cssi/SciSciGPT-SciSciNet huggingface dataset:
Grasping the message: regulated mRNA stability in free radical stress responses. Commentary on: Rodríguez-Gabriel MA, Burns G, McDonald WH et al. RNA-binding protein Csx1 mediates global control of gene expression in response to oxidative stress. EMBO J 2003; 22: 6256-6266.

Prokaryotes and eukaryotes exhibit complex geneticresponses to oxidative stress caused by excess hydrogenperoxide or other forms of reactive oxygen. These oxida-tive stress responses provide defense and resistancefunctions that limit the cytotoxic and mutagenic effectsof oxidants and free radicals. In bacteria, the systems aregoverned by redox-regulated transcription factors
Intervention research in highly unstable environments

This article highlights issues and presents strategies for conducting intervention research in highly unstable environments such as schools, critical care units, and long-term care facilities. The authors draw on their own experiences to discuss the challenges that may be encountered in highly unstable settings. The concept of validity provides a framework for understanding the value of addressing the many methodological issues that can emerge in settings characterized by instability. We explain unstable environments by elaborating on knowable elements that contribute to instability. Strategies are provided for improving success of intervention research in unstable settings by carrying out an environmental assessment prior to beginning a study.
Embryonic Developmental Progression in Lake Trout (Salvelinus namaycush) (Walbaum, 1792) and Its Relation to Lake Temperature

Abstract Developmental progression of lake trout ( Salvelinus namaycush ) embryos was examined with light and scanning electron microscopy. From this examination, key developmental stages were described in detail. The key developmental stages were then applied to individual lake trout egg lots incubated in constant temperatures of 2, 4, 6, 8, and 10°C. We used Belehradek's, Thermodynamic, and Power models, and also developed the Zero model to determine stage specific developmental rates of lake trout eggs for each background temperature. From the models, hatch dates and staging were predicted for temperature regimes from Lake Superior (1990–91) and Lake Huron (1996–97). Based on the existing lake temperature data and the observed spawning dates, the Zero and the Power models predict that post peak spawning may contribute significantly to overall recruitment success for these years.
A taxonomic investigation of Leptotheca (Rhizogoniaceae)

Leptotheca is recognized as comprising two species,L. boliviana Herzog (L. costaricensis Cardot & Ther., syn. nov.) andL. gaudichaudii Schwaegr. The latter species consists of two varieties, var.gaudichaudii and var.wattsii (Cardot) comb. nov. The genus is characterized by its acrocarpous habit, lanceolate leaves with an excurrent costa and smooth, thick-walled cells, and the occurrence of uniseriate, usually papillose propagula on the upper stems. The genus is transferred from the aulacomniaceae to the Rhizogoniaceae on the basis of gametophytic and sporophytic characters. A key to the genera of the Rhizogoniaceae is provided.
Olefin-SO2 copolymers as biomaterials

The series of olefin-SO2 copolymers prepared from the C8-C18 even-numbered carbon series of alpha-olefins and sulfur dioxide have been studied. The C16 polymer especially has high gas permeability, good biocompatibility, low, toxicity, low thrombogenicity, ease of fabrication and potential low cost. Maximum permeabilities, maximum percent elongation at the yield point and minimum density are obtained with the C16 based polymer. An explanation is proposed involving a competitive plasticizing/side chain crystallization effect.
Debating the world – Choosing the word: High school debates as academic discourse preparation for bilingual students

Abstract This paper looks at how migrant, bilingual high school students, who are speakers of both Spanish and English in their out-of-school lives, learn to master academic discourse through the use of their pre-existing internal resources. Our analysis focuses on the instances when the student debaters use their bilingualism, memorization, and flexible identities to take up academic language during the debate season. In doing so, we explore academic discourse as a situated practice. We suggest that the setting of the Migrant Education Speech and Debate Tournaments provides the opportunities for bilingual high school students to interact with academic discourse to gain proficiency in the subtle differences between codes and registers used in formal scholastic settings such as debates and in the wider, public discourse arena.
The distribution of pairwise peculiar velocities in the non-linear regime

