cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of recombinant human cytokines on mitogen-induced bovine peripheral blood mononuclear cell proliferation

Abstract The effects of interleukin 1α (IL-1α), IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, and insulin growth factor-1 (IGF-1) on proliferation of mitogen-stimulated bovine peripheral blood mononuclear cells (PBMC) were determined. Four concentrations of each cytokine were incubated 48 or 96 h with PBMC alone or with PBMC and three concentrations of three different mitogens. The mitogens included concanavalin A (Con A), phytohemagglutinin (PHA), and Escherichia coli 055:B5 lipopolysaccharide (LPS). Proliferation of unstimulated PBMC was not affected by IL-1α, IL-1β, IL-3, IL-5, IL-6, IL-8, and IGF-1 whereas IL-2, IL-4, and IL-7 increased proliferation. Incubation of PBMC with Con A plus IL-1α, IL-2, IL-4, IL-7 or IL-8 increased proliferation when compared to PBMC that were incubated with either Con A or the cytokine alone. Interleukin-1β, IL-3, IL-5, IL-6 and IGF-1 did not influence proliferation of Con A-stimulated PBMC. Proliferation of PHA-stimulated PBMC was increased when PBMC were cultured with IL-2, IL-4 or IL-7, but not when cultured with IL-1α, IL-1β, IL-3, IL-5, IL-6, IL-8 or IGF-1. Similar results occurred with LPS-stimulated PBMC in that proliferation induced by LPS was enhanced by IL-2 or IL-7, but not by any of the other cytokines. These results suggest that in the presence or absence of certain mitogens, human IL-1α, IL-2, IL-4, IL-7, or IL-8 can enhance proliferation of bovine PBMC whereas IL-1β, IL-3, IL-5, IL-6 and IGF-1 do not.
A Solar Pumped Gas Laser for the Direct Conversion of Solar Energy

The first solar pumping of a gas laser scalable to high-power levels was achieved. The solar radiation was from a xenon arc solar simulator with a 4-kW beam power and a spectral distribution of air mass zero to an accuracy of about 20%. With the lasant n-heptafluoropropyl iodide (C/sub 3/F/sub 7/I), continuous lasing at 1.315 ..mu..m for over 10 ms and peak power output of 10 W were obtained for a single static fill. Numerical simulations based on the kinetics of the iodine laser match well the experimentally observed lasing features. The laser was also operated with quasisteady flow for up to 200 ms at a 30-Hz pulse rate indicating the feasibility of continual lasing by flowing the lasant. Since an equivalent pumping power is obtainable from a modest-sized collector only 2 m in diameter, this research indicates that solar energy can be transformed effectively directly into a continuous laser output which may be useful for extended space communications, powering deep space or near-Earth missions, and possibly even supplying energy to the Earth.
Commercial plant breeding: What is in the biotech pipeline?

Of all of humankind’s endeavours, agriculture has led to the most pressure on land, its resources and biodiversity. Over the past 50 years, the need to increase food production has resulted in the loss of one-fifth of the world’s topsoil, one-fifth of its agricultural land and onethird of its forests. To slow down, and ideally reverse, this trend in the face of a predicted population increase of 50 per cent, a water shortage and climate change, new approaches will be needed. In this context, crop biotechnology and genomics have a major contributory role to play in the sustainable improvement of crop and livestock productivity, human and animal health and the development of renewable resources such as fibres, plastics, biofuels and plantmade pharmaceuticals. Manifestly, this will require both political will and international agreement.
Specificity for Human Hemoglobin Enhances Staphylococcus aureus Infection

Iron is required for bacterial proliferation, and Staphylococcus aureus steals this metal from host hemoglobin during invasive infections. This process involves hemoglobin binding to the cell wall of S. aureus, heme extraction, passage through the cell envelope, and degradation to release free iron. Herein, we demonstrate an enhanced ability of S. aureus to bind hemoglobin derived from humans as compared to other mammals. Increased specificity for human hemoglobin (hHb) translates into an improved ability to acquire iron and is entirely dependent on the staphylococcal hemoglobin receptor IsdB. This feature affects host-pathogen interaction as demonstrated by the increased susceptibility of hHb-expressing mice to systemic staphylococcal infection. Interestingly, enhanced utilization of human hemoglobin is not a uniform property of all bacterial pathogens. These results suggest a step in the evolution of S. aureus to better colonize the human host and establish hHb-expressing mice as a model of S. aureus pathogenesis.
Methodological considerations for the quantification of self-reported caffeine use.

