cssi/SciSciGPT-SciSciNet huggingface dataset:
A single residue can modify target-binding affinity and activity of the functional domain of the Rho-subfamily GDP dissociation inhibitors

Abstract The GDP dissociation inhibitors (GDIs) represent an important class of regulatory proteins for the Rho- and Rab-subtype GTP-binding proteins. As a first step toward identifying the key functional domain(s) on the Rho-subtype GDI, truncations of the amino and carboxyl termini were performed. Deletion of the final four amino acids from the carboxyl terminus of Rho GDI or the removal of 25 amino acids from the amino terminus had no significant effect on the ability of the GDI to inhibit GDP dissociation from the Rho-like protein Cdc42Hs or on its ability to release Cdc42Hs from membrane bilayers. However, the deletion of 8 amino acids from the carboxyl terminus of Rho GDI eliminated both activities. To further test the importance of the carboxyl-terminal domain of the Rho GDI molecule, chimeras were constructed between this GDI and a related protein designated LD4, which is 67% identical to Rho GDI but is less potent by a factor of 10-20 than Rho GDI in functional assays with the Cdc42Hs protein. Two sets of chimeras were constructed that together indicated that as few as 6 amino acids near the carboxyl terminus of Rho GDI could impart full GDP dissociation inhibition and membrane dissociation activities on the LD4 molecule. Further analysis of this region by site-directed mutagenesis showed that a single change at residue 174 of LD4 to the corresponding residue of Rho GDI (i.e., Asp-174-->Ile) could impart nearly full (70%) Rho GDI activity on the LD4 molecule.
Surface-Responsive Materials

Synthetic polymers offer a wealth of opportunities to design responsive materials triggered by external stimuli. Changing the length, chemical composition, architecture, and topology of the chains allows response mechanisms and rates to be easily manipulated; and devices based on the entropy of the chains, surface energies, and specific segmental interactions can readily be made. Although numerous applications exist, intriguing possibilities are emerging that have tremendous potential to further developments in surface-responsive materials.
Worst case dynamic programming and its application to deterministic systems

In this paper, we investigate the numerical solution of discrete time ,infinite horizon,stationary ,discounted Dynamic Programming(DP) problem. We introduce the worst case variant of the standard DP operator and show that it retains the nice properties of the former.We apply this worst case formulation to deterministic systems in continuous space and show that for a class of such systems, any arbitrary degree of accuracy can be attained in the numerical solution to the DP problem. Finally we illustrate our results through a simple orbital dynamics example.
NEGRO AND WAR ATTITUDES OF THE SAME PERSONS ASSESSED AT THREE POINTS OVER A THIRTY-THREE YEAR PERIOD

(95%) was obtained. Negro attitudes remained stable over the 3- and 33-yr. periods (s~.m = 91, and = .73). War attitudes, however, did not remain as stable (7u.m = .56, and TZ.~ = .27), because of shifts to neutral positions over the 33-9r. period. A factor analysis of the Negro scale revealed that 9 of the original 16 items were durable through time. Only 10 of the original 22 War-scale items were reliable through rhe same time period. Results were consistent with the idea that racial attitudes are formed at a very early age and remain rather stable while attitudes such as militarism-pacifism are formed later in life and are more subject to change. Longitudinal studies are comparatively rare due to many inherent difficulties. This is particularly true of the period prior ro the computer age. As a consequence, studies of the attitudes of the same persons through time continua havc, for the most part, been recent, and have not reflected atticude consistency of persons who are now reaching middle age. One such exception exists in a previously reported study of the consistency of attintdes of the same persons from 1935 through 1965 (Capel, 1967). The consistency of attitudes thus expressed was further analyzed to establish validity through time of the neutral position on Negro and War attitude scales (Caffrey & Capel, 1968). In each of these studies the term "attitude" was operationally defined as the mean score obtained by an individual on the respective scales. It became evident from the two studies that while changes in attitudes did occur, individual Ss retained a high degree of consistency. In other words, while the group shift in attitude toward the Negro was toward a significantly less prejudiced position from 1935 to 1965, those individuals who were most prejudiced in 1935 were also most prejudiced in 1965, those who were neutral remained neutral and those who were least prcjud~ced remained the least prejudiced. The level changed but the individual ranking did not. While a lower degree of consistency was found for War attitudes, there was a significant shift toward an increasingly militaristic position. A factor analysis isolated certain items as defining the factors of "prejudice/ non-prejudice" and "militarism/non-militarism" which were constant over the
MO‐E‐M100J‐06: Intra‐Fraction Target‐Beam Positioning

