cssi/SciSciGPT-SciSciNet huggingface dataset:
Geoengineering: What, how, and for whom?

© 2009 American Institute of Physics, S-0031-9228-0902-220-0 I have been thinking about geoengineering for climate modification since I worked on the committee that produced the 1992 National Academies report, Policy Implications of Greenhouse Warming. Over the years, and increasingly now, I have been puzzled by the scientific community’s attitudes toward the issue; those puzzles were raised again by Barbara Goss Levi’s story (PHYSICS TODAY, August 2008, page 26). It has been customary to discuss geoengineering without offering an explicit definition. I propose the following one: Geoengineering is purposeful action intended to manipulate the environment on a very large—especially global— scale. Geoengineering is, presumably, undertaken to reverse or reduce impacts of human actions. Decreasing human emissions of carbon dioxide and other greenhouse gases is a good idea for many reasons, including climate modification; yet it is not clear to me why manipulating the CO2 content of the atmosphere is not considered geoengineering. If, using the above definition but narrowing it to the case under consideration, geoengineering includes purposeful manipulation of physical, chemical, and biological variables on the global scale for the purpose of changing global climate, then manipulation of carbon dioxide concentrations fits the definition as well as do, for example, manipulating atmospheric aerosol content to control albedo or manipulating the ocean’s iron content to increase the long-term oceanic storage of carbon. Exclusion of carbon dioxide manipulation from geoengineering has led to a double standard in considering possible negative consequences. There is legitimate concern about side effects of particulate manipulation and the like, but I have not heard much worrying about manipulating carbon dioxide. In a highly nonlinear feedbackcontrolled system like global climate, we would expect complex hysteresis effects: Decreasing a control variable such as greenhouse gas will not necessarily lead the climate back along some path like the one it followed when the control variable was increased. The end state of control-variable manipulation may not at all resemble the original state before the control variable was increased, nor will it necessarily be a state we want to be in. I have heard of no concern about those possibilities, which might be rate dependent, involve transient behavior not to our liking, or lead us through bifurcations into unexpected states. It seems to me we need to be concerned about possible not-so-benign effects of decreasing carbon dioxide and other greenhouse gases before we grab the control knob and turn it down. I hope someone is at least exercising suitable climate models, if relevant ones exist, to examine possible end states, paths to them, and transient effects of carbon dioxide geoengineering. Robert A. Frosch (robert_frosch@harvard.edu) Harvard Kennedy School Cambridge, Massachusetts
Methyl Bromide Emissions from Agricultural Fields: Bare-Soil, Deep Injection

The environmental fate and transport of methyl bromide (MeBr) in an agricultural field after deep injection (68 cm) is described and compared to a recent experiment where MeBr was injected at a shallow (25 cm) depth, and the surface was covered with high-density polyethylene plastic. Three independent methods were used to estimate the total MeBr lost after application, i.e., the appearance of soil Br-, the flux chamber, and micrometeorological methods. Peak MeBr volatilization rates occurred during the first 24 h, but relatively high rates continued for more than 7 days after application. Diurnally, the largest volatilization rates oc curred from midnight to early morning during periods of decreasing barometric pressure, and the volatilization rate decreased when the barometric pressure was increasing. Due to deep injection, cooler temperatures, and smaller thermal gradients, the total MeBr mass emitted from the field was significantly less than a previous experiment. The total emissions estimate obtained...
Effect of Adsorbents on Drug Absorption: Importance of Preequilibrating Drug and Adsorbent

Absorption of promazine from the human gastrointestinal tract is unaffected by small amounts of activated attapulgite and activated charcoal when drug and adsorbent are not equilibrated before administration of the test dose. These results are contrasted to previous experiments where the marked inhibition of absorption occurred with the same doses of drug and adsorbent in equilibrated systems.
WaveFormRevealer: An analytical framework and predictive tool for the simulation of multi-modal guided wave propagation and interaction with damage:

This article presents the WaveFormRevealer—an analytical framework and predictive tool for the simulation of guided Lamb wave propagation and interaction with damage. The theory of inserting damage effects into the analytical model is addressed, including wave transmission, reflection, mode conversion, and nonlinear higher harmonics. The analytical model is coded into MATLAB, and a graphical user interface (WaveFormRevealer graphical user interface) is developed to obtain real-time predictive waveforms for various combinations of sensors, structural properties, and damage. In this article, the main functions of WaveFormRevealer are introduced. Case studies of selective Lamb mode linear and nonlinear interaction with damage are presented. Experimental verifications are carried out. The article finishes with summary and conclusions followed by recommendations for further work.
An investigation of the second heart sound in the normal horse.