Rationale The field of research regarding the effects of habitual caffeine use is immense and frequently utilizes self-report measures of caffeine use. However, various self-report measures have different methodologies, and the accuracy of these different methods has not been compared.
Learning with CyberPLAYce, a cyber-physical learning environment for elementary students promoting computational expression

CyberPLAYce is our novel, interactive-computational construction kit for elementary school children and their teachers. CyberPLAYce bridges the physical and digital worlds, allowing young students to bring their ideas, stories and class subjects to life through the construction of cyber-physical environments. The CyberPLAYce construction kit is comprised of hand-sized, magnetic modules integrating a variety of electronic components, and rectangular panels, nearly two-feet measured diagonally, that receive the modules and serve as physical building blocks for constructing cyber-physical environments imagined by children. Through play, children become comfortable with the working modules and panels; subsequently, they are provided matching non-electronic module cards allowing them to quickly compose pattern sequences to map ideas, stories and class content. Additionally, students are provided action and story cards to spark their imagination. CyberPLAYce merges play and learning in the physical world while transitioning students from consumers of virtual and digital-centric technologies into technological innovators and cyber-playful storytellers.
DNA repair gene polymorphisms and probability of p53 mutation in bladder cancer

We investigated if the presence of single nucleotide polymorphisms (SNPs) in the XRCC1, XRCC3, and XPD genes were associated with the type and frequency of p53 mutations in bladder cancer. Using a hospital-based case-control study we have previously reported risks for the XRCC1 codon 194, XRCC1 codon 399, XRCC3 codon 241, and XPD codon 751 SNPs 1–3. We have also previously reported mutation data for 149 cases from this study who were screened for mutations in exons 4 through 9 of the p53 gene 4. Here we investigate possible associations between the DNA repair SNPs mentioned above and the presence of p53 mutations by comparing the frequency of each genotype between p53 mutation positive and negative cases. We also considered different classes of p53 mutations, including any mutation (nonsense, missense or silent), transversions and transitions and estimated odds ratios (ORs) and 95% confidence intervals (CI) for these associations. Cases with the XRCC1 codon 399 Gln/Gln genotype were positively associated with the presence of p53 transversions (OR = 4.8; 94% CI = 0.8–30). Cases with the XPD codon 751 Gln/Gln genotype were positively associated with the presence of p53 transitions (OR = 2.8; 95% CI = 0.8–9.3), in particular G:C-A:T transitions (OR = 3.7; 95% CI = 1.1–13). Our data provide some limited support for the hypothesis that mutations in the p53 gene in bladder cancer may differ according to the presence or absence of certain DNA repair gene variants. Published 2006 Wiley-Liss, Inc.
The role of sympathetic nerves in the response of uterus and oviduct to field stimulation

Abstract Uteri and oviducts from rabbits treated with Human Chorionic Gonadotropin or estrogen were contracted in an electrical field. The effects of drugs blocking adrenoreceptors suggested that the response is partially (uterus) or entirely (oviduct) mediated by the release of catecholamines and ovulation alters uterine adrenoreceptors.
Soil development at Kongsfjorden, Spitsbergen

Soils at well-drained sites near Kongsfjorden, Spitsbergen, are described in terms of morphology as well as solid and solution phase chemistry. Decarbonation is the dominant soil process and results in high Mg and Ca concentrations in soil solutions, in negative enrichment of Fe, Al, and non-carbonate clasts in nearsurface horizons, and in the accumulation of dolomitic silt horizons at depth. Coatings of reprecipitated carbonates extend into the C horizon. Several developmental pathways are suggested for well-drained carbonate soils at Kongsfjorden. In vegetation-rich areas, with calcite-rich parent material, relatively rapid (= 10,000 years) carbonate dissolution precedes silicate mineral weathering. In areas of Polar Desert climate and dolomitic parent material, decarbonation is slower and the continued accumulation of dolomite silt may eventually transform the soil system to a periglacial one.
The use of sulfadiazene in acute perforated appendicitis in children

Abstract One hundred fifty-one children encountered in a 5-year period with perforated appendicitis were divided into two groups; one received wide-spectrum antibiotics and sulfadiazene to combat the peritonitis; the other was treated with antibiotics alone. Those children on antibiotics alone had a 19% incidence of major postoperative complications. When sulfadiazene was added to the therapeutic regime, only 6% of the patients had serious complications. From this statistically significant clinical study, it is apparent that the addition of sulfadiazene to the commonly used antibiotics is effective in reducing the serious postoperative complications of perforated appendicitis. It is recommended that sulfadiazene be used in the routine management of this disease.
An energy-based model of gas–solid transport in a riser

Abstract A simple and reliable method to estimate the solid holdup distribution and solid residence time in a gas–solid riser flow is essential to the optimum design and efficient operations of riser reactors. The traditional approach of equating the local solid holdup to the pressure drop in a riser overlooks the effects of solid acceleration and energy dissipation in the acceleration and dense phase transport regions. The energy dissipation in these regions is mainly due to the interfacial friction between interstitial gas and suspended solids, inter-solid collisions, as well as solid–wall fraction. Most momentum-based models fail to account for the energy dissipation of inter-solid collisions, and the models using the simple granular kinetic theory fail to account for the energy dissipation in micro-sliding or rolling from off-center inter-solid collisions. This paper presents an energy-based mechanistic model to analyze the partitions of the axial gradient of pressure by solid acceleration, collision-induced energy dissipation and solid holdup in gas–solid riser flows. Based on this model, more reasonable estimation of axial distributions of solid holdup and resulted solid velocity can be obtained. Our analysis shows that the effect of solid acceleration on the pressure drop can be significant in a range of moderate solid holdup (typically from 3.5% to 12% by solid volume fraction) whereas the effect of energy dissipation becomes important in the dense phase transport region (typically when the solid volume fraction above 5%). The exemplified results indicate that the traditional approach of equating the local solid holdup to the pressure drop overestimates the solid holdup by an error up to 50% in the acceleration and dense phase transport regions in typical gas–solid riser flow applications.
Small bowel obstruction after laparoscopic gastric bypass with nonclosure of mesenteric defects.