The problem of intrafraction tumor‐target positioning can be divided into two separate processes: (1) estimating the real‐time target position and (2) repositioning the beam to account for intrafraction target motion. Several solutions exist for both target position estimation and beam repositioning, however in principal any method of position estimation could be integrated with any method of beam repositioning. Note that beam repositioning can include moving the target to align with the beam (e.g. couch motion), which in the target reference is the same as moving the beam to align with the target. There are several common features in target position estimation systems. First, that in the absence of a real‐time volumetric imaging system, the target position is estimated from surrogates and thus there is uncertainty in the position of the target with respect to the surrogates. Second, for all but EPID‐based methods target position estimation is independent of the treatment beam and therefore careful quality assurance is required to ensure the accurate position estimation with respect to the treatment beam. There are also several common features of the beam repositioning systems. First, control systems with secondary feedback are required to ensure accurate and precise real time mechanical motion. Second, that there is a delay between the target motion and the beam repositioning. This delay causes delay‐time dependent errors which can be reduced with prediction algorithms. The various target position estimation and beam repositioning processes either in development or available for clinical use will be described and contrasted. Educational Objectives: 1. Understand the separation of the target position estimation and beam repositioning processes. 2. Understand the advantages and disadvantages of several real‐time target position estimation systems. 3. Understand the advantages and disadvantages of several beam repositioning systems. Some research in this area at Stanford is supported by Varian Medical stems.
Ectoparasites: Direct impact on host fitness

Despite being restricted to the host's first line of defence (the integument, away from vital organs), ectoparasite damage has a pronounced impact on host fitness. This generalization can be explained by the reduced dependence of most ectoparasites on their individual host, which minimizes the fitness loss linked to host death. This explanation implies that permanent ectoparasites evolve less 'aggressively' than do either nest or field ectoparasites. This, and other determinants of ectoparasitic virulence are discussed here by Tovi Lehmann.
Survival differences between peritoneal dialysis and hemodialysis among "large" ESRD patients in the United States.

Survival differences between peritoneal dialysis and hemodialysis among "large" ESRD patients in the United States. Background It has been hypothesized that peritoneal dialysis compared to hemodialysis may be less effective in large patients with end-stage renal disease (ESRD). Methods We tested this hypothesis in a cohort of 134,728 new ESRD patients who were initiated on dialysis from May 1, 1995 to July 31, 1997 using data from United States Renal Data System (USRDS). Cox regression models evaluated the association of body mass index (BMI) in quintiles (8.8–20.9, 20.9–23.5, 23.5–26.1, 26.1–30.0, 30.0–75.2 kg/m 2 ) with mortality over 2 years in peritoneal dialysis and hemodialysis patients separately, while time-dependent models evaluated the relative risk (RR) of death by modality for each BMI quintile. Results For hemodialysis, the adjusted RR of death was greatest for patients with BMI ≤ 20.9 (RR = 1.40, 95% CI 1.32–1.50 for diabetics and RR=1.27, 95% CI 1.21–1.34 for nondiabetics) and lowest for patients with BMI >30.0 (RR = 0.97, 95% CI 0.96–0.99 for diabetic and RR=0.97, 95% CI 0.95–0.98 for nondiabetic patients) compared with the referent (23.5–26.1; RR=1.00). For peritoneal dialysis, the RR of death was also higher for patients with a BMI P P P P Conclusion We conclude that body size modifies the impact of dialysis modality on mortality risk among new ESRD patients in the United States. The selection of hemodialysis over peritoneal dialysiss was associated with a survival advantage in patients with large body habitus.
Nifedipine and flunarizine block amphetamine-induced behavioral stimulation in mice

Abstract Sixteen calcium channel inhibitors (CCl's) were tested in a model utilizing amphetamine-induced behavioral stimulation in mice. Nifedipine, flunarizine and possibly PY 108-068 were effective in blocking amphetamine-induced locomotor stimulation. Verapamil, diltiazem and many other CCl's were ineffective in this experimental paradigm.
Fichte's Fictions Revisited

Fichte's most influential presentation of his Wissenschaftslehre, which coincides with his tenure at Jena, has, ironically, been subjected to incredulity, misunderstanding, and outright hostility. In a recent essay, noted scholar Daniel Breazeale has undertaken to challenge this history of neglect and misunderstanding by pointing to the significance of striking passages from Fichte's writings in which he asserts that his philosophical system is fictional. At the same time, Breazeale also notes some of the tensions between this fictionalist reading of the Jena Wissenschaftslehre and Fichte's equally forceful insistence on the reality of his system. In this essay, I argue that these two sides of Fichte's conception of his philosophy can, in fact, be reconciled by looking more carefully at distinctions that Fichte himself draws between realities, philosophical fictions, and mere fabrications. What results is a clearer picture of Fichte's conception of transcendental philosophy that builds upon Breazeale's va...
Closed-form quality measures for compressed medical images: compression noise statistics of transform coding

This paper provides a theoretical foundation for the closed-form expression of model observers on compressed images. In medical applications, model observers, especially the channelized Hotelling observer, have been successfully used to predict human observer performance and to evaluate image quality for detection tasks in various backgrounds. To use model observers, however, requires knowledge of noise statistics. This paper first identifies quantization noise as the sole distortion source in transform coding, one of the most commonly used methods for image compression. Then, it represents transform coding as a 1-D block-based matrix expression, it further derives first and second moments, and the probability density function (pdf) of the compression noise at pixel, block and image levels. The compression noise statistics depend on the transform matrix and the quantization matrix in the transform coding algorithm. Compression noise is jointly normally distributed when the dimension of the transform (the block size) is typical and the contents of image sets vary randomly. Moreover, this paper uses JPEG as a test example to verify the derived statistics. The test simulation results show that the closed-form expression of JPEG quantization and compression noise statistics correctly predicts the estimated ones from actual images.
HER-2/neu targeted delivery of a nanoprobe enables dual photoacoustic and fluorescence tomography of ovarian cancer.

