats were assessed by cystometry, by slowly infusing the bladder with physiological normal saline at 0.04 mL/min. After 1 h of cystometry one of the four compounds was administered intravenously to the rats and changes in cystometrogram tracings recorded. Seven voiding variables were calculated before and after administering each compound: the intercontractile interval (ICI) for all contractions, voiding ICI, amplitude of all contractions, amplitude of voiding contractions, time to first void (TFV), voided volumes (VVs), and first VV. Data were analysed using a paired t-test for each of the experiments. RESULTS At 1 mg/kg, the RO compound was associated with a statistically significant difference in the voiding ICI and VVs (both P < 0.05). The mean (sd) voiding ICI increased from 621 (140) to 889 (119) s (43% increase) and the VVs from 0.53 (0.13) to 0.72 (0.09) mL (36% increase). However, there was no statistically significant difference in the TFV or the first VVs. Increasing the dose to 5 mg/kg was more effective in improving the voiding ICI and the VVs (both P < 0.01). The voiding ICI increased from 716 (130) to 1346 (159) s (88% increase) and the VVs from 0.60 (0.11) to 1.05 (0.12) mL (75% increase). In addition, the higher dose had a statistically significant difference in the TFV (P < 0.05). There was more than a four-fold increase in the TFV, from 807 (138) to 3239 (883) s. At 5 mg/kg, the difference in the first VV before and after administering the compound was also almost statistically significant (P = 0.057); the first VV increased from 0.56 (0.14) to 1.01 (0.21) mL. There were no statistically significant differences in the amplitude of contractions or the ICI for all contractions for either of the dosages. Indomethacin at 3 mg/kg was the most effective compound for improving all of the voiding variables and was the only one to show a significant difference in the first VV. However, the IP antagonist at 5 mg/kg was almost as effective as indomethacin when comparing other variables, e.g. the voiding ICI and the VV. There was no statistically significant difference in any of the seven voiding variables before and after administering the vehicle. CONCLUSION The IP antagonist RO3244019 was effective in treating NDO in SCI bladders. While RO3244019 at 1 mg/kg significantly increased the voiding ICI and VVs, 5 mg/kg appeared to be more effective, suggesting a dose-dependent effect of the drug. The RO compound at 5 mg/kg was almost as effective as indomethacin in improving all of the voiding variables.
Review of the Different Sources of Uncertainty in Single Polarization Radar-Based Estimates of Rainfall

It is well acknowledged that there are large uncertainties associated with radar-based estimates of rainfall. Numerous sources of these errors are due to parameter estimation, the observational system and measurement principles, and not fully understood physical processes. Propagation of these uncertainties through all models for which radar-rainfall are used as input (e.g., hydrologic models) or as initial conditions (e.g., weather forecasting models) is necessary to enhance the understanding and interpretation of the obtained results. The aim of this paper is to provide an extensive literature review of the principal sources of error affecting single polarization radar-based rainfall estimates. These include radar miscalibration, attenuation, ground clutter and anomalous propagation, beam blockage, variability of the Z–R relation, range degradation, vertical variability of the precipitation system, vertical air motion and precipitation drift, and temporal sampling errors. Finally, the authors report some recent results from empirically-based modeling of the total radar-rainfall uncertainties. The bibliography comprises over 200 peer reviewed journal articles.
The period of the Bell numbers modulo a prime

We discuss the numbers in the title, and in particular whether the minimum period of the Bell numbers modulo a prime p can be a proper divisor of Np = (p P — 1)/(p - 1). It is known that the period always divides Np. The period is shown to equal Np for most primes p below 180. The investigation leads to interesting new results about the possible prime factors of Np. For example, we show that if p is an odd positive integer and m is a positive integer and q = 4m 2 p + 1 is prime, then q divides p m2p - 1. Then we explain how this theorem influences the probability that q divides Np.
Ultrasound-guided peripheral intravenous access program is associated with a marked reduction in central venous catheter use in noncritically ill emergency department patients