Background and objectives There is a wide variation of reported incidence of small bowel obstruction (SBO) after laparoscopic Roux-en-Y gastric bypass (LGB). There is also wide variation in technique, not only in placement of the Roux limb, but also regarding closure or nonclosure of the mesenteric defects. The objective of this study was to examine the incidence and characteristics of SBO after antecolic antegastric bypass with nonclosure of the mesenteric defect of the jejunojejunal anastomosis. Methods This is a retrospective review of a series of consecutive LGBs over a 3-year period. All procedures were performed by the same surgeon using the same technique. In no case was the mesenteric defect closed. A prospectively maintained database was used for data collection. Patients who returned with an SBO were the study group, and those who underwent revisional bariatric surgery or conversion to open operation were excluded. Results There were 249 primary LGBs performed during the study period; 15 of the operations were followed by SBO, for an incidence of 6.0%. Four cases were caused by an internal hernia (IH), for an incidence of 1.6%, and 11 were caused by adhesions, which accounted for 73% of the SBOs. Conclusions SBO after LGB is a relatively common complication. The incidence of SBO from IH with nonclosure of the mesenteric defect is similar to that in other series where the defect is closed. Regardless of the cause of the SBO, operative treatment of the patient who has a gastric bypass remains the definitive standard and should not be delayed.
On the blackness of kettles: Inter-industry comparisons in rates of technological innovation

Conventional indirect measures of technological change in industry are shown to mislead analysts of the building industry. The result is a continuing popular and academic misreading of the industry. The diffusion of 14 innovations in the industry are measured empirically rather than inferentially and differences in diffusion rates are related to the industry's “management” of those innovations. A joint public-private strategy for managing future innovations is suggested.
Rotational diffusion kinetics of triphenodioxazines in solution

Abstract Experimental determinations of fluorescence kinetics and fluorescence polarization anisotropy kinetics of four triphenodioxazine (TPD) dyes in chloroform obtained following pulsed excitation at 532 nm are presented. The experimental fluorescence depolarization kinetics are compared with rotational diffusion kinetics based on the Debye—Stokes—Einstein hydrodynamic continuum model with stick boundary conditions. Modification of the model for slip boundary conditions is also considered and compared. A CNDO/CI molecular orbital calculation on the parent TPD molecule provides theoretical information on the excited states of these dyes and support for interpretation of the experimental results.
α-Macroglobulins Are Present in Some Gram-negative Bacteria CHARACTERIZATION OF THE α2-MACROGLOBULIN FROM ESCHERICHIA COLI

α-Macroglobulins (αMs) are large glycoproteins that have been identified in a wide range of vertebrate and invertebrate species and are mostly thiol ester containing proteinase inhibitors. A recent analysis of bacterial genomes (Budd, A., Blandin, S., Levashina, E. A., and Gibson, T. J. (2004) Genome Biol. 5, R38) identified many α-macroglobulin-like sequences that appear to have been acquired by Gram-negative bacteria from their metazoan hosts. We report the first expression and characterization of such a bacterial α-macroglobulin, that from Escherichia coli. This is also the first α-macroglobulin to be characterized that is predicted to be membrane-anchored. We found that the 183-kDa protein contains an intact thiol ester, is monomeric, and is localized to the periplasmic space. Reaction with proteinase results in limited cleavage within a bait region, rapid activation of the thiol ester, cross-linking to the attacking proteinase or other available nucleophiles, and partial protection of the proteinase against macromolecular substrates. Given these properties and the co-occurrence of the αM gene with one for a repair transglycosylase, this suggests a possible role for bacterial αMs in cell defense following host attack. Such a role would make bacterial αMs appropriate novel targets for antibiotic drugs.
Learner Characteristics that Influence the Treatment Effectiveness of Early Literacy Interventions: A Meta-Analytic Review

The purpose of this article was to systematically review the available research on learner characteristics that influence the treatment effectiveness of early literacy interventions. Meta-analytic procedures were applied to a total of 30 studies that met the inclusionary and exclusionary criteria. Mean average effect sizes were computed for seven primary learner characteristic categories: (1) rapid naming, (2) alphabetic principle, (3) phonological awareness, (4) problem behavior, (5) memory, (6) IQ, and (7) demographic. The primary learner characteristics that influenced the treatment responsiveness of early literacy interventions were, in order of magnitude, rapid naming, problem behavior, phonological awareness, alphabetic principle, memory, IQ, and demographics. With the exception of the demographic category, the obtained effect sizes for the primary learner characteristics were moderately large. The demographic primary learner characteristic (i.e., disability, ethnicity, grade-level status) of children was not statistically (p < 0.05) distinct from zero. The findings, limitations, and future research needs are discussed.
Somatostatin receptor agonists and antagonists

