cssi/SciSciGPT-SciSciNet huggingface dataset:
Determination of ephedrine hydrochloride in mixtures of ephedrine hydrochloride and pseudoephedrine hydrochloride using near infrared spectroscopy

There are a number of situations where there is a need to determine the concentrations of components in solid-state mixtures without dissolving the samples. The experiments described here were designed to demonstrate that diffuse refl ectance near infrared spectroscopy coupled with partial least squares (PLS) data analysis can be used to determine the minor component in a mixture of structurally-similar solid-state compounds, in this case mixtures of ephedrine hydrochloride and pseudoephedrine hydrochloride. It is shown that when care is taken to produce homogeneous calibration samples very good results can be obtained; in this case, crossvalidated standard error of predictions of 2.30 wt% when the minor component spanned the concentration range of 0 to 50 wt% and 0.30 wt% when the minor component spanned the concentration range of 0 to 5 wt%. Results are presented that indicate that the amount of data available to the PLS calibration routine relative to the range over which the calibration is performed can limit the precision and accuracy of the determinations.
Anatomy of a regional mass extinction; Plio-Pleistocene decimation of the western Atlantic bivalve fauna

The Early Pliocene marine faunas of the southeastern United States were distinct from those of the Bahamas and Caribbean, apparently being separatedfrom them by a zone of cool upwelling. Study of the fates of 361 Early Pliocene bivalve species reveals that a regional mass extinction occurred in the Eastern United States beginning in Late Pliocene time, when continental glaciers expanded, and continued into Early Pleistocene time, eliminating perhaps as many as 65% of the Early Pliocene species. Several patterns suggest that refrigeration during intervals of glacial expansion was the primary cause. The 57 bivalve species that have survivedfrom the tropical zone of Florida all range into nontropical zones today: the mass extinction operated as a thermal filter, eliminating all purely tropical species. Endemic Early Pliocene species experienced especially low survivorship (15%7o) and most of the casualities of these stenothermal forms came early, in Late Pliocene time. A larger percentage of eurythermal Early Pliocene species survived; and most of those that did not, died out relatively late, during cold Early Pleistocene glacial intervals when even Florida became nontropical. Several observations oppose the hypothesis that Pleistocene regressions would have caused heavy extinction even in the absence of refrigeration. Among these are (1) the fact that in the Eastern Pacific Pleistocene extinction was weak even for species endemic to the temperate-warm temperate shelf, which was areally smaller than the shelf of the southeastern United States, and (2) the fact that even Western Atlantic species that were small, abundant, and adapted to muddy conditions suffered heavy losses.
Conception rates. 1. Derivation and estimates for effects of estrus detection on cow profitability.

Objectives were to derive equations and obtain estimates per cow of days to conception, milk production, semen purchases, calvings, and reproductive failures based on the probability of estrus detection and AI conception. The net benefits of changing rates of estrus detection, including changes in milk production, semen purchases, and replacement inventories (culled cows and calves) were converted to annual values and multiplied by fixed prices to obtain estimates of the annual financial benefit of a change in rates of estrus detection. Improvement in milk production because of a 1-d decrease in DIM at conception was dependent on DIM, peak milk production, and monthly rate of decline in daily milk production. Variation was considerable in expected benefits of improved estrus detection. Under the assumption that replacement was not planned prior to breeding (in which case improved estrus detection would have no value), estimated financial benefits for increasing the probability of estrus detection from 60 to 70% with a 70% AI conception rate were $6/yr; increasing from 20 to 30% the rate of estrus detection with a 50% AI conception rate increased estimated annual benefits to $83. This wide range of values occurred with fixed costs and prices so that fluctuating prices would introduce further variation in financial benefits. Derived equations allow point estimates of expected benefits with input values estimated.
Diagnostic and therapeutic applications of azulenyl nitrone spin traps

Azulenyl nitrones have been recently demonstrated to constitute a new class of nitrone-based spin traps with the unprecedented capacity to tag free radicals by yielding characteristically colored and highly visible diamagnetic (and paramagnetic) spin adducts. In addition, a comparison of the oxidation potentials of azulenyl nitrones such as 1 and congeners to those of conventional nitrone spin traps previously investigated as potential antioxidant therapeutics such as N-tert-butyl-alpha-phenylnitrone and its related ortho-sodium sulfonate reveals that the azulene-derived spin traps are far more readily oxidized. These special features render azulenyl nitrones of interest with regard to both their distinct ability to engender the convenient use of colorimetric detection to monitor free radical-mediated oxidative stress in biological systems, and to their potentially enhanced efficacy as neuroprotective antioxidants vs. those conventional nitrone spin traps earlier examined as such. Herein is reported an overview of recent developments pertaining to the use of azulenyl nitrones in the detection of oxidative stress in animal models of amyotrophic lateral sclerosis and stroke, and to their neuroprotective activity in animal models of Parkinson's disease, stroke and neurodegeneration within the retina.
Porous Alumina Protective Coatings on Palladium Nanoparticles by Self-Poisoned Atomic Layer Deposition

