cssi/SciSciGPT-SciSciNet huggingface dataset:
Miniaturized linear time-of-flight mass spectrometer with pulsed extraction.

Improved resolution for a miniaturized instrument is demonstrated at high masses using a pulsed extraction, 3″ linear time-of-flight (TOF) mass analyzer. This illustrates the utility of a small and simple mass spectrometer for biological/medical analyses. Current and future applications suggested by this instrument include rapid mass spectral reading of oligonucleotides that differ in one base (single nucleotide polymorphisms), distinction of biomarker signatures from different species of bacterial spores (biological weapons detection) and point-of-care instruments for proteomics-based diagnostics. We have incorporated a two-stage, pulsed-extraction design that places the focal plane of the ions at the detector channel plate surface. The ions are accelerated to a total energy of 12 keV to enable detection of high-mass proteins in a design that incorporates a floatable flight tube set at the voltage of the front channel plate of the detector. The resultant elimination of post-acceleration at the detector is intended to improve mass resolution by reducing the difference in arrival times between ions and their neutral products. Resolutions of one part in 1200 at m/z 4500 and one part in 600 at m/z 12 000 have been achieved. Proteins with molecular masses up to 66 000 Da, mixtures of oligonucleotides, and biological spores have all been successfully measured, results that increase the potential use of this TOF analyzer. Copyright © 2002 John Wiley & Sons, Ltd.
Profiling e-Science infrastructures with kernel and application benchmarks

Resources benchmarking is a promising though challenging opportunity for research communities to better exploit e-Science infrastructures. The paper investigates the suitability of an integrated two-level benchmarking approach in supporting resources ranking on a performance basis. The coupling of different benchmarking techniques i.e. kernel and application benchmarks is intended to grasp the behaviour of computational environments also with respect to real workloads so as to address a more suitable and efficient assignment of resources to the applications submitted by users. To confirm the appropriateness of our approach, an experimentation on a test bed was carried out which highlighted significant differences amongst the performance figures of the two levels of benchmarks. Some useful rules of thumb emerged from our experimentation that could be taken into account to fruitfully adopt this double-space approach to similar scenarios of use.
Using Soil and Meteorologic Data Bases in Unsaturated Zone Modeling of Pesticides

Various types of models are being used to evaluate pesticide transport and transformation in the unsaturated zone. Model predictions can be used, for example, to develop alternative agricultural management strategies for pesticide use. However, intensive data requirements for transient models sometimes deter their use. Site-specific measurements are preferred, but existing data bases can be used as a source of required model parameters, especially weather and soil characteristics. These existing data bases make possible the use of models to predict leaching potential in a wide variety of environments.
Acute toxicity of a native mummichog population (Fundulus heteroclitus) to mercury.

The dose-response of native mummichog populations to mercury was investigated. Male specimens weighing 3.3--3.5 g were collected in Sandy Hook Bay, New Jersey. These fish were acclimated for 7 days at 20/sup 0/C and 20% salinity prior to use in experiments. All exposure were conducted for 96 hours at 20/sup 0/C, 20% salinity, pH 8.0 and 11 different dosages of mercuric chloride. 100% survival was obtained with dosages of numeric chloride ranging up to 0.86 mg/liter. These fish showed no visible response to the presence of the toxicant. However, an increasingly sluggish behavior developed in those fish surviving exposure levels above 1.15 mg/liter. Survivors of dosages exceeding the calculated TLM (2.0 mg/liter) demonstrated a pronounced negative phototaxy. Fish exposed to intermediate levels (1.15--2.0 mg/l) developed uncoordinated swimming movements while exposure to maximal levels produced obvious respiratory stress.
Loading and unloading split hopkinson pressure bar pulse-shaping techniques for dynamic hysteretic loops

Pulse-shaping techniques are developed for both the loading and unloading paths of a split Hopkinson pressure bar (SHPB) experiment to obtain valid dynamic stress-strain loops for engineering materials. Front and rear pulse-shapers, in association with a momentum trap, are used to precisely control the profiles of the loading and unloading portions of the incident pulse. The modifications, ensure that the specimen deforms at the same constant strain rate under dynamic stress equilibrium during both loading and unloading stages of an experiment so that dynamic stress-strain loops can be accurately determined. Dynamic stress-strain loops with a constant strain rate for a nickel-titanium shape memory alloy and polymethyl methacrylate are determined using the modified SHPB. The modified momentum trap prevents repeated loading on a specimen without affecting the amplitude of the desired loading pulse and without damaging the bar at high stress levels.
Effects of several extinction treatments upon the integrity of Pavlovian stimulus-outcome associations