The distribution of pairwise, relative peculiar velocities, $f(u;r)$, on small nonlinear scales, $r$, is derived from the Press--Schechter approach. This derivation assumes that Press--Schechter clumps are virialized and isothermal. The virialized assumption requires that the circular velocity, $V_c \propto M^{1/3}$, where $M$ denotes the mass of the clump. The isothermal assumption means that the circular velocity is independent of radius. Further, it is assumed that the velocity distribution within a clump is Maxwellian, that the pairwise relative velocity distribution is isotropic, and that on nonlinear scales clump-clump motions are unimportant when calculating the distribution of velocity differences. Comparison with $N$-body simulations shows that, on small nonlinear scales, all these assumptions are accurate. For most power spectra of interest, the resulting line of sight, pairwise, relative velocity distribution, $f(u_{\rm r})$, is well approximated by an exponential, rather than a Gaussian distribution. This simple Press--Schechter model is also able to provide a natural explanation for the observed, non-Maxwellian shape of $f(v)$, the distribution of peculiar velocities.
An Efficient Algorithm for Computing the Crossovers in Satellite Altimetry

An efficient algorithm has been devised to compute the crossovers in satellite altimetry. The significance of the crossovers is twofold. First, they are needed to perform the crossover adjustment to remove the orbit error. Secondly, they yield important insight into oceanic variability. Nevertheless, there is no published algorithm to make this very time consuming task easier, which is the goal of this report. The success of the algorithm is predicated on the ability to predict (by analytical means) the crossover coordinates to within 6 km and 1 sec of the true values. Hence, only one interpolation/extrapolation step on the data is needed to derive the crossover coordinates in contrast to the many interpolation/extrapolation operations usually needed to arrive at the same accuracy level if deprived of this information.
Products of initiation, retardation, and inhibition of peroxide‐induced polymerization of styrene

The inhibition by quinone and the retardation by hydroquinone derivatives of the peroxide-induced polymerization of styrene have been studied. We have examined the end products of benzoyl peroxide at 74°C. in benzene, alone and in the presence of quinone and hydroquinone ethers, and in styrene in benzene, both with and without quinone. Absorption spectra have been obtained after several time intervals for some of these systems and for the benzoyl peroxide-styrene-benzene system, alone and in the presence of alkyl substituted hydroquinones. Consideration of the end products indicates that quinone interferes but little with the normal initiation process, particularly at low (0.0045 M) concentrations. Inhibition appears to result largely from reaction between the inhibitor and newly initiated chains. Quinone is converted to products—some of which are phenolic—which do not absorb in the visible. The phenolic products may react with the peroxide or radicals from it, interfering with the normal initiation reaction. The hydroquinone derivatives, which are retarders for the polymerization, appear to be converted initially to quinonoid products. The reactions in inhibition and retardation are discussed.
Asteroids: When planets migrate.

A study of the main asteroid belt, which lies between Mars and Jupiter, reveals an excess depletion of asteroids that was triggered by the migration of giant planets in the early history of the Solar System.
Open reduction and internal fixation of clavicular nonunions with allograft bone substitute

Background: Biologic augmentation with allograft has shown equivalent healing rates to autograft in several nonunion models. No literature exists clearly demonstrating this in the clavicle. The purpose of this study was to evaluate the healing and complication rates of clavicle nonunions treated solely with open reduction and internal fixation (ORIF) and allograft. Materials and Methods: Nineteen clavicle nonunions treated with ORIF and allograft were evaluated retrospectively to assess healing rates and complications based on clinical symptoms and radiographic findings. Results: For the 19 patients included and treated with ORIF and allograft, clinical follow-up averaged 15 months. Seven patients were smokers. Although complete radiographic healing was achieved in only 68% of patients, clinical success occurred in 16 (84%) patients who demonstrated full range of motion and strength without pain. The three patients who did not demonstrate full radiographic healing were completely pain free. Five patients experienced complications (26%). Two underwent hardware removal due to persistent irritation after union. Three had a persistent painful nonunion. Each of these three patients was a smoker ( P =0.08). Two proceeded to union after revision fixation. The other had hardware failure, which was removed, with a persistent nonunion and did not wish any further treatment. Conclusion: ORIF with allograft bone substitute is an acceptable treatment alternative to iliac crest bone graft for clavicle nonunions. However, we did not demonstrate equivalent healing rates to published results utilizing autograft. Smokers were identified to have a trend toward higher failure rates with ORIF augmented with allograft and therefore these patients may be better served by augmenting fixation with autograft. Level of Evidence: IV; retrospective comparative study.
In Vivo Bioluminescence Imaging of Inducible Nitric Oxide Synthase Gene Expression in Vascular Inflammation