Summary The second heart sound was evaluated in conscious, normal horses using intracardiac and external sound detection devices and echocardiography. The second heart sound (S2) in the normal horse is single or split by a narrow interval, not usually detected by external phonocardiographic evaluation. Splitting of S2 was classified as normal (aortic [A2] preceding pulmonic [P2] components) in 66.7 per cent and reversed (P2 preceding A2) in 33.3 per cent of the horses studied. Normal splitting appears to result from lower impedance of the pulmonary vasculature delaying the onset of P2. Reverse splitting appears to result from a delay in A2 resulting from prolongation of PEP and LVET. There does not appear to be variation in splitting of S2 due to respiration based on the cases in which this was measured.
Management of Breastfeeding During and After the Maternity Hospitalization for Late Preterm Infants

Among infants born moderately and late preterm or early term, the greatest challenge for breastfeeding management is the late preterm infant (LPI) who is cared for with the mother in the maternity setting. Breastfeeding failure among LPIs and their mothers is high. Evidence-based strategies are needed to protect infant hydration and growth, and the maternal milk supply, until complete feeding at breast can be established. This article reviews the evidence for lactation and breastfeeding risks in LPIs and their mothers, and describes strategies for managing these immaturity-related feeding problems. Application to moderately and early preterm infants is made throughout.
HETEROMETALLIC LANTHANIDE-GROUP 14 METAL CHALCOGENOLATES

Heterometallic chalcogenolate compounds containing both lanthanide (Ln) and group 14 metals (M; M = Sn, Pb) form a variety of structures that can be understood in the context of relative metal−chalcogen bond strengths. The compounds (THF)2Eu(μ2-SePh)6Pb2 (1), [Yb(THF)6][Sn(SePh)3]2 (2), and [(py)2Eu(2-S-NC5H4)2Sn(2-S-NC5H4)2]n (3) have been prepared, and their structures have been established by low-temperature single-crystal X-ray diffraction. Ln−S bonds are found to be relatively insensitive to the presence of a group 14 metal thiolate, whereas Ln−Se bonds are readily distorted upon coordination to Pb(SePh)2, and cleaved by the addition of the stronger Lewis acid Sn(SePh)2. The stereochemically active lone pair of electrons on the group 14 metal influences structure, as does the identity of the chalcogenolate. All three compounds show no interaction between the Ln ion and the group 14 metal lone pair. Crystal data (1−3 Mo Kα; −80 to −100 °C): 1, triclinic space group P1, a = 10.582(3) A, b = 12.114(2)...
Catecholamine Interference in Enzymatic Creatinine Assays

Background: Enzymatic creatinine assays are routinely used in clinical laboratories to provide more accurate estimated glomerular filtration rates and to avoid a perceived lack of analytical specificity associated with picrate (Jaffe) methods. Negative interferences with the enzymatic creatinine assay, which we noted in several patients on dopamine or dobutamine, prompted our further investigation into interference of catecholamines with enzymatic methods. Methods: Spiked solutions of dopamine, dobutamine, epinephrine, and norepinephrine were added to pooled sera at catecholamine concentrations consistent with clinically relevant dosing. Creatinine was measured enzymatically on the Roche P-Modular, Ortho Clinical Diagnostics Vitros 350, and Abbott i-STAT. Jaffe methods were performed on the Roche P-Modular and Siemens Dimension RxL. In 10 patients receiving dopamine and/or dobutamine via a venous or arterial line we evaluated and compared the extent of in vivo creatinine interference in paired serum samples obtained by venipuncture and from indwelling catheters. Results: All catecholamines caused significant negative interference with the Roche enzymatic creatinine assay, most pronounced for dopamine and dobutamine. The Vitros enzymatic assay demonstrated slight negative interferences, and i-STAT enzymatic and Jaffe methods were unaffected by the presence of catecholamines. Significant ( P < 0.001) differences in creatinine concentrations by Roche enzymatic vs Jaffe methods were observed in venipuncture specimens compared with arterial or venous catheter specimens, suggesting dopamine and dobutamine reversibly adhere to the catheter lumen. Conclusions: Negative interferences were pronounced for Roche enzymatic results in blood samples obtained from indwelling catheters, a phenomenon not observed in peripheral draws. Physicians and laboratorians should be alert to the possibility of a falsely low creatinine result and reevaluate questionable samples using a method unaffected by catecholamines.
The Non-Achievement Syndrome, Group Therapy, and Achievement Change

174 selected failing students at Illinois Institute of Technology were provided group counseling as a condition of their remaining in school. The assumption of the psychodynamics of the non-achievement syndrome was made regarding these students and a group counseling approach (NAS therapy) derived from an approach delineated by Roth and Meyersburg seemed appropriate and was utilized. 52 male subjects in this population were randomly selected for study as were 52 probationary, noncounseled males who were used as a comparison group. The results indicated that the counseled group increased their GPA's significantly and that these changes held over time. The GPA's of the comparison group did not increase significantly. The differences were attributable to the counseling experience.
Role of the RNA polymerase trigger loop in catalysis and pausing