Pavlovian-to-instrumental transfer tests were used to assess the sensitivity of Pavlovian stimulus-outcome (S-O) associations to various extinction treatments in four appetitive conditioning experiments with rats. In Experiment 1, simple nonreinforcement of a stimulus was shown to have little impact on the ability of that stimulus to display outcome-specific transfer of control. Extinguishing a stimulus by pairing the stimulus with an alternative reinforcement in Experiment 2 also had no detectable effect on the S-O associations as assessed with the outcome-specific transfer measure. The third and fourth experiments, respectively, examined the impact of postconditioning exposures to random and explicitly unpaired S-O contingencies upon previously learned S-O associations. These treatments, as well, had no detectable harmful effects upon the integrity of the S-O associations. In contrast to the consistent failures of various extinction treatments to influence the ability of stimuli to display outcome-specific transfer, these treatments often did reduce the strength of conditioned responding initially trained to these stimuli. These results support the view that extinction entails the preservation of S-O associations as well as the parallel development of inhibitory stimulus-response associations. Other notions of extinction are also discussed.
Joint-sparse recovery in compressed sensing with dictionary mismatch

In traditional compressed sensing theory, the dictionary matrix is given a priori, while in real applications this matrix suffers from random noise and fluctuations. This paper considers a signal model where each column in the dictionary matrix is affected by a structured noise. This formulation is common in radar related applications and direction-of-arrival estimation. We propose to use joint-sparse signal recovery in this compressed sensing problem with dictionary mismatch and also give a theoretical result on the performance bound for this joint-sparse method. We show that under mild conditions the reconstruction error of the original sparse signal is bounded by both the sparsity and the noise level in the measurement model. Moreover, a fast first-order method is implemented to speed up the computing process. Numerical examples demonstrate the good performance of the proposed algorithm, and also show that the joint-sparse recovery method converges faster and gives a better reconstruction result than previous methods.
Learning science through talking science in elementary classroom

Elementary students in grade two make sense of science ideas and knowledge through their contextual experiences. Mattis Lundin and Britt Jakobson find in their research that early grade students have sophisticated understandings of human anatomy and physiology. In order to understand what students’ know about human body and various systems, both drawings and spoken responses provide rich evidence of their understanding of the connections between science drawings and verbal explanations. In this forum contribution, we present several theoretical connections between everyday language and science communication and argue that building communication skills in science are essential. We also discuss how young participants should be valued and supported in research. Finally we discuss the need for multimodal research methods when the research participants are young.
Inhibitory copper binding site on the spinach cytochrome b6f complex: implications for Qo site catalysis.

The isolated cytochrome (cyt) b6f complex from spinach is inhibited by Cu2+ with a KD of about 1 μM at pH 7.6 in the presence of 1.6 μM decyl−plastoquinol (C10−PQH2) as a substrate. Inhibition was competitive with respect to C10−PQH2 but noncompetitive with respect to horse heart cyt c or plastocyanin (PC). Inhibition was also pH-sensitive, with an apparent pK at about 7, above which inhibition was stronger, suggesting that binding occurred at or near a protonatable amino acid residue. Equilibrium binding titrations revealed ca. 1.4 tight Cu2+ binding sites with a KD of about 0.5 μM and multiple (>8) weak (KD > 50 μM) binding sites per complex. Pulsed electron paramagnetic resonance (EPR) techniques were used to identify probable binding sites for inhibitory Cu2+. A distinct enhancement of the relaxation time constant for the EPR signal from bound Cu2+ was observed when the cyt f was paramagnetic. The magnitude and temperature-dependence of this relaxation enhancement were consistent with a dipole interac...
A Comparison of Traditional and Computer-Based Methods of Teaching Students to Administer Individual Intelligence Tests

AbstractA computer-assisted training method was compared to traditional training methods for teaching the administration of the Wechsler Intelligence Test for Children-Revised (WISC-R). Two subtests of the WISC-R and in introductory administration segment were simulated through a computer program in BASIC. Twenty-seven undergraduate students randomly divided into three groups of nine comprised a No Practice group, a Child Practice group and a Computer Practice group. The No Practice group received only materials to study, the Child Practice group practiced administering the test with children as subjects, and the Computer Practice group practiced using the simulation program. All three groups then were tested using the computer simulation program. The Computer Practice group made significantly fewer errors than either of the other groups. These results suggest that a computer simulation program can be very effective in teaching some aspects of administering the WISC-R.
Chebyshev approximation of log-determinants of spatial weight matrices

Abstract To cope with the increased sample sizes stemming from geocoding and other technological innovations, this paper introduces an O( n ) approximation to the log-determinant term required for likelihood-based estimation of spatial autoregressive models. It takes as a point of departure Martin's (1993) Taylor series approximation based on traces of powers of the spatial weight matrix. Using a Chebyshev approximation along with techniques to efficiently compute the initial matrix power traces results in an extremely fast approximation along with bounds on the true value of the log-determinant. Using this approach, it takes less than a second to compute the approximate log-determinant of an 890,091×890,091 matrix. This represents a tremendous increase in speed relative to exact computation that should allow researchers to explore much larger problems and facilitate spatial specification searches.
Sensitized photocatalytic oxidation of herbicides using natural sunlight

Abstract The sensitized photocatalytic oxidation (SPCO) of the herbicide terbutryne using tris(bipyridyl)ruthenium complexes as sensitizer and titanium dioxide as semiconductor was investigated. Tris(4,4′-dicarboxy-2,2′-bipyridyl)ruthenium(II) chloride is an excellent sensitizer, and on exposure to sunlight complete degradation of the pollutant occurs. The thermodynamic and kinetic requirements for successful SPCO are discussed. The adsorption of the components on the semiconductor surface, electron transfer and electron back transfer determine the efficiency of the process.
Crotylsilane Reagents in the Synthesis of Complex Polyketide Natural Products: Total Synthesis of (+)-Discodermolide