Somatostatin is a cyclic peptide that is widely distributed in the CNS, the periphery and in a variety of tumours. Two biologically active forms, somatotropin release-inhibiting factor (SRIF)-14 an...
Placental transfer of cefoperazone and sulbactam in the isolated in vitro perfused human placenta

The transfer of cefoperazone and sulbactam across the human placenta was studied qualitatively and quantitatively with the isolated in vitro bidirectiohally perfused human placental lobule. Clearance indexes for both cefoperazone and sulbactam were derived. The absence of active transport and facilitated diffusion were documented, implying simple diffusion as the mechanism of placental transfer for both drugs. Placental tissue levels were also studied.
A power amplifier based on an extended resonance technique

A new power amplifier based on an extended resonance technique is presented. This technique produces high power through multiplying the power handling capability of a single device by the number of devices employed while maintaining the gain of a single-device amplifier. An X-band power combining amplifier employing four 100 mW MESFET's was designed and constructed. The small signal gain was measured at 11.5 dB, and a maximum of 480 mW was obtained at 9.57 GHz with a power-added efficiency of 30.8%. >
Magnetic Resonance in Ferrites

Ferromagnetic resonance in ferrites is reviewed. The concept of tensor permeability, the influence of magnetic anisotropy, demagnetizing fields, and damping mechanisms are discussed. Special consideration is given to coupled magnetic systems and the behavior in ferrites with compensation points. The general theoretical results are compared with a few illustrative examples. The behavior in polycrystalline material, g-value, line width, and anisotropy as a function of temperature and external magnetic field are outlined.
Power routers with impedance-matched switchable 1:1/1:0 ratios for dual-operating mode amplifier applications

The authors present the full even–odd mode analysis of two novel power routing schemes and the router-integrated dual-operating mode amplifier. The routers provide two switchable operating states: a two-way 3-dB power divider (1 : 1) or a one-way signal path (1 : 0). These power routers, which satisfy matching requirements for the two different operations, are realised by means of coupled-line couplers. A 2.12 GHz GaAs FET dual-operating mode amplifier was demonstrated by employing the power routers. Switching the ratio in the amplifier prevents power losses through both the divider and combiner in a conventional balanced amplifier when one of the amplifiers is inoperable. Moreover, it has an attractive feature to enhance the amplifier efficiency by dynamically switching power dividing and combining ratios as well as controlling the operation of two reference amplifiers in a balanced-like configuration. The measured results of the implemented GaAs FET dual-mode amplifier in both the static and dynamic operations showed advantages over an in-phase balanced amplifier with an ordinary 3-dB Wilkinson power divider/combiner.
Thermomechancial characterization in a radiant energy imager using null switching

Thermomechanical noise for a MEMs-based infrared detector using null switching (US patent 7977635) depends on vibrational amplitude, since IR radiation is transduced to a change in the duty cycle of a repetitively closing switch. Equipartition theorem gives a maximum rms vibrational amplitude of 45 pm for the fabricated cantilever switch at its natural frequency. This gives a worst case timing uncertainty of 700 ns and an NEP of 2 pW/Sqrt[Hz].
Evaluation of turbulent Prandtl (Schmidt) number parameterizations for stably stratified environmental flows

Abstract In this study, we evaluate four different parameterizations of the turbulent Prandtl (Schmidt) number Prt = νt/Γt where νt is the eddy viscosity and Γt is the scalar eddy diffusivity, for stably stratified flows. All four formulations of Prt are strictly functions of the gradient Richardson number Ri, which provides a measure of the strength of the stratification. A zero-equation (i.e. no extra transport equations are required) turbulence model for νt in a one-dimensional, turbulent channel flow is considered to evaluate the behavior of the different formulations of Prt. Both uni-directional and oscillatory flows are considered to simulate conditions representative of practical flow problems such as atmospheric boundary layer flows and tidally driven estuarine flows, to quantify the behavior of each of the four formulations of Prt. We perform model-to-model comparisons to highlight which of the models of Prt allow for a higher rate of turbulent mixing and which models significantly inhibit turbulent mixing in the presence of buoyancy forces resulting from linear (continuous) stratification as well as two-layer stratification. The basis underlying the formulation of each model in conjunction with the simulation results are used to emphasize the considerable variability in the different formulations and the importance of choosing an appropriate parameterization of Prt given a model for νt in stably stratified flows.
RNA metabolism in rat intestinal mucosa of normal and vitamin A-deficient rats.

