cssi/SciSciGPT-SciSciNet huggingface dataset:
Spectra and structure of gallium compounds: Part VII. Microwave, infrared and raman spectra and normal coordinate analysis of trimethylamine-trimethylgallane

Abstract The infrared (100–3500 cm−1) and Raman (25–3200 cm−1) spectra of the solid phases of (CH3)3NGa(CH3)3 and (CH3)315NGa(CH3)3 have been recorded near liquid nitrogen temperatures as well as the Raman spectrum (100–3200 cm−1) of the liquid phase at ~50°C and the low resolution microwave spectrum (26.5–39.0 GHz) of (CH3)3NGa(CH3)3. The spectra have been interpreted on the basis of C3v molecular symmetry and a vibrational assignment is proposed for all but the torsional modes. The B value calculated from the microwave spectrum is consistent with published structural parameters reported from an electron diffraction study. A modified valence force field has been used to calculate the observed frequencies and the potential energy distribution. The force constants presented are consistent with changes in the structural parameters of the Lewis acid and base upon adduct formation. Extensive mixing has been observed among the low-frequency modes. The Ga-N stretching force constant (1.6 mdyn A−1) has a value intermediate between those of (CH3)3NGaH3 and H3NGa(CH33). The lack of apparent factor group splitting indicates that only one molecule occupies each primitive cell, situated on either a C3 or C3v site. A rhombohedral space group such as R3m(C53v) is consistent with these observations.
Larval settlement of the polyhaline barnacle Balanus eburneus (Gould): cue interactions and comparisons with two estuarine congeners

The effect of salinity on larval settlement of the polyhaline estuarine barnacle Balanus eburneus (Gould) was investigated by challenging laboratory reared cyprids to settle (permanently attach and metamorphose) under a number of permutations of salinity and adult extract (settlement factor). When cyprids were exposed to an array of salinities ranging from 2 to 35 ppt in the presence of conspecific extract adsorbed to slate panels, maximum settlement occurred at salinities of 15 and 20 ppt. In the absence of adult extract, few larvae settled at any salinity. No differences in settlement frequencies across the array of test salinities were observed between replicate aliquots within a cyprid batch, but significant differences in settlement were observed between batches of cyprids. When settlement of newly molted cyprids was contrasted with that of cyprids forced to postpone metamorphosis, settlement peaked at 20 and 15 ppt salinity, respectively, and overall settlement levels of the “delayed” cohort increased. B. eburneus cyprids settled significantly more frequently on substrata adsorbed with conspecific extract than on substrata adsorbed with extract from B. improvisas (Darwin) or B. subalbidus (Henry), but settlement on these latter two treatments did not differ. Although post-settlement processes cannot be overlooked, our results indicate that larval behavior at settlement could play a substantial role in determining adult distribution of B. eburneus along the estuarine salinity gradient. Contrasting settlement patterns of B. eburneus with those obtained previously for mesohaline B. improvisus and oligohaline B. subalbidus indicates that settlement behavior of the former two species could be influential in structuring their distribution, whereas pre-settlement behavior could be a determining factor in B. subalbidus distribution.
Quenching of 1-anilinonaphthalene-8-sulfonate fluorescence by a spin-labeled local anesthetic: a membrane phenomenon.

Abstract A series of local anesthetics, the 2-(N,N-diethylamino) ethyl p-alkoxybenzoates, have been found to enhance the fluorescence of 1-anilinonaphthalene-8-sulfonate in the presence of bovine red blood cell ghosts. However a spin-labeled analog of these local anesthetics was found to quench the fluorescence. This quenching phenomenon was shown to be due to the interaction of the spin-labeled analog's nitroxide radical with the chromophore on the membrane. Since the quenching of fluorescent chromophores by nitroxide radicals involves an interaction distance of 4–6A, this suggests that the local anesthetics are in very close proximity to the dye on the membrane.
Dynamic functional imaging of brain glucose utilization using fPET-FDG

Glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[(18)F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits the utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. This new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis are straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism.
Developing Teaching Skills Through Understanding

(1981). Developing Teaching Skills Through Understanding. Action in Teacher Education: Vol. 3, Professional Development: Issues and Answers, pp. 11-18.
A pilot study of endoscopic closure of colonic perforations with endoclips in a swine model

