cssi/SciSciGPT-SciSciNet huggingface dataset:
An investigation of a stratified catalyst bed for small-scale hydrogen production from methanol autothermal reforming

Abstract This research project explored a methanol reforming system using a stratified catalyst bed. Commercially available catalysts were used within a single reactor and the system was run autothermally (fuel, steam and oxidizer). The investigation explored the fuel conversion and reactor temperature profile at various O2/CH3OH ratios. The experiments showed that the stratified system had fairly high conversions at low O2/CH3OH ratios. Additionally, it showed high selectivity towards hydrogen, and low selectivity for carbon monoxide. The experimental results gathered show a promising use of stratified catalyst beds for small-scale reforming systems.
Robust design of stochastic controllers for nonlinear systems

The previous results are generalized on the stabilizing property of a control scheme designed for a class of discrete-time nonlinear stochastic systems. First, the existing controller is made more robust with a prescribed degree of stability by proper modifications. Next, the inherent robustness is illustrated by a design utilizing erroneous noise characteristics. Reconsideration of the stability analysis used allows one to treat a larger class of nonlinear stochastic systems with more general structures. >
Radial deformation of the solar current sheet as a cause of geomagnetic storms

It is suggested that the solar current sheet, extending from a coronal streamer, develops a large-scale radial deformation, at times with a very steep gradient at the earth's distance. The associated magnetic field lines (namely, the interplanetary magnetic field (IMF) lines) are expected to have also a large gradient in the vicinity of the current sheet. It is also suggested that some of the major geomagnetic storms occur when the earth is located in the region where IMF field lines have a large dip angle with respect to the ecliptic plane for an extended period (6-48 h), as a result of a steep radial deformation of the current sheet.
Abundance and spatial distribution of copepods on Georges Bank during the winter/spring period

Abstract Abundant copepods on Georges Bank during the winter–spring period (January–June) 1995–1999 were Calanus finmarchicus, Metridia spp. (primarily M. lucens), Pseudocalanus spp., Oithona spp (primarily O. similis), Temora longicornis, Centropages typicus, and C. hamatus. The first four taxa had off-bank sources (Group I) while the last three (Group II) had on-bank sources. All Group I taxa were relatively low in abundance in January and then increased in abundance throughout the sampling period. C. finmarchicus and Metridia spp. showed similar changes in age structure with large numbers of nauplii initially, a maturation of the population in April, followed by a decline in nauplii in May and a resurgence in their numbers in June. These species never achieved high abundance on the shallow crest region of the Bank and became very low in abundance there during May and June. By contrast Pseudocalanus spp. and Oithona spp. increased in abundance throughout the sampling period and, although they were lower in abundance on the crest during winter (January–March) and early spring (April), were able to establish populations there and became abundant during May and June. Group II taxa were low in abundance during winter (C. typicus was abundant initially but declined through April) and did not begin to increase until spring (April–June). Their populations were centered over the crest of the bank indicating a local source, either from resting eggs, or because of high egg production rates due to the higher chlorophyll levels there.
Rhenium in seawater - Confirmation of generally conservative behavior

A depth profile of the concentration of Re was measured in the Pacific Ocean using a technique we have developed for the clean chemical separation and the precise measurement of Re by isotope dilution and negative thermal ionization mass spectrometry (ID-NTIMS). This technique permits Re concentrations to be determined from 200 mL of seawater with a typical precision of ±5‰. This is an improvement of at least a factor of 100 over the techniques used in previously published determinations of Re in seawater. We obtain a narrow range for Re from 7.20 ± 0.03 to 7.38 ± 0.03 ng/kg for depths between 45 m and 4700 m. This demonstrates that Re is relatively well mixed throughout the water column and confirms the theoretical prediction that the behavior of Re in the oceans is conservative. When examined in detail, both salinity and the concentration of Re increase by approximately 1.5% between 400 and 4700 m, a correlation consistent with conservative behavior. However, Re appears to be depleted relative to salinity by 1.0–1.5% at 100 m, and enriched by approximately 4% at the surface. These observations suggest a minor level of Re scavenging in near surface waters, and an input of Re to the ocean surface. This work demonstrates the utility of ID-NTIMS for geochemical investigations of certain trace elements that have not previously been amenable to detailed study.
Cardiorespiratory response to exercise testing in individuals with Alzheimer’s disease

Abstract Billinger SA, Vidoni ED, Honea RA, Burns JM. Cardiorespiratory response to exercise testing in individuals with Alzheimer's disease. Objective To examine exercise testing response in Alzheimer's disease (AD) and possible disease-related change over time. Design Retrospective assessment of a 2-year observational study. Setting University medical center. Participants Individuals without dementia (n=50) and with AD (n=31). Interventions Not applicable. Main Outcome Measures Participants underwent a clinical dementia evaluation and performed an incremental exercise test using a treadmill and the modified Bruce protocol at baseline and at a 2-year follow-up. We examined oxygen consumption, minute ventilation, heart rate, and ventilatory equivalents for oxygen and carbon dioxide at submaximal and peak exercise intensities to determine whether the measures were different between groups or over time. Results Participants with AD and those without dementia performed similarly at submaximal effort, and both groups showed similar changes in exercise response over 2 years. However, nondemented individuals had consistently higher values of oxygen consumption ( P ≤.02) and minute ventilation at peak effort at baseline ( P =.003). Conclusions Individuals with AD demonstrate physiologic responses to submaximal exercise effort that are not significantly different than individuals without dementia. However, differences are apparent at the extreme of effort.
The heating of the solar corona by the resonant absorption of alfven waves