An efficient, highly convergent stereocontrolled synthesis of (+)-discodermolide has been achieved with 2.1% overall yield (27 steps longest linear sequence). The absolute stereochemistry of the C1−C6 (12), C7−C14 (13), and C15−C24 (11) subunits was introduced using asymmetric crotylation methodology. Key elements of the synthesis include the use of hydrozirconation−cross-coupling methodology for the construction of C13−C14 (Z)-olefin, acetate aldol reaction to construct the C6−C7 bond and install the C7 stereocenter with high levels of 1,5-anti stereoinduction, and the use of palladium-mediated sp2−sp3 cross-coupling reaction to join the advanced fragments, which assembled the carbon framework of discodermolide.
Studies in helminth enzymology. III. Malic dehydrogenases of Ascaris suum

Abstract Three isozymes of malic dehydrogenase were shown to be present in extracts of Ascaris suum by starch-gel electrophoresis. Approximately a 36-fold purification of these isozymes was achieved through the use of cellulose ion exchangers, and a partial separation was obtained. The malic dehydrogenases from A. suum had an optimum pH of 8.5 for reduction of oxalacetate and a pH of 9.5 for oxidation of malate. Maximum activity for reduction of oxalacetate occurred at 55 °C, but the enzymes became denatured when incubated at this temperature. The addition of nicatinamide adenosine dinucleotide, reduced form (NADH), helped to stabilize the enzymes during incubation at 55 °. The Michaelis constant (oxalacetate) was estimated to be 5.4 × 10−6 M with a maximum velocity of 500 μmoles of NADH oxidized per minute per milligram of protein. Extract of swine heart was also shown by starch-gel electrophoresis to contain three isozymes of malic dehydrogenases which were isolated separately with cellulose ion exchangers. These enzymes differed from one another and from those in A. suum in (1) relative migration rate in starch-gel electrophoresis, (2) conditions for adsorption and elution from cellulose ion exchangers, (3) stability at 55 °, (4) inhibition by zinc ion, and (5) relative activity at different pH values.
Lymphocyte transformation initiated by galactose oxidase coupled to latex microspheres and formalinized erythrocytes.

Summary Galactose oxidase (GO) induces lymphocytes pretreated with neuraminidase (NAse) to undergo blastic transformation. Our studies provide evidence that the critical site for GO-induced lymphocyte transformation is on the cell surface. We have activated human peripheral blood lymphocytes by using GO covalently linked to solid-phase supports which are excluded from the cell interior. A variety of solid-phase supports were used: 1 000, 3 000, and 7 000 A latex microspheres, and formalinized red blood cells (fRBC). Transformation was observed when NAse pretreatment was followed with as little as a 10 min exposure to solid-phase GO. It was demonstrated that transformation was not caused by GO removed from the solid-phase during cell exposure. Mitogen response was attributed to the enzyme activity of GO since ( a ) free galactose suppressed transformation; ( b ) bovine serum albumin (BSA) linked to the solid-phase was not mitogenic.
A novel hemispherical spectro-polarimetric scattering instrument for skin lesion imaging

We present a novel spectro-polarimetric instrument based on hemispherical backscattering for the assessment of superficial skin lesions. The system is capable of capturing polarized light images non-invasively. The effect of the rough skin backscattering is eliminated with the use of out-of-plane illumination. A glass slide with an index matching fluid, commonly used in polarized light imaging, is no longer necessary. The system is composed of sixteen polarized light sources that provide red, green, or blue illumination. The light sources are distributed on a hemispherical shell, and each source produces a collimated beam incident on the center of the hemisphere. A Stokes vector imaging system is mounted on the shell at an oblique angle to the sample normal and consists of a 12-bit scientific camera, two liquid crystal variable retarders, and a fixed polarizer. Stokes vector images of light scattered towards the camera direction are generated for each source. A useful decomposition of the Stokes vector is presented. Examples of images generated by the system are presented.
EPR spectra of Fe3(CO)−11 ions and [Fe3(CO)−11]2 triplet ion-pairs trapped in single crystals of PPN+HFe3(CO)−11

Abstract The paramagnetic ion Fe 3 (CO) − 11 was introduced into single crystals of PPN + HFe 3 (CO) − 11 by direct doping or by 60 Co γ-irradiation. EPR spectroscopy shows that the doped crystals contain the impurity Fe 3 (CO) − 11 as isolated electronic doublets, whereas the irradiated crystals contain only pairs of the same radical observed as an electronically excited triplet. The orientation of the g tensor of the isolated monoradical clearly indicates that it does not have the C s symmetry of the host anion. It is believed that the unpaired electron is essentially localized in a xy or x 2 – y 2 orbital of one of the terminal Fe atoms in a structure analogous to those of the bridged radicals Fe 3 (CO) 7 μ-PPh 2 and Fe 2 (CO) − 8 . The g 2 matrix of the [Fe 3 (CO) − 11 ] 2 triplet shows that constituents of the pair occupy symmetry-related sites of the host. Maximum interelectronic interaction occurs very nearly along the a axis of the monoclinic host crystal, with |D| = 168 MHz and | E | = 3 MHz. The D value is equivalent to a point dipole separation of 0.79 nm, which corresponds closely to the separation of two anion sites within the unit cell.
An in situ X-ray absorption spectroscopy study of InSb electrodes in lithium batteries