The trigger loop (TL) is a polymorphous component of RNA polymerase (RNAP) that makes direct substrate contacts and promotes nucleotide addition when folded into an α-helical hairpin (trigger helices; TH). However, the roles of the TL/TH in transcript cleavage, catalysis, substrate selectivity, and pausing remain ill-defined. Based on in vitro assays of Escherichia coli RNAP bearing specific TL/TH alterations, we report that neither intrinsic nor regulator-assisted transcript cleavage of backtracked RNA requires formation of the TH. We find that the principal contribution of TH formation to rapid nucleotidyl transfer is steric alignment of the reactants, rather than acid-base catalysis, and that the TL/TH cannot be the sole contributor to substrate selectivity. The similar effects of TL/TH substitutions on pausing and nucleotide addition provide additional support for the view that TH formation is rate-limiting for escape from nonbacktracked pauses.
Learning from Healthy Older Adults: An Analysis of Undergraduate Students’ Reflective Essays

Service learning has been utilized as an effective type of pedagogy, and students involved in service learning projects gain real-world experiences outside the classroom. Research suggests that intergenerational service learning projects are becoming increasingly common and such projects are likely to enhance the quality of both academic and civic outcomes for students. There is, however, relatively little research on the learning outcomes of event management students involved with physically active older adults. This study investigated the learning outcomes of undergraduate students who facilitated a sporting event for older adults. Students participated in structured service learning opportunities at the Indiana Senior Games, a multi-sport event for those aged 50 and older. Three investigators independently used content analysis methodology to analyze 142 student reflection papers. It was found that the students developed relationships with older adults, were less likely to negatively stereotype older adults, and realized the importance of maintaining an active lifestyle when they grow old. Service learning opportunities with older adults are a promising practice for undergraduate students, as self-esteem and a sense of social responsibility may be affected.
A Bayesian criterion for cluster stability

We present a technique for evaluating and comparing how clusterings reveal structure inherent in the data set. Our technique is based on a criterion evaluating how much point-to-cluster distances may be perturbed without affecting the membership of the points. Although similar to some existing perturbation methods, our approach distinguishes itself in five ways. First, the strength of the perturbations is indexed by a prior distribution controlling how close to boundary regions a point may be before it is considered unstable. Second, our approach is exact in that we integrate over all the perturbations; in practice, this can be done efficiently for well-chosen prior distributions. Third, we provide a rigorous theoretical treatment of the approach, showing that it is consistent for estimating the correct number of clusters. Fourth, it yields a detailed picture of the behavior and structure of the clustering. Finally, it is computationally tractable and easy to use, requiring only a point-to-cluster distance matrix as input. In a simulation study, we show that it outperforms several existing methods in terms of recovering the correct number of clusters. We also illustrate the technique in three real data sets. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining, 2013
Effect of glucose on aspartic acid racemization

Abstract The racemization of aspartic acid in aqueous solution with and without phosphate buffer was found to increase in the presence of d -glucose. This increase in racemization appears to involve the formation of an imine intermediate (Schiff base). Subsequent proton tautomerization leading to the loss of asymmetry during the early stages of melanoidin formation could account for the observed increase in racemization. The racemization reaction did not follow reversible first order kinetics when glucose was added to buffered aspartic acid solution at 80°C; in unbuffered solution reversible first order kinetics were followed up to 624 hr.
The engineering economist of the future

The engineer who aspires to solve modern economic problems by applying his well tried scientific methods, should take thought of the limitations of those methods; he must expect to do an unusual amount of studying before he can hope to replace old economic theories with others better suited to present conditions; and because of the capricious nature of the many variables involved, he should not attempt to predict future trends on the basis of past experience.
social classification in Creole Louisiana

Synchronic and diachronic variation in the definition and composition of the Creole population presents theoretical problems. Neither a strictly empirical historical analysis of social groups nor a strictly paradigmatic analysis of social categories renders a satisfactory explanation of semantic and empirical variation. Suggested in this paper as a more adequate alternative is a syntagmatic analysis of social classification that is at once structural and diachronic.
Inhalability of Large Particles into the Human Nasal Passage: In Vivo Studies in Still Air

The aspiration of large particles (18–30.5 μm) in the human nose was studied to determine the inhalation efficiency as a function of particle size, and to evaluate the upper size cutoff for inhalable particles in still air. Under these conditions, the ability of a particle to be inhaled is dependent on the inhalation velocity entering the nose and the particle terminal settling velocity. Nasal inhalation of radiolabeled pollen and wood dust aerosols was measured in four subjects at normal resting breathing rates. The efficiency of nasal aspiration was found to decrease as the square of the particle size. The upper size cutoff for inhalability was estimated to be approximately 39 μm in still air.
Design of highly efficient coal-based integrated gasification fuel cell power plants