Purpose Inflammation plays a critical role in atherosclerosis and is associated with upregulation of inducible nitric oxide synthase (iNOS). We studied bioluminescence imaging (BLI) to track iNOS gene expression in a murine model of vascular inflammation.
Confirmatory Factor Analysis of the Temperament Assessment Battery With A Learning Disabled Sample

Use of the proposed factor structure of the Temperament Assessment Battery for diagnosis of learning disabled children's temperament was examined. Data were collected from 99 parents and 77 teachers, who were asked to rate their LD children and students, respectively. Confirmatory factor analysis using a maximum likelihood solution was applied to the data. Results indicated that the proposed factor structure does not fit the data from teachers. For parent data, goodness-of-fit approached acceptable levels. It was recommended that diagnosis of LD children's temperament not be made on the basis of the eight temperament constellations derived from the factor structure.
A Fractal-Based Clustering Approach in Large Visual Database Systems

Large visual database systems require effective and efficient ways of indexing and accessing visual data on the basis of content. In this process, significant features must first be extracted from image data in their pixel format. These features must then be classified and indexed to assist efficient access to image content. With the large volume of visual data stored in a visual database, image classification is a critical step to achieve efficient indexing and retrieval. In this paper, we investigate an effective approach to the clustering of image data based on the technique of fractal image coding, a method first introduced in conjunction with fractal image compression technique. A joint fractal coding technique, applicable to pairs of images, is used to determine the degree of their similarity. Images in a visual database can be categorized in clusters on the basis of their similarity to a set of iconic images. Classification metrics are proposed for the measurement of the extent of similarity among images. By experimenting on a large set of texture and natural images, we demonstrate the applicability of these metrics and the proposed clustering technique to various visual database applications.
The Menopause Experience: A Woman's Perspective

Objective To understand the complexities of the experience of menopause in American women from diverse ethnic and socioeconomic backgrounds. The specific aims of this phenomenologic study were to (a) examine and interpret the reality of the menopausal transition as experienced by American women and (b) identify common elements and themes that occur as a result of the complexities of this experience. Design Data for this qualitative study were gathered through semistructured interviews with 15 women who experienced natural menopause. Participants A multiethnic sample of 15 menopausal American women in Massachusetts was selected from a pool of voluntary participants from the Boston area. Data Analysis The interviews were analyzed to identify themes pertinent to the personal experience of menopause. Those themes, extracted from the similarities and differences described, represent broad aspects of these women's experiences. Results Three major themes or phases were identified: expectations and realization, sorting things out, and a new life phase. Although some women expressed similar thoughts in particular categories, no two women had the same experience of menopause. Conclusions The data support the premise that the experience of menopause in American women is unique to each individual and that the meaning or perspective differs among women. The data revealed the complexities of this human experience by explicating personal meanings related to experiences, expectations, attitudes, and beliefs about menopause.
The Labor Market Status of Black Americans: 1939-1985