Abstract In this paper, upward propagating Magnetoacoustic waves in an ideal atmosphere are considered. It is shown that the magnetic field creates a nonabsorbing reflecting layer. An equation for the resonance is derived, which shows that resonance may occur for many values of the magnetic field and of the frequency if the wavelength is matched to the strength of the magnetic field. At the resonance frequencies the values of the magnetic and kinetic energies will increase to very large values, and this may account for the heating process. Consequently, for large β-plasma the mechanism for coronal heating will be acoustic.
Spin diode in the ballistic regime

We propose a spin diode based on two semiconducting quantum wires coupled by a tunnel barrier. Applying a voltage and a magnetic field gradient between the two semiconductor wires, we obtain a spin current rectification device which operates in the ballistic regime. Using the scattering states formalism, we derive an exact analytic expression for the tunneling current. The characteristics $I(V,H)$ of the spin diode are determined.
A comparison of three invariant tests of additivity in two-way classifications with no replications

Abstract Tusell (1990) proposed an innovative test of additivity in non-replicated two-way classifications. Tusell's procedure consists of employing the well-known likelihood ratio (LR) test of sphericity as a test of additivity. Ordinarily, additivity is assumed when testing sphericity. Tusell deduced that if sphericity is assumed, then application of the LR criterion results in a test of additivity. This article gives the limiting distribution of the LR sphericity criterion under nonadditivity. Simulation studies that compare Tusell's test with Johnson and Graybill's (1972) LR test against a rank-1 alternative and with Boik's (1990) locally best invariant test of addivity are reported. The LR sphericity test is the most powerful test (among the three) when the noncentrality matrix has multiple non-zero eigenvalues which are comparable in magnitude. For most other conditions, the locally best invariant test is the most powerful test. In practice, prior information about the structure of the noncentrality matrix is generally not available. For these cases, the locally best invariant test is recommended.
Steady state bioequivalence study of dipyridamole ER and acetyl salicylic acid 200 mg + 25 mg capsules in adult healthy male and female volunteers under fasting condition

AbstractThe aim of the study was to evaluate the steady state pharmacokinetics and establish bioequivalence between the test (dipyridamole ER and acetyl salicylic acid 200 mg + 25 mg capsules of Dr. Reddy’s Laboratories Limited, India) against equal doses of reference (AGGRENOX® retard capsule of Boehringer Ingelheim Pharma GmbH & Co., KG 55216 Ingelheim am Rhein, Germany) formulations in 72 healthy adult male and female volunteers under fasting conditions. This was an open-label, block randomized, multiple dose, two-period, two-sequence, cross-over study separated by a washout period of 8 days. On day 5 of each period, post-dose blood samples were collected up to 12 h and analyzed for dipyridamole, salicylic acid and acetyl salicylic acid using a validated LC-MS/MS method. The 90% CI for dipyridamole (AUC(0–τ).ss, Cmax.ss and Cmin.ss) and for salicylic acid (AUC(0–τ).ss, Cmax.ss and %ptf) lie within the accepted bioequivalence range of 80.00–125.00%, thus permitting one to conclude for bioequivalence. In...
Decentralisation, Governance and the Structure of Local Political Institutions: Lessons for Reform?

Abstract Many governments are devolving power to elected local councils, hoping to improve service delivery and citizen representation by bringing officials closer to the people. While these decentralisation reforms hold the promise of improved governance, they also present national and sub-national leaders with a complex array of options about how to structure newly empowered local political institutions. This article draws on cross-national experience and the latest research to identify the trade-offs inherent in structuring local political institutions. The study's specific interest is in the impact of strong, locally elected councils on governance and representation. Proceeding from an empirical basis that competitive elections are vital for the legitimacy and efficiency of local political institutions, the analysis first questions the impact of four institutional features – central versus local control, local executive versus local council authority, local council structure, and the role of parties –...
Electrophysiology of human muscle in culture.