Integrated gasification fuel cell (IGFC) technology combining coal gasification and solid oxide fuel cell (SOFC) is believed to be the only viable solution to achieving U.S. Department of Energy (DOE)'s performance goal for next generation coal-based power plants, producing electricity at 60% efficiency (coal HHV-AC) while capturing more than 90% of the evolved CO2. Achieving this goal is challenging even with high performance SOFCs; design concepts published to date have not demonstrated this performance goal. In this work an IGFC system concept consisting of catalytic hydro-gasification, proven low-temperature gas cleaning and hybrid fuel cell-gas turbine power block (with SOFC operating at about 10 bar) is introduced. The system is demonstrating an electricity efficiency greater than 60% (coal HHV basis), with more than 90% of the carbon present in the syngas separated as CO2 amenable to sequestration. A unique characteristic of the system is recycling de-carbonized, humidified anode exhaust back to the catalytic hydro-gasifier for improved energy integration. Alternative designs where: (1) anode exhaust is recycled directly back to SOFC stacks, (2) SOFC stack operating pressure is reduced to near atmospheric and (3) methanation reactor in the reactor/expander topping cycle is removed, have also been investigated and the system design and performance differences are discussed. © 2010 Elsevier B.V.
Density, viscosity, and speed of sound in the ternary mixtures of 2-ethoxyethanol + N, N-dimethylformamide + N, N-dimethylacetamide and 2-ethoxyethanol + dimethyl sulfoxide + N, N-dimethylacetamide at 308.15 K

Experimental values of density, viscosity, and speed of sound of the ternary mixtures of 2-ethoxyethanol (1) + N,N-dimethylformamide (2) + N,N-dimethylacetamide (3) and 2-ethoxyethanol (1) + dimethyl sulfoxide (2) + N,N-dimethylacetamide (3) at 308.15 K and at 18 different concentrations are reported. From the data, the excess volume and the deviations in adiabatic compressibility, viscosity, and speed of sound for the ternary mixtures over the additive values were calculated. The deviations were fitted using the Redlich-Kister equation.
A comparative network analysis of the Korean Society of Journalism and Communication Studies (KSJCS) and the International Communication Association (ICA) in the era of hybridization

This article examines the structure of the Korean Society for Journalism and Communication Studies (KSJCS) and the International Communication Association (ICA) based on the division membership of scholars. Theoretically, hybridization as coexistence of similarities and differences between the two organizations of different cultural backgrounds were explored. Using network analysis, the study found that in the KSJCS media and journalism-related divisions formed the nucleus of the communication discipline, and that two dimensions, ‘humanities vs. social science’ and ‘interpersonal vs. mediated communication,’ constituted the ICA. Suggestions for future research were addressed.
Local retinal adaptation and spatial frequency channels.

Abstract We have presented evidence that local retinal adaptation is not the cause of spatial frequency channels. This was done by minimizing local retinal adaptation with gratings whose contrast was a sinusoidal function of time. The gratings were viewed through an image stabilization apparatus to ensure that the subject would not fixate preferentially on certain portions of the grating providing uneven retinal adaptation.
Acquaintance, singular thought and propositional constituency

In a recent paper, Armstrong and Stanley (Philos Stud 154:205–222, 2011) argue that despite being initially compelling, a Russellian account of singular thought has deep difficulties. I defend a certain sort of Russellian account of singular thought against their arguments. In the process, I spell out a notion of propositional constituency that is independently motivated and has many attractive features.
A Comparison of Methods for Approximating the Mean Eigenvalues of a Random Matrix

This paper proposes several methods for approximating the expected value of an eigenvalue of a random matrix. A comparative study assesses the accuracy of these methods. The proposed methods for approximating the mean value of an eigenvalue of a random matrix consist of a regression approach using the dimensions of the data and position of the eigenvalue as predictors, two methods using expected values of order statistics for the normal distribution, and another approach using percentiles of the normal distribution. These methods provide researchers who desire to readily determine the dimensionality of data by using parallel analysis, with easy-to-implement alternatives to calculate the mean eigenvalues of a random matrix.
The Impact of Previous Suicide Ideations, Traumatic Stress, and Gender on Future Suicide Ideation Trajectories Among Black American Adolescents: A Longitudinal Investigation

It has long been asserted that previous suicide behaviors (gestures and attempts) are a significant predictor of future suicide behaviors. Less is known about the extent to which this axiom applies to suicide ideations. The current investigation explored suicide ideations in a longitudinal sample of Black American adolescents (N = 977) aged 11 to 18. Logistic growth models were conducted with future suicide ideations as the dependent variable and the number of previous suicide ideations, traumatic stress, and gender as independent variables. Results show, first, that previous suicide ideations and traumatic stress are potent predictors of future suicide ideations. Second, the probability of future suicide ideations is higher when both the number of previous suicide ideations and traumatic stress levels increase, and this probability remains higher as the adolescent ages. These results demonstrate that the long-held proposition that previous suicide behaviors are predictive of future suicide behavior traje...
Binding of copper(II) to thyrotropin-releasing hormone (TRH) and its analogs