A fter substantial economic gains near the time of World War I, black Americans experienced little progress during the interwar period, 1918-1939. When Gunnar Myrdal (1944) made his famous argument that the contradiction between Americans' espoused commitment to equal opportunity and whites' actual discrimination against blacks would pose an "American Dilemnma" for the coming era of democracy, serious students of race relations seldom disagreed about the dismal economic position of black Americans. But since Myrdal's prediction, there have been great changes in race relations and in blacks' economic status. In this paper, I document some of these changes and I discuss some arguments that have been offered as explanations of the changes in blacks' economic status. Among the empirical changes since 1939, three stand out: 1) three decades of rapid progress followed by two decades of relative stagnation in many aggregate measures of relative black earnings and incomes; 2) declining employment of black males; and 3) heightened inequality within the black population. Students of the economics of race relations must address a fundamental question: Why has relative black employment fallen when blacks' wages and their access to occupations and to institutions of higher education have improved so much? This question leads to a consideration of the extent to which these changes may be interpreted as changes in discrimination and its consequences; changes and differences in skills; and changes in the relative wages of workers of different skills.
Immediate Reactions to Darwin: The English Catholic Press' First Reviews of the ‘Origin of the Species’

English Roman Catholic reactions to the issues presented by Charles Darwin's On the Origin of Species (1859) were as varied as the elements which made up the English Catholic community itself. Any reading of the Catholic periodical press in England during the years immediately after Darwin's epochal publication will bear this out. These reactions ranged from a simple reaffirmation of childhood formulations of the account of creation in “Genesis,” to rather disingenuous allegorical reinterpretations of the meaning of what “Moses”—and Darwin—had said.
Observations of the latitudinal structure of plasmaspheric convection plumes by IMAGE‐RPI and EUV

Received 22 May 2002; revised 16 April 2003; accepted 2 May 2003; published 15 August 2003. [1] Recent IMAGE Extreme Ultraviolet Imager (EUV) observations showed the first global images of plasmaspheric convection plumes, which have been interpreted as the plasmaspheric tails predicted theoretically 3 decades earlier. Using observations by the IMAGE Radio Plasma Imager (RPI), we show that these convection plumes have large latitudinal extent. These results complement those recently made by others in correlating IMAGE EUV data with measurements of total electron content in the ionosphere. By correlating in situ RPI density measurements with global plasmaspheric EUV images, we have shown that apparently detached plasma structures, as appear in RPI dynamic spectrograms, are in many cases plasmaspheric convection plumes. The temporal separation between the RPI and EUVobservations help constrain the interpretation of one data set in the context of the other, thereby enabling an examination of the threedimensional plasma density structures outside the core plasmasphere. The data sets are mutually reinforcing because the data are collected within a few hours of one another. We used the EUV data to provide unambiguous identification of density enhancements in the region outside the plasmasphere and used the RPI data to obtain accurate number densities and extend information from the EUV data set by measuring densities below the EUV sensitivity threshold. INDEX TERMS: 2768 Magnetospheric Physics: Plasmasphere; 2740 Magnetospheric Physics: Magnetospheric configuration and dynamics; 2730 Magnetospheric Physics: Magnetosphere—inner; 2788 Magnetospheric Physics: Storms and substorms; KEYWORDS: plasmasphere, plasmapause, inner magnetosphere, convection plumes, RPI, EUV
High-performance liquid chromatographic determination of 1,1′-ethylidenebis(L-tryptophan) in L-tryptophan preparations

In studies to determine the cause or causes of the eosinophilia myalgic syndrome (EMS) and to monitor the purity of L-tryptophan preparations, an HPLC method has been developed for determining 1,1'-ethylidenebis(L-tryptophan) (EBT) in L-tryptophan (W) preparations. The W preparations are extracted with 0.1% trifluoroacetic acid (TFA) and filtered, and the EBT is purified by passage through a Sep-Pak C18 cartridge. The cartridge is washed with water and 6% acetonitrile in water, and EBT is eluted with methanol. The water-diluted eluate is then chromatographed on a silica-based, reversed-phase HPLC column with a gradient of water and 80% acetonitrile, both solvents containing 0.1% TFA. EBT absorbance is measured at 280 nm. The average recovery of EBT from L-tryptophan powder, spiked over the range 1.2-4.8 micrograms/g, was 91%. The limit of determination was approximately 0.6 micrograms/g. Sixteen test samples of W products manufactured by the company to which most of the cases of EMS have been traced contained > 70 micrograms of EBT/g. Three nonpatient-related test samples either did not contain EBT or contained < 2 micrograms of EBT/g.
Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

