cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurement of bile acid synthesis in man by release of14CO2 from [26-14C]cholesterol: Comparison to isotope dilution and assessment of optimum reference cholesterol specific activity

Bile acid synthesis can be measured as release of14CO2 from [26-14C]cholesterol divided by cholesterol specific activity, but this method has not been validated in human subjects. We made twelve comparisons of this CO2 method to standard isotope dilution in six normal subjects and found a mean discrepancy of 6%. Linear regression analysis of one value with respect to the other revealed a correlation coefficient of 0.83 (P<0.001), a Y-intercept close to zero (−4.98) and a slope close to 1 (1.06), suggesting good correspondence between the two methods. To assess the potential for error arising from use of serum cholesterol to estimate specific activity of cholesterol used for bile acid synthesis, we compared synthesis measured using serum free cholesterol specific activity to that measured using bile cholesterol specific activity, which is known to be near isotopic equilibrium with the precursor pool used for bile acid synthesis. Synthesis calculated in these two ways differed by less than 10%. The data indicate that the CO2 method using either serum or bile cholesterol specific activity provides a valid estimate of bile acid synthesis in man.
Fundamental differences in the action of estrogens and antiestrogens on the uterus: comparison between compounds with similar duration of action.

In order to understand differences in the mechanism of action of estrogens and antiestrogens, it is essential to make comparisons between compounds with similar duration of action. Hence, in these studies, we compare the action of a longacting estrogen (17α-ethinyl estriol-3-cyclopentyl ether, EE3CPE) and a long-acting antiestrogen (U-ll,100A, UA) on the immature rat uterus and analyze different dosage regimens (single and multiple injections) in studying the effects of these compounds on the uterine estrogen receptor and on uterine growth and sensitivity to estradiol. During the first 24 h, UA (50 μg) and EE3CPE (5 μg) evoke remarkably similar receptor distribution patterns and uterine wet weight increase; however, pronounced differences are seen with longterm, multiple injection regimens (every 12 or 24 h for 72 h). Such treatment with UA results in maintenance of high nuclear receptor levels and very low cytoplasmic receptor levels (ca. 10% of total), but no further increase in uterine weight, DNA or p...
Pairing correlations in the attractive Hubbard model on chains, ladders, and squares

We report the results of zero-temperature quantum Monte Carlo simulations and zero-temperature mean-field calculations of the attractive Hubbard model on chains, ladders, and square lattices. We investigated the predictability of the BCS approximation, the dimensional crossover of the pairing correlation function from one to two dimensions as a function of the ladder width, and the scaling of these correlations to the thermodynamic limit of the two-dimensional model. We found that the BCS wave function is quantitatively correct only for small values of U/t. For the system sizes, electron fillings, and interaction strengths studied, we never saw the dimensional crossover. In general, our ability to achieve the dimensional crossover and accurate scaling to the thermodynamic limit was limited by the size of the systems we could simulate. For these sizes, although we saw the necessary signature of off-diagonal long-range order, the properties of the model did not vary monotonically with increasing system size because of shell effects. We contrast this situation with the dimensional crossover and scaling to the thermodynamic limit of the Ising model. (c) 2000 The American Physical Society.
Cloning and characterization of hamster fetal retinoic acid receptor isoforms

Summary Hamsters are routinely employed in toxicology evaluation, particularly for investigating the teratologic potential of chemicals. We have employed Syrian golden hamsters in retinoid-induced teratogenesis, mechanisms of which involve various retinoic acid receptor (RAR) isoforms. The purpose of this study was to clone and characterize different full-length hamster RAR isoforms. A 12-day old fetal hamster cDNA library was constructed and screened for RAR isoforms using human or mouse probes. Three full-length clones representing RARα, β, and γ were isolated, amplified and sequenced, and based on their homology to known mammalian isoforms were termed as hamster RARα variant, RARβ2 and RARγ2, respectively. The respective translated products for these clones were 430, 448 and 406 amino acids long. The clones were homologous to their human or mouse counterparts, although differences, particularly in the N-terminal region, were observed. These differences may represent differential splicing of exons controlled by two promoters for each isoform.
Interferometric effect with semiconductors in the millimeter-wave region

The reflectance of millimeter waves has been studied for a planar arrangement of a semiconductor panel, an air space, and a metal reflector. For a given wavelength, by adjusting mechanical dimensions and material properties, we observed complete absorption. In these types of systems, changes of conductivity of the semiconductor panel resulted in variations of reflectance. New devices using this physical effect are suggested, such as a device for amplitude modulation of millimeter and submillimeter waves, a simplified interferometer, and an arrangement for conversion of millimeter- and submillimeter-wave images into visual displays.
Colonization and Growth of Attached Algae at the Lake Michigan Water Line