Abstract The decreased rate of leucine incorporation into leucyl-tRNA by the pH 5 enzyme fraction from vitamin A-deficient rat intestinal mucosa was investigated. When tRNA from either normal or vitamin A-deficient rat intestinal mucosa was added to the vitamin A-deficient pH 5 enzyme fraction, the yield of leucyl-tRNA rose to normal levels. Freon column chromatography of iso-accepting leucyl-tRNAs and threonyl-tRNAs failed to show any qualitative difference between normal and vitamin A-deficient iso-accepting species. Hence, a decrease in the amount of tRNA available for charging is responsible for the decrease in charging activity of the pH 5 enzyme fraction from vitamin A-deficient rat intestinal mucosa. RNA synthesis in the intestinal mucosa of normal and vitamin A-deficient rats was studied after intraperitoneal injection of either 14 C-6-orotic acid or 3 H-G-uridine. In three experiments the amount of label incorporated into all RNA fractions was 30–45% higher in the vitamin A-normal than the vitamin A-deficient rats. Measurements of uridine, UMP, and UDP pool sizes and their specific radioactivities 1 hr after injection of the label revealed that the difference in RNA synthesis between normal and vitamin A-deficient rat intestinal mucosa represented a true difference in the incorporation of the label into RNA and not a dilution effect on the label in deficient rats.
Dynamic Impacts of Rising Lumber Prices on Housing-Related Prices

A monthly vector autoregression model of lumber, lumber futures, construction materials, housing, and shelter prices was shocked with a 10% lumber price increase, and dynamic responses were examined. Futures and materials price increases were immediate and endured 1 and 3 years, respectively. Housing and shelter price increases required at least 9 months to begin, and endured for about 3 years. Effects on materials, housing, and shelter prices were less than one-for-one. Price effects from a 10% future price increase imposed on the model were more delayed, weaker, and less enduring than those generated by lumber price shocks. ©1994 by John Wiley & Sons, Inc.
Impact of magnetic resonance imaging on computed tomography-based treatment planning and acute toxicity for prostate cancer patients treated with intensity modulated radiation therapy

Abstract Purpose To evaluate rectal and bladder dosimetric and clinical acute toxicity endpoints for prostate patients treated with intensity modulated radiation therapy (IMRT) using magnetic resonance images (MRI) registered to computed tomographic (CT) simulation images versus CT alone. Materials and Methods The charts of 155 consecutive prostate cancer patients at our institution from 2004 to 2008 were reviewed. A cohort of 15 IMRT treatment plans was created to compare dosimetric endpoints for CT-MRI vs CT alone. A subsequent clinical comparison involved 81 patients (CT-MRI [n = 28] vs CT alone [n = 53]). Acute genitourinary and rectal toxicity rates for the CT-MRI and CT cohorts were compared; also, univariate and multivariate regression analyses were performed using all major demographic, disease, and treatment factors as covariates. Results Contoured prostate volumes were 43.0 vs 55.7 cm 3 ( P P = .024) and 39%, 29%, and 32% vs 32%, 28%, and 40% (acute rectal, P = .495). On univariate regression, only MRI use and International Prostate Symptom Scores reached significance for acute GU toxicity. On multivariate regression, age, prostate volume, and MRI use reached statistical significance for acute GU toxicity. No factor reached significance for rectal toxicity. Conclusions This study demonstrates a statistically significant reduction in clinical acute GU toxicity with the clinical implementation of MRI in the treatment planning process.
Reactions of Neopentylindium(III) Derivatives with Isopropylphosphorus Compounds

A 1:1 mixture of In(CH2CMe3)3 and HP(i-Pr)2 at room temperature undergoes a very slow hydrocarbon elimination reaction to form [(Me3CCH2)2InP(i-Pr)2]2 and neopentane. The indium phosphide [(Me3CCH2)2InP(i-Pr)2]2 has also been prepared by reacting KIn(CH2CMe3)3H with ClP(i-Pr)2 in pentane. When pentane solutions of these reagents were combined at −78 °C and then maintained at ∼20 °C for 2 days, [(Me3CCH2)2InP(i-Pr)2]2, (Me3CCH2)3In·P(H)(i-Pr)2, (Me3CCH2)3In·P2(i-Pr)4, (Me3CCH2)3In·P(CH2CMe3)(i-Pr)2, H2, indium metal, and KCl were observed. The formation of all products is explained by a set of experimentally verified reactions. An X-ray structural study of [(Me3CCH2)2InP(i-Pr)2]2 shows each molecule to have an unusual puckered four-membered In2P2 core.
Intracortical 5,7-dihydroxytryptamine depletes brain serotonin concentrations without affecting spontaneous activity.

Abstract Microinjections of either 2 or 4 μg of the serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) were made into either the right or left frontal cortex of male rats pretreated with desmethylimipramine. Although both the 2 and 4 μg doses produced significant depletions of serotonin concentrations in the cortex and median raphe, neither dose produced a significant increase in spontaneous activity. This is in contrast to our findings with the noradrenergic neurotoxins, 6-hydroxydopamine and DSP-4, which produced hyperactivity following right but not left hemisphere injections. These findings do not rule out the involvement of 5-HT in the asymmetrically elicited hyperactivity but they do suggest some transmitter and neural pathway specificity to the lateralized response to cortical injury.
Experimental Analysis of Natural Convection Within a Thermosyphon