Background Surgical closure of a colon perforation is accompanied by the risks of general anesthesia and prolonged recovery from surgery because of ileus and other sequelae. Very little is known about the effectiveness of endoluminal repair of colon perforations with clips, which eliminates incisions of the abdominal wall and provides a less invasive alternative to surgical closure. The aim of this study is to evaluate the feasibility and the safety of endoscopic closure of colonic perforations with endoclips in a porcine model. Methods Approximately 1.5- to 2-cm colon perforations created with a needle knife in 4 50-kg, female pigs that were under general anesthesia were closed with endoclips. After 24 hours of recovery, the animals were allowed to eat. All the animals received intravenous antibiotics and were carefully monitored for signs of sepsis. After a follow-up of 1 week, the pigs were euthanized for postmortem examination. The fifth pig was euthanized immediately after closure of a 5-cm colon perforation with clips to evaluate the extent of transmural closure with endoclips. Results The animals recovered well, without any clinical features of sepsis or peritonitis. Postmortem examination did not reveal fecal peritonitis, and there was no evidence of pericolonic abscess formation at the site of perforation. The perforation site showed signs of healing without any evidence of transmural dehiscence. Histopathology demonstrated granulation tissue bridging the site of perforation. In the fifth pig, euthanized immediately after closure of the perforation, nice mucosal apposition was seen, while the muscular and serosal coats remained dehisced. Conclusions Endoscopic closure of small iatrogenic colon perforations with clips results in mucosal and submucosal healing and prevents fecal soiling of peritoneal cavity.
Massive Hemothorax Complicating Heparin Therapy for Pulmonary Infarction

The occurrence of hemothorax during heparin therapy for pulmonary infarction should alert the clinician to the potentially lethal possibilities inherent in such a situation. Caution should be exercised to prevent excessive anticoagulation.
The prevalence and associated features of posterior embryotoxon in the general ophthalmic clinic.

To estimate the prevalence of posterior embryotoxon (PE) in the general ophthalmic clinic and to identify any features of PE that suggest that it is pathological rather than physiological. Over 700 consecutive patients of all ages were examined with the slit lamp during their routine eye clinic appointment. Patients with posterior embryotoxon were invited to return for full ocular examination including keratometry, corneal topography, and gonioscopy. In all, 49 out of 723 patients were found to have PE. This gives a prevalence of 6.8% with an age range of 18 months to 95 years. There was a higher prevalence in the younger age group of 22.5% (age range 18 months to 20 years) compared to 5.9% in the older age range (21–95 years). A total of 29 patients with PE returned for further examination. Six patients had glaucoma (two with Axenfeld's syndrome and one with aniridia), and one had ocular hypertension. In all, 20 patients had bilateral PE on slit-lamp examination, which increased to 24 with gonioscopy. The majority of the PE was seen temporally (97.9%) and limited to a few clock hours. Gonioscopy showed that eight patients with PE had associated inferior pigmentation of schwalbes line. This large series found the prevalence of PE the general ophthalmic clinic to be 6.8%. Its presence should prompt careful anterior segment examination, including gonioscopy, to identify any associated abnormalities that may carry a risk of glaucoma. Children should also be assessed for any associated systemic or genetic abnormality.
Comparison of adherence and urine growth rate properties of Staphylococcus saprophyticus and Staphylococcus epidermidis

To compare the adherence properties ofStaphylococcus saprophyticus andStaphylococcus epidermidis in vitro studies were conducted with clinical isolates and cell culture monolayers (Hela, Vero, MDCK).Staphylococcus saprophyticus exhibited greater cell adherence, but no significant difference in mean urine growth rate. Its cell-adherence properties seem to explain in part its virulence.
Diazepam: prediction of pharmacodynamics from pharmacokinetics.

The use of a pharmacokinetic/pharmacodynamic/receptor binding model to predict the onset and duration of the parmacological effect of diazepam was explored. The analysis examined the effects of diazepam (0.28 mg/kg) on the wheel-tracking and digit-symbol substitution performance of young healthy adults. Both free-plasma drug concentration and relative amount of diazepam bound to the benzodiazepine receptor were calculated and compared to the behavioral measures across time. Performance was more significant correlated with relative receptor occupancy (RRO) than with unbound plasma-drug levels. For both tasks hysteresis plots indicated greater similarity between time profiles of performance and RRO than between those of performance and blood concentration alone. These results provide support for the inclusion of both receptor binding kinetics and plasma pharmacokenetics as the bases for the prediction of the parmacologic activity of diazepam.
Coaxing HIV-1 from resting CD4 T cells: histone deacetylase inhibition allows latent viral expression.

Background Histone deacetylase (HDAC), a host mediator of gene repression, inhibits HIV gene expression and virus production and may contribute to quiescence of HIV within resting CD4 T cells. Objectives To test the ability of valproic acid (VPA), an inhibitor of HDAC in clinical use, to induce expression of HIV from resting CD4 T cells. Methods Chromatin immunoprecipitation measured the capability of VPA to deacetylate the HIV promoter, a remodeling of chromatin linked to gene expression. The effect of VPA on resting CD4 T cell phenotype was measured by flow cytometric analysis, and its effect on de novo HIV infection of peripheral blood mononuclear cells was measured ex vivo. Outgrowth of HIV from resting CD4 T cells of aviremic, HIV-infected donors treated with highly active antiretroviral therapy was compared in limiting-dilution cultures after mitogen stimulation or exposure to VPA. Results VPA induced acetylation at the integrated HIV proviral promoter, but CD4 cells exposed to VPA did not become activated or more permissive for de novo HIV infection. VPA induced outgrowth of HIV from the resting CD4 cells of aviremic patients at concentrations achievable in vivo as frequently as did mitogen stimulation. Conclusions With advances in antiretroviral therapy, HIV infection might be cleared by intensive time-limited treatment coupled with practical strategies that disrupt latency without enhancing new infection. HDAC inhibitors are capable of inducing expression of quiescent provirus, without fully activating cells or enhancing de novo infection, and may be useful in future clinical protocols that seek to eradicate HIV infection.
Preliminary design of a zone plate based hard X-ray monochromatic diffraction nanoprobe for materials studies at APS