Atomic layer deposition (ALD) of Al2O3 using trimethylaluminum (TMA) and water on Pd nanoparticles (NPs) was studied by combining in situ quartz crystal microbalance (QCM) measurements, in situ quadrupole mass spectrometry (QMS), and transmission electron microscopy (TEM) with density functional theory (DFT) calculations. TEM images of the ALD Al2O3 overcoated Pd showed conformal Al2O3 films on the Pd NPs as expected for ALD. However, hydrogen detected by in situ QMS during the water pulses suggested that the ALD Al2O3 films on the Pd NPs were porous rather than being continuous coatings. Additional in situ QCM and QMS measurements indicated that Al2O3 ALD on Pd NPs proceeds by a self-poisoning, self- cleaning process. To evaluate this possibility, DFT calculations were performed on Pd(111) and Pd(211) as idealized Pd NP surfaces. These calculations determined that the TMA and water reactions are thermodynamically favored on the stepped Pd(211) surface, consistent with previous observations. Furthermore, the DFT studies identified methylaluminum (AlCH3*, where the asterisk designates a surface species) as the most stable intermediate on Pd surfaces following the TMA exposures, and that AlCH3* transforms into Al(OH)3* species during the subsequent water pulse. The gas phase products observed using in situ QMS support this TMA dissociation/hydration mechanism. Taken together, the DFT and experimental results suggest a process in which the Pd surface becomes poisoned by adsorbed CH3* species during the TMA exposures that prevent the formation of a complete monolayer of adsorbed Al species. During the subsequent H2O exposures, the Pd surface is cleaned of CH3* species, and the net result is a porous Al2O3 film. This porous structure can retain the catalytic activity of the Pd NPs by providing reagent gases with access to the Pd surface sites, suggesting a promising route to stabilize active Pd catalysts.
Switch mode power supplies: an EMI engineer's point of view

Almost every electronic device requires some level of power conversion in which the required operational voltages are generated from the input power. The majority of these supplies consist of Switch Mode Power Supplies (SMPS) which all operate on the same basic principles (Lent's Law) but can take on several different design topologies. The downfall of this small and efficient power conversion source is that it can be a primary RF noise source. Radiated and conducted emissions from SMPS have been the source of many failures during certification testing (FCC, VDE, and 461). To effectively solve this problem the responsible person has to have a certain level of understanding of SMPS. As an EMI Design engineer responsible for EMI filter design and testing, the author has recently been involved with several different design topologies as well as voltage/current requirements and shares some observations concerning the different designs. The discussion starts with a short introduction on SMPS and then progresses into the important aspects of an EMI filter design process. From this discussion the author hopes to provide the reader with the understanding of SMPS design required to effectively design an EMI filter.
Robotic hand biomimicry: The effect of finger force and position abduction feedback during contour interaction

The joint motion profiles of 10 human test subjects were recorded as they ran their hands over a flat surface and a convex surface. From this data, three controllers for a dexterous robotic hand were developed to mimic this behavior. Specifically, this work examines the role of finger abduction force and position feedback to motors that control finger extension. Experimental results show the biomimetic controller that uses both abduction force and position feedback within the controllers for finger extension successfully approximates human motion. Further, this controller reduces joint torques and oscillations that occur during contour interaction.
High altitudes, anxiety, and panic attacks: is there a relationship?

People exposed to high altitudes often experience somatic symptoms triggered by hypoxia, such as breathlessness, palpitations, dizziness, headache, and insomnia. Most of the symptoms are identical to those reported in panic attacks or severe anxiety. Potential causal links between adaptation to altitude and anxiety are apparent in all three leading models of panic, namely, hyperventilation (hypoxia leads to hypocapnia), suffocation false alarms (hypoxia counteracted to some extent by hypocapnia), and cognitive misinterpretations (symptoms from hypoxia and hypocapnia interpreted as dangerous). Furthermore, exposure to high altitudes produces respiratory disturbances during sleep in normals similar to those in panic disorder at low altitudes. In spite of these connections and their clinical importance, evidence for precipitation of panic attacks or more gradual increases in anxiety during altitude exposure is meager. We suggest some improvements that could be made in the design of future studies, possible tests of some of the theoretical causal links, and possible treatment applications, such as systematic exposure of panic patients to high altitude.
Some Field Methods in Medical Ethnobiology

The authors provide a summary of methods that they have used in their long-term interdisciplinary research that incorporates a series of semi-independent, complementary methods of data collection d...
Transplantation: All for one and one for all--alloimmunization and polyreactivity.

In a new study, Porcheray et al. provide evidence that a single antibody generated by alloimmunization can recognize multiple antigens in a paradigm-changing fashion. Although these results require confirmation, the presence of polyreactive antibody may offer an explanation as to why some patients with a single sensitizing event develop a wide breadth of panel-reactive antibody.
H2M- and MHC class II recycling-independent loading of a hemagglutinin-derived epitope