Abstract Human muscle obtained from biopsy specimens was grown in a primary tissue culture system and studied electrophysiologically. Myotubes with well-developed striations were formed after 3 to 5 weeks in culture. The myotubes had stable resting potentials (−50 mV), and generated all-or-none action potentials (92 mV amplitude) when stimulated. The resting permeability of the myotubes was found to be primarily dependent on K+ and to a lesser extent Na+ ( P Na P K = 0.14 ± 0.06 ). Changes in external Cl− did not affect the resting potential or resting conductance indicating that the Cl− permeability is low compared with the permeabilities of K+ and Na+. A small but significant electrogenic NaK pump component to the resting potential was identified at low K+ concentrations ( m ). The passive membrane parameters of myotubes were determined by analyzing the voltage decay transients of uniform fibers in response to the injection of a short hyperpolarizing pulse of current. The resting membrane resistance was 7780 ohm-cm2; membrane time constant, 22.9 ms; membrane capacitance, 3.8 μF; and electrotonic length, 1.1. The identification of the electrical characteristics of normal human muscle grown in primary tissue culture will serve as the basis for detailed comparative studies on diseased human muscle.
Effect of Spatial Variation of a Wave Field on the Resulting Ripple Characteristics and Comparison to Present Ripple Predictors

Laboratory experiments analyzed herein focus on the validity of ripple predictors under spatially variable wave envelopes. Present-day ripple predictors commonly derived from laboratory data (for smaller wave periods of about 1 to 4 s) within which only small regions of the facilities were used to observe and measure the sand ripple geometric characteristics of the nearly progressive waves measured overhead. When extended to large sediment test sections, our results show that the predictors are still valid along the tank under wave conditions which have significant wave envelope spatial variation (e.g., standing waves), provided that ripple predictors use the wave measurements directly above the respective locations within the computations. Results indicate that even under the case of mild reflection, noticeable variation in ripple characteristics can be seen along the sediment test section; thus, compels the necessity of measuring the wave field along the entire sediment section to achieve accurate results.Copyright © 2009 by ASME
Promise of pharmacogenomics in smoking cessation.

Individual differences in the ability to quit smoking provide an important model for ‘higher order’ pharmacogenomics. Twin studies document strong, ca 0.5 heritability for success in smoking cessation [1,2]. This behavior change yields sizable health benefits. Smoking remains one of the largest preventable causes of death, causing more than 400,000 premature US deaths per year [3]. Many of these deaths could have been deferred by successful midlife cessation, even in individuals who have smoked for years prior to quitting. While many smokers attempt to quit each year, only approximately one in ten or one in 20 are able to remain abstinent [4]. This rate can be augmented twoor more-fold by treatments that target the brain nicotinic acetylcholine receptors at which nicotine (nicotine replacement or varenicline), or the dopamine transporter (bupropion) exerts its effect. Nevertheless, the odds that a smoker who attempts to quit will relapse are still much greater than the chances that he will achieve and maintain abstinence. Improving these odds is a major goal of academic and pharmaceutical therapeutic development programs, and a promising setting in which thoughtfully applied pharmaco genomics could provide substantial health improvements with favorable cost:benefit ratios. Pharmacogenomics’ promise for smoking c essation includes:
High Capsid–Genome Correlation Facilitates Creation of AAV Libraries for Directed Evolution

Directed evolution of adeno-associated virus (AAV) through successive rounds of phenotypic selection is a powerful method to isolate variants with improved properties from large libraries of capsid mutants. Importantly, AAV libraries used for directed evolution are based on the “natural” AAV genome organization where the capsid proteins are encoded in cis from replicating genomes. This is necessary to allow the recovery of the capsid DNA after each step of phenotypic selection. For directed evolution to be used successfully, it is essential to minimize the random mixing of capsomers and the encapsidation of nonmatching viral genomes during the production of the viral libraries. Here, we demonstrate that multiple AAV capsid variants expressed from Rep/Cap containing viral genomes result in near-homogeneous capsids that display an unexpectedly high capsid–DNA correlation. Next-generation sequencing of AAV progeny generated by bulk transfection of a semi-random peptide library showed a strong counter-selection of capsid variants encoding premature stop codons, which further supports a strong capsid–genome identity correlation. Overall, our observations demonstrate that production of “natural” AAVs results in low capsid mosaicism and high capsid–genome correlation. These unique properties allow the production of highly diverse AAV libraries in a one-step procedure with a minimal loss in phenotype–genotype correlation.
Inhibition of Blastomyces dermatitidis by topical lidocaine.

This study was designed to determine if lidocaine inhibited growth of Blastomyces dermatitidis and thereby reduced recovery of the fungus from bronchoscopy specimens. Case records of 36 patients with pulmonary blastomycosis showed that when the fungus was present at microscopy, whether the specimen was sputum or bronchial washings, culture of the bronchoscopic specimen was more frequently negative than the culture of the sputum specimen (p B dermatitidis in vitro , with the inhibition depending on the concentration of the drug and the duration of exposure (p B dermatitidis from bronchoscopic specimens.
ESTIMATING DIRECTIONAL MIGRATION FLOWS FROM AGE‐SPECIFIC NET MIGRATION DATA

This paper focuses on a method for indirectly inferring migration flows in the absence of migration data, using two successive counts of birthplace-specific population stocks. Such stocks have been used in the past to infer patterns of mortality and indeed of net migration. But a workable method for using such population stocks to indirectly estimate directional migration flows still eludes us. Widely observed regularities in the age patterns of outmigration indicate that age-specific propensities of migration are correlated, and this characteristic suggests an estimation method that directs attention to the age-specific relative propensities of two or more flows exhibited in the historically preceding time intervals, and then uses those past measures of relative propensities to disaggregate residually estimated net migration flows into the underlying contributions of inmigration and outmigration. A detailed demonstration of the method, applied to US data, is set out in this paper.
Histochemical changes in rat skeletal muscle after exercise