Aiming at studies of the micro/nano-structures of a broad range materials and electronic devices, Advance Photon Source (APS) is developing a dedicated diffraction nanoprobe (DNP) beamline for the needs arising from a multidiscipline research community. As a part of the APS Upgrade Project, the planed facility, named Sub-micron 3-D Diffraction (S3DD) beamline 1 , integrates the K-B mirror based polychromatic Laue diffraction and the Fresnel zone-plate based monochromatic diffraction techniques that currently support 3D/2D microdiffraction programs at the 34-ID-E and 2-ID-D of the APS, respectively. Both diffraction nanoprobes are designed to have a 50-nm or better special resolution. The zone-plate based monochromatic DNP has been preliminarily designed and will be constructed at the sector 34-ID. It uses an APS-3.0-cm period or APS-3.3-cm period undulator, a liquid-nitrogen cooled mirror as its first optics, and a water cooled small gap silicon double-crystal monochromator with an energy range of 5-30 keV. A set of zone plates have been designed to optimize for focusing efficiency and the working distance based on the attainable beamline length and the beam coherence. To ensure the nanoprobe performance, high stiffness and high precision flexure stage systems have been designed or demonstrated for optics mounting and sample scanning, and high precision temperature control of the experimental station will be implemented to reduce thermal instability. Designed nanoprobe beamline has a good management on thermal power loading on optical components and allows high degree of the preservation of beam brilliance for high focal flux and coherence. Integrated with variety of X-ray techniques, planed facility provides nano-XRD capability with the maximum reciprocal space accessibility and allows micro/nano-spectroscopy studies with K-edge electron binding energies of most elements down to Vanadium in the periodic table. We will discuss the preliminary design of the zone-plate based monochromatic DNP and its technical relevance to a broad range of scientific applications.
Teacher Education, Experience, and the Practice of Aligned Instruction:

Research over the past two decades has shown the alignment of teachers’ instruction with state standards is generally weak. Proposing that alignment is a useful measure of teachers’ curricular knowledge (Shulman, 1986), this study uses a large database of teacher reports of their content coverage to understand the relationship of teacher educational and career experience variables with instructional alignment. The results of the fixed effects models indicate significant, positive associations, though they are generally modest in magnitude. Implications for research and policy are discussed.
Pharmacological Screening of Various Species of Thalictrum III

Eleven different species of Thalictrum have been examined for hypotensive and smooth muscle relaxing effects. Thalictrum minus race B, T. rochebrunianum , and T. rugosum appeared to be the most promising and worthy of further investigation.
A thin-film prism as a beam separator for multimode guided waves in integrated optics

Abstract We discuss a new application of a thin-film prism as a beam separator for multimode guided waves in integrated optics. For each mode of propagation, the angle of deflection by the thin-film prism is different and each deflected beam can be processed subsequently. Deflection angles for different modes can be predicted by using the concept of effective index of refraction. The thickness and index of refraction of the guiding film are determined simultaneously by measuring the coupling angles of the laser beam and a simple graphical method. Calculated and observed angles of deflection are in good agreement. The thin-film prism is made by using preferential etching technique in order to obtain linear, well defined, tapered edges. Furthermore, silicon is used as the base material for possible future integration of optical and electronic components.
Elevated expression of the ribosomal protein S2 gene in human tumors

Differential screening of a cDNA library was used to isolate genes differentially expressed in a nontumorigenic clone and a ras-transformed variant of the human teratocarcinoma cell line PA-1. The RNA transcript for one of the cDNA clones that we identified was expressed at a 25-fold higher level in the ras-transformed PA-1 cells than in the nontumorigenic PA-1 cells. DNA sequence analysis of this clone showed that it had 86% nucleic acid homology to the mouse LLRep3 gene and only differed at a single amino acid codon (codon 198), which is changed from serine in LLRep3 to threonine in this cDNA clone. The rat ribosomal S2 protein is closely related to the yeast omnipotent informational suppressor SUP44, which encodes the yeast ribosomal protein S4; to the mouse protein LLRep3; and to the human cDNA clone we describe in this report. We therefore concluded that this clone codes for the human ribosomal S2 protein. In situ hybridization experiments revealed that expression of this gene was elevated in cultured human head and neck squamous cell carcinomas compared with normal keratinocytes. In situ hybridization experiments also demonstrated that expression of this gene was elevated in histological sections of human premalignant leukoplakia, head and neck squamous cell carcinomas, and colon and breast cancers compared with the adjacent normal tissues. S2 expression may be a useful diagnostic or prognostic marker for grading human tumors.
Surface reconstruction on semiconductors