Abstract Background: Helper T Cells are stimulated by antigenic peptides (epitopes) displayed at the cell surface by major histocompatibility complex (MHC) class II molecules. Thus far, two pathways for peptide loading have been defined. The first requires the participation of a chaperonin-like protein, H2M but not the ability of class II molecules to traffic from the cell surface to early endosomes. The second is the reverse in not requiring H2M expression but requiring class II internalization. The studies described here were undertaken to test the hypothesis that loading of an epitope, termed S3, within the A/PR/8/34 influenza (PR8) hemagglutinin (HA) molecule is via this second pathway, as we previously determined its presentation to be H2M-independent. Methods: Genes encoding the α and β chains of the murine I-Ed class II molecule were truncated to remove putative internalization motifs in the cytosolic tails. Loss of internalization was confirmed by confocal immunofluorescence microscopy. COS cells were transiently transfected with wild-type or truncated genes and tested for the ability to present the S3 epitope to an S3-specific T cell hybridoma that expresses β-galactosidase upon activation. Results: Removal of the recycling motif had no discernable impact upon the presentation of S3. Conclusions: Results suggest the existence of a third route of class II-restricted antigen processing, one that requires neither H2M expression nor class II recycling. Future experiments are aimed at further defining this pathway.
Law and Economics—Valuable but Controversial

On 15 October 1991 the Royal Swedish Academy of Sciences awarded Ronald Coase the Nobel Prize in Economics for his pioneering work on transaction costs and property rights. Undoubtedly, Coase's 1960 article "The Problem of Social Cost"' was the single most important element that led to the Nobel Committee's decision. This article, together with Guido Calabresi's "Some Thoughts on Risk Distribution and the Law of Torts"2 and some early work by Richard Posner, can be looked on as the beginning of Law and Economics as an independent, specialized field of intellectual inquiry. While economists before that time had been interested in such issues as monopoly and antitrust law as well as various forms of business regulation, the interaction between law and economics was quite haphazard. Coase, Calabresi, and Posner more than anyone else are responsible for a more formalized and systematic effort in Law and Economics.
Grafting of model primary amine compounds to cellulose nanowhiskers through periodate oxidation

This study demonstrates regioselective oxidation of cellulose nanowhiskers using 2.80–10.02 mmols of sodium periodate per 5 g of whiskers followed by grafting with methyl and butyl amines through a Schiff base reaction to obtain their amine derivatives in 80–90 % yield. We found a corresponding increase in carbonyl content (0.06–0.14 mmols/g) of the dialdehyde cellulose nanowhiskers with the increase in oxidant as measured by titrimetric analysis and this was further evidenced by FT-IR spectroscopy. Grafting of amine compounds to the oxidized cellulose nanowhiskers resulted in their amine derivatives, which are found to be partially soluble in DMSO. Therefore, the reduction reaction between amines and carbonyl groups was confirmed through 13C NMR spectra, which was also supported by copper titration, XPS, and FT-IR spectroscopy. Morphological integrity and crystallinity of the nanowhiskers was maintained after the chemical modification as studied by AFM and solid-state 13C NMR, respectively.
Sampling frequency impacts measurement of walking activity after stroke.

Abstract The purpose of this study was to examine the effect of sampling epoch on total time spent walking and number of walking bouts/day in persons with stroke. 98 persons post-stroke with average age of 63.8±10.3 years and 43.6±58.1 months post-stroke participated in this study. Participants wore a StepWatch Activity Monitor (SAM) for 3–5 consecutive days. The number of strides taken was collected in consecutive 5 second epochs and down sampled into 10, 20, 30, and 60 second epochs. Total time walking and total number of walking bouts were determined for each day. Low and high activity days were determined as days below and above the 25 th and 75 th percentile of total steps/day, respectively. Total time walking and total number of bouts were different for each sampling epoch (p<0.001 for all). The 5 second sampling epoch resulted in calculation of ~40% of the walking time and ~6 times as many bouts as a 60 second sampling epoch. Differences were greater for low activity days (p<0.001 for all). Sampling epoch affects the calculation of daily step activity variables whose calculation depends on time, especially during low activity days. Sampling epoch must be carefully considered when designing studies aimed at understanding patterns of daily walking activity.KeywordsAmbulation; CVA; Hemiparesis; Hemiplegia; Locomotor activity; Neurological Disorders; Physical activity; Physical exercise; Stroke; Walking
Bus automata, brains, and mental models

The author suggests that bus automata (BAs) may serve as better brain models than sequential computers of cellular automata. He proposes to view self-simulationability, together with the use of status flags and the like, as a primitive model of self-consciousness, analogous to viewing a regulator as exhibiting rudimentary purposive behavior. A discussion of what meanings might be ascribed in a BA context to terms like intelligence, pattern, theory, and meaning itself is also given. It is concluded that the BA-UTM (universal Turing machine) is a promising candidate for a brain model whose operation may actually be relevant to mental processes. Prospects for actual BA-UTM realization are briefly discussed. >
The practice of clinical pathology: a quantitative description of laboratory director activities at a large academic medical center.