Abstract Development of sensitive and specific imaging approaches for the detection of ovarian cancer holds great promise for improving survival of ovarian cancer patients. Here we describe a dual-modality photoacoustic and fluorescence molecular tomography (PAT/FMT) approach in combination with a targeted imaging probe for three-dimensional imaging of ovarian tumors in mice. We found that the selective accumulation of the HER-2/neu targeted magnetic iron oxide nanoparticles (IONPs) led to about 5-fold contrast enhancements in the tumor for PAT, while near-infrared (NIR) dye labeled nanoparticles emitted strong optical signals for FMT. Both PAT and FMT were demonstrated to be able to detect ovarian tumors located deep in the peritoneal cavity in mice. The targeted nanoprobes allowed mapping tumors in high resolution via PAT, and high sensitivity and specificity via FMT. This study demonstrated the potential of the application of HER-2/neu-targeted PAT/FMT approach for non-invasive or intraoperative imaging of ovarian cancer. From the Clinical Editor This paper details the development of a dual-modality photoacoustic and fluorescence molecular tomography approach in combination with a targeted imaging probe for three-dimensional imaging of ovarian tumors in a mouse model, demonstrating the application of the HER-2/neu-targeted approach for non-invasive or intraoperative imaging of ovarian cancer.
The processing of plutonium by ion exchange—I The concentration dependence of distribution coefficients on dowex 1X4 from 7 M nitric acid

Abstract An expression was derived and experimentally confirmed for the change in the volume distribution coefficient for plutonium (IV) on Dowex 1X4 from 7 M nitric acid with varying concentrations of plutonium (IV) in the aqueous phase. A few experiments with other sorbable species indicate the equations may be applicable to other systems. These calculations require one measurement of the volume distribution coefficient at a trace level of resin loading. These trace level coefficients were determined for many elements.
The de Haas-van Alphen effect in the intermetallic compound Cu 2 Sb

The de Haas-van Alphen effect has been studied in the intermetallic compound Cu2Sb (tetragonal structure) by the modulation method in fields up to 100 kG. Numerous frequency branches have been obtained in the (100), (110), and (001) planes, and several cyclotron effective masses have been determined. The results show some compatibility with the nearly-free-electron model in the single- or double-zone scheme. The lattice parameters have been determined at room temperature and at liquid-helium temperatures.
‘Metabolic’ factors in thermal injury: role of nucleic acids

Abstract We believe that toxic events observed after thermal injury may be caused by the release of normally intracellular substances into the circulation. We define these substances as ‘metabolic’ factors. Analysis of extracts prepared from normal and burned mouse skin indicates that the burned skin extract contains increased clot-promoting (Thromboplastin-like) substances and, perhaps, less RNA than normal skin extracts. Injection of RNA or its breakdown products into the burned site significantly increases the acute mortality in burned mice. No increase in mortality is observed when these substances are injected into a non-burned site on burned mice. We suggest that (Thromboplastin-like substances and RNA or RNA breakdown products may be some of the ‘metabolic’ factors involved in acute burn toxicity. Upon being released from their intracellular residence after thermal injury, their combined activity contributes to the acute mortality observed.
Localization of DNase I-hypersensitive regions during rat spermatogenesis: stage-dependent patterns and unique sensitivity of elongating spermatids.

DNase I-hypersensitivity of rat spermatogenic cells was analyzed (1) to establish overall patterns of hypersensitivity in individual cell types, (2) to correlate these patterns with known changes in chromatin organization and function, and (3) to provide a foundation for further analyses examining DNase I-hypersensitivity and the localization of specific genes during spermatogenesis. Parameters for in situ nick translation, using radioactive and fluorescent probes to visualize DNase I-hypersensitive regions (DHR), were established for fixed and sectioned testicular preparations, permeabilized cells, and isolated germ cell nuclei. As anticipated, the pattern of DHR changed in a cell-type specific manner during the course of spermatogenesis, reflective of known stage-dependent alterations in the composition and structure of both the chromatin and the nuclear lamina/matrix as well as changes in gene expression. DHR in preleptotene spermatocytes were primarily peripheral, while in pachytene spermatocytes they were localized along the condensed chromosomes. The pattern of DHR changed from “checkerboard” in steps 7–8 round spermatid nuclei to “lamellar” in steps 10–11 elongating spermatids. In steps 12–13 elongating spermatids, DHR were localized throughout the nuclei or in a graded manner—increasing from anterior to posterior and mirroring the pattern of chromatin condensation. However, unlike the case in other stages, DNA of steps 12–13 elongating spermatids was exquisitely sensitive to nick translation even in the absence of exogenous DNase I. In contrast to the labeling of earlier stages, steps 16–19 spermatids and mature spermatozoa did not demonstrate DNase I-hypersensitivity under any conditions employed. A variety of agents that interact with topoisomerase II and DNA (teniposide, novobiocin, ethidium bromide, and adenosine triphosphate) were tested to determine the basis for the unique sensitivity to nick translation of steps 12–13 elongating spermatids. None of the agents tested, however, affected this unique labeling. The sensitivity of steps 12–13 elongating spermatids to nick translation in the absence of exogenous nuclease indicates the presence of endogenous nicks, which may relieve torsional stress and aid rearrangement as the chromatin is packaged into a form characteristic of the mature spermatozoon.
Slowed enzymatic turnover allows characterization of intermediates by solid-state NMR.