We present a detailed in situ extended X-ray absorption fine-structure spectroscopy (EXAFS) study of structural and compositional changes in InSb intermetallic electrodes under electrochemical cycling conditions in a lithium battery. Analysis of the EXAFS data shows that Li is inserted into and In is extruded from the zinc-blende-type InSb network during the first discharge from 1.5 to 0.5 V, yielding changing Li{sub x+y}In{sub 1-y}Sb compositions (0 < x {le} 2, 0 < y {le} 1), with a lattice parameter that varies between that of InSb (a = 6.478 A) and Li{sub 3}Sb (a = 6.572 A). The structural features of tetragonal metallic In and lithiated (i.e., In depleted) InSb are evident. The fully recharged electrode, at 1.2 V, has a zinc-blende framework closely resembling InSb. However, 40% of the In remains permanently outside the face-centered-cubic Sb lattice, explaining a loss in capacity after the first discharge. After the second discharge, at 0.51 V, Li has replaced about 80% of the indium in the InSb lattice, while the Li{sub x}In{sub y}Sb volume has expanded less than 4% compared to the initial electrode. Finally, as the cell is discharged below 0.51 V, Li reacts with the In metal, forming LiIn. Our resultsmore » indicate that intermetallic electrodes are promising alternative negative electrodes for Li batteries.« less
Elastic constants and grüneisen parameters of pyrolytic graphite

Abstract The room-temperature elastic constants of a pyrolytic graphite were measured by an ultrasonic transmission technique and compared with values calculated on the basis of the constant strain and constant stress models from the elastic constants of compression-annealed pyrolytic graphite (CAPG). It was found that the constant stress model gives better agreement; and that the measured C 11 and C 44 can be bracketed by calculations with the basal plane shear constants of neutron-irradiated and unirradiated CAPG respectively as inputs, as would be expected because of the high mobility of dislocations in the basal plane. Gruneisen parameters, for sample temperatures between 80 and 300°k, were determined from measurements of inertial thermoelastic stress. Calculations from single-crystal thermal expansion and elastic constant values showed reasonable agreement with the measured parameters and indicated that the elastic constants of a given pyrolytic graphite, being extremely structure sensitive, can be u...
A Mackey Imprimitivity Theory for Algebraic Groups

Let G be an affine algebraic group over an algebraically closed field k and let H be a closed subgroup of G. If V is a rational H-module (a comodule for the coordinate ring of H) there is a now well-known notion of an induced module VI G for G, defined as the space Morph/~(G, V) of all H-equivariant morphisms from G to a finite dimensional subspace of V, with obvious G-action. The question arises, given a rational G-module M, how can one recognize M as an induced module VIG? For a finite group G the answer is the Mackey imprimitivity theorem: the module M is induced if and only if it is a direct sum of subspaces permuted transitively by G (with H the stabilizer of one of these subspaces, called V). One uses this result, for example, in proving the famous Mackey decomposition theorem which describes the restriction of any induced module to a second subgroup L as a direct sum of suitable induced modules; given the imprimitivity theorem, the proof is just a matter of grouping the summands permuted by G into their orbits under L. In the case of algebraic groups the situation is quite different. For some subgroups H, all G-modules are induced. This occurs, for example, if G is connected and k [G/H] ,= k, e.g., if H is parabolic. Also, if G is a connected unipotent group, then a rational G-module M is induced from some proper subgroup if and only if its endomorphism ring contains a two dimensional submodule E, for the conjugation action of G, with E___ k. 1 and such that k. l is precisely the subspace annihilated by the action of the Lie algebra of G on E [27] (cf. also (5.5) below). The latter is an application of a general criterion in case G/H is affine: a rational G-module M is induced if and only if there is an action of the coordinate ring A of G/H compatible with the action of G on both A and M. Note that this generalizes the imprimitivity theorem in the case of finite groups, since then A has a k-basis of [G:H] orthogonal idempotents permuted transitively by G.
Anatomic findings and outcomes after antireflux procedures in morbidly obese patients undergoing laparoscopic conversion to Roux-en-Y gastric bypass