Objectives The scope of activities performed by clinical laboratory directors is sometimes unfamiliar to other physicians or hospital administrators. Consequently, hospital leadership may undervalue the role and assume that many director level activities could be delegated to a professional manager. In this study, we sought to define the activities of academic laboratory directors, and to determine which activities require doctorate level medical or scientific expertise. Methods We performed an audit of laboratory director activities at a large academic medical center by reviewing electronic calendars and other available records from the preceding 12 consecutive months. For episodic activities, the directors estimated the average number of hours devoted over the 1-year period. Results On average, directors worked 54.9 hours per week and performed at least some service work 47.7 weeks per year. Administrative duties accounted for the greatest proportion of effort (47.1%), followed by clinical activities (33.1%) and academic activities (19.8%). Among administrative duties, those that required doctorate level medical or scientific expertise comprised 60.3% of the total administrative effort, whereas the remaining 39.7% (18.7% of total activity) could be performed by a professional manager.. Conclusions Although the activities of clinical laboratory directors have been described elsewhere, this is the first study detailing the effort allocated to these various activities in quantitative terms. The study demonstrated that less than 20% of an academic laboratory director's effort involves administrative activities that could potentially be performed by a professional manager lacking doctorate level medical or scientific expertise.
Understanding Gene Expression Heterogeneity in Living Cells with Single-Molecule Fluorescence Microscopy

Gene expression refers to the sum of processes that enable cells to control their complement of RNA, and the study of gene expression has been spurred by genome-wide techniques such as microarrays and chromatin immunoprecipitation. Placing these data within a cellular context to reveal the underlying mechanisms of gene regulation has been a central challenge in the field of systems biology. In recent years, through parallel advances in microscopy, fluorescent probe development, and computational modeling, it has become possible to describe gene expression in a fundamentally different way: one can now directly observe single molecules of RNA in living and fixed cells using the fluorescence microscope. In this talk, I will describe the use of this single-molecule approach to study transcription kinetics of the GAL10 locus in budding yeast, which is regulated by sugar availability. Transcription is observed to occur in bursts of high activity followed by periods of inactivity, each lasting several minutes. This stochastic, punctate behavior results in ‘noise’ in gene expression and is not visible in population studies, which instead give the impression of a gradual response to sugar availability. I will describe recent results on the role of non-coding RNA in transcriptional regulation. Genomic data indicates that eukaryotic genomes are ubiquitously transcribed, but the function of these RNAs is largely unknown. Our results indicate that noncoding RNA displays different behavior during repression and activation, suggesting multiple roles, even at the same locus.
Heterologous desensitization of β-adrenoceptor signal transduction in vivo

Abstract The hemodynamic actions of pituitary adenylate cyclase-activating polypeptide (PACAP-27) rapidly diminish upon repeated i.v. injection in rats treated with the nitric oxide synthase inhibitor, N G -nitro- l -arginine methyl ester ( l -NAME). We now report that the β-adrenoceptor agonist isoproterenol (0.5 μg/kg, i.v.) produces pronounced hypotensive and vasodilator effects in anesthetized rats pretreated with l -NAME (100 μmol/kg, i.v.). However, the hypotensive and vasodilator actions of isoproterenol were markedly diminished in l -NAME-treated rats in which tachyphylaxis to PACAP was induced immediately prior to the injection of the β-adrenoceptor agonist. This suggests that a reduction in tissue concentrations of nitric oxide-containing factors allows tachyphylaxis to PACAP-27-mediated vasodilation to occur in vivo and that this process leads to the heterologous desensitization of β-adrenoceptor-mediated responses.
Operational infrastructure for a clinical PACS

Current and future operational requirements that support a picture archiving and communication system that manages filmless digital modality images are described.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Collagen and glycosaminoglycans in cell adhesion

Abstract Human skin fibroblasts plated in medium (DMEM+10% fetal calf serum, FCS) containing active bacterial collagenase, chondroitinase ABC, and streptomyces hyaluronidase; and controls without the enzymes attach and spread equally well on plastic culture dishes. This observation suggests that collagen and glycosaminoglycans degraded by the enzymes, either separately or in combination with one another, are not necessary components in the early attachment and spreading of human skin fibroblasts on plastic.
Comparing Canonical Correlation Analysis with Partial Least Squares Regression in Estimating Forest Leaf Area Index with Multitemporal Landsat TM Imagery

The leaf area index (LAI) of plant canopies is an important structural variable for assessing terrestrial ecosystems. This research examined the use of multitemporal Landsat TM imagery to estimate and map LAI in mixed natural forests in the southeastern USA. The performances of canonical correlation analysis (CCA) and partial least squares (PLS) regression techniques were evaluated for feature extraction to estimate forest LAI. The experimental results indicate that use of multitemporal TM imagery can improve the accuracy of estimating the forest LAI, and that CCA analysis outperforms PLS regression for feature extraction.
Reservoir sizing using inert and chemically reacting tracers

Non-reactive tracer tests in prototype hot dry rock (HDR) geothermal reservoirs indicate multiple fracture flow paths that show increases in volume due to energy extraction. Tracer modal volumes correlate roughly with estimated reservoir heat-transfer capacity. Chemically reactive tracers are proposed which will map the rate of advance of the cooled region of an HDR reservoir, providing advanced warning of thermal drawdown. Critical parameters are examined using a simplified reservoir model for screening purposes. Hydrolysis reactions are a promising class of reactions for this purpose.
Analysis of the measurement of polarization-shaped ultrashort laser pulses by tomographic ultrafast retrieval of transverse light E fields