Abstract Previous studies led us to suspect that the proportion of fibers within a given muscle which show relatively high activity of the enzymes associated with mitochondria should be related to the nature of the work load placed on that muscle. Following a 52-day swimming program for white rats (one and two 30-min exercise bouts each day) the proportion of fibers having intermediate and high malate dehydrogenase, succinate dehydrogenase, and reduced nicotinamide adenine dinucleotide diaphorase was not altered in the soleus. Neither was the proportion of fibers having low and high mitochondrial α-glycerophosphate dehydrogenase (mito α-GPD) and myosin adenosine triphosphatase altered in the soleus. Myosin adenosine triphosphatase showed no changes in the plantaris. However, the plantaris of moderately and heavily exercised rats did show a greater proportion of fibers having high malate and succinate dehydrogenase, and nicotinamide adenine dinucleotide diaphorase than did the plantaris of sedentary rats. This increase in the proportion of fibers having these high enzyme activities appears to be one mechanism through which a muscle can adapt to a chronic repetitive overload. If one wishes to think in terms of fiber types as determined by these enzymes, this study demonstrates that muscle fiber types can be changed in a nonpathologic condition.
Synthesis of a Conjugated Donor/Acceptor/Passivator (DAP) Polymer

A conjugated polymer is described here that possesses main-chain donor/acceptor repeat units separated by aryl passivating units. This donor/acceptor/passivator (DAP) polymer was constructed of sequential electron-rich N,N‘-dimethyl-3,4-diaminothiophene, electron-deficient 3,4-dinitrothiophene, and passivating phenylene repeat units via Stille coupling reactions. Several new transformations were conducted on thiophene cores in order to construct the monomer units: tert-butoxycarbonyl (Boc) amine protections, selective monostannylations, selective monodebrominations, lithium tetramethylpiperidide (LTMP) induced lithiation on nitrothiophenes, and selective stannylations using Bu3SnSnBu3/Pd on phenylene iodides over thienyl bromides. The Stille polymerization afforded the Boc-protected DAP polymer that was characterized at this stage. ZnCl2-catalyzed Boc removal afforded the desired DAP polymer; however, its insolubility curtailed detailed investigations of the properties.
Muon energy losses and straggling for high energy muons

Abstract The non-Gaussian nature of energy loss straggling is examined. At NAL large muon shields must be designed to reduce flux by about a factor of 10 12 . Fortunately it is shown here that on the long range end, the straggling falls off much faster than Gaussian and the amount of shielding needed is significantly reduced.
Swedish physicians' perspectives on work and the medical care system—v. comparisons across specialties

Treating medical specialties as segments, Swedish ambulatory care physicians were interviewed to identify their perspectives on work and the medical care system. Those perspectives were analyzed and compared across segments. Physician segments differed substantially in the themes they put forward. Perspectives tended to be homogeneous within segments and sharply differentiated between segments. Both positive and negative perspectives were expressed more with respect to immediate work situations than with respect to the medical care system. Child health and maternal health physicians were more likely to express satisfactions with both work and the system, while district general practitioners were more likely to note problems. It is contended that this study has identified well grounded (valid) categories for the analysis of the Swedish medical care system.
A novel arrangement of tandemly repeated genes at a major heat shock site in D. melanogaster

Abstract Three cloned segments of Drosophila melanogaster DNA have been isolated that derive from the major heat shock site at 87C in chromosome 3. Each of these segments contains sequences homologous to a class of polysomal poly(A) + RNAs whose synthesis is induced by heat shock of cultured cells. A combination of R loop, heteroduplex and restriction fragment maps of these segments reveals that their RNA-homologous sequences are arranged in tandemly repeated units, each unit consisting of an α element (0.49 kb) joined to a β element (1.10 kb). The polysomal RNAs homologous to these αβ units (1.59 kb) are distributed into three size classes exhibiting approximate lengths of 1, 2 and 3 kb. R loop mapping demonstrated that the sequence of the 2 kb RNA is αβα, indicating that it, and presumably the 3 kb RNA, derive from transcripts covering more than one repeated unit. One of the cloned segments contains a variant repeat unit, αγ, located between two αβ units. This unit has the same α element, but the β element has been replaced by a nonhomologous γ element (0.87 kb). Analysis of the total D. melanogaster DNA indicates that the 87C locus contains at least 21 tandemly repeated units, twelve of which were identified as αβ units and six as αγ units. The 21 or more units are distributed among at least three different tandem arrays separated by different spacer regions, one of which is within a cloned segment. Sequences in the γ element, but not those in the α or β elements, are also found at 87A, which contains another heat shock site. The possible roles of the αβ-type RNAs and of the γ sequences are discussed in the light of these results.
Reliable resonance assignments of selected residues of proteins with known structure based on empirical NMR chemical shift prediction