Abstract Reconstruction of semiconductor surfaces is considered in a tight-binding framework using the bond orbital approximation to simplify the total energy calculation. A Jahn-Teller type of distortion, based upon a dehybridization of the dangling hybrids, is found to dominate and to lead to distortions larger than those customarily proposed at surfaces. This result, together with experimental knowledge of the surfaces, leads to specific forms for the reconstruction expected on the principal symmetry surfaces of both polar and nonpolar semiconductors. The forms found for (111) and (110) silicons surfaces are among forms which have been proposed earlier, but a canted ridge structure for the (100) surface is new. The reconstruction is large enough to drop the occupied dangling hybrid state deep into the valence band, suggesting that observed structure near the top of the valence band is due to back bonds, in agreement with Pandey and Phillips. The reconstruction also tends to increase the work function above the unreconstructed value on all surfaces. The effect of adsorption of atoms on the reconstruction as a function of the valence of the adsorbate, is summarized. It is found that while the energy to form a vacancy on a silicon (111) surface is very large, silicon atoms outside the nominal surface should be quite stable. This suggests that the 7 × 7 reconstruction is a pattern of add-atoms rather than (and topologically unrelated to) a pattern of vacancies.
The Icon programming language

From the Publisher: Icon is a general purpose programming language, much more powerful than C, C++, or other languages for prototyping, text processing, and manipulating data structures. This edition covers the new Icon Version 9, which offers many new features and enhancements. Anyone studying this unique language will want to have this latest edition of the "Icon bible."
Sex difference in polybrominated diphenyl ether concentrations of walleyes

Abstract Polybrominated diphenyl ether (PBDE) concentrations were determined for mature male and mature female walleyes ( Sander vitreus ) sampled from the Saginaw Bay population during 2007. PBDE concentrations in prey fish caught in the Saginaw River, the primary tributary to Saginaw Bay, and in Saginaw Bay during 2005 and 2007 also were determined. Mature male and mature female walleyes averaged 70.3 ng/g and 24.8 ng/g, respectively, in ΣPBDE, which was equal to the sum of concentrations of six PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154). This sex difference was likely due to males spending more time in the Saginaw River system than females. Prey fish captured in the Saginaw River were roughly ten times higher in ΣPBDE than those caught in Saginaw Bay. BDE-47 was the predominant congener in both walleyes and prey fish, and this congener contributed about 50%, on average, to ΣPBDE. Congener profiles differed significantly between the two sexes of walleyes. In contrast, congener profiles of the prey fish did not differ significantly between the river-caught fish and the bay-caught fish. One plausible explanation for these congener profile results was that net trophic transfer efficiencies of PBDEs to walleyes from their prey were similar for all congeners except BDE-28, and that diet composition differed between the two sexes of walleyes.
A mechanism for nitrate transport and reduction

Abstract It is proposed that a tetrahedron-shaped, transmembrane nitrate reductase tetramer functions as a carrier for nitrate transport. Reduction and transport are thereby brought about by the same enzyme complex. An ATPase is visualized to be closely associated with the nitrate reductase tetramer. The tetramer is apparently oriented such that one monomer is exposed to the outside of the plasmalemma while the other three are exposed to the cytoplasmic side. This orientation yields a reaction mechanism where the transport and reduction of one nitrate ion is accompanied by the transport of two additional nitrate ions (i.e. a 3 : 1 transport-reduction ratio). The proportion of transported nitrate that is reduced is apparently modulated by thiol reversible ADP inhibition of reduction. This inhibition, however, is probably the result of adenylate binding at sites on the proposed nitrate-activated ATPase to which nitrate reductase is tightly coupled. An analogous system consisting of a nitrate reductase dimer that spans a unit membrane plus an ATPase is proposed to be responsible for nitrate transport and reduction in some algae and chloroplasts.
Localization of pectins and arabinogalactan-proteins in lily (Lilium longiflorum L.) pollen tube and style, and their possible roles in pollination