Spectroscopy (UV-Vis, (1)H NMR, ESR) and electrochemistry revealed details of the structure of the Cu(II)-TRH (pyroglutamyl-histidyl-prolyl amide) complex. The (1)H NMR spectrum of TRH has been assigned. NMR spectra of TRH in the presence of Cu(II) showed that Cu(II) initially binds TRH through the imidazole. TRH analogs, pGlu-His-Pro-OH, pGlu-(1-Me)His-Pro-amide, pGlu-His-(3,4-dehydro)Pro-amide, pGlu-His-OH, pGlu-Glu-Pro-amide, and pGlu-Phe-Pro-amide provided comparison data. The stoichiometry of the major Cu(II)-TRH complex at pH 7.45 and greater is 1:1. The conditional formation constant (in pH 9.84 borate with 12.0 mM tartrate) for the formation of the complex is above 10(5) M(-1). The coordination starts from the 1-N of the histidyl imidazole, and then proceeds along the backbone involving the deprotonated pGlu-His amide and the lactam nitrogen of the pGlu residue. The fourth equatorial donor is an oxygen donor from water. Hydroxide begins to replace the water before the pH reaches 11. Minority species with stoichiometry of Cu-(TRH)(x) (x = 2-4) probably exist at pH lower than 8.0. In non-buffered aqueous solutions, TRH acts as a monodentate ligand and forms a Cu(II)-(TRH)(4) complex through imidazole nitrogens. All the His-containing analogs behave like TRH in terms of the above properties.
Cartilage collagens. What is their function, and are they involved in articular disease?

La synthese, la structure, la fonction, des collagenes de type II, IX, XI, X et XI sont etudies, ainsi que leurs implications en pathologie articulaire
Cassini/Huygens science instruments

The Cassini spacecraft will carry eighteen scientific instruments to Saturn. After it is inserted into Saturn's orbit, it will separate into a Saturn Orbiter and an atmospheric probe, called Huygens, which will descend to the surface of Titan. The Orbiter will orbit the planet for four years, making close flybys of five satellites, including multiple flybys of Titan. Orbiter instruments are body- mounted; the spacecraft must be turned to point some of them toward objects of interest. Optical instruments provide imagery and spectrometry. Radar supplied imaging, altimetry, and radiometry. Radio links contribute information about intervening material and gravity fields. Other instruments measure electromagnetic fields and the properties of plasma, energetic particles, and dust particles. The Probe is spin- stabilized. It returns data via S-band link to the Orbiter. The Probe's six instruments include sensors to determine atmospheric physical properties and composition. Radiometric and optical sensors will provide data on thermal balance and obtain images of Titan's atmosphere and surface. Doppler measurements between Probe and Orbiter will provide wind profiles. Surface sensors will measure impact acceleration, thermal and electrical properties, and, if the surface is liquid, density and refractive index.
Polymer layer ordering of polyaniline derivatives in PLED devices: Surface adsorption and characterization

The fabrication and characterization of polyaniline (PANI) derivatives deposited on ITO coated glass is investigated as possible hole injection layers for MEH-PPV based polymer light emitting diode (PLED) devices. This involved multilayer ordering by the alternate polyelectrolyte adsorption of polyaniline and sulfonated poyaniline with an oppositely charged polyelectrolyte from solution. A combination of spectroscopic and microscopic techniques was utilized to determine the layer ordering, film structure, morphology, and homogeneity. The deposition process generally showed a linear behavior for all pairs as shown by ellipsometry and UV-vis spectroscopy. However, surface plasmon spectroscopy (SPS) and AFM revealed that thicker films are accompanied by increased surface roughness regardless of concentration. Comparison in performance was made between bare ITO and PANI or SPANI coated devices. Initial investigations of PLED performance showed significant improvements in lifetime and efficiency compared to bare ITO.
Improvement of the dynamic on-resistance characteristics of GaN-on-Si power transistors with a sloped field-plate

High Electron Mobility Transistors (HEMTs) based on GaN are attractive for high-speed and high-voltage applications. The performance advantages of the GaN HEMTs rely on the high breakdown field of the GaN material and the high electron mobility of the 2-dimesional electron gas (2DEG) in the AlGaN/GaN heterojunction [1, 2]. In order to take full advantage of the excellent material properties, the shape of the electric-field distribution in the GaN HEMTs must be carefully optimized to operate the device at its highest switching speed while handling a large voltage swing. Without proper field-shaping, a high electric-field can cause electron injection into traps, hence degrading the output current and on-resistance during switching operation. This phenomenon is often referred to as dynamic on-resistance (Ron dynamic) degradation, current collapse or DC-RF dispersion. As an effective approach of shaping the electric-field, the use of field-plates in GaN HEMTs has received extensive studies [3]. For microwave applications, a V-shaped gate with integrated sloped field-plate was used to control the electric-field with minimal added capacitance associated with the field-plate [5, 6]. For high-voltage applications, a multiple field-plates structure was used to scale up the operating voltage [2, 4]. In this paper, we report a sloped field-plate approach for high-voltage applications.
Mitochondrial morphological changes in mucosal epithelial cells.