We consider in detail the technique of tomographic ultrafast retrieval of transverse light E fields (TURTLE) for measuring the evolution of an arbitrary, potentially complex, and ultrashort laser pulse's intensity-and-phase and polarization-state evolutions in time. TURTLE involves making three ultrashort-pulse measurements using established single-polarization pulse-measurement techniques. Two of the measurements are of the pulse's orthogonal linear polarizations (e.g., horizontal and vertical) and the third occurs for an arbitrary additional polarization angle (e.g., 45°). If the field projections are measured using second-harmonic-generation frequency-resolved optical gating, we demonstrate that a simple optimization can accurately and reliably retrieve the time-dependent polarization state, even for very complex polarization-shaped pulses.
A method for measuring the time structure of synchrotron X-ray beams

Abstract We described a method employing a plastic scintillator coupled to a fast photomultiplier tube to generate a timing pulse from the X-ray bursts emitted from a synchrotron radiation source. This technique is useful for performing synchrotron experiments where detailed knowledge of the timing distribution is necessary, such as time-resolved spectroscopy or fluorescence lifetime experiments. By digitizing the time difference between the timing signal generated on one beam crossing with the timing signal generated on the next beam crossing, the time structure of a synchrotron beam can be analyzed. Using this technique, we have investigated the single-bunch time structure at the National Synchrotron Light Source (NSLS) during pilot runs in January 1989, and found that the majority of the beam (96%) is contained in one rf bucket, while the remainder of the beam (4%) is contained in satellite rf buckets preceding and following the main rf bucket by 19 ns.
Ki-67 Expression in a Cervical Cancer Organotypic Model Correlates with Growth and EGF-R Expression.

:Objective. The study objective was to measure the effects of retinoid treatment on Ki-67 expression in a cervical carcinoma organotypic culture model and to determine whether a correlation exists between retinoid effects on Ki-67 expression and effects on growth and epidermal growth factor receptor (EGF-R) expression. Methods. Organotypic cultures of the cervical carcinoma cell line were treated for 7 days with all-trans retinoic acid, 9-cis retinoic acid, or control solvent. Cultures were fixed and embedded in paraffin, and sections were stained with Ki-67 antibodies. Ki-67 expression was determined by light microscopy. Results. Ki-67 expression was inhibited 25% in the organotypic culture treated with 9-cis retinoic acid and 32% in the culture treated with all-trans retinoic acid. Previous data demonstrated a 45% and 44% inhibition of EGF-R expression and a 49% and 63% inhibition of growth, respectively. Discussion. The inhibition of Ki-67 expression by retinoids correlates with inhibition of EGF-R expression and growth as determined by a Pearson correlation (R = 0.88). Inhibition of Ki-67 and EGF-R demonstrates quantifiable effects of retinoids at both the membrane receptor and nuclear protein levels in our organotypic culture model.
THE KONDO BOSON THEORY OF THE DYNAMIC SUSCEPTIBILITY OF HEAVY FERMIONS

Abstract We apply the Kondo-boson - 1/ N expansion to the microscopic Anderson lattice model, properly generalized to include the effects of spin-orbit coupling. We compute the imaginary susceptibility for a generic cubic band structure including the effects of the leading order Fermi liquid interactions. We show that the antiferromagnetic correlations (at the zone boundary) which occur at frequencies of the order of the Kondo temperature, arise naturally as a consequence of transitions across the hybridization gap or the Fermi surface. Finite frequency structure at the zone center derives from f-spin non conserving interactions mediated by exchange of Kondo boson propagators. We discuss alternate “interacting impurities” approaches in light of the experimental evidence for coherence and a sharp Fermi surface at low temperatures.
Development of contrast-induced nephropathy in subarachnoid hemorrhage: a single center perspective.

The use of iodinated contrast-enhanced imaging studies is increasing in acute cerebrovascular diseases, especially in subarachnoid hemorrhage (SAH). In SAH, such studies are essential for both diagnosis and treatment of the cause and sequela of hemorrhage. These patients are often subjected to multiple contrast studies such as computed tomographic angiography, computed tomographic perfusion, and cerebral angiography. They are also predisposed to intravascular volume depletion as a part of the disease process from cerebral salt wasting (CSW) and as a result of multiple contrast exposure can develop contrast-induced nephropathy (CIN). Data regarding CIN in this population are scarce. We aimed to examine the incidence of CIN in SAH and identify potential associative risk factors. We analyzed data from a prospectively collected patient database of patients with SAH admitted to the neurocritical intensive care unit in a single center over a period of 1 year. CIN was defined as an increase in serum creatinine by >1.5 times or >0.3 mg/dl greater than the admission value, or urine output <0.5 ml/kg/h during one 6-h block. In this cohort of 75 patients with SAH who had undergone at least one contrast study, the mean age was 57.3 ± 15.6 years and 70.7 % were women. Four percent developed CIN which resolved within 72 h and none required renal replacement therapy or dialysis. Patients older than 75 years (20 %, p < 0.05), those with borderline renal function (14.3 %, p = 0.26), diabetics (11.1 %, p = 0.32), and those with lower recommended “maximum contrast dose” volume (33.3 %, p = 0.12) had a trend toward development of CIN, although most were not statistically significant. Twenty-seven patients (36 %) were on 3 % hypertonic saline (HTS) for CSW during the contrasted study but none developed CIN. The incidence of CIN in SAH patients is comparable to previously published reports on non-neurological cohorts. No definite association was noted with any predisposing factors postulated to be responsible for CIN, except for advanced age. Concurrent use of 3 % HTS was not associated with CIN in this population.
Engineering a model protein cavity to catalyze the Kemp elimination