Abstract Background To report the anatomic findings and outcomes in patients undergoing laparoscopic takedown of Nissen fundoplication with conversion to Roux-en-Y gastric bypass. Methods We reviewed the records of patients who underwent laparoscopic Nissen takedown with conversion to Roux-en-Y gastric bypass from January 2001 to April 2006 at the University of Minnesota Medical Center. Results Eleven patients were identified. Nine patients had gastroesophageal reflux disease preoperatively, of whom six underwent 24-hour pH monitoring. In 2 patients, the pH study findings were negative. Eight prior procedures had been performed laparoscopically. Eight patients were women. The mean age was 44 years. The average body mass index preoperatively was 44 kg/m 2 (range 35–61). The mean follow-up was 13.8 months (range 4–39). The body mass index at follow-up was 30.2 kg/m 2 . The operative time was 349 minutes (range 222–624). The hospital length of stay was 3.4 days (range 2–6). No conversions to open surgery were required. No major short-term complications developed. Minor complications included wound or drain site infection in 3 patients, with abscess in 2, pressure sore of the lateral aspect of the foot in 1, pneumonia in 2, and marginal ulcer in 2 patients. No strictures were observed. One internal hernia occurred. Of the 9 patients with gastroesophageal reflux disease preoperatively, all had 100% improvement in symptoms, with complete resolution in 7 (78%). Wrap disruption was present in 5 (45%) of 11 patients. Herniation of an intact wrap had occurred in 1 patient. One patient had both herniation and wrap disruption. Conclusion Laparoscopic conversion of Nissen fundoplication to Roux-en-Y gastric bypass is a feasible salvage operation for recurrent gastroesophageal reflux disease in the morbidly obese. The incidence of wrap disruption appears to be relatively high and the incidence of intact wrap herniation low in obese patients after failed Nissen fundoplication, suggesting that the mechanism of failure after primary antireflux surgery in obese patients may be different than that in normal-weight patients.
Computational simulations of high-intensity x-ray matter interaction

Free electron lasers have the promise of producing extremely high-intensity short pulses of coherent, monochromatic radiation in the 1-10 keV energy range. For example, the Linac Coherent Light Source at Stanford is being designed to produce an output intensity of 2x1014 W/cm2 in a 230 fs pulse. These sources will open the door to many novel research studies. However, the intense x-ray pulses may damage the optical components necessary for studying and controlling the output. At the full output intensity, the dose to optical components at normal incidence ranges from 1-10 eV/atom for low-Z materials (Z<14) at photon energies of 1 keV. It is important to have an understanding of the effects of such high doses in order to specify the composition, placement, and orientation of optical components, such as mirrors and monochromators. Doses of 10 eV/atom are certainly unacceptable since they will lead to ablation of the surface of the optical components. However, it is not precisely known what the damage thresholds are for the materials being considered for optical components for x-ray free electron lasers. In this paper, we present analytic estimates and computational simulations of the effects of high-intensity x-ray pulses on materials. We outline guidelines for the maximum dose to various materials and discuss implications for the design of optical components.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Disobedience and driving in patients with epilepsy.

OBJECTIVE: Motor vehicle accidents direct legislators to ensure pubic safety. We attempted to characterize and quantify driving risk in patients with seizures (PWS). METHODS: We delivered 12-question surveys to 287 consecutive PWS at an epilepsy clinic in Florida. Illegal and disobedient driving practices were analyzed. RESULTS: Eighty-three of 236 (35.2%) PWS were eligible to drive and 62.3% were ineligible with a seizure in Language: en
Selective Determination of Adenine-Containing Compounds by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

Abstract Capillary electrophoresis coupled with laser-induced fluorescence detection provides a selective analysis of mixtures of adenine-containing compounds (adenine, adenosine, cAMP, AMP, ADP, and ATP) that are derivatized using chloroacetaldehyde as a fluorogenic reagent. The components can be detected with linear response over the concentration range of 10 −4 to 10 −9 M, and the detection limit corresponds to 5 to 10 × 10 −19 mol for each nucleotide. Analysis is achieved in less than 10 min with high separation efficiencies (up to 400,000 theoretical plates) and chows good reproducibility for migration times (0.5 to 1.0%) and peak heights (2.8 to 7.7%). To demonstrate the rapid analysis of small-volume samples, the adenine-containing compounds present in an oocyte from Xenopus laevis are determined.
Recent progress in Alzheimer's disease: animal models lead the way

Alzheimer's disease (AD) is a worldwide major public health problem. Much recent research has focused on amyloid precursor protein (APP), the secretase enzymes that cleave APP to generate Aβ peptides, and the roles of these peptides in neurotoxicity. Specifically, there has been great interest in the pathogenic role of Aβ peptide oligomers and influences of apoE4 and other Aβ clearance enzymes on Aβ amyloidosis. Genetically engineered animal models are a central tool for studies into the disease mechanisms and for testing experimental therapeutics.
Two-dimensional polar format algorithm for high-quality radar image formation

An effective two-dimensional polar format algorithm based on the circular sampling theorem is implemented and tested. The algorithm interpolates samples from a polar to a rectangular raster for the purpose of focusing ISAR imager. The imagery are generated from samples collected in the frequency space utilizing a uniform polar set of coordinates. An example of an extended target is offered to show the versatility of the algorithm. In addition, a point target model is used to test its effectiveness. The distortion introduced by interpolation is calculated and compared to errors introduced by two standard interpolation techniques. Experimental data provided by the Pacific Missile Test Center was used to test the proposed algorithm.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Origin of the Bear Gulch Beds (Namurian, Montana, USA)