Elektronenmikroskopische Beobachtungen zeigen, dass die Innenmembran der Mitochondrien von Epithelzellen des Darms invaginieren und die Innenabteilung in zwei Einheiten teilen kann, jede mit einem unterschiedlichen Grad von Matrixverdichtung.
Power and particle exhaust in an ST-FNSF

A spherical tokamak (ST) configuration is favorable for a Fusion Nuclear Science Facility (FNSF), due to its small size and relatively low cost. However, the compactness of the ST also exacerbates the power and particle handling problems anticipated in next-step devices, since local fluxes are higher and less space is available for optimizing plasma-facing components. Here we present an analysis of the power and particle handling requirements of a candidate ST-FNSF, based on 0-D exhaust projections as well as 2-D edge plasma modeling using the SOLPS code. These show that, for reasonable assumptions on cross-field transport, operating points can be identified that are consistent with both core plasma operation and power and particle exhaust requirements.
Cell intercalation during notochord development in Xenopus laevis.

Analyse des evenements cellulaires intervenant au cours de la morphogenese de la notocorde pendant la gastrulation et la neurulation chez le xenope. Donnees morphometriques a partir de micrographies de microscopie a balayage de cellules d'embryon et d'analyse par haute resolution
HEp-2 Cell-Adherent Escherichia coli in Patients with Human Immunodeficiency Virus-Associated Diarrhea

Diarrhea occurs commonly in African human immunodeficiency virus (HIV) infections. A case-control (HIV-positive vs. -negative) study of adults with diarrhea was done in Lusaka, Zambia, to determine the prevalence of intestinal infection by HEp-2 cell-adherent Escherichia coli. Adherent E. coli were more common in HIV-positive patients with acute diarrhea than among HIV-negative controls (60% vs. 33%) and were found significantly more often in HIV-positive patients with chronic diarrhea than among HIV-negative controls with chronic diarrhea (79% vs. 17%, P < .002). Adherent strains were found significantly more often among HIV-positive patients (69%) than in 22 asymptomatic subjects (36%, P < .02). The HEp-2 cell adherence of the E. coli strains did not show a common pattern. Adherent bacteria were also observed in colonic biopsies from 32% of Zambians with chronic diarrhea who underwent endoscopy. Adherent E. coli may be an important cause of HIV-associated diarrhea in Zambia.
From Conservation to Crowdsourcing: A Typology of Citizen Science

Citizen science is a form of research collaboration involving members of the public in scientific research projects to address real-world problems. Often organized as a virtual collaboration, these projects are a type of open movement, with collective goals addressed through open participation in research tasks. Existing typologies of citizen science projects focus primarily on the structure of participation, paying little attention to the organizational and macrostructural properties that are important to designing and managing effective projects and technologies. By examining a variety of project characteristics, we identified five types-Action, Conservation, Investigation, Virtual, and Education- that differ in primary project goals and the importance of physical environment to participation.
Inhibition of Androgen-independent Growth of Prostate Cancer Xenografts by 17β-Estradiol

Purpose: Estrogen treatment has long been known to be of benefit in prostate cancer (CaP), but its mechanism was thought to involve merely a reduction in androgen levels. However, new evidence indicates that estrogen may exert effects on CaP cells in the absence of androgens. Experimental Design: Implantation of CaP xenografts (LuCaP 35, LuCaP 49, LuCaP 58, LuCaP 73, PC-3, and LNCaP) into intact and ovariectomized female mice was done to characterize growth and take rates in the absence of androgens. Ovariectomized female mice were supplemented with 17β-estradiol, and LuCaP 35 CaP xenograft take and growth rates were determined. Reverse transcription-PCR was used to evaluate the presence of the estrogen receptor messages in CaP xenografts. Results: We have observed significant inhibition of CaP growth in intact versus ovariectomized female animals in five of six CaP xenograft lines. 17β-Estradiol supplements given to ovariectomized female mice led to inhibition of tumor establishment and diminished growth of LuCaP 35 similar to that observed in intact female mice. Using reverse transcription-PCR, we have shown that these xenografts express the estrogen receptor β message. Conclusions: We have determined that 17β-estradiol supplementation causes inhibition of CaP growth in an animal model by mechanisms that are independent of androgen action. This gives rise to the possibility that estrogen therapy may be of potential use with hormone-refractory cancers. The xenograft models we describe herein may be useful as well in elucidating the pathways mediating the androgen-independent effects of estrogen on CaP.
The use of the terms phonetics and phonology in the description of disordered speech

We discuss the use of the distinction between phonetics and phonology both in traditional descriptive linguistics and in psycholinguistic models of speech production and perception. We note that both these ways of using this distinction have been applied to the description of speech and language disorders. We describe three problems in applying the terms phonetics and phonology to clinical data: one problem involved describing speech error data; one problem involved using a binary distinction in modeling speech production; and one problem derived from these two differing approaches to the terms, that is, the problem of disentangling the speaker's production from the listener's perception. We conclude by offering some suggestions for refining our classificatory systems while retaining the basic insight offered by the division into phonetic and phonological domains.
Period Doubling Motions of a Nonlinear Rotating Beam at 1:1 Resonance