In lily, adhesion of the pollen tube to the transmitting-tract epidermal cells (TTEs) is purported to facilitate the effective movement of the tube cell to the ovary. In this study, we examine the components of the extracellular matrices (ECMs) of the lily pollen tubes and TTEs that may be involved in this adhesion event. Several monoclonal antibodies to plant cell wall components such as esterified pectins, unesterified pectins, and arabinogalactan-proteins (AGPs) were used to localize these molecules in the lily pollen tube and style at both light microscope (LM) and transmission electron microscope (TEM) levels. In addition, (β-d-Glc)3 Yariv reagent which binds to AGPs was used to detect AGPs in the pollen tube and style. At the LM level, unesterified pectins were localized to the entire wall in in-vivo- and in-vitro-grown pollen tubes as well as to the surface of the stylar TTEs. Esterified pectins occurred at the tube tip region (with some differences in extent in in-vivo versus in-vitro tubes) and were evenly distributed in the entire style. At the TEM level, esterified pectins were detected inside pollen tube cell vesicles and unesterified pectins were localized to the pollen tube wall. The in-vivo pollen tubes adhere to each other and can be separated by pectinase treatment. At the LM level, AGP localization occurred in the tube tip of both in-vivo- and in-vitro-grown pollen tubes and, in the case of one AGP probe, on the surface of the TTEs. Another AGP probe localized to every cell of the style except the surface of the TTE. At the TEM level, AGPs were mainly found on the plasma membrane and vesicle membranes of in-vivo-grown pollen tubes as well as on the TTE surface, with some localization to the adhesion zone between pollen tubes and style. (β-d-Glc)3 Yariv reagent bound to the in-vitro-grown pollen tube tip and significantly reduced the growth of both in-vitro- and in-vivo-grown pollen tubes. This led to abnormal expansion of the tube tip and random deposition of callose. These effects could be overcome by removal of (β-d-Glc)3 Yariv reagent which resulted in new tube tip growth zones emerging from the flanks of the arrested tube tip. The possible roles of pectins and AGPs in adhesion during pollination and pollen tube growth are discussed.
Pursuing the president: White House access and organized interests

Abstract How do interest groups get the president to hear their problems? Specifically, what channels of access do they exploit in order to contact the president? What researchers need is an effective tool to examine the full range of access routes to the presidency. This paper attempts to develop such a mechanism. The interest group-presidency relationship becomes clear when two factors are examined: channel of access (formal and informal) and level of access (remote and proximate). The typology that is created allows the relationship to be fully explicated.
Two-photon photoemission spectroscopy: naphthalene on Cu(1 1 1)

Abstract Two-photon photoemission (2PPE) spectroscopy is used to investigate the electronic structure of naphthalene dosed on Cu(1 1 1) at 86 K. The three transitions involving unoccupied orbitals were found and identified as having π ∗ molecular orbital character––the first lying 0.40 eV above the vacuum level and identified as having π ∗ b 1 u character; the second 0.30 eV below the vacuum level and having π ∗ b 3 g character; and the third lying 1.10 eV below the vacuum level with π ∗ b 2 g character. The results accord with both inverse photoemission spectroscopy (IPES) and electron transmission spectroscopy (ETS) data. There are interesting relatively unique features in the temperature programmed desorption (TPD) spectra indicative of structural reorganization of as-dosed naphthalene. Thermal processing also has a marked influence on 2PPE intensities and is taken as reflecting changes, with respect to the Cu(1 1 1) surface, of the ensemble average orientation of the naphthalene overlayer.
Public health considerations in the management of meningococcal disease.

Abstract We discuss chemoprophylaxis of household contacts of cases, the current status and use of meningococcal vaccine, and the role of surveillance of household contacts. Available data on secon...
High depth of field microscopic imaging using an interferometric camera

We describe the design of a microscope combining rotational shear interferometer (RSI)-based coherence imaging with an objective lens to simultaneously obtain high numerical aperture and high depth of field imaging. We present experimental results showing the operation of this instrument.
EXCITED STATE INTRAMOLECULAR PROTON TRANSFER IN ANIONIC ANALOGUES OF MALONALDEHYDE

The transfer of a proton in malonaldehyde takes place within an intramolecular H-bond involving a five-membered ring. This process is compared via ab initio methods with the transfer in analogous systems in which the size of the ring is altered to four and to six and in which the system bears an overall negative charge. In addition to the ground state, calculations are applied to the singlet and triplet ππ* states, as well as to 1nπ* and 3nπ*. The barriers to proton transfer are found to correlate strongly with various geometric and energetic markers of the strength of the H-bond. The H-bond is weakened by n → π* excitation, particularly for the neutral molecule, resulting in a higher transfer barrier. In the case of the two anions, excitation to 3ππ* strengthens the H-bond, while the result is more ambiguous for the 1ππ* state. This trend is reversed in malonaldehyde where the singlet is strengthened by the excitation and the triplet weakened. Some of these patterns are traced directly to the nature of t...
Credibility of Social Network Sites for Political Information Among Politically Interested Internet Users

Scholars have confirmed that political candidates are increasingly turning to social network sites SNS to persuade voters to vote for them, and that these sites have become prominent sources of political information. But a fundamental question arises about the sustainability of social networks as a campaign tool: How much do users trust the information they find there? This study employed an online survey to examine the degree to which politically interested online users view SNS as credible. SNS were ranked the least credible among the nine traditional and online sources examined. Reliance on social networks proved the strongest predictor of SNS credibility.
Autoregulation of androgen production in a primary culture of rat testicular cells