Crescent-shaped bedforms with wavelengths from 20 to 80 m, amplitudes to 2.5 m, and concave down-canyon crests occur in the axial channel of Monterey Canyon (offshore California, USA) in water depths from 11 to more than 350 m. The existence of these features may be an important new clue as to how sediment moves through submarine canyons. Three complementary studies were initiated in 2007 to understand the origin and evolution of these bedforms. (1) Vibracoring. Three transects of closely spaced remotely operated vehicle–collected vibracores were obtained across these bedforms. The seafloor underneath these features is composed of gravity-flow deposits. (2) Acoustic array. Three boulder-sized concrete monuments containing acoustic beacons were buried just below the surface of the canyon floor in ∼290 m water depth and their locations were redetermined on 17 subsequent occasions. Although the beacons became more deeply buried >0.6 m below the seafloor, they still could be tracked acoustically. Over a 26-month period the position of 1 or more of the beacons moved down-canyon during at least 6 discrete transport events for a total displacement of 994–1676 m. The movement and burial of the monuments suggest that the seabed was mobilized to >1 m depth during gravity-flow events. (3) Autonomous underwater vehicle (AUV) repeat mapping. AUV-acquired high-resolution multibeam mapping, and CHIRP (compressed high-intensity radar pulse) subbottom profiling surveys of the seafloor in the active channel were repeated four times in the first half of 2007. In addition, the movement of large instrument frames deployed in 2001–2003 within the axis of Monterey Canyon in the area now known to be associated with the crescent-shaped bedforms is documented. The fate of the frames has helped elucidate the frequency, transport potential, and processes occurring within the axis of Monterey Canyon associated with these bedforms. The crescent-shaped bedforms appear to be produced during brief gravity-flow events that occur multiple times each year, commonly coincident with times of large significant wave heights. Whether the bedforms are generated by erosion associated with cyclic steps in turbidity flows or internal deformation associated with slumping during gravity-flow events remains unclear.
Civilization and international society: the case of European Union expansion

Joining a society of some kind requires the fulfillment of certain standards. In international society, states acknowledge the need for certain collective standards of international conduct if international order is to be maintained. The first truly global application of international norms took place during the nineteenth century through the process of the expansion of the European society of states and its gradual transformation to the contemporary global international society. In this process, the standard of ‘civilization’ played an essential role in determining which states would join the expanding European society and which ones would not. Despite the major changes that have occurred, the standard of ‘civilization’ has remained an international practice as well as a benchmark against which the attitudes and policies of states are assessed. Nowhere can this be seen more clearly than in the EU policy of ‘membership conditionality’. Although many explanations for EU expansion have been put forward rath...
VLA stereoscopy of solar active regions. 2: Altitude, relative motion, and center-to-limb darkening of 20 centimeter emission

A newly developed method of stereoscopic correlation is applied to solar radio maps at a wavelength of 20 cm. On the basis of stereoscopic correlations between radio maps obtained on 6 different days we establish the presence of 66 radio source components associated with 22 active regions. We find the following statistical results for active region source structures at 20 cm: 1. The observed lifetime is consistent with an exponential distribution having an e-folding time scale of greater than 18 days. 2. The average altitude of 20 cm sources is 25 +/- 15 Mm; 90% of the sources are found in heights less than 40 Mm. 3. The average diameter of discrete source structures is 48 +/- 15 Mm, implying a vertical/horizontal aspect ratio of q(sub A) approx. = 0.5. 4. No significant source motion has been found with respect to the standard differential rotation rate of Omega = 13.45 deg - ((3 deg (sin(exp 2)B)). 5. We find a statistical limb darkening, which can be described by the relation (T(sub B)(alpha))/T(sub B)(0)) = 0.4 + ((0.6(cos(exp 2) alpha)) for sources with T(sub B) greater than 0.5 MK. 6. The degree of source polarization is 15% +/- 10% and is independent of source location. 7. Bright sources (greater than or approximately equal to 0.5 MK), or equivalently, long-lived sources (greater than or approximately equal to 5 days) show a systematic variation of their altitude as function of the center-limb distance.
Design and implementation of the “Tiny RISC” microprocessor