Abstract The heat transfer characteristics of a thermosyphon designed to passively cool cylindrical heat sources are experimentally studied. The analysis is based on recognizing the physics of the flow within different regions of the thermosyphon to develop empirical heat transfer correlations. The basic system consists of three concentric cylinders, with an outer channel between the outer two cylinders, and an inner channel between the inner two cylinders. Tests were conducted with two different process material container diameters, representing the inner cylinder, and several different power levels. The experimentally determined local and average Nu numbers for the inner channel are in good agreement with previous work for natural convection between vertical parallel plates, one uniformly heated and the other thermally insulated. The implication is that the heat transfer off of each surface is independent of the adjacent surface for sufficiently high Ra numbers. The heat transfer is independent because of limited interaction between the boundary layers at sufficiently high Ra numbers. As a result of the limited interaction, the maximum temperature within the system remained constant, or decreased slightly when the radii of the inner cylinders increased for the same amount of heat removal.
AN APPROACH TO HUMANISM IN A MEDICAL SETTING: THE PRECEPTOR PROGRAM AT THE WAYNE STATE UNIVERSITY SCHOOL OF MEDICINE*

This paper describes an effort to influence the thoughts, feelings, and behavior of groups of medical students by providing special experiences which, it is hoped, will provide antigens for the “dehumanizing influences that are found in traditional medical education.
Bayesian state-space model of fin whale abundance trends from a 1991–2008 time series of line-transect surveys in the California Current

Summary 1. Estimating temporal trends in animal abundance is central to ecology and conservation, but obtaining useful trend estimates is challenging when animal detection rates vary across surveys (e.g. because of differences in observers or conditions). Methods exist for obtaining abundance estimates using capture–recapture and distance sampling protocols, but only recently have some of these been extended to allow direct estimation of abundance trends when detection rates vary. Extensions to distance sampling for >2 surveys have not yet been demonstrated. 2. We demonstrate a Bayesian approach for estimating abundance and population trends, using a time series of line-transect data for endangered fin whales Balaenoptera physalus off the west coast of the United States. We use a hierarchical model to partition state and observation processes. Population density is modelled as a function of covariates and random process terms, while observed counts are modelled as an overdispersed Poisson process with rates estimated as a function of population density and detection probability, which is modelled using distance sampling theory. We used Deviance Information Criteria to make multi-model inference about abundance and trend estimates. 3. Bayesian posterior distributions for trend parameters provide strong evidence of increasing fin whale abundance in the California Current study area from 1991 to 2008, while individual abundance estimates during survey years were considerably more precise than previously reported estimates using the same data. Assuming no change in underlying population dynamics, we predict continued increases in fin whale numbers over the next decade. Our abundance projections account for both sampling error in parameter estimates and process variance in annual abundance about the mean trend. 4. Synthesis and applications. Bayesian hierarchical modelling offers numerous benefits for analysing animal abundance trends. In our case, these included its implicit handling of sampling covariance, flexibility to accommodate random effects and covariates, ability to compare trend models of different functional forms and ability to partition sampling and process error to make predictions. Ultimately, by placing distance sampling within a more general hierarchical framework, we obtained more precise abundance estimates and an inference about fin whale trends that would have otherwise been difficult.
Actual pentamidine dose delivered by Respigard II nebulizer.

The Respigard II nebulizer system is the approved method to deliver pentamidine aerosols in the USA. Although continuous operation of the nebulizer until dryness is a designated regimen, the actual pentamidine dose delivered under the operating condition has not been thoroughly studied. Pentamidine solutions (300 mg in 6 mL water) were nebulized continuously with the Respigard II nebulizer system until dryness (40 min operation). Aerosols were delivered to the lower airways via an oropharyngeal model and sampled on a filter with a standard breathing mode of 20 breaths.min-1 frequency and 750 mL tidal volume. Intermediate samples were also obtained for the initial 20 min delivery. The pentamidine dose delivered to the mouth was 1.6% of the dose placed in the nebulizer. Of the dose delivered to the mouth, 92% was delivered during the initial 20 min period. Aerosol loss in the oropharyngeal model was 15% of the dose delivered to the mouth or 0.24% of the dose initially placed in the nebulizer. Pentamidine dose delivered to the lower airways was a very small fraction of the initial dose in the nebulizer. A partial delivery for the initial 20 min was nearly comparable to complete delivery.
Intrauterine Growth Retardation

Intrauterine growth retardation can result from a variety of environmental and genetic influences on fetal growth. The sequelae of intrauterine growth retardation resulting from impairment of nutrient flow include low birth weight with sparing of brain growth, polycythemia, and hypoglycemia resulting from decreased storage fuels and defective gluconeogenesis. Available data suggest that the vast majority of nutritionally growthretarded infants have normal postnatal development without significant difference in IQ or neurologic scores from normal infants. The outcome of infants in whom there is decreased growth potential relates to the condition underlying growth retardation and may, of course, result in later severe handicap. Infants with nutritional intrauterine growth retardation may exhibit decreased fetal size and sparing of brain growth as an adaptive stage in the presence of lower oxygen and substrate availability. Under such conditions, a smaller size may decrease substrate and oxygen needs and improve outcome. All infants with intrauterine growth retardation, however, require follow-up and careful developmental evaluation.
The Role of Comprehension in Learning Concrete and Abstract Sentences.