Abstract A robust NMR resonance assignment method is introduced for proteins whose 3D structure has previously been determined by X-ray crystallography. The goal of the method is to obtain a subset of correct assignments from a parsimonious set of 3D NMR experiments of 15 N, 13 C labeled proteins. Chemical shifts of sequential residue pairs are predicted from static protein structures using PPM_One, which are then compared with the corresponding experimental shifts. Globally optimized weighted matching identifies the assignments that are robust with respect to small changes in NMR cross-peak positions. The method, termed PASSPORT, is demonstrated for 4 proteins with 100–250 amino acids using 3D NHCA and a 3D CBCA(CO)NH experiments as input producing correct assignments with high reliability for 22% of the residues. The method, which works best for Gly, Ala, Ser, and Thr residues, provides assignments that serve as anchor points for additional assignments by both manual and semi-automated methods or they can be directly used for further studies, e.g. on ligand binding, protein dynamics, or post-translational modification, such as phosphorylation.
The Ambivalence of Departing Employees: Reactions of Involuntary and Voluntary Exiters

The research reported in this article uses a clinical methodology to explore the complex process of organizational exits from the perspective of both voluntary and involuntary exiters. In particular, it focuses on the ambivalence manifested by all exiters in regard to three emotional themes that shaped the exit experience: termination, separation, and change. The article also reflects on the way in which the researcher's group membership influenced the choice of a research topic and the research itself. Implications for research and practice are discussed
The Interaction of Top-Down and Bottom-Up Statistics in the Resolution of Syntactic Category Ambiguity.

Abstract This paper investigates how people resolve syntactic category ambiguities when comprehending sentences. It is proposed that people combine: (a) context-dependent syntactic expectations (top–down statistical information) and (b) context-independent lexical-category frequencies of words (bottom–up statistical information) in order to resolve ambiguities in the lexical categories of words. Three self-paced reading experiments were conducted involving the ambiguous word “that” in different syntactic environments in order to test these and other hypotheses. The data support the top–down/bottom–up approach in which the relative frequencies of lexical entries for a word are tabulated independent of context. Data from other experiments from the literature are discussed with respect to the model proposed here.
Auditory Thresholds in Children for Narrow-Band Noise and Warble Tones in Sound Field

Auditory thresholds for frequency-modulated (warble) tones and narrow bands of noise in a sound field were obtained for children between the ages of eight and 48 months. Differences between the two types of stimuli centered at either 500 Hz or 4,000 Hz and among three age groups were not statistically significant (P greater than 0.01). Auditory thresholds for these frequency-selective stimuli did coincide closely with the speech awareness and spondee threshold measurements obtained in the present study, and with thresholds for complex noise obtained in previous reports. Sound field warble tone thresholds differed, however, from published data in adults and unpublished data in children. Explanations for discrepancies between data in present study and previous studies are suggested, and a cautious recommendation for the use of frequency-selective stimuli in the assessment of auditory thresholds in children is emphasized.
Monte Carlo Simulation Test of Pore Blocking Effects

We present a Monte Carlo (MC) simulation study of capillary condensation and desorption in a spherical cavity connected with the bulk phase by cylindrical necks of smaller diameter. We confirm two mechanisms of spontaneous evaporation from the cavity and, correspondingly, two types of adsorption hysteresis, which depend on the relation between the sizes of the cavity and the connecting pores. When the necks are sufficiently wide, evaporation from the cavity is determined by the conditions of evaporation from the neck. This is a classical ink-bottle or pore blocking effect: desorption from the cavity is controlled by the size of the neck. When the necks are narrow, evaporation from the cavity is determined by the conditions of cavitation in the stretched metastable liquid and thus does not depend on the size of blocking pores. MC simulations were performed for a Lennard-Jones fluid at the normal boiling temperature mimicking sorption of nitrogen at 77.4 K in silica mesopores. The simulation results agree ...
Stable high order methods for differential equations with small coefficients for the second order terms

Abstract Stable high-order methods are developed for solving differential equations with small coefficients for the second order terms. In particular, second-, fourth- and sixth-order methods are developed. The methods are developed for general linear two-point boundary value problems and proved to be stable and accurate. Results are presented for the one-dimensional convection-diffusion equation involving problems with and without boundary layers. The methods converged for all values of parameters attempted and the results compared favorably with other methods. The methods developed in this paper are accurate, stable, easy to use and applicable to other problems.
Superconductivity in Silver Induced by the Proximity Effect

Thermal measurements have been carried out on the proximity effect in silver. Two independent determinations of NV, one from the energy gap and the other from saturation temperature were made. The electron-electron interaction is found to be attractive and it is concluded that silver is an intrinsic superconductor at sufficiently low temperatures. 35 references.
Renal artery stenosis and ischemia. Effect on renal blood flow and extraction fraction.