Changes in populations of attached algae growing near the water line along the west shore of Lake Michigan were observed. Emphasis was placed on harbor populations with particular focus on the algae of Milwaukee Harbor during 1979 and 1980. Vertical zonation on rocks and harbor structures is documented and seasonal growth patterns and selected interrelationships are described. Of the three major filamentous algal forms present in this habitat, Bangia appears as a permanent resident, while Ulothrix may be considered a seasonal and opportunistic plant, responding rapdily to changes in water level. Cladophora is a perennial, but plants above a depth of approximately 30 cm tend to grow as annuals due to conditions of ice scour. It is suggested that seasonal and spatial variation in the abundance of particular species is related to the physical growth requirements of the species.
An Analysis of the Association Between U.S. Mortality and Air Pollution

Abstract U.S. mortality rates (total, infant and disease-specific) across 117 standard metropolitan statisical areas in 1960 and 1961 are investigated in an attempt to estimate their association with measures of air pollution. Multivariate regression analysis is utilized to control for some of the important factors affecting mortality with the underlying hypothesis that air pollution will exhibit a significant association with mortality in the presence of other relevant factors. Taken as a whole, the analysis demonstrates a close association between air pollution and mortality and the estimated magnitude of the relationship is substantial.
Occurrence of resistance-breaking Beet necrotic yellow vein virus of sugar beet

Rhizomania is an important virus disease of sugar beet and is caused by Beet necrotic yellow vein virus (BNYVV). During 2002-03, several sugar beet fields with cultivars partially resistant to BNYVV grown in the Imperial Valley of California were observed with severe rhizomania symptoms, suggesting that resistance conditioned by Rz1 had been compromised. Soil testing with sugar beet baiting plants followed by enzyme-linked immunosorbent assay (ELISA) was used to diagnose virus infection. Resistant varieties grown in BNYVV-infested soil from Salinas, CA, were ELISA-negative. In contrast, when grown in BNYVV-infested soil collected from the Imperial Valley, CA, all resistant varieties became infected and tested positive by ELISA. Based on host reaction, eight distinct BNYVV isolates have been identified from Imperial Valley soil (IV-BNYVV) by single local lesion isolation. Reverse transcription-polymerase chain reaction (RT-PCR) assays showed that the eight IV-BNYVV isolates did not contain RNA-5. Single-strand conformation polymorphism banding patterns for the IV-BNYVV isolates were identical to A-type and different from P-type. Sequence alignments of PCR products from BNYVV RNA-1 near the 3' end of IV-BNYVV isolates revealed that both IV-BNYVV and Salinas BNYVV isolates were similar to A-type and different from B-type. Our results suggest that the resistance-breaking BNYVV isolates from Imperial Valley likely evolved from existing A-type isolates.
Genetically engineered crops: their potential use for improvement of human nutrition.

Great success has been achieved in increasing agriculture productivity to fulfill human needs during the second half of the 20th century. However, there will be much greater challenges in the future. Based on the current population growth rate of 1.4% per year, the world's population is forecast to increase from the current level of approximately six billion to nine to twelve billion in 50 years. In addition to continuously increasing demand for agricultural production, there is an urgent need to improve the nutritional quality of human diets for this rapidly growing human population. Malnutrition is still a worldwide health issue. Macronutrient and micronutrient deficiencies are prevalent in developing countries, and over-consumption of certain nutrients in developed countries (e.g., saturated fatty acids) is associated with high incidence of certain chronic diseases. Furthermore, there will be declining natural resources such as arable land and water, and the challenges to humans must be met without further degrading the environment. Biotechnology offers a valuable tool to help achieve these goals. This review focuses on the most recent advances in biotechnology, which promise to improve human nutrition by enhancing the nutrient density of plant foods. Issues relating to the safety of food products from genetically engineered crops are also discussed.
The Role of Tyrosine at the Ligand-Binding Site of the Nicotinic Acetylcholine Receptor

Identification of the critical residues in a receptor's ligand-binding site provides valuable structural information important for understanding the basis for ligand recognition. The design of specific ligands targeted for receptor action will depend to a great extent on detailed structural knowledge of this kind. Although the nicotinic acetylcholine receptor (nAChR) is perhaps the best characterized of all receptors, the detailed configuration of the ligand-binding site remains unknown. Structural comparisons of nicotinic agonists and antagonists have long predicted a negative subsite on the receptor to interact with the positively charged alkyl-ammonium moiety common to nearly all nicotinic agents. We have used intrinsic fluorescence spectroscopic analyses together with binding studies of selectively modified peptide fragments of the nAChR to suggest that one or two invariant tyrosine residues at positions 190 and 198 on the alpha-subunit provide the critical negative subsite required for ligand binding. Tyrosines may similarly be part of the negative subsite of muscarinic receptors and other neurotransmitter receptors that bind cationic ligands.
LIQUID–LIQUID EQUILIBRIUM ANALYSIS IN PERSPECTIVE II. COMPLETE MODEL OF WATER, NITRIC ACID, AND URANYL NITRATE EXTRACTION BY DI-2-ETHYLHEXYL SULFOXIDE IN DODECANE