Studies on hypophysectomized rats have suggested that testicular androgen production may be locally autoregulated via an ultra-short loop negative feedback mechanism1,2. Conclusive demonstration of this phenomenon in vitro has been hampered by lack of a functional testicular cell culture and the use of native androgens which are subject to extensive metabolism and interfere with measurements of endogenous androgens. We have now used a recently developed primary culture of rat testicular cells3 and synthetic steroids, and report that a synthetic androgen (R1881)4 decreases, whereas a synthetic anti-androgen (cyproterone acetate)5 increases, the gonadotropin-stimulated accumulation of testosterone in vitro. Furthermore, cyproterone acetate antagonized the inhibitory effect of R1881 on the accumulation of testosterone. In contrast, R5020 (ref. 6), a highly specific and metabolically stable progestin, did not affect the gonadotropin-stimulated accumulation of testosterone. These findings are the first in vitro demonstration of local autoregulation of testicular androgen production and suggest that the intratesticular negative feedback action of androgens may be mediated by specific testicular androgen receptors.
Angular correlation studies of nuclear polarization following inelastic scattering of alpha particles from C12 and Mg24

Abstract Alpha-gamma angular correlations have been measured at 73 scattering angles in the reaction plane for the reaction C12(α, α′γ4.43) and at 40 scattering angles for the reaction Mg24 (α, α′γ1.37). The correlation functions were determined at each alpha-particle scattering angle by measuring the coincidence gamma-ray yield for at least 11 different gamma-ray detection angles. All of the particles in both reactions except the excited nuclei and the gamma rays are spinless, greatly simplifying interpretation of the correlation data. These data have been analysed in terms of the polarization of the excited nucleus, and show the presence of curious and distinctive behaviour in the functional dependence of the polarization parameters on scattering angle for both reactions studied. These results are compared with the predictions of reaction theories and show strong disagreement with semi-classical, plane-wave, and adiabatic theory predictions, while giving at least qualitative agreement with DWBA calculations. Predictions of compound nucleus theory are investigated, and the relevance of this type of measurement to the investigation of reaction mechanisms and their interference effects is discussed.
Electronic Charge Densities and the Temperature Dependence of the Forbidden (222) Reflection in Silicon and Germanium

Using nonlocal pseudopotentials for silicon and germanium we are able to calculate the temperature dependence of the forbidden (222) reflection and we find it to be in excellent agreement with experiment. The accuracy of the pseudocharge density for the case of silicon is also examined and found to be in good agreement with recent x-ray experimental results.
Halflife measurements of the rp-process nuclei 61Ga, 63Ge, and 65As

Abstract Using the A1200 beam analysis device at the National Superconducting Cyclotron Laboratory, we have measured the halflives of several nuclei along the rp-process path near the proton-drip line. Halflife results for 61 Ga, 63 Ge, and 65 As (0.15±0.03 s, 95 −25 +23 ms, and 0.19 −0.07 +0.11 s, respectively) and their implications for the rp-process are presented.
Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment

Recent changes in the risk assessment landscape underscore the need to be able to compare the results of toxicity and dose-response testing between a growing list of animal models and, quite possibly, an array of in vitro screening assays. How do we compare test results for a given compound between vastly different species? For example, what dose level in the ambient water of a small fish model would be equivalent to 10 ppm of a given compound in the rat's drinking water? Where do we begin? To initially address these questions, and in order to compare dose-response tests in a standard rodent model with a fish model, we used the concept of molecular dose. Assays that quantify types of DNA damage that are directly relevant to carcinogenesis integrate the factors such as chemical exposure, uptake, distribution, metabolism, etc. that tend to vary so widely between different phyletic levels. We performed parallel exposures in F344 rats and Japanese medaka (Oryzias latipes) to the alkylating hepatocarcinogen, dimethylnitrosamine (DMN). In both models, we measured the DNA adducts 8-hydroxyguanine, N(7)-methylguanine and O(6)-methylguanine in the liver; mutation frequency using lambda cII transgenic medaka and lambda cII transgenic (Big Blue(R)) rats; and early morphological changes in the livers of both models using histopathology and immunohistochemistry. Pulse dose levels in fish were 0, 10, 25, 50, or 100 ppm DMN in the ambient water for 14 days. Since rats are reported to be especially sensitive to DMN, they received 0, 0.1, 1, 5, 10, or 25 ppm DMN in the drinking water for the same time period. While liver DNA adduct concentrations were similar in magnitude, mutant frequencies in the DMN-exposed medaka were up to 20 times higher than in the Big Blue rats. Future work with other compounds will generate a more complete picture of comparative dose response between different phyletic levels and will help guide risk assessors using "alternative" models.
Beta ratio, swirl and Reynolds number dependence of wall pressure in orifice flowmeters