EPSP (5-enolpyruvylshikimate-3-phosphate) synthase catalyzes condensation of shikimate 3-phosphate (S3P) and phosphoenolpyruvate (PEP) to form EPSP, a precursor to the aromatic amino acids. S3P and [2-13C]PEP were bound to mutant or wild type E. coli forms of the enzyme prior to lyophilization. CPMAS-echo and rotational-echo double-resonance (REDOR) NMR experiments, employing a slow catalytic EPSP synthase mutant and a long prelyophilization incubation interval, allowed our observation of the gradual formation of a strong 31P−13C coupling consistent with the well characterized tetrahedral intermediate. However, after shorter low temperature incubation intervals of substrates with mutant or wild-type enzymes, carbon CPMAS-echo NMR spectra showed the 13C label at 155 ppm, consistent with sp2 geometry of this carbon. REDOR revealed that the phosphorus of PEP was cleaved. However, phosphorus at a distance of 7.5 A was observed, due to the phosphate of a nearby bound S3P. Heating the sample allowed the reactio...
691 DEMONSTRATION OF DIRECT GLUCOSE ABSORPTION THROUGH INFANT RECTAL MUCOSA

Previous studies of the fate of malabsorbed glucose in the colon provided kinetic evidence that glucose can be transported through the rectal mucosa of the infant without being broken down to volatile fatty acids. To obtain evidence for the direct absorption of glucose across rectal mucosa in vivo, UL-13C6-glucose was administered rectally through a small catheter to 3 healthy newborn infants within the first hour of life and to 3 infants recovering from diarrhea. Three samples of peripheral blood were drawn between 5 and 30 min following the administration of the isotope. Glucose was isolated from deproteinized plasma and converted to its aldonitrile penta-acetate derivative with hydroxylamine hydrochloride, and analyzed by gas chromatography/mass spectrometry for the presence of di-, tri-, tetra- and hexa-13C-labeled glucose molecules. Maximum ratios of hexa-13C-glucose to endogenous plasma glucose in the range of .3-.5% were detected in 2/3 of newborns and 2/3 of infants with diarrhea. These levels exceeded three times the standard deviation of the isotopic ratiometric measurement. Statistically significant levels of the di-, tri-, and tetra-13C-labeled glucose were not found when glucose was administered rectally. However, maximum mole ratios of 1.7, 0.8, and 0.3% were observed for hexa-, tetra-, and tri-13C-labeled glucose, respectively, after IV administration. Conclusion: These data provide the first direct evidence for the systemic availability of intact glucose molecules absorbed from the human rectum.
Changes in blood pressure, heart rate and blood constituents during heat exposure in men with elevated blood pressure

Although the vascular volume response of hypertensive men during exercise has been rather well characterized, the effect of resting heat exposure in this patient population has not been examined. This was done in the present report in seven men with high blood pressure (BP) (i. e., diastolic pressure>12 kPa (90 mmHg) upon initial interview) and 5 normotensive control subjects. 50 min after each subject had consumed an amount of water equal to 1% of his body weight, he reclined on a cot. 10 min later the subject was carried into an environmental chamber equilibrated at Tdb=45‡ C, Twb=28‡ C. Free-flowing venous blood samples were obtained from a cubital vein, and BP and heart rate were measured, before the heat exposure and at 15 min intervals during the experiment. Within 30 min systolic, diastolic and mean BP of the high BP subjects had decreased to normal levels; no BP changes were detected in normotensive subjects. Accompanying this depressor response was an exaggerated elevation in plasma glucose concentration. No alterations were found with haematocrit, plasma osmolality or electrolytes, or total protein and albumin. The data suggest that heat exposure may have been more stressful for the subjects with high BP than for their controls. This finding implies that phasic depressor responses may be as important as phasic pressor episodes in the aetiology of established essential hypertension.
MO‐E‐204C‐02: Bedside SPECT Imaging with Pinhole Collimation