Abstract The Bear Gulch Beds of the Heath Formation are well known for their diverse and well-preserved assemblage offish, arthropods, and soft-bodied animals (they constitute a Lagerstatte). The Bear Gulch is a lens of lithographic limestone (approximately 12 km in lateral extent and up to 30 m thick) surrounded by black, platy shale. The lens is composed primarily of alternating massive beds (up to 25 cm thick) and argillaceous platy beds (up to 30 cm thick). Platy and massive beds are both composed primarily of normally graded laminations (1–15 mm thick). Laminations typically have sharp bases and grade upward from microspar to micrite. Lateral continuity of individual beds (at least 1 km) and laminations (at least 500 m), lack of evidence of bottom currents, and paucity of erosional features all suggest a quiet-water environment. Fossils are generally rare in the Bear Gulch Beds. The most common fossils in most beds are cephalopods, shrimp, fish, and soft-bodied organisms. Rare beds contain abundant benthic fossils including brachiopods, sponges, bivalves, conulariids, and crinoids. Fish preservation ranges from completely articulated with traces of internal organs and preserved color patterns to completely disarticulated, however most fish are well preserved. Fish and shrimp occur at the boundaries between laminations. Preservational quality of fossils and presence of abundant dewatering structures suggest rapid deposition. Lack of normal-marine shelly fossils in most beds may indicate stressful conditions at the seafloor, however some fish and shrimp were apparently well adapted for a benthic habitat. No evidence of current-modified fish debris has been observed and only rarely are fish aligned on a single bedding plane. Conditions at the seafloor were calm, possibly inhospitable, but frequently disturbed by rapid depositional events. The mechanism of deposition of the laminations remains enigmatic.
Heterologous expression and characterization of a "Pseudomature" form of taxadiene synthase involved in paclitaxel (Taxol) biosynthesis and evaluation of a potential intermediate and inhibitors of the multistep diterpene cyclization reaction.

The diterpene cyclase taxadiene synthase from yew (Taxus) species transforms geranylgeranyl diphosphate to taxa-4(5),11(12)-diene as the first committed step in the biosynthesis of the anti-cancer drug Taxol. Taxadiene synthase is translated as a preprotein bearing an N-terminal targeting sequence for localization to and processing in the plastids. Overexpression of the full-length preprotein in Escherichia coli and purification are compromised by host codon usage, inclusion body formation, and association with host chaperones, and the preprotein is catalytically impaired. Since the transit peptide-mature enzyme cleavage site could not be determined directly, a series of N-terminally truncated enzymes was created by expression of the corresponding cDNAs from a suitable vector, and each was purified and kinetically evaluated. Deletion of up to 79 residues yielded functional protein; however, deletion of 93 or more amino acids resulted in complete elimination of activity, implying a structural or catalytic role for the amino terminus. The pseudomature form of taxadiene synthase having 60 amino acids deleted from the preprotein was found to be superior with respect to level of expression, ease of purification, solubility, stability, and catalytic activity with kinetics comparable to the native enzyme. In addition to the major product, taxa-4(5),11(12)-diene (94%), this enzyme produces a small amount of the isomeric taxa-4(20), 11(12)-diene ( approximately 5%), and a product tentatively identified as verticillene ( approximately 1%). Isotopically sensitive branching experiments utilizing (4R)-[4-(2)H(1)]geranylgeranyl diphosphate confirmed that the two taxadiene isomers, and a third (taxa-3(4),11(12)-diene), are derived from the same intermediate taxenyl C4-carbocation. These results, along with the failure of the enzyme to utilize 2, 7-cyclogeranylgeranyl diphosphate as an alternate substrate, indicate that the reaction proceeds by initial ionization of the diphosphate ester and macrocyclization to the verticillyl intermediate, followed by a secondary cyclization to the taxenyl cation and deprotonation (i.e., formation of the A-ring prior to B/C-ring closure). Two potential mechanism-based inhibitors were tested with recombinant taxadiene synthase but neither provided time-dependent inactivation nor afforded more than modest competitive inhibition.
AAAS Forum on Science & Technology Policy: Largest Attendance Ever in 2009

Purpose – The purpose of this paper is to report on The American Association for the Advancement of Science (AAAS)'s 34th Annual Forum on Science and Technology Policy, held at the Ronald Reagan Building in Washington, DC on 30 April and l May 2009.Design/methodology/approach – This is a descriptive report.Findings – The attendance this year was the largest ever. The thrust was money – government expenditures for science and technology/project/subjects. Other topics in the program included: grant‐seeking processes, trust in science, science journalism and scientific literacy.Originality/value – The Forum on Science and Technology Policy is of particular interest to those involved in public policy issues facing the science, engineering and higher education communities.
Survey for Meningeal Worm (Parelaphostrongylus tenuis) and Ear Mites in White-tailed Deer from Northern Idaho

During the fall hunting season of 1990, 95 white-tailed deer (Odocoileus Virginianus) heads were collected from hunters in Boundary and Bonner Counties in northern Idaho (USA), an area currently occupied by woodland caribou (Rangifer tarandus caribou). The heads were examined for adult and larval meningeal worms (Parelaphostrongylus tenuis) by physical examination of the brain surfaces, and the Baermann technique, respectively, and for ear mites by examination of ear scrapings. Meningeal worms or mites were not detected.
Effect of chronic administration of ethanol on the regulation of tyrosine kinase phosphorylation of the GABAA receptor subunits in the rat brain.