The clearance of [131I]orthoiodohippurate and 99mTc-mercaptoacetyltriglycine provide a measure of effective renal plasma flow, yet these clearances are proportional to renal plasma flow only if the extraction fraction remains constant. To determine the effect of unilateral renal artery stenosis, captopril, renal ischemia, and partial renal vein occlusion on renal blood flow and the extraction fraction of [131I]orthoiodohippurate, 99mTc-mercaptoacetyltriglycine, and [125I]iothalamate, we conducted a series of constant infusion studies in Sprague-Dawley rats. Renal artery flow reduction of approximately 70% decreased the extraction fraction of all three agents (P < or = .05). Captopril had no effect on extraction fraction in controls, but it produced a further decrease in extraction fraction of 99mTc-mercaptoacetyltriglycine and [131I]orthoiodohippurate in rats with renal artery stenosis (P < or = .05). Ischemia resulted in a 16% decrease in flow (P < .01) but a much larger (47% to 65%) decrease in extraction fraction of all three agents (P < .002). Partial renal vein occlusion also decreased the extraction fraction of all three agents (P < or = .05). The changes in extraction fraction imply that the clearances of [131I]orthoiodohippurate and 99mTc-mercaptoacetyltriglycine in disease states may not be proportional to renal plasma flow. Furthermore, in rats with renal artery stenosis it appears that renal blood flow must fall below a critical threshold of approximately 58% before extraction fraction decreases; as renal blood flow is further reduced below this threshold, there is a corresponding reduction in extraction fraction (P < .01).
Polyamine alterations in blood of male homozygotes and heterozygotes for cystic fibrosis

Abstract The polyamines, spermidine and spermine, have been measured in whole blood extracts from control volunteers, patients with cystic fibrosis, and obligate cystic fibrosis heterozygotes. Male homo- and heterozygotes for cystic fibrosis exhibit a consistent and significant decrease in blood spermine resulting in an elevated spermidine/spermine ratio when compared to control males. In contrast, control females exhibited reduced spermidine and spermine levels as compared to control males. Blood from female cystic fibrosis homo- and heterozygotes showed similar results. The sex difference is probably due to fluctuations of blood polyamines during the menstrual cycle. Abnormal polyamine levels are the first observation of an alteration of a low molecular weight metabolite characteristic of both male homo- and heterozygotes for cystic fibrosis.
Higher-order Algebras and Coalgebras from Parameterized Endofunctors

The study of algebras and coalgebras involve parametric description of a family of endofunctors. Such descriptions can often be packaged as parameterized endofunctors. A parameterized endofunctor generates a higher-order endofunctor on a functor category. We characterize initial algebras and final coalgebras for these higher-order endofunctors, generalizing several results in the literature.
Information theory based design of phase-change memories

Due to the high device density and the advent of multiple bits per cell, modern nonvolatile memories are characterized by a non-deterministic behavior. We focus on phase-change memory (PCM), whose memory cell can be seen as a programmable resistor, and use information theory tools to investigate how the cell structure influences the storage capacity of this memory technology. In particular, we numerically compute the storage capacity of two known cell structures, i.e., the series cell, and the parallel cell. The results suggest that, in practical scenarios, the parallel cell structure is characterized by significantly larger storage capacity.
Ecoacoustic and shamanic technologies for multimedia composition and performance

The author's close connection to traditional Alaskan culture has inspired the creation and implementation of new multimedia instruments based on the use of ritual objects in shamanic cultures of the far north. Simultaneously, the musical processes articulated by this music are structurally tied to environmental systems in a technique discussed here as ‘ecoacoustics’. In this work, performer/composer interaction, musical composition theory, multimedia performance, and musical instrument design have been transformed in response to these influences.
Direct Synthesis of Hybrid Organic−Inorganic Nanoporous Silica by a Neutral Amine Assembly Route: Structure−Function Control by Stoichiometric Incorporation of Organosiloxane Molecules

The co-condensation of tetraethoxysilane (TEOS) and organotrialkoxysilane molecules by neutral alkylamine surfactant assembly (S0I0) is a convenient synthesis methodology for the one-step preparation of organically functionalized mesostructured materials. Two distinct approaches were considered for the formation of such hybrid inorganic−organic compounds, denoted as the template substitution and direct addition pathways. The template substitution pathway, involving the replacement of both surfactant and TEOS by an equivalent amount of organosilane (up to 11% substitution), was convenient for the functionalization of mesostructures with moieties whose size is comparable to that of the structure-directing amine surfactant. The direct addition method, involving the equimolar replacement of TEOS with organosilane (up to 9% of total silicon) while keeping the surfactant amount constant in the reaction mixture, was successful for the incorporation of organic groups whose sizes were smaller than that of the temp...
Selective import of nuclear-encoded tRNAs into mitochondria of the protozoan Leishmania tarentolae