Purpose: The objective of this study is to evaluate the imaging performance of a mobile SPECT system with a pinhole collimator and compare the results with parallel hole collimators. The goal is to obtain both planar and tomographic performance measures with Tc‐99m and F‐18. This abstract presents the results using Tc‐99m. Method and Materials: The system utilizes a small field of view camera with pixilated NaI crystal and position‐sensitive photomultiplier tubes. The pinhole collimator is a tungsten knife edge with a hole diameter of 3mm, a focal length of 12.5cm, and an acceptance angle of 90 degrees. The parallel hole collimators have been previously described along with their imaging performance evaluation [1]. The following performance measures with the pinhole collimator were obtained and are presented here: count rate performance, energy resolution, flood field uniformity, system spatial resolution, system sensitivity. Results: The maximum count rate was calculated to be 1.58×105 cps corresponding to an activity of 161 μCi at 30cm. An energy spectrum from the flood acquisition demonstrated an energy resolution of 20% FWHM. Magnification corrected, system planar spatial resolution was 1.03 cm with a system sensitivity of 1.39 cps/μCi at a source to collimator distance of 10 cm. Conclusion: The imaging performance of a mobile SPECT system with a pinhole collimator has been presented. In comparison to parallel hole collimation, the pinhole collimator provides superior spatial resolution and sensitivity at distances less than 5cm. However, at further distances, pinhole sensitivity declines while parallel hole sensitivity remains relatively constant. Research sponsored by the United States Army Medical Research and Material Command under Award No. W81XWH‐04‐1‐0594
With a Little Help from My Friends: Library, Faculty, and Instructional Technology Collaboration.

This article highlights a project on information literacy that began in the fall semester of 2003 at the University of Redlands. The faculty in the School of Education needed an information literacy component for their teacher credential program. The Manager of Instructional Technology believed that a tutorial of this type would work well in the Blackboard Course Management System, and the Off-Campus Services Librarian, who is the library liaison for the School of Education, was a natural choice as the person to present the tutorial to the students. The beginning information literacy workshop was developed in the fall of 2003, and the advanced workshop was developed in the spring of 2004. This article provides an overview of the content of the tutorial and workshops, as well as some conclusions about the project in general.
Postpartum stroke: a twenty-year experience.

Abstract Objective: The aim of this study was to characterize the clinical presentation, etiology, and acute and subsequent outcomes of postpartum stroke. Study Design: This 20-year, single-center, retrospective review included 20 women without previous neurologic deficit with clinical and neuroimaging diagnoses of postpartum stroke. Results: Eight of 20 women (40%) were delivered abdominally. Conduction anesthesia was induced in 9 of 20 women (45%). Causes of stroke included cerebral infarction (n = 13; 7 venous, 6 arterial), intracerebral hemorrhage (n = 5; 1 cocaine-induced, 1 anatomic malformation), cerebritis (n = 1), and cerebral atrophy (n = 1). The median time at onset of stroke was 8 days post partum (range, 3-35 days). Headache, seizures, visual change, and hemiparesis were the most common presenting findings but were neither specific to the underlying pathologic condition nor predictive of ultimate maternal outcome. There were 2 maternal deaths, both caused by severe intracerebral hemorrhage. Intracerebral hemorrhage was associated with the poorest outcome (2 deaths and 1 residual neurologic deficit). Eight women had residual neurologic deficit. There was no correlation between a trial of labor ( P =.4; odds ratio, 0.4; 95% confidence interval, 0.01-6.5) or vaginal versus cesarean mode of delivery ( P =.6; odds ratio, 1.3; 95% confidence interval 0.1-16.8) and ultimate neurologic diagnosis (cerebral infarction or intracerebral hemorrhage). However, the incidence of cesarean delivery was greater in the cohort of women with postpartum stroke than in the overall obstetric population ( P =.015; odds ratio, 3.2; 95% confidence interval, 1.2-8.5). One of the 20 women received methergine; 1 received bromocriptine. All women were either normotensive or had well-controlled hypertension at postpartum discharge. New-onset hypertension or exacerbation of existing hypertension occurred after the acute neurologic insult; subsequent mean (±SD) arterial blood pressure was 128.9 ± 24.0 mm Hg. Conclusion: Postpartum stroke is a multifactorial, uncommon, and nonpreventable complication of pregnancy. There was an association between postpartum stroke and hypertensive disorders of pregnancy and cesarean delivery. However, this study refutes any etiologic association between conduction anesthesia and postpartum stroke. (Am J Obstet Gynecol 2000;183:83-8.)
ELIMINATING THE CONTINUUM HYPOTHESIS

In this paper we show how the assumption of the generalized continuum hypothesis (GCH) can be removed or partially removed from proofs in Zermelo-Frankel set theory (ZF) of statements expressible in the simple theory of types. We assume the reader is familiar with the latter language, especially with the classification of formulas and sentences of that language into En and rJn form (cf. [1]) and with how that language can be relatively interpreted into the language of ZF. In ?1 we relativize the construction of Shoenfield [2] to show that if the [l4 sentence 'D is provable in ZF from the axiom of choice (AC) and GCH, then it is already provable in ZF. This result is best possible if one wishes to completely eliminate AC as well as GCH. Let ZFC be ZF + AC. In ?3 we show that if the Fl1 sentence 0 is provable in ZFC from GCH then it is provable in ZEC (we also examine what forms of AC are actually needed in the conclusion). In particular this shows that ZFC + GCH is a conservative extension of ZFC with respect to all second order number-theoretic statements. This result is best possible since "2mo =Xi" is a El-sentence in ZFC which is provable in ZFC + GCH but not in ZFC. We generalize these results to higher finite types by showing that if (D is a I-In2 sentence provable in ZFC + GCH then it is provable in ZFC from
Metrics compatible with a symmetric connection in dimension three