A rotating beam subjected to a torsional excitation is studied in this paper. Both quadratic and cubic geometric stiffening nonlinearities are retained in the equation of motion, and the reduced model is obtained via the Galerkin method. Saddle-node bifurcations and Hopf bifurcations of the period-1 motions of the model were obtained via the higher order harmonic balance method. The period-2 and period-4 solutions, which are emanated from the period-1 and period-2 motions, respectively, are obtained by the combined implementation of the harmonic balance method, Floquet theory, and Discrete Fourier transform (DFT). The analytical periodic solutions and their stabilities are verified through numerical simulation.
A Survey of Congestion+Dilation Results for Packet Scheduling

This paper surveys a collection of theoretical results that relate the congestion and dilation of the paths taken by a set of packets in a network to the time required for their delivery, or to the rate at which they can be delivered, where the congestion is the maximum number of paths that pass through a link, over all links, and the dilation is the length of the longest path. Results are stated first for batch routing algorithms and then for continuous routing. Most of the given results are for store-and-forward algorithms (e.g., as implemented in Internet routers), while some are for wormhole or connection-based routing. None of the algorithms described in this survey ever drop packets. The first result in this area was proved by Leighton, Maggs, and Rao in 1988. They showed that any set of packets whose paths have congestion c and dilation d (and are loop free) can be delivered to their destinations in a synchronous store-and-forward network in O(c+d) steps.
PIGMENTS AND THEIR APPLICATION IN MAXILLOFACIAL ELASTOMERS : A LITERATURE REVIEW

Abstract Purpose. This literature review provides information about pigments used for facial and somatoprostheses. Material. This information includes common pigment and index names and numbers, lightfastness categories, chemical type and class, and the chemical formulas of the common pigments used in maxillofacial prosthetics. Conclusion. It can be deduced from this review that the pigments used with silicone elastomers do exhibit a color change, and that a color change is to be expected. (J Prosthet Dent 1998;80:204-8.)
Benefits of Exercise for Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune, inflammatory disorder of unknown etiology and is the most common type of inflammatory arthritis. The disease is most often characterized by morning stiffness, tenderness, and swelling. Other systemic symptoms, such as anemia, increased free radical production, muscle atrophy, and weakness, also occur. Most likely, a combination of these factors contributes to physical inactivity as well, which, in turn, reinforces the muscle wasting. Despite these barriers, it is now becoming recognized that patients with well-controlled RA can tolerate increased physical activity under carefully supervised conditions and that there are many benefits to exercise. This article reviews the effects of various types of physical activity on RA, with particular emphasis on studies that have examined the use of strength training in clinical practice for the management of RA. Without exception, the studies have shown that increased physical activity in patients with RA improves physical capacity without exacerbating disease activity. Important criteria to consider when recommending an exercise program for patients with RA are outlined.
Light scattering of interacting gold nanorods

The optical field intensity of light scattering from nanorods of gold has been imaged at distances that are intermediate between the near-field and far-field regimes using a near-field scanning optical microscope (NSOM). For scattering from isolated nanorods the Fraunhofer diffractive behaviour is modified slightly by the dipolar nature of metal nanoantannae as would be expected at these imaging distances. However, when the nanorods are brought into close proximity, interactions between the nanorods alter the scattering behaviour substantially creating large field intensities between the structures. By sampling the field with the near-field microscope tip scanned at different heights, detailed maps of the scattering profile can be generated. The NSOM image of far-field scattered light from an isolated gold nanorod. The nanorod was imaged at a distance of roughly 8 μm above the support substrate using a scanning near-field microscope operated at constant height mode.
Instruction replication for reducing delays due to inter-PE communication latency

As feature sizes are becoming smaller, wire delays are becoming very critical. Clustering is a popular decentralization approach to reduce the impact of shrinking technologies on clock speed. In this approach, the centralized instruction window is replaced with multiple smaller windows, called clusters (PEs). The performance of these clustered processors depends on the amount of inter-PE communication and load imbalance incurred by the distribution algorithm used to distribute instructions among the PEs. In this paper, we investigate a novel approach of reducing the impact of inter-PE communication latency, while preserving good load balance. The basic idea is to selectively replicate instructions in those PEs where their results are required. The replication is done based on heuristics that weigh the potential benefits of replication. We found that, with instruction replication, the IPC of a clustered processor is significantly higher than that obtained without instruction replication and is within just 8 percent of that of a superscalar configuration with a centralized instruction scheduler.
Timothy P. Johnson on Steve Magura's “Failure of Intervention or Failure of Evaluation: A Meta-Evaluation of the National Youth Anti-Drug Media Campaign Evaluation”Failure of Intervention and Evaluation?: A Review of an Anti-Drug Campaign Evaluation

Steve Magura presents an interesting reassessment of the National Youth Anti-Drug Media campaign evaluation. He makes several important points regarding the design and analysis of this project, whi...
System Modeling Resurrected

Over the past few years, research into system modeling has dwindled in favor of other interests in the field of configuration management. Outside influence, in the form of the emergence of the discipline of software architecture, demands that renewed attention is paid to system modeling because it places new requirements on, and offers new opportunities to, system modeling. In this paper we investigate these requirements and opportunities in more detail.
Role of arachidonic acid and other free fatty acids in mitochondrial dysfunction in brain ischemia.