Abstract The trypanosomatid mitochondrial genome does not encode tRNA genes at all and experimental evidence obtained with Leishmania tarentolae shows that tRNAs in mitochondrial represent a selected set of imported nuclear-encoded tRNAs. In this paper we present the data showing that tRNAs derived from the clustered genomic tRNA genes are invariably imported into mitochondria, while tRNA from the solitary gene is not. By sequencing a cosmid DNA clone of L. tarentolae genomic DNA, we have identified a 1.5-kb subclone encoding a duplicate set of the closely linked tRNATyr (GTA) and tRNAThr (AGT) genes. Northern analysis shows that these tRNAs are imported into mitochondria. In contrast, when the tRNA gene [tRNAGln (CUG)] located alone in a 40-kb DNA fragment was examined, the corresponding tRNA was not detected in the mitochondrion. This “loner” tRNA gene is highly unusual since the 3′-flanking putative RNA polymerase III transcription termination signal sequence is characterized by a long string of 8 Ts followed by an A and a stretch of 7 Cs, while all other trypanosomatid tRNA genes whose tRNA transcripts are imported are terminated by a possible transcription termination signal of only 4–6 Ts. Whether the correlation found between the gene organization and tRNA-import characteristics is of general significance needs to be investigated further. A simple computer analysis presented in this paper rules out the possibility that tRNAs found in the trypanosomatid mitochondrion are the products of the U-addition type ‘RNA editing’ of maxicircle DNA.
Predictors of persistence of social anxiety disorder: a national study.

Abstract Social anxiety disorder (SAD) is highly prevalent and impairing. Little is known about rates and predictors of persistence of SAD in the community. The current study derived data from the National Epidemiologic Survey on Alcohol and Related Conditions, Wave 1 (2001–2002, n = 43,093) and Wave 2 (2004–2005, n = 34,653), a large survey of a representative sample of the United States adult population. Individuals with current DSM-IV SAD at Wave 1 were re-interviewed 3 years later at Wave 2 using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM IV Version (AUDADIS-IV). We found that in the community, 22.3% of respondents with SAD at the Wave 1 evaluation met DSM-IV criteria for SAD three years later, and endorsement of social interaction fears and a higher number of avoided social situations, treatment-seeking during past year, and comorbidity with mood disorders independently predicted persistence of SAD. These results suggest that persistence of SAD in the community is common and associated with symptom severity and comorbid mood disorders.
Lithium intercalation of WO2Cl2

Abstract The layered solid WO 2 Cl 2 was intercalated with lithium via chemical techniques. The electronic properties of the solid change during reaction from an insulator to a narrow band semiconductor.
Analogs of human epidermal growth factor which partially inhibit the growth factor-dependent protein-tyrosine kinase activity of the epidermal growth factor receptor

Three site-directed mutants of human epidermal growth factor, Leu-26 → Gly, Leu-47 → Ala, and He-23 → Thr, were examined for their ability to stimulate the protein-tyrosine kinase activity of the epidermal growth factor receptor. The receptor binding affinities of the mutant growth factors were 20- to 50-fold lower, as compared to wild-type growth factor. At saturating concentrations of growth factor, the velocities of the phosphorylation of exogenously added substrate and receptor autophosphorylation were significantly lower with the mutant analogs, suggesting a partial ‘uncoupling’ of signal transduction. The mutant analogs were shown to compete directly with the binding of wild-type, resulting in a decrease in growth factor-stimulated kinase activity.
Modified Suturing Contact Lens For Penetrating Keratoplasty

Summary The authors have previously described a suturing contact lens that protects the corneal endothelium by aiding in the maintenance of the anterior chamber during penetrating keratoplasty. This report describes structural modifications of the suturing contact lens, which improve its stability and effectiveness. An additional configuration for use in corneal lacerations is presented.
Anastomotic recurrence in the oesophagus complicating gastrectomy for adenocarcinoma of the stomach

Gastric adenocarcinomas often spread to the distal oesophagus. Failure to control the disease in this area during total and proximal subtotal gastrectomy results in recurrence at the oesophageal anastomosis. The incidence of recurrence in a series of 351 such patients was 10 per cent and was influenced by the location of the main lesion, the stage of the disease, the presence of tumour at the margin of resection and the length of clearance of the oesophageal margin. Recurrences were prevented only with in vivo margins greater than 12 cm. Dysphagia combined with radiological signs of oesophageal obstruction was diagnostic of anastomotic recurrence regardless of the results obtained by oesophagoscopy and biopsy. Treatment was seldom effective in patients developing recurrence. Complete excision of the entire recurrent process offered the only hope for a long survival in these patients. Prevention by obtaining adequate oesophageal clearance at the time of gastrectomy is the only reasonable approach to this problem. The adequacy of resection cannot be judged accurately by intraoperative palpation of the oesophagus or by frozen section examination of the surgical margins.
How to overcome (and exploit) tumor hypoxia for targeted gene therapy