Synthetic cavitands and protein cavities have been widely studied as models for ligand recognition. Here we investigate the Met102 → His substitution in the artificial L99A cavity in T4 lysozyme as a Kemp eliminase. The resulting enzyme had kcat/KM = 0.43 M-1 s-1 and a (kcat/KM)/kuncat = 107 at pH 5.0. The crystal structure of this enzyme was determined at 1.30 Å, as were the structures of four complexes of substrate and product analogs. The absence of ordered waters or hydrogen bonding interactions, and the presence of a common catalytic base (His102) in an otherwise hydrophobic, buried cavity, facilitated detailed analysis of the reaction mechanism and its optimization. Subsequent substitutions increased eliminase activity by an additional four-fold. As activity-enhancing substitutions were engineered into the cavity, protein stability decreased, consistent with the stability-function trade-off hypothesis. This and related model cavities may provide templates for studying protein design principles in radically simplified environments.
Failure mechanisms during isothermal fatigue of SiC/Ti-24A1-11Nb composites

Failure mechanisms during isothermal fatigue of unidirectional SiC/Ti-24Al-11Nb (at.%) composites have been determined by microstructural analysis of samples from tests interrupted prior to the end of life and from tests conducted to failure. Specimens from three regions of life were examined based on the maximum strain from a fatigue life diagram: Region 1 (high strain), Region 2 (mid-strain) and Region 3 (low strain). Crack lengths were also measured from interrupted samples and compared based on temperature (23-815 C), region of life and numbers of cycles. Region 1 was controlled by fiber-dominated failure. A transition zone was observed between Regions 1 and 2 due to competition between failure mechanisms. Failure in Region 2 was generally described as surface-initiated cracking with varying amounts of fiber bridging. However, the specific descriptions of crack propagation through the fibers and matrix varied with strain and temperature over this broad region. Region 3 exhibited endurance behaviour at 23 C with no cracking after lO(exp 6) cycles. However at 425 C, surface-initiated cracking was observed after 10(exp 6) cycles with fractured fibers in the crack wake. If endurance behaviour exists for conditions of isothermal fatigue in air at temperatures of greater than or equal to 425 C, it may only be found at very low strains and at greater than 10(exp 6) cycles.
Formalism for dilepton production via virtual photon bremsstrahlung in hadronic reactions.

We derive a set of new formulas for various distributions in dilepton production via virtual photon bremsstrahlung from pseudosclar mesons and unpolarized spin-1/2 fermions. These formulas correspond to the leading and subleading terms in the Low-Burnett-Kroll expansion for real photon bremsstrahlung. The relation of our leading-term formulas to previous works is also shown. Existing formulas are examined in the light of Lorentz covariance and gauge invariance. A numerical comparison is made in a simple example, where an ``exact`` formula and real photon data exist. The results reveal large discrepancies among different bremsstrahlung formulas. Of all the leading-term bremsstrahlung formulas, the one derived in this work agrees best with the exact formula. The issues of {ital M}{sub {ital T}} scaling and event generators are also addressed.
An investigation of the semantic meaning assigned to concepts affiliated with sts education and of STS instructional practices among a sample of exemplary science teachers

The semantic meaning assigned to concepts associated with science-technology-society (STS) education, the percentage of science course time allotted to STS instruction, the categories of STS issues infused into sciences courses, and the instructional procedures used to do so, were examined among a sample of 65 exemplary secondary-level science teachers. The teachers were volunteers from the 87 science teachers from a Midwestern state locally nominated for the Presidential Awards Program. Data were collected using the Science Teaching Issue Opinionnaire (STIO) and a questionnaire, both developed and validated by the investigator. The STIO used a semantic differential format; it was composed of 23 STS education affiliated concepts (e.g., science; technology; students' need to understand the interrelationships among science, technology, and society; my ability to teach …), each followed by 13 seven-point bipolar adjective scales (alpha reliability = 0.97). The instruments were distributed and returned by mail. The exemplary science teachers were found to hold positive opinions of (1) science, (2) technology, (3) their understanding of science, and (4) their ability to teach science. The teachers expressed slightly positive opinions of (1) students' understanding of STS, (2) students' need to understand STS, (3) their own understanding of STS interrelationships, and (4) their ability to teach STS. The teachers suggested that 15% of secondary science course instructional time be dedicated to STS, but did not appear to dedicate near that amount of time to STS. “Pollution” headed a brief and rather predictable list of STS issues infused into science courses. On average a teacher infused 2.5 STS issues into a science course. The discussion, lecture, and a combination of these dominated the list of 35 instructional procedures which are not unique to or necessarily appropriate for STS instruction.
End-to-end numerical modeling of AFTA coronagraphs