The purpose of the present study was to assess the effect of comprehension on the recognition of meaning and wording changes with concrete and abstract sentences. One group was presented the sentences embedded in a context paragraph designed to increase comprehension. Recognition for meaning changes in abstract sentences was significantly higher for the paragraph-embedded group than for a group presented the sentences without the paragraphs. There was no appreciable differences between the groups in recognition for wording changes in abstract sentences, nor in recognition for both meaning changes and wording changes in concrete sentences. The results of the experiment were discussed in light of recent models which propose different storage mechanisms for concrete and abstract sentences.
Customized learning algorithms for episodic tasks with acyclic state spaces

The work presented in this paper provides a practical, customized learning algorithm for reinforcement learning tasks that evolve episodically over acyclic state spaces. The presented results are motivated by the Optimal Disassembly Planning (ODP) problem described in [14], and they complement and enhance some earlier developments on this problem that were presented in [15]. In particular, the proposed algorithm is shown to be a substantial improvement of the original algorithm developed in [15], in terms of, both, the involved computational effort and the attained performance, where the latter is measured by the accumulated reward. The new algorithm also leads to a robust performance gain over the typical Q-learning implementations for the considered problem context.
Radiation protection of dental personnel

Responsibilities of dentists in reducing exposure to themselves and their assistants below the maximum permissible limit (0.1 r per week) are discussed. Modifications of equipment suggested for reducing occupational radiation exposure to dental personnel are: filtration to a total of 2.5 mm of Al should be used in units operating above 70 kvp, and 1.5 mm for those operating up to 70 kvp; a Pb jacket should be inserted in the housing to prevent excessive leakage, if necessary; collimation by means of a Pb diaphragm should be used to reduce the diameter of the primary beam at the tip of the cone to 3 in.; and the timer cord should be of sufficient length to permit the operator to be at least 6 ft away from the primary beam and patient during exposure. Modifications of technic suggested to reduce exposure are: shields or screens should be used where the minimum distance of 6 ft cannot be maintained; the operator should assume a position that will enable him and assisting personnel to be in back of the primary beam, or if this is not possible, the position should be at right angles to the beam and preferably behind the patient; exposuremore » times should be kept to a minimum while still obtaining good roentgenograms; and the path of the primary beam should be directed toward an outside wall. Film badge service is recommended as an inexpensive, simple means to determine whether, through fault of equipment or technic, personnel are receiving excessive radiation. (TCO)« less
Calculation and Design of Class C Amplifiers

A method of calculating the performance of class C triode amplifiers is presented which is based on the assumption that the total space current (I p +I g ) is proportional to (E g +E p /μ)α, where α is a constant, usually close to three halves. The direct-current and fundamental alternating-current components of such a space current pulse are presented (graphically) as a function of the angle of current flow, for various values of α, and it is shown how to obtain the plate current components by estimating the direct grid current, and correcting for the current diverted to the grid. It is shown how the results of the analysis may be applied in a straightforward manner to lay out class C amplifiers on paper, and to predict power output, power input, plate loss, etc., for any particular set of operating conditions. The method is applied to several examples and the accuracy shown to be satisfactory for all ordinary design requirements.
Fellows as Teachers: The Teacher-Assistant Experience During Pulmonary Subspecialty Training

Study objectives Physicians undergoing medical subspecialty training, referred to as “fellows” in the United States, often serve as small group tutors. There are few reports, however, on whether fellows benefit from their experience teaching in the classroom. The purpose of this article is to describe the teacher-assistant requirement for fellows in a pulmonary and critical care training program and gain the perspectives of program graduates on their experiences as teacher assistants. Design, setting, and participants The structure of the teacher-assistant requirement is described in detail. We also surveyed 55 consecutive graduates of our Pulmonary and Critical Care Fellowship program located in the United States on the educational value of teaching pathophysiology to preclinical medical students. Results Fellows and one or two faculty members coteach groups of 15 to 25 second-year medical students during 22 h of case-based conferences over a 6-week period. Weekly meetings for teacher assistants foster improved teaching skills and provide insight into the basic tenets of structuring and implementing the course. Fellows receive formal and informal feedback on their performance. Fifty of 55 graduates (91%) returned the survey. Respondents rated the acquisition of teaching skills and knowledge of pulmonary pathophysiology as the most useful aspects of their experience. Eighty-seven percent rated their overall experience favorably, and 90% agreed that teaching the course should remain a curriculum requirement. The responses of physicians in academic and community practice were comparable. Conclusions Graduates of our Pulmonary and Critical Care Fellowship valued their teacher-assistant experience. This article may serve as a model for other subspecialty programs that are interested in formally incorporating teaching into their training program and may provide an impetus for the additional exploration of teacher-assistant experiences at other institutions.
Oxygen in egg masses: interactive effects of temperature, age, and egg-mass morphology on oxygen supply to embryos.