Study objective We examine the central venous catheter placement rate during the implementation of an ultrasound-guided peripheral intravenous access program. Methods We conducted a time-series analysis of the monthly central venous catheter rate among adult emergency department (ED) patients in an academic urban ED between 2006 and 2011. During this period, emergency medicine residents and ED technicians were trained in ultrasound-guided peripheral intravenous access. We calculated the monthly central venous catheter placement rate overall and compared the central venous catheter reduction rate associated with the ultrasound-guided peripheral intravenous access program between noncritically ill patients and patients admitted to critical care. Patients receiving central venous catheters were classified as noncritically ill if admitted to telemetry or medical/surgical floor or discharged home from the ED. Results During the study period, the ED treated a total of 401,532 patients, of whom 1,583 (0.39%) received a central venous catheter. The central venous catheter rate decreased by 80% between 2006 (0.81%) and 2011 (0.16%). The decrease in the rate was significantly greater among noncritically ill patients (mean for telemetry patients 4.4% per month [95% confidence interval {CI} 3.6% to 5.1%], floor patients 4.8% [95% CI 4.2% to 5.3%], and discharged patients 7.6% [95% CI 6.2% to 9.1%]) than critically ill patients (0.9%; 95% CI 0.6% to 1.2%). The proportion of central venous catheters that were placed in critically ill patients increased from 34% in 2006 to 81% in 2011 because fewer central venous catheterizations were performed in noncritically ill patients. Conclusion The ultrasound-guided peripheral intravenous access program was associated with reductions in central venous catheter placement, particularly in noncritically ill patients. Further research is needed to determine the extent to which such access can replace central venous catheter placement in ED patients with difficult vascular access.
Active correction of thermal lensing through external radiative thermal actuation

Absorption of laser beam power in optical elements induces thermal gradients that may cause unwanted phase aberrations. In precision measurement applications, such as laser interferometric gravitational-wave detection, corrective measures that require mechanical contact with or attachments to the optics are precluded by noise considerations. We describe a radiative thermal corrector that can counteract thermal lensing and (or) thermoelastic deformation induced by coating and substrate absorption of collimated Gaussian beams. This radiative system can correct anticipated distortions to a high accuracy, at the cost of an increase in the average temperature of the optic. A quantitative analysis and parameter optimization is supported by results from a simplified proof-of-principle experiment, demonstrating the method’s feasibility for our intended application.
Solution to treatment planning problems using coordinate transformations

The majority of radiation treatment planning problems are relatively straightforward, involving only specified gantry angles in a treatment plane which is perpendicular to the patient longitudinal axis. In addition, there are a number of more complex three‐dimensional problems which require combined rotation of the gantry, collimator, and turntable for their solutions. These include, for example, the use of non‐coplanar fields and oblique treatment planes, the matching of field edges in three dimensions, the treatment of the breast with opposing tangential fields, and the treatment of inclined elongated lesions. Unfortunately, there is no general systematic approach to the solution of these more complex problems. One may attempt an analytic solution, but this approach is often too cumbersome and tedious. On the other hand, one may resort to a ‘‘trial and error’’ session with the simulator. This paper, therefore, presents a mathematical method which is easily applied and applicable to a wide variety of complex three‐dimensional treatment planning problems. The method considers the gantry, collimator, and turntable as coordinate systems. These coordinate systems are derivable from each other by specified coordinate transformations, which contain the rotation angles of the gantry, collimator, and turntable. Within this mathematical framework, the treatment planning problems are found to reduce to two general types, of which various clinical examples are then given. Key words: treatment planning, coordinate systems, coordinate transformations, three‐dimensional treatment planning, rotation operators
A Redetermination of the Relative Abundances of the Isotopes of Neon, Krypton, Rubidium, Xenon, and Mercury

A careful redetermination of isotopic abundance ratios in neon, krypton, rubidium, xenon, and mercury has been made. The mass spectrometer employed was calibrated for mass discriminative effects with a synthetic argon isotope mixture made from essentially pure samples of ${\mathrm{A}}^{36}$ and ${\mathrm{A}}^{40}$. The present results together with those obtained from an earlier study on carbon, nitrogen, oxygen, argon, and potassium enable one to use the several elements investigated as sub-standards for calibrating mass spectrometers for mass discriminative effects in other instances.
Rivanol, Resin and the Isolation of Thrombins

HUMAN, cow, and horse thrombins were quickly fractionated from citrate- or bio-activated prothrombin preparations by precipitation of residual prothrombin and inert protein(s) with the cationic dye 6,9-diamino-2-ethoxyacridine lactate (often referred to as rivanol, available under the trade name ‘Ethodin’ from the Winthrop Laboratories, New York, New York). This is a general procedure previously applied in purifying γ-globulin1, β1-metal-combining globulin2, and caeruloplasmin3. A more efficient yet rapid fractionation, however, was achieved by the adsorption of preparations containing thrombin on filter cakes or short columns of ‘IRC-50’ (‘XE-64-Rivanol’), this resin form being prepared by stirring ‘XE-64-Na+’ with an excess of rivanol. After the impurities, including other rivanol-soluble proteins, were washed off, the thrombins were eluted with 0.15 M calcium chloride. The thrombins were recovered from all eluates by acetone precipitation.
Forward transport of glycoproteins on leading lamellipodia in locomoting cells.