The aim of the present investigation was to evaluate the possible role of arachidonic acid and other free fatty acids in ischemia-induced mitochondrial dysfunction. Respiratory activities were measured in mitochondria isolated from rat brains subjected to 15–30 min of decapitation ischemia. Addition of bovine serum albumin (BSA) to the mitochondria, isolated in BSA-free media, abolished an ischemia-induced increase in substrate-stimulated (state 4) respiration but only partly reversed a marked inhibition of substrate-, phosphate-, and ADP-stimulated (state 3) respiration caused by the ischemia. Individual free fatty acids were measured in aliquots of the same mitochondrial preparations before and after treatment with BSA. There was a significant increase in arachidonic (20:4), stearic (18:0), palmitic (16:0), and docosahexaenoic (22:6) acid during ischemia. BSA treatment removed all 20:4 and reduced the amount of 18:0 and 16:0, but had no significant effect on 22:6. The main conclusions were (1) that 20:4, 18:0, and 16.0 were responsible for the partial uncoupling (increase in state 4 respiration) of mitochondrial respiration during ischemia, (2) that the inhibition of state 3 respiration caused by ischemia could only partly be attributed to an effect of FFAs, and (3) that the ischemia-induced mitochondrial dysfunction was caused by a combination of factors including 20:4.
Limitations to the statistical analysis of episodic and periodic models of geologic time series

Nonrandom distributions of ages of mass extinctions, magnetic reversals, and other geologic phenomena have been used to support the hypothesis that catastrophic events driven by the periodic motions of planets, stars, or our galaxy play a major role in the history of Earth and its life. Such conclusions have been based on statistical comparison of observed ages to a single reference model, the Poisson distribution. However, probability grids based on multiple reference models show that a wide range of distributions, including some that are periodic and some that are intrinsically random (episodic), can fit the observations. Viable models include some with a fairly large variability in age interval (∼30%). There is no statistical motivation for favoring periodic motions of extraterrestrial objects over the organized, dissipative processes that operate on Earth as an explanation for mass extinctions.
Conditioning the human pupillary response.

Research on classical conditioning of human pupillary responses is reviewed and evaluated. Es have usually employed an auditory CS with illumination change as the UCS. While positive findings were reported in early studies, later investigators generally met with little success both in replications and in more sophisticated designs. Crude methodology, lack of proper control group data, and the subjective nature of response measurement were characteristics of earlier studies which contributed to the presumably erroneous findings. However, Young's (1958) contention that pupillary responses cannot be conditioned is not supported by results of mote recent investigations using shock as the UCS. Implications of these findings are discussed and suggestions for future research are offered.
Why “Feed the Lawn”? Exploring the Influences on Residential Turf Grass Fertilization in the Minneapolis−Saint Paul Metropolitan Area

We contribute to scholarly understanding of lawn fertilization behavior by formulating and testing models of fertilization and fertilization frequency that incorporate a wide range of human and str...
Ultra wideband transparent RF aperture for electro-optical integration

Wideband RF and optical arrays are crucial for sensing both in defense and commercial applications [1], [2]. RF technology for warning sensors is relatively mature, albeit mostly narrowband compared to optical sensors. Therefore, RF sensors can provide a suitable foundation in developing combined RF/Optical imaging apertures. In this paper, we describe an ultra wideband RF aperture as an enabler in a combined conformal Radio Frequency (RF) and Electro-Optical (EO) aperture. The proposed aperture is intended for RF to Mid-IR operation. The RF-EO aperture is based on a novel, planar, Interweaved SPiral Array (ISPA) [3]. We present a 19:1 bandwidth aperture printed using optically transparent conductor (OTC) on a glass superstrate placed conformally on a ground plane. The OTC enables vertical integration of the EO and RF (with the RF aperture above the EO layer). Multiple RF aperture layers can be used to achieve 1–180GHZ operation.
Prospect Theory in Political Science: Gains and Losses From the First Decade

Prospect theory offers a number of advantages that justify its use in the analysis of political behavior but it also has some aspects that limit its wider applicability in political contexts. This article reviews recent research highlighting these successes and limitations. Future research on the incorporation of prospect theory into models of political behavior should focus on such areas as group decision-making, reference point specification, and emotion.