The Astrophysics Focused Telescope Assets (AFTA) is one of a pair of space-qualified 2.4 meter diameter telescopes given to NASA. One plan is to use the telescope for WFIRST with a coronagraph as a secondary instrument for high contrast imaging of exoplanets and disks. Because the system is obscured by a secondary mirror and spiders, it is not the optimal unobscured configuration to which most of current proposed space coronagraphs have been designed. In the later half of 2013 a study was undertaken to evaluate coronagraphs designed specifically for the AFTA telescope. As part of this process, end-to-end numerical modeling was performed with a realistically aberrated system to determine the contrast limits of each technique. Reported here are the simulation procedures and a summary of results for four coronagraphs (hybrid Lyot, shaped pupil, vector vortex, and PIAA complex mask) evaluated for the technology downselect.
Design, calibration, and characterization of a field radiometer using light-emitting diodes as detectors

The Remote Sensing Group at the University of Arizona has developed multispectral ground-viewing radiometers that use light-emitting diodes as detectors. This work describes the optical design, electrical design, and laboratory calibration of a three-channel radiometer that operates in the visible and near-infrared region of the spectrum. The optical and electrical design of the radiometer is introduced, and then the calibration and characterization of the radiometer are described. Laboratory measurements include the spectral responsivity for each channel of the radiometer, the temperature dependence of the total responsivity for each channel, system linearity, field of view, and finally, the absolute radiometric calibration. A solar-radiation-based calibration is used to determine the absolute responsivity.
CDC7/DBF4 Functions in the Translesion Synthesis Branch of the RAD6 Epistasis Group in Saccharomyces cerevisiae

CDC7 and DBF4 encode the essential Cdc7-Dbf4 protein kinase required for DNA replication in eukaryotes from yeast to human. Cdc7-Dbf4 is also required for DNA damage-induced mutagenesis, one of several postreplicational DNA damage tolerance mechanisms mediated by the RAD6 epistasis group. Several genes have been determined to function in separate branches within this group, including RAD5 , REV3 / REV7 (Pol ζ), RAD30 (Pol η), and POL30 (PCNA). An extensive genetic analysis of the interactions between CDC7 and REV3 , RAD30 , RAD5 , or POL30 in response to DNA damage was done to determine its role in the RAD6 pathway. CDC7 , RAD5 , POL30 , and RAD30 were found to constitute four separate branches of the RAD6 epistasis group in response to UV and MMS exposure. CDC7 is also shown to function separately from REV3 in response to MMS. However, they belong in the same pathway in response to UV. We propose that the Cdc7-Dbf4 kinase associates with components of the translesion synthesis pathway and that this interaction is dependent upon the type of DNA damage. Finally, activation of the DNA damage checkpoint and the resulting cell cycle delay is intact in cdc7 Δ mcm5-bob1 cells, suggesting a direct role for CDC7 in DNA repair/damage tolerance.
Optical Properties of Various Evaporated Rare Earth Oxides and Fluorides

To furnish a greater choice of film materials for application in optical multilayer coatings, the optical properties of evaporated rare earth compounds such as Y2O3, La2O3, Pr6O11, Nd2O3, Sm2O3, Gd2O3, LaF3, NdF3, and CF3 were studied in the wavelength region from 0.22 micron to 2 microns. The materials were evaporated from tungsten boats and condensed on glass and fused quartz substrates at various temperatures. The optical constants n and k were determined mainly from reflectance, transmittance, and true thickness measurements. The following oxides were found to be useful because of their low absorption in the visible: La2O3 with n ranging from 1.85 to 1.95 with increasing thickness, Pr6O11 with n ranging from 1.92 to 2.05, also with increasing thickness, and Nd2O3 with n=2.05 for films of sufficiently low absorption. LaF3 (n=1.60) and NdF3 (n=1.61) showed no appreciable absorption in the whole wavelength region studied; CeF3 (n=1.63), however, exhibited two weak absorption bands at 0.234 and 0.248 microns. All n values are given at a wavelength of 0.5 micron and for unbaked films deposited at 300°C substrate temperature. The oxides condensed as almost amorphous films, whereas the fluorides developed fairly large grains as indicated by their sharp electron diffraction rings. All films were hard and showed excellent chemical and mechanical durability.
Gram-positive cocci from apiarian sources

Abstract Frass from the greater wax moth, Galleria mellonella, obtained from feral colonies of honey bees, Apis mellifera; from domesticated (managed) honey bee colonies; and from a laboratory culture of the wax moth was sampled for Gram-positive cocci. One hundred twenty-three of these organisms were isolated and identified. Frass from domesticated colonies yielded only one isolate. Equal numbers of isolates (61) were obtained from frass from feral bee colonies and from the wax moth culture. Catalase-negative cocci were predominant in frass from feral colonies, whereas catalase-positive cocci were the most common isolates from frass from the wax moth culture. Catalase-positive cocci were identified as Staphylococcus epidermidis and Micrococcus sp. Catalase-negative cocci were Streptococcus faecalis var. faecalis and S. faecium. These results are discussed in relation to the rarity of Gram-positive cocci associated with honey bees, pollen, and nectar in Arizona and the frequency of association with honey bees and wax moth frass of bacteria resembling Arthrobacter spp. that appear as Gram-positive cocci during one stage of the life cycle.
Research results from the Advanced Lead–Acid Battery Consortium point the way to longer life and higher specific energy for lead/acid electric-vehicle batteries