Abstract The problem of characterizing symmetric connections that are Levi-Civita connections of a pseudo-Riemannian metric is considered. A more or less complete solution of the problem in three dimensions is presented. In particular the single class of Levi-Civita connections whose metric is not determined up to a conformal factor by the curvature tensor alone is characterized in geometric terms.
Polarization and birefringency considerations in rendering

In this work we render non-opaque anisotropic media. A mathematical formalism is described in which polarization effects resulting from light/material interactions are represented as transformation matrices.When applying the matrices a skewing is performed to ensure that like reference coordinates are used. The intensity and direction of an extraordinary ray is computed.
Is library anxiety important

The prevalence of library anxiety among college students has been acknowledged by librarians and educators for over a decade. However, there are still people who question whether library anxiety is a real phenomenon. The importance of library anxiety among graduate students is particularly challenged. This study examined the relationship between library anxiety and trait anxiety of 115 graduate students in the United States. Findings revealed that trait anxiety was not significantly related to any of the five dimensions of library anxiety, suggesting that library anxiety is a unique, independent phenomenon. Therefore, library anxiety should be taken seriously. An action‐research approach to addressing library anxiety was recommended.
Dual comb-type electrodes as a plasma source for very high frequency plasma enhanced chemical vapor deposition

Abstract Dual comb-type electrodes were developed as a plasma source in very high frequency (VHF) plasma enhanced chemical vapor deposition system for uniform deposition of silicon films. Two VHF powers introduced to each electrode produced parallel plasma bands, and their positions could be changed by manipulating the phase difference between the supplied VHF waves. Excitation frequency was 80 MHz. The maximum plasma density using this plasma source was 1.5 × 10 10 /cm 3 and the electron temperature was around 2 eV with input power of 2.5 kW, which were measured by double tip Langmuir probe. The uniformity of deposition rate under ± 13% was achieved on 1 m 2 area with optimal plasma conditions.
Decreased bilayer stability due to transmembrane potentials

Abstract Transmembrane potentials serve to increase the rate of production of pores associated with thermal fluctuations. The critical pores previously described by Litster increase in frequency in a way that can account for observed critical voltages for bilayer rupture.
Sympathetic modulation of activity in Aδ- and C-primary nociceptive afferents after intradermal injection of capsaicin in rats

Neuropathic and inflammatory pain can be modulated by the sympathetic nervous system. In some pain models, sympathetic postganglionic efferents are involved in the modulation of nociceptive transmi...
Optimal prediction of cyclical downturns

Abstract In the conventional way of visualizing economic time series, the prediction problem does not dichotomize into predicting turning points and predicting conditional means. Yet, the prediction of turning points has always been considered a separate issue in Business Cycle literature. The paper first discusses these issues and then describes a model where the prediction of turning points does separate from the prediction of conditional means. Using the model an ‘optimal’ way of predicting turning points is derived and applied to U.S. data. The paper uses time series methodology and the theory of optimal stopping times.
Generalization slope as a function of the density of variable interval reinforcement

Five groups of 10 pigeons each were trained to peck a vertical line under VI 14-sec, 21-sec, 35-sec, 56-sec, and 4-min reinforcement schedules and then were tested for angularity generalization in extinction. Both absolute and relative generalization gradients were sharpest with the intermediate schedule densities and flattest following training with the richest and the leanest schedules. Only the differences based upon relative gradients achieved statistical significance however.
Stability Analysis of Complex Multibody Systems

The linearized stability analysis of dynamical systems modeled using finite element based multibody formulations is addressed in this paper. The use of classical methods for stability analysis of these system, such as the characteristic exponent method or Floquet theory, results in computationally prohibitive costs. Since comprehensive multibody models are “virtual prototypes” of actual systems, the applicability to numerical models of the stability analysis tools that are used in experimental settings is investigated in this work. Various experimental tools for stability analysis are reviewed. It is proved that Prony’s method, generally regarded as a curve fitting method, is equivalent, and sometimes identical, to Floquet theory and to the partial Floquet method. This observation gives Prony’s method a sound theoretical, footing, and considerably improves the robustness of its predictions when applied to comprehensive models of complex multibody system. Numerical applications are presented to demonstrate the efficiency of the proposed procedure.Copyright © 2005 by ASME
Heparin-induced Thrombocytopenia: What is its Real Frequency?