Abstract This paper describes the design and implementation of ‘Tiny RISC’, a 16-bit RISC-style microprocessor designed at UC Irvine. It was fabricated by MOSIS in a 2 μm n-well CMOS technology. Tiny RISC has been designed for optimized data path operation. A simple 32-bit extension of the data path results in a generic functional unit of a VLIW (very long instruction word) processor that is currently being developed at UC Irvine.
Dependence of heart chamber dimensions and dynamics on chamber demands and myocardial properties.

A heart chamber undergoes eccentric hypertrophy in response to a chronic elevation of stroke-displacement demand, and it undergoes concentric hypertrophy in response to a chronic elevation of systolic-pressure demand. Both of these adaptations, which occur in various combinations, involve two myocardial plastic properties, “stretch normalization” and “stress normalization”. We have developed a model which predicts dimensions and dynamics of the left ventricle as functions of myocardial properties and of the loads to which the chamber is adapted. The model involves: (1) a stress-normalization rule which describes how myocardial volume depends on average systolic pressure, cavity volumes and the responsiveness of growth to stress; (2) a stretch-normalization rule which describes how the cavity volume of standard stretch relates to average end-diastolic and end-systolic volumes; and (3) a pressure-volume-curve equation giving isometric pressures as functions of cavity volume and myocardial volume relative to standard-stretch cavity volume, and elastic properties including contractility. The model shows how the relations among average dimensions, dynamics and loads depend on myocardial properties, particularly contractility and the growth response to stress. These properties are the main determinants of myocardial performance. In addition to the load adaptations mentioned above, the model predicts eccentric hypertrophy incident to reduced contractility, chronic dilation incident to reduced growth response to stress, myocardial stricture incident to excessive growth response to stress, and concentric hypertrophy (similar to high-pressure adaptation) incident to deposition of inert material. It allows some refinements in the evaluation of myocardial performance and in the evaluation of the abnormal properties responsible for abnormal performance.
Cutoff size need not strongly influence molecular dynamics results for solvated polypeptides.

The correct treatment of van der Waals and electrostatic nonbonded interactions in molecular force fields is essential for performing realistic molecular dynamics (MD) simulations of solvated polypeptides. The most computationally tractable treatment of nonbonded interactions in MD utilizes a spherical distance cutoff (typically, 8−12 A) to reduce the number of pairwise interactions. In this work, we assess three spherical atom-based cutoff approaches for use with all-atom explicit solvent MD: abrupt truncation, a CHARMM-style electrostatic shift truncation, and our own force-shifted truncation. The chosen system for this study is an end-capped 17-residue alanine-based α-helical peptide, selected because of its use in previous computational and experimental studies. We compare the time-averaged helical content calculated from these MD trajectories with experiment. We also examine the effect of varying the cutoff treatment and distance on energy conservation. We find that the abrupt truncation approach is...
Interaction of small peptides with lipid bilayers

Molecular dynamics simulations of the tripeptide Ala-Phe-Ala-O-tert-butyl interacting with dimyristoylphosphatidylcholine lipid bilayers have been carried out. The lipid and aqueous environments of the peptide, the alkyl chain order, and the lipid and peptide dynamics have been investigated with use of density profiles, radial distribution functions, alkyl chain order parameter profiles, and time correlation functions. It appears that the alkyl chain region accommodates the peptides in the bilayer with minimal perturbation to this region. The peptide dynamics in the bilayer bound form has been compared with that of the free peptide in water. The peptide structure does not vary on the simulation time scale (of the order of hundreds of picoseconds) compared with the solution structure in which a random structure is observed.
High and low doses of haptens dictate whether dermal or epidermal antigen‐presenting cells promote contact hypersensitivity