Abstract Experimental work has been performed in an effort to gain a better understanding of the flow field inside orifice flowmeters and the pressure field generated on the walls of the pipe and orifice plate. As a part of a larger study, extensive wall pressure measurements have been made on the pipe wall from four pipe diameters upstream of the orifice plate to six pipe diameters downstream, as well as on both the upstream and downstream faces of the orifice plate. These measurements were performed for Reynolds numbers of 54 700; 91 100 and 122 800; for beta ratios of 0.50 and 0.75 with air as the working fluid. An adjustable swirl plate was installed, which was used to impart varying amounts of swirl into the flow upstream of the orifice plate. For each swirl case, Pitot and static pressure probes were used to characterize the upstream flow field while the pipe wall and orifice plate surface pressures were measured.
Dislocation-density mechanisms for void interactions in crystalline materials

Abstract Dislocation-density based evolution formulations that are related to a heterogeneous microstructure and is representative of different crystalline interactions, have been developed and used to investigate the dominant dislocation density mechanisms for void interactions, localized plastic strains, failure paths and ligament damage in face centered cubic (f.c.c.) and body centered cubic (b.c.c.) crystalline materials. The balance between the generation and annihilation of dislocation-densities, through glissile and forest interactions at the slip system level is taken as the basis for the evolution of mobile and immobile dislocation densities. The evolution equations are coupled to a multiple-slip crystal plasticity formulation, and a framework is established that relates it to a general class of crystallographies and deformation modes. Specialized finite-element (FE) methodologies have then been used to characterize void interactions in f.c.c. and b.c.c. crystals at different orientations, to obtain a detailed understanding of the interrelated physical mechanisms that can result in ductile material failure. The results indicate that dislocation-density interaction mechanisms, such as dislocation-density junction formation and annihilation, can have significant effects on shear strain localization and void interaction behavior.
A lemma on G-inverse of a matrix and computation of correlation coefficients in the singular case

Formulae for multiple, partial and canonical correlation coefficients are generally expressed in terms of the elements of inverse covariance matrix. They are not applicable when the covariance matrix is singular. In this paper, a unified approach is presented to cover the singular and non-singular cases. The formulae involve g-inverse of singular matrices and the results are derived from a lemma on the structure of the idempotent matrix AA− where A− is any g-inverse (i.e., AA−A=A). The conditions under which some columns of AA− are unit vectors are obtained. The formulae for canonical correlations and the canonical transformations of two sets of variables in the singu-lar case are shown to be of the same form as in the non-singular case, with the convention that only the proper eigen values and vectors of determinantal equations are considered.
Advances in pediatric palliative medicine in the United States

Over the past decade, pediatric palliative medicine in the United States has advanced to a remarkable degree. This article situates these changes in the general context of the growth of adult-focused palliative medicine, and enumerates several landmark reports, studies, programmatic initiatives, and professional developments that serve as milestones marking the progress of the field, while also underscoring the continuing need to better educate families and health care providers about what pediatric palliative care can offer patients, to expand the evidence base regarding specific pediatric palliative care interventions, and to further our abilities to finance and improve these services.
NSF's focus on infrastructure research

Abstract The National Science Foundation has been the major funding agency for basic engineering research in academia for more than 20 years. Throughout this period, funding for geotechnical research in specific, and civil engineering research in general, has been available in relatively small amounts and through several frequently reorganized programs. Through the efforts of several recent program directors (including Roy Olson, The University of Texas at Austin, Tom Zimmie and Rensselaer Polytechnic Institute, and Mehmet Tumay from Louisiana State University), the funding for geomechanics and geo-environmental research has been stabilized. The opportunity for civil research have also been expanded into the broad and integrative research area identified as CIS (civil infrastructure systems). These programs are generally described in this paper.
Perceptions of high risk sports

High risk sports were rated as to risk, appeal, and likelihood of participation by 282 men and 162 women. Ascending order of perceived risk was skiing, scuba diving, bungee jumping, rock climbing, motorcycle racing, hang gliding, cliff jumping, and skydiving. Profile analysis showed stated likelihood of participation to be directly related to appeal and inversely related to perceived risk.
B meson decays to open charm and charmonium at BaBar

Since it began recording data in 1999, the BaBar detector at the SLAC B Factory has collected nearly 90 million B meson pairs. Using this sample, they are able to make precise measurements of B decays to open charm and charmonium. In particular, they have measured the rates for B {yields} D{bar D}K, for the color-suppressed modes B{sup 0} {yields} D{sup 0}{pi}{sup 0}, B{sup 0} {yields} D{sup 0}{eta}, and B{sup 0} {yields} D{sup 0}{omega}, for B{sup +} {yields} {chi}{sub c}{sup 0}K{sup +}, and for B{sup 0} {yields} D(*){sub s}{sup +} D*{sup -}. They have also begun preparations for a measurement of the CKM angle {gamma} by studying the modes B{sup +} {yields} D{sup 0}K{sup +}, B{sup 0} {yields} D(*){sub s}{sup +} {pi}{sup -}, and B{sup 0} {yields} D(*){sub s}{sup +} K{sup -}.
Review article: moderate sedation for endoscopy: sedation regimens for non-anaesthesiologists.