New and previously reported data on the extraction of water (W), HNO3 (HX), and UO2(NO3)2 (MX2) from aqueous mixtures by DEHSO (B) in dodecane are combined to develop a comprehensive model of U(VI) extraction from nitric acid by DEHSO. The computer program SXFIT used for this modeling estimates solute activity coefficients and solvent activities in the aqueous phase by the Pitzer treatment and in the nonaqueous phase by the Hildebrand-Scott treatment. Included is a critical evaluation of the Pitzer parameters needed and an estimate of the smaller effect of the solubility parameters assigned to the nonaqueous solutes. The resulting model indicates that: (1) The small amount of water extracted by dodecane alone is monomolecular (W). (2) The additional water extracted by B requires three hydrated species (BW, B2W, and an aggregate assigned as B2W5). (3) The extraction of HX by B requires four species (BHX, B(HX)2W5, and two species of B2HX, probably B2HX, and B2HXW2). (4) Finally, the extraction of MX2 yield...
Reaction of N-acylsulfilimines with diphenyl ketene. A new synthesis of 2-oxazolin-4-ones

Abstract 2-Substituted-5,5-diphenyl-2-oxazolin-4-ones 1 are prepared in good to high yields by reaction of diphenyl ketene and N-acylsulfilimes.
Population size bias in descendant-weighted diffusion quantum Monte Carlo simulations

We consider the influence of population size on the accuracy of diffusion quantum Monte Carlo simulations that employ descendant weighting or forward walking techniques to compute expectation values of observables that do not commute with the Hamiltonian. We show that for a simple model system, the d-dimensional isotropic harmonic oscillator, the population size must increase rapidly with d in order to ensure that the simulations produce accurate results. When the population size is too small, expectation values computed using descendant-weighted diffusion quantum Monte Carlo simulations exhibit significant systematic biases.
Emergent ethics consultation requested from the operating room.

Mr. N is a 45-year-old gentleman with a history of nonischemic cardiomyopathy. On September 1, 2011, Mr. N's cardiologist refers him to a tertiary facility due to refractory ventricular tachycardia...
Evolution in the Profession

The early growth ofprofessionalism in educational administration is traced, and the pervasive hope and energetic activity that characterized the field in the early 1950s and gave promise for continued development of the profession are noted. The promise was unfulfilled, largely because any progress made in knowledge expansion was overshadowed by powerful and rapidly changing influences upon the schools and upon the practice of administration. It is contended that these influences may have had greater impact on shaping the profession than did any of the rational efforts being expended in the universities. Finally, the various areas in which educational administration stillfalls short of meeting the criteria established for full acceptance as profession are examined.
FINITE ELEMENT ANALYSIS IN COMBUSTION PHENOMENA

This paper is concerned with the exposition of finite element applications to combustion problems. The subject of computational fluid dynamics, including combustion calculations, has long been dominated by finite differences. Recently, however, the finite element method has emerged as a potential candidate for computational modelling in fluid mechanics. It is well known that reactive fluids with combustion present additional complications because of disparity in reaction rates commonly referred to as ‘stiff’. The present paper reviews basic questions arising from combustion problems in applications of finite element techniques to the solution of problems associated with chemical kinetics, diffusion, waves, convection, etc. Finally, an example of a hydrogen-oxygen reaction is presented for practical applications. Extension to the finite element modelling of turbulence, sprays, boundary layers, shock waves, etc. in combustion must await significant developments of numerical strategies associated with a more complete understanding of physical phenomena and chemical kinetics.
Shared Genetic Factors Influence Amygdala Volumes and Risk for Alcoholism

Alcohol abuse and dependence (alcohol use disorders, AUDs) are associated with brain shrinkage. Subcortical structures including the amygdala, hippocampus, ventral striatum, dorsal striatum, and thalamus subserve reward functioning and may be particularly vulnerable to alcohol-related damage. These structures may also show pre-existing deficits impacting the development and maintenance of AUD. It remains unclear whether there are common genetic features underlying both subcortical volumes and AUD. In this study, structural brain images were acquired from 872 Mexican-American individuals from extended pedigrees. Subcortical volumes were obtained using FreeSurfer, and quantitative genetic analyses were performed in SOLAR. We hypothesized the following: (1) reduced subcortical volumes in individuals with lifetime AUD relative to unrelated controls; (2) reduced subcortical volumes in individuals with current relative to past AUD; (3) in non-AUD individuals, reduced subcortical volumes in those with a family history of AUD compared to those without; and (4) evidence for common genetic underpinnings (pleiotropy) between AUD risk and subcortical volumes. Results showed that individuals with lifetime AUD showed larger ventricular and smaller amygdala volumes compared to non-AUD individuals. For the amygdala, there were no differences in volume between current vs past AUD, and non-AUD individuals with a family history of AUD demonstrated reductions compared to those with no such family history. Finally, amygdala volume was genetically correlated with the risk for AUD. Together, these results suggest that reduced amygdala volume reflects a pre-existing difference rather than alcohol-induced neurotoxic damage. Our genetic correlation analysis provides evidence for a common genetic factor underlying both reduced amygdala volumes and AUD risk.
Erratum: Radiative decays of the 16.6 and 16.9 MeV states in 8Be and tests of the conservation of the vector current in the A=8 multiplet