In the induction of contact hypersensitivity (CH) to an epicutaneously applied hapten, we have previously proposed that low doses of hapten sensitize primarily through epidermal Langerhans' cells (LC), whereas high doses rely largely on dermal antigen-presenting cells (APC). To examine this issue further, we applied either high or low doses of dinitrofluorobenzene (DNFB) epicutaneously to mice. We observed reduced LC density at the site after 12 h (nadir), which returned to normal levels at 24 h only after a low dose of hapten. When a low dose of an unrelated hapten, oxazolone, was painted on skin that had been painted 12 h previously with high dose of DNFB, oxazolone-specific CH was impaired. When grafts of whole skin, dermis alone, and epidermis alone prepared from skin painted 2 h previously with low or high doses of DNFB were placed onto naive, syngeneic mice, CH was induced by whole skin after both types of doses, by epidermis only after a low dose, and by dermis only after high dose. When epidermal cell suspensions were derivatized in vitro with low or high doses of DNFB, only cells exposed to a low dose induced proliferation of hapten-specific Tcells. Thus, only a low dose of hapten reveals the APC functions of LC without the participation of dermal APC.
Using social network methods to study school leadership

Social network analysis is increasingly used in the study of policy implementation and school leadership. A key question that remains is that of instrument validity – that is, the question of whether these social network survey instruments measure what they purport to measure. In this paper, we describe our work to examine the validity of the School Staff Social Network Questionnaire (SSSNQ), an instrument designed to study instructional leadership practice. To examine the validity of the survey, we conducted two studies. The first involved administration of the SSSNQ in 22 schools and interviews with a sub‐sample of school staff in six of these schools. The second study involved cognitive interviews in which interviewees were asked to ‘think aloud’ as they completed a revised version of the SSSNQ. Our findings indicate that the SSSNQ did identify leadership operationalized as social influence interactions. Furthermore, the SSSNQ allowed us to move away from an exclusive focus on school principals and oth...
Hepatitis C virus and lichen planus: a review.

Abstract Introduction The relationship between hepatitis C virus (HCV) infection and oral lichen planus (OLP) remains a matter of controversy. It is important to determine whether there is an association between OLP and HCV infection so that guidelines regarding the routine HCV testing of patients with OLP can be developed for clinicians. Objectives The objective of this article was to review and summarize the published literature on the association between OLP and HCV and to describe future directions. Methods A search of the computerized database MEDLINE (1966–June 2003) was conducted. The bibliographies of articles identified by means of MEDLINE were also searched. Any studies reporting the prevalence of HCV in a group of patients with LP either with or without a control group were included in this review. Also included were studies comparing the clinical and histologic features of LP among patients with and without HCV infection, studies on the presence of HCV within LP lesions, and studies of HCV genotypes among patients with LP. Results Thirty-two studies conducted in various parts of the world were identified. Study types included prevalence studies on HCV exposure among patients with OLP (0%-62%), prevalence of OLP among patients with HCV infection (1.6%-20%), and case-control studies of this association. In addition, the results from 3 studies on the replication of HCV in the oral mucosa, 3 studies on the genotype of HCV in OLP patients, and 4 studies comparing the clinical and histologic features of OLP in HCV-infected and uninfected individuals have been summarized. Conclusion At present, studies on the association of OLP and HCV provide enough information to raise a number of interesting questions about this association. Important biases—including selection bias; investigator bias due to lack of blinding and the possible resultant nondifferential misclassification of disease; and possible confounding by age in the studies published—make it difficult to draw firm conclusions. However, the need for future studies that take into consideration all these factors in the study methodology is highlighted by this review.
Tolerance competition graphs

Abstract The o-tolerance competition graph is introduced as a generalization of the p-competition graphs defined by Kim, McKee, McMorris, and Roberts. Let o be a symmetric function defined from N × N into N, where N denotes the nonnegative integers. G = (V, E) is a o-tolerance competition graph if there is a directed graph D = (V, A) and an assignment of a nonnegative integer ti to each vertex vi ∈ V such that, for i ≠ j, vivj ∈ E(G) if and only if |O(vi) ∩ O(vj)| ≥ o(ti, tj), where O(x) = {y : xy ∈ A}. A general characterization of o-tolerance competition graphs is given, and specific results are obtained when o is the minimum, maximum, and sum functions.
Effective electrical conductivity of functional single-wall carbon nanotubes in aqueous fluids