One of the many pharmacological targets of ethanol is the GABA inhibitory system, and chronic ethanol (CE) is known to alter the polypeptide levels of the GABAA receptor subunits in rat brain regions. In the present study, we investigated the regulation of the tyrosine kinase phosphorylation of the GABAA receptor α1-, β2- and γ2-subunits in the rat cerebellum, cerebral cortex and hippocampus following chronic administration of ethanol to the rats. We observed either down-regulation or no change in the tyrosine kinase phosphorylation of the α1 subunit, whereas there was an up-regulation or no change in the case of β2- and γ2-subunits of the GABAA receptors depending on the brain region following chronic administration of ethanol to the rats. These changes reverted back to the control level following 48 h of ethanol-withdrawal. These results suggest that tyrosine kinase phosphorylation of GABAA receptors may play a significant role in ethanol dependence.
Dispositional Resiliency and Adjustment in Protestant Pastors: A Pilot Study

Several studies of pastoral adjustment have examined sources of stress and support. This pilot study, drawing upon a positive psychological perspective of resilience, examined the role of dispositional hope and gratitude in coping with the demands of ministry. A non-random sample of 24 pastors completed online surveys containing measures of congregational demand and support, hope and gratitude, and pastoral well-being and adjustment. As expected, demand was negatively associated with adjustment, while gratitude was positively associated. Regression analyses suggested that gratitude is the more salient variable.
HOSPITAL COSTS PER SURVIVOR FOR INBORN INFANTS AT 24-26 WEEKS OF GESTATION.• 1443

Survival among the least mature liveborn infants continues to increase. Currently, with adequate intensive care, more babies born between 24 & 26 weeks gestational age (GA) can survive and be healthy. A cost related question, still unanswered, is “How much is too much?” The aim of this study is to establish the current hospital costs and the cost to produce a survivor (cost per survivor= cost/surv.) among inborn infants delivered at 24, 25 & 26 wks GA. Between 1/90 & 12/94 we admitted to ICN 134 infants born at our Institution with GA 24-26 weeks. GA was assigned by early ultrasound, dates & neonatal exam; doubtful cases were solved by two investigators. We obtained hospital charges for each baby from the computerized hospital billing system. To calculate hospital costs for each year we multiplied the charges by the corresponding institutional cost-charge ratio (HCFA). These costs were converted into 1994 dollars ($). Seven babies(2 born @ 24 wks, 4 @ 25 wks and 1 @ 26wks) were excluded due to incomplete billing information (all 7 died at <72 hs of age). Hospital costs for all 127 babies were $19.35 million (Mi). Other data is shown intable: For infants 24-26 GA, the estimated total cost(hospital costs + professional fees) to produce a survivor is approximately$250,000. However, the cost per survivor for infants born at 24 wks GA is significantly higher than the one for babies born with one more week of GA and is very close to the cost per survivor we reported for babies with congenital diaphragmatic hernia treated with ECMO (J Ped Surg, 30:226, 1995). These data provides information about the economic impact of extreme prematurity and emphasizes the importance of prolonging gestation to at least 25 weeks.
Decreased interleukin-18 response in asthmatic children with severe Mycoplasma pneumoniae pneumonia

Abstract Purpose Mycoplasma pneumoniae ( M. pneumoniae ) is a common causative agent of pneumonia in children. The aim of this study is to determine whether there is any difference in selected cytokine or chemokines response in asthmatic children compared to non-asthmatic children during acute M. pneumoniae pneumonia. Methods Seventy-five children, 6–12 years of age, admitted with M. pneumoniae pneumonia were enrolled. Two patient groups were defined: the children with known asthma ( N = 40) and non-asthmatic children ( N = 35). Interleukin (IL)-18 and selected chemokines, IL-8, CXCL9, CXCL10, and regulation upon activation normal T-cell expressed and secreted (RANTES) were measured by means of ELISA in the plasma samples of the patients collected on admission. We investigated the values of these mediators in relation to the asthma status and symptom severity of the patients. Twenty age-matched, non-infected controls were also studied. Results Plasma levels of IL-18 and the chemokines increased significantly in the patients with M. pneumoniae pneumonia compared to non-infected, age-matched controls ( P P P P Conclusions Our study suggests that IL-18 and the chemokines are importantly involved in the pathogenesis of M. pneumoniae pneumonia. It also indicates that some asthmatic children have deficient IL-18 response when affected by M. pneumoniae pneumonia, which might be associated with more severe pneumonia observed in this group of patients.
Demographics, pharmacoeconomics, assessment, and treatment of pain in the elderly.