IN several types of locomoting cells, active rearward transport of particles on the cell surface has been observed and correlated with motility1-4. No forward transport of particles has previously been reported, however. Here we report rapid forward transport of concanavalin A-coated gold particles on the dorsal surfaces of lamellipodia of fish epidermal keratocytes. These movements are active, not diffusive, and more rapid than either rearward particle transport or the rate of cell locomotion. We observed forward transport in migrating, but not in stationary cells, and could block the movement by treatment with cytochalasin D. These studies demonstrate for the first time that small numbers of glycoproteins can be actively transported on the surface of the cell to the front of the lamellipodium. We suggest that this mechanism transports proteins involved in cell locomotion, such as proteins necessary for adhesion, and could also produce an extensile force.
Mapping dominant markers using F2 matings.

The development of efficient methods for amplifying random DNA sequences by the polymerase chain reaction has created the basis for mapping virtually unlimited numbers of mixed-phase dominant DNA markers in one population. Although dominant markers can be efficiently mapped using many different kinds of matings, recombination frequencies and locus orders are often mis-estimated from repulsion F2 matings. The major problem with these matings, apart from excessive sampling errors of recombination frequency (θ) estimates, is the bias of the maximum-likelihood estimator (MLE) of θ (θ ML). $$\hat \theta _{ML} = 0$$ when the observed frequency of double-recessive phenotypes is 0 and the observed frequency of double-dominant phenotypes is less than 2/3 — the bias for those samples is — θ. We used simulation to estimate the mean bias of θ ML. Mean bias is a function of n and θ and decreases as n increases. Valid maps of dominant markers can be built by using sub-sets of markers linked in coupling, thereby creating male and feamle coupling maps, as long as the maps are fairly dense (about 5 cM) — the sampling errors of θ increase as θ increases for coupling linkages and are equal to those for backcross matings when θ=0. The use of F2 matings for mapping dominant markers is not necessarily proscribed because they yield twice as many useful markers as a backcross population, albeit in two maps, for the same number of DNA extractions and PCR assays; however, dominant markers can be more effeciently exploited by using doubled-haploid, recombinant-inbred, or other inbred populations.
Traveling waves in GaAs semiconductors

Abstract In this paper we analyse the existence and stability of traveling wave solutions for a simplified form of the semiconductor device equations in the case of one space dimension. These special solutions are caused by the particular, nonlinear dependence of the electron velocity on the electric field in certain semiconductor materials. We determine the possible wavespeeds and waveforms by a phase plane analysis of the travelling wave problem for two different velocity models. A reformulated version of the equations is used to discuss the stability of these waves. Furthermore we perform numerical experiments to investigate the generation and the stability of these solutions.
Overcoming a Permeability Barrier by Microinjecting Cryoprotectants into Zebrafish Embryos (Brachydanio rerio)

Abstract The goal of this research was to examine the developmental effects on zebrafish embryos ( Brachydanio rerio ) when cryoprotectants were directly microinjected into the yolk. Our objectives were to: (i) determine the final concentration of propylene glycol (PG) and dimethyl sulfoxide (Me 2 SO) that the embryos could tolerate without causing teratogenic effects; (ii) determine if the toxicity of Me 2 SO could be reduced by the simultaneous presence of various proportions of amides; and (iii) examine whether this intracellular cryoprotectant incorporation could reduce the cryodamage to the yolk syncytial layer (YSL) after vitrification trials. The rationale for conducting these microinjection experiments was to overcome the permeability barrier of the YSL. Intracellular PG produced better survival than Me 2 SO ( P 2 SO, survival was lower than PG at 60 ± 4 and 14 ± 4% at 2.4 and 5.2 M. Unlike other cellular systems, the presence of amides, specifically acetamide or formamide, did not reduce the toxicity of Me 2 SO in zebrafish embryos ( P > 0.05). During vitrification trials, we estimated a 25% dehydration of the yolk, yielding an effective PG concentration of 5.9 M. However, the incorporation of this vitrifiable concentration of PG was not sufficient to improve the postthaw morphology of the YSL ( P > 0.05). Clearly, other factors need to be examined in establishing a successful vitrification protocol for zebrafish embryos.
The contour problem for restricted-orientation polygons

The problem of finding the contour of the union of a collection of polygons in which all vertices have integer coordinates and the slopes of the sides belong to a finite fixed collection of orientations is studied from two perspectives. The first is that of determining which algorithms for finding the contour of the union for rectilinear polygons and/or rectangles can be generalized to handle polygons with sides of two or more additional directions while still retaining efficiency. The second is that of determining which algorithms for computing the union of arbitrary polygons in general position can be revised to handle degeneracies and possibly to take advantage of the restricted number of orientations to improve robustness, efficiency, or both. Three distinct rectilinear algorithms are detailed, and general preprocessing and postprocessing procedures which allow all three rectilinear algorithms to operate on polygons of additional orientations are presented. Two general algorithms for computing the contour of union based on line segment intersection algorithms and plane sweeping are also presented and analyzed. >