We measured the $^{4}\mathrm{He}$(\ensuremath{\alpha},\ensuremath{\gamma}) cross section at ${\mathrm{\ensuremath{\theta}}}_{\ensuremath{\gamma}}$=90\ifmmode^\circ\else\textdegree\fi{} across the 16.6 and 16.9 MeV resonances in $^{8}\mathrm{Be}$ and obtained angular distributions on the peaks of both resonances. The decays of the 16 MeV doublet to the 3.0 MeV ${2}^{+}$ final state have an (isovector E2)/(isovector M1) mixing ratio of (0.01\ifmmode\pm\else\textpm\fi{}0.03), an (isoscalar E2)/(isovector M1) mixing ratio of (0.21\ifmmode\pm\else\textpm\fi{}0.04), and an isovector M1 width of (2.80\ifmmode\pm\else\textpm\fi{}0.18) eV. Our result for the isovector E2 strength disagrees markedly with previous work. We observe ground-state E2 decays of both members of the doublet. We use our results, plus existing $^{8}\mathrm{Li}$ and $^{8}\mathrm{B}$ \ensuremath{\beta}-decay data, to test the conservation of the vector current and to constrain the second-class induced-tensor form factor. Finally, we compare our results to shell-model calculations.
Fitting Weibull duration models with random effects.

Duration time models often should include correlated failure times, due to clustered data. These random effects hierarchical models sometimes are called “frailty models” when used for survival analyses. The data analyzed here involve such correlations because patient level outcomes (the times until graft failure following kidney transplantation) are observed, but patients are clustered in different transplant centers. We describe fitting such models by combining two kinds of software, one for parametric survival regression models, and the other for doing Poisson regression in a hierarchical setting. The latter is implemented by using PRIMM (Poisson Regression and Interactive Multilevel Modeling) methods and software (Christiansen & Morris, 1994a). An illustrative example for profiling data is included withk=11 kidney transplant centers andN=412 patients.
Persistence in stochastic food web models

A sufficient condition is given for stochastic boundedness persistence of a top predator in generalized Lotka-Volterra-type stochastic food web models in arbitrary bounded regions of state space. The main result indicates that persistence in the corresponding deterministic system is preserved in the stochastic system if the intensities of the random fluctuations are not too large.
Characterization of the Human Mitochondrial Ribosomal S12 Gene

Translation of mitochondrial encoded mRNAs occurs on mitochondrial ribosomes. The ribosomal RNA components of the mitochondrial ribosomes are coded for by mitochondrial DNA, while all the protein subunits are coded for by nuclear chromosomes. The only mitochondrial protein subunit cloned in mammals is MRPL12, making the study of the role of mitochondrial translation in human disease difficult. We have now cloned the gene for the human mitochondrial ribosomal protein S12, termed RPMS12, based on its homology to the Drosophila tko gene. The gene stretches over 1.7 kb of genomic DNA and maps to chromosome 19q13, near marker D19S881. The mRNA shows three distinct patterns of splicing within the 5' untranslated region in all tissues examined, one form being predominant over the other two. The coding region of the leader sequence is interrupted in codon 17 by a second intron of 990 bases. The mRNA is predicted to be translated to a prepeptide of 138 amino acids in length and processed to a peptide of 112 aa and a molecular mass of 12.3 kDa. The protein is very basic, with a predicted pI of 10.3, and is highly conserved through evolution. The functional role and map location of the gene make it a candidate gene for susceptibility to aminoglycoside ototoxicity and for the autosomal dominant deafness gene DFNA4.
Neuronotrophic and neurite-promoting factors: effects on early postnatal chromaffin cells from rat adrenal medulla

Adrenal chromaffin cells from early postnatal rats maintained in culture have previously been shown to grow neuritic processes and survive better in the presence of nerve growth factor (NGF). In the present study we have quantitated the effects on chromaffin cell (postnatal day (D) 8) survival and neurite outgrowth of: NGF, ciliary neuronotrophic factor (CNTF), activities contained in various types of conditioned media (CM), and various substrata (laminin, fibronectin and polyornithine-binding neurite-promoting factor from RN 22 Schwannoma cells - PNPF). At saturating concentrations CNTF (50 ng/ml) and C6 glioma cell CM, (50-fold concentrated) supported survival over the 4-day culture period of all the chromaffin cells present in culture 2 h after seeding. NGF (50 ng/ml) and the non-concentrated CMs from primary Schwann cell and astrocytes as well as Schwannoma and C6 glioma cell cultures, achieved the maintenance of only about half the number of cells above the baseline survival as compared to CNTF and the concentrated C6-CM. These results are compatible with two subsets of D8 chromaffin cells, one only supported by CNTF and the concentrated CM and the other supported by either NGF or CNTF. Either NGF or CNTF elicited neurite outgrowth from 15-20% of the surviving cells. Combination of maximal doses of NGF and CNTF caused a small increase in neurite recruitment beyond that elicited by either factor alone. Low doses of CNTF added to the effect of NGF, shifting the NGF titration curve by about 4-fold. Neurite outgrowth was also induced by the concentrated, but not the unconcentrated C6-CM. Laminin, fibronectin and PNPF did not affect the fibronectin and PNPF did not affect the recruitment of neurites as compared to a polyornithine substratum unless the cultures were supplemented with a neuronotrophic factor and carried for 7 days. However, even before showing effects on neurite recruitment these substrata affected various neuritic performances, such as length, neurite numbers and endings per cell.
Mescaline convulsive spikes triggered by direct cortical stimulation.