The burden of pain in the elderly population of our society is observed by the greater numbers of the aged who suffer from pain as compared to their younger counterparts. The elderly present difficult challenges for pain clinicians in terms of the ability to assess for pain, amid other medical and pain problems, due to cognitive, sensory, and functional impairment. Treatment with pharmaceuticals may be altered by the impact of aging. Finally, the elderly suffer financial restraints that often prevent optimal treatment of pain even if pain is identified. Principles of pain management in the elderly are reviewed in the context of special attention to assessment tools for the elderly, the evaluation of comorbid factors in the presentation of pain, and pharmacokinetic/pharmacodynamic concerns in the aging. Pharmacologic and nonpharmacologic treatment strategies are described relative to the elder.
A conic manifold perspective of elliptic operators on graphs

We give a simple, explicit, sufficient condition for the existence of a sector of minimal growth for second-order regular singular differential operators on graphs. We specifically consider operators with a singular potential of Coulomb type and base our analysis on the theory of elliptic cone operators.
Correlation of left atrial appendage histopathology, cardiac rhythm and response to maze procedure in patients undergoing surgery for rheumatic valvular heart disease

Introduction All patients with atrial fibrillation (AF) do not revert to sinus rhythm (SR) with hemodynamic correction and procedures to restore SR. We co-relate left atrial appendage (LAA) histopathology and cardiac rhythm, and its response to maze procedure, in patients undergoing surgery for rheumatic valvular heart disease.
Identification of a novel OCT1 binding site that is necessary for the elaboration of pulses of rat GnRH promoter activity

Abstract Recent evidence from our laboratory demonstrated that the OCT1 protein was necessary for GnRH gene promoter pulse activity through its interaction with a specific OCT1 binding site (OCT1BS-a, −1774/−1781). In light of the importance of this POU homeoprotein in pulsatile function, we focused on two other highly conserved OCT1 sites within this region, OCT1BS-b (−1694/−1701, previously AT-b), and OCT1BS-c (−1569/−1562). Mutagenesis of these sites revealed that alteration of OCT1BS-c, but not OCT1BS-b, virtually abolished gene expression pulses in GT1-7 cells. EMSAs confirmed that OCT1 can bind to both sites. Taken together, our findings demonstrate clearly that more than one Oct1 binding site is necessary for GnRH promoter pulses. Moreover, the lack of an influence observed with OCT1BS-b on pulse activity indicates that OCT1 action is not general to all OCT1 sites, but specific to certain octamer sequences in the NSE region of the GnRH promoter.
Effects of parallel electron dynamics on plasma blob transport

The 3D effects on sheath connected plasma blobs that result from parallel electron dynamics are studied by allowing for the variation of blob density and potential along the magnetic field line and using collisional Ohm’s law to model the parallel current density. The parallel current density from linear sheath theory, typically used in the 2D model, is implemented as parallel boundary conditions. This model includes electrostatic 3D effects, such as resistive drift waves and blob spinning, while retaining all of the fundamental 2D physics of sheath connected plasma blobs. If the growth time of unstable drift waves is comparable to the 2D advection time scale of the blob, then the blob’s density gradient will be depleted resulting in a much more diffusive blob with little radial motion. Furthermore, blob profiles that are initially varying along the field line drive the potential to a Boltzmann relation that spins the blob and thereby acts as an addition sink of the 2D potential. Basic dimensionless param...
On the expected optimal value and the optimal expected value

Abstract Approaches to stochastic optimization have followed a variety of modeling philosophies, but little has been done to systematically compare different models found in the literature. This article is concerned with the basic concepts (and a comparison between them) underlying optimality under uncertainty, which is ubiquitous in all realistic problems of science and engineering. Specifically, it discusses two basic ideas—the minimum (maximum) expected value criterion and the expected minimum (maximum) value criterion—in a theoretical context. Illustrative applications are presented to justify the theoretical results.
A general model of intra-annual tree growth using dendrometer bands

Tree growth is an important indicator of forest health, productivity, and demography. Knowing precisely how trees' grow within a year, instead of across years, can lead to a finer understanding of the mechanisms that drive these larger patterns. The growing use of dendrometer bands in research forests has only rarely been used to measure growth at resolutions finer than yearly, but intra-annual growth patterns can be observed from dendrometer bands using precision digital calipers and weekly measurements. Here we present a workflow to help forest ecologists fit growth models to intra-annual measurements using standard optimization functions provided by the R platform. We explain our protocol, test uncertainty in parameter estimates with respect to sample sizes, extend the optimization protocol to estimate robust lower and upper annual diameter bounds, and discuss potential challenges to optimal fits. We offer R code to implement this workflow. We found that starting values and initial optimization routines are critical to fitting the best functional forms. After using a bounded, broad search method, a more focused search algorithm obtained consistent results. To estimate starting and ending annual diameters, we combined the growth function with early and late estimates of beginning and ending growth. Once we fit the functions, we present extension algorithms that estimate periodic reductions in growth, total growth, and present a method of controlling for the shifting allocation to girth during the growth season. We demonstrate that with these extensions, an analysis of growth response to weather (e.g., the water available to a tree) can be derived in a way that is comparable across trees, years, and sites. Thus, this approach, when applied across broader data sets, offers a pathway to build inference about the effects of seasonal weather on growth, size- and light-dependent patterns of growth, species-specific patterns, and phenology.