A prospective study of 104 patients was undertaken to determine the frequency of severe heparin-induced thrombocytopenia in patients receiving either bovine lung or porcine mucosal heparin. One of 54 patients randomized to receive bovine heparin and two of 50 patients randomized to receive porcine heparin developed heparin-induced thrombocytopenia (platelet count
Archaeological evidence for dating the Loma Caldera eruption, Ceren, El Salvador

A Classic Period agricultural village in El Salvador was partially destroyed and encased in pyroclastic debris during the eruption of Loma Caldera about A.D. 590. The eruption was phreatomagmatic in nature, depositing alternating units of “muddy” pyroclastic surge beds and units of air fall lapilli, pumice, and volcanic bombs. This ephemeral eruptive left only a partially eroded collapsed tephra ring. The eruption began with earth tremors and possible steam explosions, giving enough warning to allow the inhabitants of the nearby village to flee, but violent enough that they left behind many of their most valuable personal items. The low temperature of wet ash surge units, which were likely emplaced as “ash hurricanes,” preserved much of the vegetation and other botanical remains surrounding the village. Analysis of the maturity of maize preserved in agricultural fields, and the presence or absence of blossoming and fruiting plants indicates that the eruption occurred in the mid-rainy season, probably late August or September. The placement of artifacts within buildings indicate that the eruption occurred in the early evening, after the inhabitants had returned from their agricultural fields and eaten an evening meal, but before retiring for the night. Although the exact year of the eruption can only be estimated within the uncertainty of radiocarbon dating, the season of the year and the time of day can be identified with unusual precision. © 1996 John Wiley & Sons, Inc.
Dexamethasone increases the expression of membrane macrophage colony stimulating factor from retrovirally transduced tumor cells expressing macrophage colony stimulating factor

Abstract Many different tumor cell types (breast, ovarian, glioma, liver and colon) were retrovirally transduced with the human macrophage colony stimulating factor (M-CSF) gene (either the membrane associated form [mM-CSF] or the secreted form [sM-CSF]). These cells were tested for their ability to display increased amounts of mM-CSF in response to dexamethasone. M-CSF-transfected tumor cells expressed additional mM-CSF in response to 18–72 h incubations with 3–15 μg/ml dexamethasone, while non-transfected parental cells were unaffected by this treatment. Increased mM-CSF protein expression on the M-CSF transduced cells was observed by flow cytometry and Western blotting using M-CSF specific antibodies. Northern blot analysis revealed an increase in the mM-CSF specific transcripts within the dexamethasone-treated mM-CSF transduced cells, but this was not seen within the non-transfected tumor cells that were treated with dexamethasone. ICAM-1 expression was unaffected by dexamethasone treatment, indicating that this response is mM-CSF specific. All trans-retinal and 1,25-dihydroxy vitamin D3 compounds that have been reported to induce M-CSF expression failed to increase mM-CSF. When dexamethasone-treated mM-CSF transfected clones were used as target cells for macrophage-mediated cytotoxicity assays, an increased killing with the dexamethasone-treated cells was seen. The macrophage-mediated cytotoxicity of these mM-CSF expressing tumor cells was blocked with excess recombinant M-CSF by saturating M-CSF receptors on the macrophage that is required for this form of tumor cell killing. This work suggests the possibility that dexamethasone may prove useful for vaccination purposes using mM-CSF retrovirally transfected tumor cells.
Pena-Shokeir type I syndrome: In utero sonographic appearance

Pena-Shokeir type I syndrome, described in 1974, in a complex syndrome comprising abnormalities of the extremeties pulmonary hypoplasia, intrauterine growth retardation and facial anomalies. Sonographie appearance, pathogenesis, inheritance and prognosis are discussed
On the coordination of La3+ in aqueous LaBr3 solutions

Abstract The structure of the average solute species in two concentrated aqueous LaBr 3 solutions has been measured. In each solution La 3+ has 8.0 (± 0.2) nearest oxygen neighbors and several outer-sphere bromide neighbors. The average LaO nearest neighbor distance is 2.48 A and the ion-paired La ⋯ Br distance is 4.8 A.
Data Reduction in Multidetector Size Exclusion Chromatography

Abstract A comprehensive analysis of multidetector size exclusion chromatography (SEC) is presented. The system examined consists of differential refractometer, capillary viscometer, and light-scattering detector combination. New approaches for interpreting multidetector data have been developed. The first one consists in eliminating the concentration chromatogram from the data reduction process. The traces of two molecular-weight-sensitive detectors alone allow calculating molecular weight and intrinsic viscosity distributions of an unknown polymer, assuming the validity of the universal calibration concept for this polymer. This approach can dramatically improve the characterization of polymers with long high-molecular-weight tails, when small amounts of high-molecular-weight fractions are detected by the light-scattering and viscometer detectors, but the concentration is too low to be registered by the refractometer. Another opportunity discovered is the calculation of the hydrodynamic volume of each f...
The synergistic effect of concurrent spinal and supraspinal opiate agonisms is reduced by both nociceptive and morphine pretreatment.

The antinociceptive effect of morphine administered into the periaqueductal gray (PAG), the intrathecal space (ITH) and concurrently, into both sites (in a 1:1 dose ratio), was assessed in 1) nontolerant rats, 2) rats made tolerant to the effect of morphine on the tail-flick (TF) test and 3) rats that were tested on the TF during chronic saline administration. In nontolerant rats, concurrent morphine injections produced a multiplicative antinociceptive effect (ED50 = 0.392 μg, total dose) relative to that obtained after separate PAG (ED50 = 2.8 μg) or ITH (ED50 = 6.7 μg) injections. The multiplicative effect of concurrent morphine administration was significantly reduced in rats made tolerant to morphine (one 3 mg/kg SC injection and TF test per day for six days). Opiate synergy was also reduced but to a smaller extent in rats that were repeatedly tested on the TF during chronic saline administration (one SC injection and TF test per day for six days). Neither chronic morphine nor saline pretreatment altered the dose-response function to intrathecal morphine. However, both morphine and saline pretreatment significantly reduced the antinociceptive effect of morphine administered into the PAG. The data indicate that concurrent morphine administration into the PAG and ITH space results in a synergistic antinociceptive action which is reduced by performance of the nociceptive response, even in the absence of opiate administration. We suggest that the decrease in opiate synergism produced by nociceptive assessment (behavioral tolerance) is mediated supraspinally, while the additional decline resulting from morphine administered in conjunction with the nociceptive tests (opiate tolerance) is mediated by a combined action at spinal and supraspinal sites.
Hemorrhage control by microsecond electrical pulses