Abstract 1. 1. Mescaline topically applied to the cerebral cortex in a 1 per cent concentration elicits paroxysmal spikes of up to 6 mV in amplitude and 30–60 msec in duration which can be driven by a brief electrical stimulation applied to the nearby cortex. Driven spikes were found in a number of cortical regions—including frontal regions of the rabbit and suprasylvian gyrus of the cat, in addition to the visual cortex of the rabbit. Spikes could be elicited in the acute and in the chronic cortical island preparation. The latency of the spike may be short and the response give the false appearance of an exaggerated direct cortical response (DCR) or the latency may be longer than 100 msec and varied by changing the stimulus strength. 2. 2. The DCR is usually decreased in size soon after mescaline application and does not appear to have a causal relation to the spike. GABA rapidly blocks both the DCR and the spike, producing an inversion of the DCR but not of the spike. 3. 3. The spike excited in the intact cortex or in an island preparation can be blocked by intravenous injections of pentobarbital while the DCR remains. A direct intracortical action of pentobarbital to depress the excitability of mescaline-sensitized intracortical neurons is thereby indicated. The sensitized neurons are believed to be deeper in the cortex and to synapse on pyramidal cell apical dendrites to generate the large convulsive wave in those membranes.
Algorithm 849: A concise sparse Cholesky factorization package

The LDL software package is a set of short, concise routines for factorizing symmetric positive-definite sparse matrices, with some applicability to symmetric indefinite matrices. Its primary purpose is to illustrate much of the basic theory of sparse matrix algorithms in as concise a code as possible, including an elegant method of sparse symmetric factorization that computes the factorization row-by-row but stores it column-by-column. The entire symbolic and numeric factorization consists of less than 50 executable lines of code. The package is written in C, and includes a MATLAB interface.
Caveolin-1: a new locus for human lipodystrophy.

Caveolae are specialized plasma membrane microdomains appearing as 50- to 100-nm vesicular invaginations (1,2). These organelles were initially identified by Yamada (3) more than 50 yr ago and can be found individually or in clusters at the surface of several cell types, including adipocytes, endothelial cells, fibroblasts, and myocytes. These plasma membrane domains, often referred to as lipid rafts, are rich in cholesterol, glycosphingolipids, and signaling proteins, especially caveolins. Caveolins are major components of the caveolae, and three members of this family (caveolins 1, 2, and 3) have been identified.
Lifestyle Factors Associated with the Sexual Assault of Men: A Routine Activity Theory Analysis:

This paper explores the role of lifestyle and routine activities in the sexual assault of adult men. Little is known about the individual factors that are associated with the likelihood of male vic...
Salutary effects of 17β-estradiol on Peyer’s patch T cell functions following trauma–hemorrhage

Abstract Although 17β-estradiol (E2) administration following trauma–hemorrhage (T–H) improves immune functions in male rodents, it remains unclear whether E2 has salutary effects on Peyer’s patch (PP) T cell functions. We hypothesized that T–H induces PP T cell dysfunction and E2 administration following T–H will improve PP T cell function. T–H was induced in male C3H/HeN mice (6–8 weeks) by midline laparotomy and ∼90 min of hemorrhagic shock (blood pressure 35 mmHg), followed by fluid resuscitation (4× the shed blood volume in the form of Ringer’s lactate). Estrogen receptor (ER)-α agonist propyl pyrazole triol (PPT; 5 μg/kg), ER-β agonist diarylpropionitrile (DPN; 5 μg/kg), E2 (50 μg/kg), or vehicle was injected subcutaneously at resuscitation onset. Two hours later, mice were sacrificed and PP T cells isolated. PP T cell capacity to produce cytokines in response to in vitro stimulation, PP T cell proliferation and MAPK (p38, ERK-1/2, JNK) activation were measured. Results indicate PP T cell proliferation, cytokine production and MAPK activation decreased significantly following T–H. E2, PPT or DPN administration normalized these parameters. Since PPT or DPN administration following T–H was effective in normalizing PP T cell functions, the salutary effects of E2 are mediated via ER-α and ER-β.
Interrupted Time-Series Designs for Evaluating Health Communication Campaigns

Interrupted time series (ITS) constitute a class of powerful quasi-experimental designs for evaluating health communication campaigns. This article: 1) describes the basic elements of time-series designs in general and interrupted time-series designs in particular; 2) discusses briefly some of the more widely recognized ITS designs in order of increasing methodological rigor; 3) introduces the two major types of time-series statistical analysis, and; 4) provides a detailed example of a sophisticated ITS design used to evaluate the effectiveness of anti-marijuana campaigns in two communities. While ITS designs have been used infrequently in campaign evaluation, enough such studies have been conducted to demonstrate their utility in this domain. It is hoped that future campaign evaluations will make much greater use of this sophisticated technique which appears tailor-made to investigate many of the questions of greatest interest to campaign researchers and practitioners.
Spectroscopic ellipsometry study of optical anisotropy in Gd5Si2Ge2 and comparison with reflectance difference spectra