SUMMARY Embryos of many marine invertebrates are encased in gelatinous masses for part or all of development. Because gel and intervening embryos retard oxygen flux, such a life-history mode profoundly affects partial pressures of metabolic gases surrounding embryos. However, little is known about relationships between egg-mass structure and the opportunities and constraints imposed on structure by metabolic gas transport. We examined the effects of four factors (temperature, embryo age, embryo density and egg-mass size) on the metabolism of egg masses using both natural egg masses of a nudibranch and artificial egg masses made from sand dollar embryos and low-melting point agarose. Both temperature and embryo age strongly affected metabolic rates of nudibranch embryos. For embryos of a given age (stage), rates of oxygen consumption roughly doubled between 12 and 21°C; from early cleavage to the veliger stage, consumption rose two- to fourfold, depending on temperature. Oxygen profiles in egg masses showed that advanced embryonic age, and to a lesser extent high temperature, both led to steeper oxygen gradients into egg masses. Egg masses containing advanced embryos at 21°C had very low central oxygen levels. Small-diameter artificial masses (2 mm diameter) had virtually no internal oxygen gradients regardless of embryo density or temperature, while medium (4 mm) and large diameter (10 mm) artificial masses had oxygen profiles that depended strongly and interactively on embryo density and temperature. Together, our data on natural and artificial egg masses suggest that (i) multiple factors have strong effects on metabolic rate; (ii) rates of oxygen transport are relatively invariant with temperature in simple, artificial systems but may vary more strongly with temperature in natural egg masses; and (iii) the four factors – temperature, embryo age, embryo density and egg-mass size – interact in important ways bearing on egg mass design. A simple mathematical model is developed to provide a quantitative means of estimating primary and interactive effects of the different factors. We also show that in T. diomedea the gel itself is the main barrier to oxygen transport into egg masses, and that the metabolic activity of embryos increases substantially when embryos are artificially released from the capsules that contain them within the gel mass.
Special Cases and Applications

We present here well-known examples and applications of continuous-time Principal–Agent models. The seminal work of Holmstrom and Milgrom (Econometrica 55:303–328,1987) is the first to use a continuous-time model, showing that doing that can, in fact, lead to simple, while realistic optimal contracts. In particular, if the principal and the agent maximize expected utility from terminal output value, and have non-separable cost of effort and exponential utilities, the optimal contract is linear in that value. With other utilities and separable cost of effort, the optimal contract is nonlinear in the terminal output value, obtained as a solution to a nonlinear equation that generalizes the first best Borch condition. In the case of the agent deriving utility from continuous contract payments on an infinite horizon, and if the principal is risk-neutral, the problem reduces to solving an ordinary differential equation for the principal’s expected utility process as a function of the agent’s expected utility process. That equation can then be solved numerically for various cases, including the case in which the agent can quit, or be replaced by another agent, or be trained and promoted. These cases are analyzed by studying the necessary conditions in terms of an FBSDE system for the agent’s problem, and, in Markovian models, by identifying sufficient conditions in terms of the HJB differential equation for the principal’s problem.
Chylous Bronchial Casts After Fontan Operation

A 4-year old boy with D-transposition of the great arteries, pulmonary atresia with intact ventricular septum, and a hypoplastic left ventricle with mitral atresia underwent a Fontan operation. He had previously been treated with neonatal balloon atrial septostomy followed by a left modified Blalock-Taussig shunt and, at the age of 2 years, a Hemi-Fontan operation was performed. The Fontan operation was completed with an extracardiac conduit (Goretex) from the inferior vena cava to the superior vena cava. High central venous pressures and bilateral chylothoraces complicated the postoperative course. Despite 6 weeks of conservative treatment with fat-free …
Crystallographic Studies of Bacterial Exoribonucleases

INTRODUCTION. Ribonucleases (RNases) play a central role in all cellular RNA processes. These processes include mRNA degradation, and maturation and turnover of stable RNAs, which are vital for the proper functioning of all cells. E. coli has served as a model system for understanding the role of ribonucleases in RNA metabolism, and eight distinct exoribonucleases have been identified in this bacterium. Of these, three (RNase T, RNase D, and oligoribonuclease) are members of a larger exonuclease superfamily (named the DEDD exonuclease family, after the four invariant acidic residues in these proteins) that includes the proof-reading domains of DNA polymerases[1].
Microstructural and mechanical differences between digested collagen-fibrin co-gels and pure collagen and fibrin gels.

Abstract Collagen and fibrin are important extracellular matrix (ECM) components in the body, providing structural integrity to various tissues. These biopolymers are also common scaffolds used in tissue engineering. This study investigated how co-gelation of collagen and fibrin affected the properties of each individual protein network. Collagen–fibrin co-gels were cast and subsequently digested using either plasmin or collagenase; the microstructure and mechanical behavior of the resulting networks were then compared with the respective pure collagen or fibrin gels of the same protein concentration. The morphologies of the collagen networks were further analyzed via three-dimensional network reconstruction from confocal image z-stacks. Both collagen and fibrin exhibited a decrease in mean fiber diameter when formed in co-gels compared with the pure gels. This microstructural change was accompanied by an increased failure strain and decreased tangent modulus for both collagen and fibrin following selective digestion of the co-gels. In addition, analysis of the reconstructed collagen networks indicated the presence of very long fibers and the clustering of fibrils, resulting in very high connectivities for collagen networks formed in co-gels.