Summary Background Moderate sedation is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands with or without light tactile stimulation. Moderate sedation is typically accepted in the anaesthesia community as an appropriate target for sedation by non-anaesthesiologists. Aim To describe drug regimens that can be successfully and safely targeted to moderate sedation for endoscopy by non-anaesthesiologists. Results Moderate sedation can be achieved using narcotics and benzodiazepines. There is interest in some countries in propofol for endoscopy, which is often viewed as an agent for deep sedation. Indeed, propofol cannot be targeted to moderate sedation for endoscopy as a single agent because of coughing during upper endoscopy and pain withdrawal responses during colonoscopy. Pre-treatment with low doses of narcotic and/or benzodiazepine blocks these effects, allowing propofol to be targeted to moderate sedation. Fospropofol, a prodrug of propofol in clinical development, can also be targeted to moderate sedation if co-administered with narcotic. Conclusion Moderate sedation provides a safety margin when compared with deep sedation and general anaesthesia. Development of protocols that target agents such as propofol to moderate sedation will expand the sedation agents available to non-anaesthesiologists and help ensure that this expansion occurs safely.
Crossed cerebellar atrophy: An old problem revisted

The problem of crossed cerebellar atrophy is re-examined in the light of an illustrative case, recent literature and the authors' previous experience. There types of lesions emerge from this analysis: (1) transneuronal atrophy of the nuclei pontis and contralateral middle cerebellar peduncle, (2) atrophy of nuclei pontis with secondary transneuronal degeneration of the granular layer of the cerebellar cortex, and (3) lobular sclerosis of the cerebellar folia of a postictal pattern. The pathogenesis of these lesions is discussed in the light of present-day concepts of transneuronal atrophy and degeneration and of the spread of the epileptic impulse. It is concluded that many cases of crossed cerebellar atrophy represent post-ictal and not transneuronal lesions.
Ionic liquid-catalyzed alkylation of isobutane with 2-butene

A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides–aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions, respectively. The emphasis has been to delineate the role of both cations and anions in this reaction. The ionic liquids bearing a larger alkyl group on their cation ([C8mim]) displayed relatively higher activity than a smaller one ([C 6 or C4mim]) with the same anionic composition, due to the high solubility of reactants in the former. Among the ionic liquids with different halide groups, bromides ([C 8mim]Br–AlCl3) showed outstanding activity, because of the higher inherent acidity relative to others. From the 27 Al NMR study, a major peak at ∼ 99.5 ppm corresponding to [AlCl3Br] − (∼ 99.5 ppm) was observed. Moreover, the anion showed a strong acidity based on FT-IR characterization; the largest peak related to acidity (1570 cm −1 ) was detected. Under various composition conditions, catalytic activity and amount of TMPs increased with concentration of anion. This is mainly attributed to a higher amount of strong acid ions [Al 2Cl6Br] − which can react with hydrogen atoms at the 2-position of an imidazolium ion to form Bronsted acid. However, the ionic liquid with strong acidity (X = 0.58) deactivated rapidly due to a higher sensitivity to moisture, causing decomposition. Under various reaction temperature conditions, optimum catalytic activity was observed at 80 ◦ C. The result is also attributed to the effect of anion composition. The strong acidic anion increased with temperature. However, at higher reaction temperatures (120 ◦ C), the ionic liquid showed a lower activity and TMP selectivity, since the
Culture as Information and Culture as Affective Process: A Comparative Study

: This paper describes an application of the Cross-Cultural Adaptability Inventory or CCAI (Kelley and Meyers 1995a) to measure the effects of two ways to teach about German culture in beginning language courses. A first language (L1) process-oriented approach and a second language (L2) knowledge-based approach were implemented in separate classes. Students filled out the CCAI in pretreatment and post-treatment conditions. Quantitative analyses of results established that the treatment group, taught with constructivist, process-oriented tasks as articulated in the National Standards (1996), experienced significantly positive results on the CCAI composite score and on two out of four subscales that assess cultural sensibilities. Conversely, the control group, which spent commensurate time working with knowledge-based orientations characteristic of many textbooks on the market today, experienced a nonsignificant decrease in cultural receptivity in those same CCAI measures.
Ethanol oxidation by components of rat liver microsomes.

Abstract A new method was employed for the purification of cytochrome P-450 from rat liver microsomes. The purified cytochrome was essentially free from possible contaminants and the recovery and degree of purification were high. Although 15% of the original P-450 was recovered through the purification procedure used, only 0.8% of the total original microsomal ethanol oxidation activity was associated with this fraction. Addition of this purified fraction to other fractions isolated did not further stimulate ethanol oxidation. The component of rat liver microsomes that was found most efficient in the oxidation of ethanol was the mixture of catalase and NADPH - cytochrome c - reductase. It is concluded that highly purified cytochrome P-450 by itself does not oxidize ethanol to any appreciable degree.