The complex dielectric functions of single crystals of Gd5Si2Ge2 were obtained using spectroscopic ellipsometry (SE) in the photon energy range of 1.5–5.0 eV at room temperature. Reflectance difference (RD) spectra for the a‐b and b‐c planes of single crystals of Gd5Si2Ge2 were derived from these dielectric functions and compared to those obtained from reflectance difference spectroscopy (RDS) at near-normal incidence. The two experimental RD spectra from SE and RDS agreed well. The in-plane optical anisotropy of the sample is mainly due to intrinsic bulk properties because of its larger magnitude (4×10−2) compared to surface-induced optical anisotropies, with a magnitude of only about 10−3 for a typical cubic material.
Immature astrocytes promote CNS axonal regeneration when combined with chondroitinase ABC

Regeneration of injured adult CNS axons is inhibited by formation of a glial scar. Immature astrocytes are able to support robust neurite outgrowth and reduce scarring, therefore, we tested whether these cells would have this effect if transplanted into brain injuries. Utilizing an in vitro spot gradient model that recreates the strongly inhibitory proteoglycan environment of the glial scar we found that, alone, immature, but not mature, astrocytes had a limited ability to form bridges across the most inhibitory outer rim. In turn, the astrocyte bridges could promote adult sensory axon re-growth across the gradient. The use of selective enzyme inhibitors revealed that MMP-2 enables immature astrocytes to cross the proteoglycan rim. The bridge-building process and axon regeneration across the immature glial bridges were greatly enhanced by chondroitinase ABC pretreatment of the spots. We used microlesions in the cingulum of the adult rat brains to test the ability of matrix modification and immature astrocytes to form a bridge for axon regeneration in vivo. Injured axons were visualized via p75 immunolabeling and the extent to which these axons regenerated was quantified. Immature astrocytes coinjected with chondroitinase ABC-induced axonal regeneration beyond the distal edge of the lesion. However, when used alone, neither treatment was capable of promoting axonal regeneration. Our findings indicate that when faced with a minimal lesion, neurons of the basal forebrain can regenerate in the presence of a proper bridge across the lesion and when levels of chondroitin sulfate proteoglycans (CSPGs) in the glial scar are reduced.
Improved survival in resected biliary malignancies.

Background. For many years the prognosis for patients with biliary malignancies has been poor. However, recent advances in radiology and laparoscopy have improved staging, and active biliary stent management may improve outcome in these patients. In the past the goal with surgery was to excise all gross tumor. Now, the surgical goal is to achieve negative microscopic margins even if a major hepatic resection is required. Similarly, chemotherapy or radiation was frequently given in isolation, but chemoradiation has become the standard. Therefore, the aim of this analysis was to determine whether survival has improved with better staging, active stent management, more aggressive surgery, and chemoradiation. Methods. From 1990 through 2001, 140 patients with biliary malignancies were treated at the Medical College of Wisconsin. One hundred eleven malignancies were cholangiocarcinomas (intrahepatic, 22%; perihilar, 65%; and distal, 13%), and 29 were gallbladder (GB) cancers. Eighty-six of the 140 patients (61%) underwent exploration (intrahepatic, 58%; perihilar, 57%; distal, 67%, and GB, 72%). Forty-four of these 86 patients (51%) underwent resection (intrahepatic, 64%; perihilar, 41%; distal, 70%; and GB, 52%). Chemoradiation with confocal radiation, 5-fluorouracil, and gemcitabine was used more frequently in the patients resected since 1998. Results. Thirty-day operative mortality was 4%. In the resected patients (n = 44) the 5-year actuarial survival was 31% and the median survival was 27.8 months. Patients resected between 1998 and 2001 (n = 25) had a median survival longer than 44 months with a 3-year actuarial survival of 70% as compared to patients resected between 1990 and 1997 (n = 19), who had a median survival of 13 months and a 3-year actuarial survival of 21% (P <.01). Conclusions. These data suggest that (1) approximately one third of patients with biliary malignancies have resectable disease and (2) surgery in carefully selected patients with adjuvant chemoradiation has improved survival in resected patients. We suspect that a combination of improved staging, active biliary stenting, safe but extensive surgery to obtain negative margins, and newer techniques for chemoradiation have resulted in improved outcomes for patients with biliary malignancies. (Surgery 2002;132:555-64.)
“Tragedy-lite” or “Melodrama”? In Search of a Standard Generic Tag

Among critics who work from a dramatic or dramatistic perspective, our field seems to be at odds over what generic label or labels to use for discourse that is other, or mainly other, than comic or burlesque. For quite a long time, the name “tragic” was the stated or implied choice for much, or at least some, of that rhetoric. Some recent scholars are now describing such address as “melodramatic.” Their reasons for doing so carry some weight. This essay, however, argues for retention of “tragic frame” as title of choice for explicitly persuasive speech of the most virulent, victimizing kind.
Quantitative high-efficiency cadmium-zinc-telluride SPECT with dedicated parallel-hole collimation system in obese patients: results of a multi-center study.

Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride parallel-hole SPECT MPI for coronary artery disease (CAD) in obese patients. 118 consecutive obese patients at three centers (BMI 43.6 ± 8.9 kg·m−2, range 35-79.7 kg·m−2) had upright/supine HE-SPECT and invasive coronary angiography > 6 months (n = 67) or low likelihood of CAD (n = 51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD), and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5 = excellent; < 3 nondiagnostic) was compared among BMI 35-39.9 (n = 58), 40-44.9 (n = 24) and ≥45 (n = 36) groups. ROC curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P = .02). C-TPD normalcy rate was higher than U-TPD (88% vs 75%, P = .02). Mean IQ was similar among BMI 35-39.9, 40-44.9 and ≥45 groups [4.6 vs 4.4 vs 4.5, respectively (P = .6)]. No patient had a nondiagnostic stress scan. In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions.
Expression of a multifunctional DNA repair enzyme gene, apurinic/apyrimidinic endonuclease (APE; Ref-1) in the suprachiasmatic, supraoptic and paraventricular nuclei

Abstract Apurinic / apyrimidinic endonuclease (APE; also referred to as Ref-1) repairs oxidative damage to DNA and regulates the redox state of DNA binding proteins. This later property influences the ability of DNA binding proteins, which include Fos and Jun, to bind to AP-1 complexes. Since DNA binding proteins may play important roles in regulating neuronal activity in the hypothalamus, we examined the expression of APE in the hypothalami of rats. In situ hybridization studies revealed high levels of APE mRNA expression in the suprachiasmatic nuclei (SCN), supraoptic nuclei (SON) and paraventricular nuclei (PVN). Since the SCN are the site of a biological clock, we examined whether APE gene expression was regulated by the circadian cycle or by light. Quantitative in situ hybridization studies showed that APE mRNA levels remained constant over the circadian cycle and were not increased by light exposure at night. We also tested if APE expression was under osmotic control in the SON and PVN. Hypertonic stimulus, however, did not induce further expression of APE mRNA in either the SON or the PVN. These findings identify the SCN, SON and PVN as sites of high level APE gene expression. These data suggest that APE may play an important role in these structures either to facilitate DNA repair or DNA binding protein action.
Improved Near-Infrared Spectral Responsivity Scale

A cryogenic radiometer-based system was constructed at the National Institute of Standards and Technology for absolute radiometric measurements to improve detector spectral power responsivity scales in the wavelength range from 900 nm to 1800 nm. In addition to the liquid-heliumcooled cryogenic radiometer, the system consists of a 100 W quartz-tungstenhalogen lamp light source and a 1 m single-grating monochromator for wavelength selection. The system was characterized and the uncertainty in spectral power responsivity measurements evaluated. A variety of photodetectors, including indium gallium arsenide photodiodes (InGaAs), germanium (Ge) photodiodes, and pyroelectric detectors, were subsequently calibrated. Over most of the spectral range, the spectral power responsivity of the photodetectors can be measured with a combined relative standard uncertainty of 0.4 % or less. This is more than a factor of two smaller than our previous capabilities, and represents a significant improvement in the near infrared (NIR) spectral power responsivity scale maintained at NIST. We discuss the characterization of the monochromator-based system and present results of photodetector spectral power responsivity calibrations.
Within-Seed Distribution of Selected Mineral Elements among Soybean Genotypes that Vary in Iron Efficiency

Genotype, severity of iron (Fe) deficiency, and inter - actions of Fe with Zn or Mn are important factors related to production of soybeans ( Glycine max. L.) grown on high-pH, highly calcareous soils. We studied the within seed distribution (whole seed, seed coat, and embryo) of major and minor ele - ments in 21 soybean genotypes (G)s character - ized as susceptible (S), moderately resistant (M r), and resistant ( r) to Fe deficiency based on plant- ing seed (Fe). Trials were grown at three locations (Loc) in northwest MN (Ada, Crookston, and Fisher) during 2003. Differences among Locs in within seed distribution of N, p , K, Ca, and Mg concen- trations were generally quite small, although often statistically significant. Differences among geno - types involving macronutrient contents highlighted large differences among S, M r, and r genotypes. Zinc and Mn, but not Fe, concentrations varied markedly with location, whereas (Fe)s were con - siderably higher in genotypes categorized as more resistant to Fe deficiency. Seed size declined, whereas seed (Fe)s and contents increased as resistance to Fe deficiency increased. Seed coat (Fe)s were greater than embryo (Fe)s within each genotypic classification, whereas seed tissue (Fe) s were greater in r and M r genotypes than in S ones. As seed tissue Fe increased, Mn decreased, and their sum remained nearly constant. p lanting
Ensemble Transform Kalman Filter-based ensemble perturbations in an operational global prediction system at NCEP