Tumor hypoxia has long been recognized as a critical issue in oncology. Resistance of hypoxic areas has been shown to affect treatment outcome after radiation, chemotherapy, and surgery in a number of tumor sites. Two main strategies to overcome tumor hypoxia are to increase the delivery of oxygen (or oxygen-mimetic drugs), and exploiting this unique environmental condition of solid tumors for targeted therapy. The first strategy includes hyperbaric oxygen breathing, the administration of carbogen and nicotinamide, and the delivery of chemical radiosensitizers. In contrast, bioreductive drugs and hypoxia-targeted suicide gene therapy aim at activating cytotoxic agents at the tumor site, while sparing normal tissue from damage. The cellular machinery responds to hypoxia by activating the expression of genes involved in angiogenesis, anaerobic metabolism, vascular permeability, and inflammation. In most cases, transcription is initiated by the binding of the transcription factor hypoxia-inducible factor (HIF) to hypoxia responsive elements (HREs). Hypoxia-targeting for gene therapy has been achieved by utilizing promoters containing HREs, to induce selective and efficient transgene activation at the tumor site. Hypoxia-targeted delivery and prodrug activation may add additional levels of selectivity to the treatment. In this article, the latest developments of cancer gene therapy of the hypoxic environment are discussed, with particular attention to combined protocols with ionizing radiation. Ultimately, it is proposed that by adopting specific transgene activation and molecular amplification systems, resistant hypoxic tumor tissues may be effectively targeted with gene therapy.
Brain injury after head trauma: pathophysiology, diagnosis, and treatment

Brain injury after impact to the head is due to both immediate mechanical effects and delayed responses of neural tissues. In horses, traumatic brain injury occurs in three main settings: (1) poll impact in horses that flip over backwards; (2) frontal/parietal impact in horses that run into a fixed object, and (3) injury to the vestibular apparatus secondary to temporohyoid osteoarthropathy. Distinct forebrain, vestibular, midbrain, hindbrain, or multifocal syndromes may be encountered in horses with traumatic brain injury. The most important components of treatment are those consistent with principles of "evidence-based medicine". Accordingly,secondary brain injury can most effectively be prevented by establishing normal blood pressure, temperature, blood glucose concentration, and tissue oxygenation. Pain must be controlled and brain swelling may be treated with infusions of hypertonic saline or mannitol. Surgical procedures, including unilateral hyoid bone transaction or elevation of skull fracture fragments, are indicated in selected cases. Optional additional treatments include use of anti-oxidants, conventional doses of corticosteroids, magnesium sulfate and drainage of CSE There is no indication for the use of massive doses of methyl prednisolone sodium succinate.
Genome Editing in Mouse Spermatogonial Stem/Progenitor Cells Using Engineered Nucleases

Editing the genome to create specific sequence modifications is a powerful way to study gene function and promises future applicability to gene therapy. Creation of precise modifications requires homologous recombination, a very rare event in most cell types that can be stimulated by introducing a double strand break near the target sequence. One method to create a double strand break in a particular sequence is with a custom designed nuclease. We used engineered nucleases to stimulate homologous recombination to correct a mutant gene in mouse “GS” (germline stem) cells, testicular derived cell cultures containing spermatogonial stem cells and progenitor cells. We demonstrated that gene-corrected cells maintained several properties of spermatogonial stem/progenitor cells including the ability to colonize following testicular transplantation. This proof of concept for genome editing in GS cells impacts both cell therapy and basic research given the potential for GS cells to be propagated in vitro, contribute to the germline in vivo following testicular transplantation or become reprogrammed to pluripotency in vitro.
MeV Si Ions Bombardment Effects on SiO2/SiO2-ZrNiSn Nano-layered Thermoelectric Generator

We have deposited 50 nano-layers of 710 nm of SiO2/SiO2+ZrNiSn with a periodic structure consisting of alternating layers where each layer is about 14 nm thick. The purpose of this research is to generate nanolayers of nanostructures of ZrNiSn with SiO2 as host and as buffer layer using a combination of co-deposition and MeV ion bombardment taking advantage of the energy deposited in the MeV ions track to nucleate nanostructures. The performance of the thermoelectric materials and devices is shown by a dimensionless figure of merit, ZT = S2σT/ĸ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature and ĸ is the thermal conductivity. ZT can be increased by increasing S, increasing σ, or decreasing ĸ. The electrical and thermal properties of the layered structures were studied before and after bombardment by 5 MeV Si ions at seven different fluences ranging from 1014 to 1015 ions/cm2 in order to form nanostructures in layers of SiO2 containing few percent of ZrNiSn. Rutherford Backscattering Spectrometry (RBS) was used to monitor elemental analysis of the film.
Efficient wide-band evaluation of mobile communications antennas using [Z] or [Y] matrix interpolation with the method of moments

The development of novel antennas for mobile communications often relies on performance simulations. The evaluation of the antenna surface currents for many frequencies using the method of moments (MoM) can take a long time since the impedance matrix must be computed for each new frequency. This paper investigates and compares two efficient methods for the computation of the broad-band performance of mobile communications antennas using frequency interpolation of either the MoM impedance matrix [Z] or admittance matrix [Y]. In either method, the elements of only a few matrices at relatively large frequency intervals are directly computed. These matrices are then used to interpolate the elements of the respective [Z] or [Y] matrices at the intermediate frequencies. Both methods reduce the time it takes to compute the antenna performance over a wide frequency band. The implementation of each method to evaluate the performance of several different antennas used for mobile communications is discussed. Examples with both frequency-domain and time-domain results are presented and both near-field and far-field quantities are considered. The accuracy, the simulation run times, and the computational requirements of direct MoM, [Z] matrix interpolation, and [Y] matrix interpolation are compared.