Abstract Amidst the welter of publicity devoted to the newer battery chemistries, the remarkable progress made by lead/acid battery technologists in response to the needs of the emerging electric-vehicle market has tended to be overlooked. The flooded design of battery, launched by Gaston Plante around 1860, has given way to a valve-regulated variant which has a history dating only from the 1970s. The key parameters of this `maintenance free' battery have been improved markedly during the course of the development programme of the Advanced Lead–Acid Battery Consortium (ALABC), and it is likely that lead/acid will continue to feature strongly in motive-power applications as a result of its cost advantage and of its enhanced effectiveness.
Do Previsit Expectations Correlate With Satisfaction of New Patients Presenting for Evaluation With an Orthopaedic Surgical Practice

Background Patient satisfaction is associated with increased compliance, improved treatment outcomes, and decreased risk of litigation. Factors such as patient understanding and psychological well-being are recognized influences on satisfaction. Less is known about the relationship between previsit expectations and satisfaction.
The Yanomami: Truth and Consequences

I was one of those who received the anonymously and pseudonymously mailed materials questioning Napoleon Chagnon’s account of the activities of the Salesian Mission a m o n g the Yanomami of Venezuela, against which Eric Wolf and Robin Fox protest in their letters (March 1994 A N , p 2). Like them. I hold no brief for the bizarre and devious way in which these documents were disseminated. The clandestine manner in which the materials were circulated, however, is not the only issue raised by their contents, nor by the s ta tements by Chagnon to which they respond. Above all, I am concerned that this ugly, public mud-slinging contest has had the effect of transforming the tragedy of the Yanomami massacre into a stage for the drama of Chagnon versus the Salesians. and the persecution of Chagnon’s sociobiological theories. Worse, i t threatens to have g rave pract ical consequences for the Yanomami themselves and those who are working to help them.
Alpha-fetoprotein and tumour size are associated with microvascular invasion in explanted livers of patients undergoing transplantation with hepatocellular carcinoma

Abstract Background To determine factors associated with outcomes and microvascular invasion (MVI) in patients undergoing liver transplantation (LT) for hepatocellular carcinoma (HCC). Methods Between July 1996 and August 2008 at the Universities of Kentucky or Tennessee, LT recipients were retrospectively analysed. Results One hundred and one patients had HCC in the explanted liver; one patient was excluded because of fibrolamellar histology. Seventy-nine (79%) were male and 81 (81%) were older than 50. HCC was incidental in 32 patients (32%). Median follow-up was 31 months. Ten patients (10%) developed recurrence, which was associated with poor survival ( P = 0.006). Overall 1-, 3-, and 5-year survival rates were 87%, 69% and 62%, respectively. Excluding patients with lymph node metastasis (LNM) or MVI yielded 91%, 81% and 75% survival at the same time points. MVI was independently associated with recurrence (OR 28.40, 95% CI 1.77–456.48, P = 0.018) and decreased survival (OR 4.70, 95% CI 1.24–17.80, P = 0.023), and LNM with decreased survival (OR 6.05, 95% CI 1.23–29.71, P = 0.027). Tumour size (OR 4.1, 95% CI 1.2–13.5, P = 0.013) and alpha-fetoproptein (AFP) > 100 (OR 5.0, 95% CI 1.4–18.1, P = 0.006) were associated with MVI. Conclusions MVI greatly increases the risk of recurrence and death after LT for HCC, and is strongly associated with tumour size and AFP > 100.
The Urokinase-type Plasminogen Activator Receptor Mediates Tyrosine Phosphorylation of Focal Adhesion Proteins and Activation of Mitogen-activated Protein Kinase in Cultured Endothelial Cells

Urokinase-type plasminogen activator (uPA) binds to cells via a specific glycosylphosphatidylinositol-anchored receptor. Although occupancy of the uPA receptor (uPAR) has been shown to alter cellular function and to induce gene expression, the signaling mechanism has not been characterized. Urokinase induced an increase in the tyrosine phosphorylation of multiple proteins in bovine aortic endothelial cells. In contrast, low molecular weight uPA did not induce this response. Analysis by immunoblotting demonstrated tyrosine phosphorylation of focal adhesion kinase (FAK), the focal adhesion-associated proteins paxillin and p130(cas), and mitogen-activated protein kinase (MAPK) following the occupancy of the uPAR by uPA. Treatment of cells with phosphatidylinositol-specific phospholipase C, which cleaves glycosylphosphatidylinositol-linked proteins from the cell surface, blocked the uPA-induced tyrosine phosphorylation of FAK, indicating the requirement of an intact uPAR on the cell surface. The uPA-induced activation of MAPK was completely inhibited by genistein, but not by 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3, 4-d]pyrimidine, a specific inhibitor of Src family kinases. Thus, this study demonstrates a novel role for the uPAR in endothelial cell signal transduction that involves the activation of FAK and MAPK, which are mediated by the receptor-binding domain of uPA. This may have important implications for the mechanism through which uPA influences cell migration and differentiation.