The initial perturbations used for the operational global ensemble prediction system of the National Centers for Environmental Prediction are generated through the breeding method with a regional rescaling mechanism. Limitations of the system include the use of a climatologically fixed estimate of the analysis error variance and the lack of an orthogonalization in the breeding procedure. The Ensemble Transform Kalman Filter (ETKF) method is a natural extension of the concept of breeding and, as shown byWang and Bishop, can be used to generate ensemble perturbations that can potentially ameliorate these shortcomings. In the present paper, a spherical simplex 10-member ETKF ensemble, using the actual distribution and error characteristics of real-time observations and an innovation-based inflation, is tested and compared with a 5-pair breeding ensemble in an operational environment. The experimental results indicate only minor differences between the performances of the operational breeding and the experimental ETKF ensemble and only minor differences to Wang and Bishop’s earlier comparison studies. As for the ETKF method, the initial perturbation variance is found to respond to temporal changes in the observational network in the North Pacific. In other regions, however, 10 ETKF perturbations do not appear to be enough to distinguish spatial variations in observational network density. As expected, the whitening effect of the ETKF together with the use of the simplex algorithm that centres a set of quasi-orthogonal perturbations around the best analysis field leads to a significantly higher number of degrees of freedom as compared to the use of paired initial perturbations in operations. As a new result, the perturbations generated through the simplex method are also shown to exhibit a very high degree of consistency between initial analysis and short-range forecast perturbations, a feature that can be important in practical applications. Potential additional benefits of the ETKF and Ensemble Transform methods when using more ensemble members and a more appropriate inflation scheme will be explored in follow-up studies.
Semantic Models for Ad Hoc Interactions in Mobile, Ubiquitous Environments

One of the goals of mobile and ubiquitous computing is to enable ad-hoc interactions between different kinds of entities to help end-users perform different kinds of tasks. These entities, which include devices and services, may either be mobile or situated in the surrounding physical environment. However, these interactions require the use of rich semantic models describing the capabilities of the entities, the data exchanged between them and the desires of end-users. These semantic models enable the discovery of entities that satisfy certain constraints as well as the composition of different entities into applications for performing different kinds of tasks. In this paper, we describe two models that we have used in our systems for describing data and entities. The first model is based on OWL ontologies, where all data is described by a set of OWL facts, and component inputs and outputs are described using RDF graph patterns. The second model is based on folksonomies, where all data is described by a set of tags, and component inputs and outputs are also described using sets of tags. The two models have very different properties in terms of expressiveness and ease of use. We present our experiences in using these models for discovery of entities and for the automatic composition of complex flows in response to dynamic end-user goals. We also describe some of the future challenges that lay in the path of semantically-enabled ad-hoc interactions.
Applications Of Green's Theorem In Two-dimensional Filtering

There seems to be considerable interest in the design of a discrete two‐dimensional filter from band‐pass and band‐reject area specification in the ω‐k plane. The calculation of such a filter requires the evaluation of a double integral for each filter point. Considerable effort has been expended in efforts to give the results of these integrations in closed form for special cases. The present note was written to point out that a rather general class of filters can be calculated from a single computer program. The simplicity of this program is a result of an elementary application of Green’s Theorem in the plane.
Allele age and a test for selection on rare alleles

An approximate expression for the probability distribution of the age of a neutral allele as a function of its frequency is derived for a population undergoing arbitrary changes in population size....
Alcohol consumption decreases rat hepatic creatine biosynthesis via altered guanidinoacetate methyltransferase activity.

Background: We have previously shown that decreased S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio generated in livers of alcohol-fed rats can impair the activities of many SAM-dependent methyltransferases. One such methyltransferase is guanidinoacetate methyltransferase (GAMT) that catalyzes the last step of creatine synthesis. As GAMT is the major utilizer of SAM, the purpose of the study was to examine the effects of ethanol (EtOH) on liver creatine levels and GAMT activity. Methods: Male Wistar rats were pair-fed the Lieber–DeCarli control and EtOH diet for 4 to 5 weeks. At the end of the feeding regimen, the liver, kidney, and blood were removed from these rats for subsequent biochemical analyses. Results: We observed ~60% decrease in creatine levels in the livers from EtOH-fed rats as compared to controls. The reduction in creatine levels correlated with lower SAM:SAH ratio observed in the livers of the EtOH-fed rats. Further, in vitro experiments with cell-free system and hepatic cells revealed it is indeed elevated SAH and lower SAM:SAH ratio that directly impairs GAMT activity and significantly reduces creatine synthesis. EtOH intake also slightly decreases the hepatocellular uptake of the creatine precursor, guanidinoacetate (GAA), and the GAMT enzyme expression that could additionally contribute to reduced liver creatine synthesis. The consequences of impaired hepatic creatine synthesis by chronic EtOH consumption include (i) increased toxicity due to GAA accumulation in the liver; (ii) reduced protection due to lower creatine levels in the liver, and (iii) reduced circulating and cardiac creatine levels. Conclusions: Chronic EtOH consumption affects the hepatic creatine biosynthetic pathway leading to detrimental consequences not only in the liver but could also affect distal organs such as the heart
A note on the slope of a density interface between two stably stratified fluids under wind

Experiments were conducted with two layers of stably stratified fluid in a wind-wave tank. The slope of the density interface was measured and was related to the wind stress, the density difference between the two fluids and the depth of the interface.