Non-compressible hemorrhages are the most common preventable cause of death on battlefield or in civilian traumatic injuries. We report the use of sub-millisecond pulses of electric current to induce rapid constriction in femoral and mesenteric arteries and veins in rats. Extent of vascular constriction could be modulated by pulse duration, amplitude and repetition rate. Electrically-induced vasoconstriction could be maintained at steady level until the end of stimulation, and blood vessels dilated back to their original size within a few minutes after the end of stimulation. At higher settings, a blood clotting could be introduced, leading to complete and permanent occlusion of the vessels. The latter regime dramatically decreased the bleeding rate in the injured femoral and mesenteric arteries, with a complete hemorrhage arrest achieved within seconds. The average blood loss from the treated femoral artery was about 7 times less than that of a non-treated control. This new treatment modality offers a promising approach to non-damaging control of bleeding during surgery, and to efficient hemorrhage arrest in trauma patients.
Stimulatory and Inhibitory Analogs of Luteinizing Hormone Releasing Hormone (LHRH)

The isolation and the determination of the structure of porcine luteinizing hormone-releasing hormone (LHRH) (Fig. 1) in our laboratory (1–4) paved the way for its synthesis by our group (3,5) and by others (6). Intense activity which has been occurring since then in the field of synthesis of analogs of LHRH was caused by the desire to: (a) establish a relationship between the structure and biological activity of this hormone, (b) synthesize analogs with prolonged biological activity so that they would be more useful therapeutically than LHRH itself which has a very short halflife of about 2 min, and (c) develop inhibitory antagonistic analogs which would form the basis of new birth control methods.
Metabolic fate and disposition of 2-acetylaminofluorene in rainbow trout, Oncorhynchus mykiss

Abstract Rainbow trout, Shasta strain, in contrast to several mammalian species, are highly resistant to hepatocarcinogenesis by 2-acetylaminofluorene (AAF). In order to examine factors that may contribute to this resistance, we investigated the metabolic fate of AAF. Trout treated orally with [14C]AAF rapidly eliminated AAF derivatives via the liver (in which the concentration of AAF-derived radioactivity decreased 4-fold between 8 and 24 h) into the bile which, at 24 h, contained 83% of the recovered radioactivity. At 24 h only 3.5% of the AAF-derived radioactivity retained by the liver represented unmetabolized AAF. In the bile, unmetabolized AAF and 2-aminofluorene accounted for 3.3% and 4.8%, respectively, of total biliary radioactivity, while glucuronide and sulfate conjugates accounted for 63% and 12%, respectively. Analysis of extracts of the deconjugated metabolites revealed that conjugates of 7-OH-AAF and 5-/8-/9-OH-AAF accounted for 49% and 14%, respectively, of total radioactivity. The potentially carcinogenic metabolite N-OH-AAF occurred predominately as the glucuronide conjugate which amounted to only 2% of total metabolites. These data demonstrate that the liver of Shasta trout is highly efficient in the detoxification and elimination of AAF and its derivatives.
In situ stratospheric measurements of CH4, 13CH4, N2O, and OC18O using the Bliss tunable diode laser spectrometer

Simultaneous in situ measurements of stratospheric CH4, (C-13)H4, N2O, OC(O-18), pressure, and temperature have been made from Palestine, Texas (32 deg N) in September 1988 with the JPL Balloon-borne Laser In Situ Sensor. Measurements of CH4 and N2O in the altitude range 30-35 km agree well with other measurements, except for an anomalously high value for the N2O at 31 km. Measurements of CH4 support earlier observations of fold in the vertical profile. A ratio for stratospheric (C-13)H4/CH4 of 0.0105 +/- 0.0010 implies an enrichment of delta(C-13) = -45 +/- 92 parts per thousand over the PDB value, in agreement with previous measurements in the troposphere. A large mixing ratio of 1.9 +/- 0.2 ppmv for OC(O-18) is measured, corresponding to an enrichment of delta(O-18) = 280 +/- 50 parts per thousand for the (O-18) isotopic species over the SMOW value.
Monitoring blood flow changes induced by nicotinamide injection in mouse leg using diffuse correlation spectroscopy

Diffuse Correlation Spectroscopy was employed to monitor relative blood flow in mouse leg before and after injection of nicotinamide (1000 mg/kg). The result shows an average increase of 172% in relative blood flow, 30 minutes after injection.