Abstract In this paper, for the first time, we have used a coaxial fixture to successfully obtain the relatively low and precise electrical conductivity values of nanofluids based on functional sulfonated carbon nanotubes. From 0 to 0.5 wt.% nanotube loading, the conductivity increased approximately 13 times. However, no percolation threshold phenomenon is observed. The linear conductivity increase versus the weight percentage indicates that the dominant conduction mechanism might be the ionic conduction, which is in agreement with the chemical structure of functional SWNT (anion SO 3 − group).
Broadening the Reactivity Spectrum of a Phthalocyanine Catalyst While Suppressing its Nucleophilic, Electrophilic and Radical Degradation Pathways

A robust molecule that resists degradationvia nucleophilic, electrophilic and radical attacks is described. Coordinated O2 is reduced catalytically, producing efficiently thyil radicals in spite of the extreme electronic deficiency of the catalyst.
Predicting High‐Throughput Screening Results With Scalable Literature‐Based Discovery Methods

The identification of new therapeutic uses for existing agents has been proposed as a means to mitigate the escalating cost of drug development. A common approach to such repurposing involves screening libraries of agents for activities against cell lines. In silico methods using knowledge from the biomedical literature have been proposed to constrain the costs of screening by identifying agents that are likely to be effective a priori. However, results obtained with these methods are seldom evaluated empirically. Conversely, screening experiments have been criticized for their inability to reveal the biological basis of their results. In this paper, we evaluate the ability of a scalable literature-based approach, discovery-by-analogy, to identify a small number of active agents within a large library screened for activity against prostate cancer cells. The methods used permit retrieval of the knowledge used to infer their predictions, providing a plausible biological basis for predicted activity.
Effect of free stream turbulence on local mass transfer from a circular cylinder

Abstract The effect of free stream turbulence on local mass transfer from a circular cylinder is experimentally investigated for free stream Reynolds number from 3.0×10 4 to 8.3×10 4 , turbulence intensity from 0.2% to 23.7% and integral length scale from 0.8 to 6.3 cm. The pattern of mass transfer distribution changes considerably with free stream turbulence. The effect of a splitter plate on local mass transfer is also studied. Information on the flow field near the surface is obtained from flow visualization using an oil/lampblack mixture.
Low-temperature rate coefficients for the reaction of ethynyl radical (C2H) with benzene

The reaction of the C2H radical with benzene is studied at low temperature using a pulsed Laval nozzle apparatus. The C2H radical is prepared by 193-nm photolysis of acetylene, and the C2H concentration is monitored using CH(A2Delta) chemiluminescence from the C2H + O2 reaction. Measurements at very low photolysis energy are performed using CF3C2H as the C2H precursor to study the influence of benzene photodissociation on the rate coefficient. Rate coefficients are obtained over a temperature range between 105 and 298 K. The average rate coefficient is found to be five times greater than the estimated value presently used in the photochemical modeling of Titan's atmosphere. The reaction exhibits a slight negative temperature dependence which can be fitted to the expression k(cm3 molecule(-1) s(-1)) = 3.28(+/-1.0) x 10(-10) (T/298)(-0.18(+/-0.18)). The results show that this reaction has no barrier and may play an important role in the formation of large molecules and aerosols at low temperature. Our results are consistent with the formation of a short lifetime intermediate that decomposes to give the final products.
A nitric oxide synthase inhibitor, L-NAME, attenuates saccharin drinking in a two-choice test in water-deprived rats.

The nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME) [0 (veh)], 10, 25, and 50 mg/kg s.c.) was administered to water-deprived, saccharin-preferring, rats in a 30-min two-bottle choice test of 0.1% sodium saccharin and tap water in a within subjects design. Saccharin intake was selectively attenuated in a dose-related manner with increasing dose of l-NAME, reaching statistical significance at 25 and 50 mg/kg l-NAME when compared to vehicle control condition (p < 0.01). In contrast, water intake was not appreciably affected. Total fluid intake was attenuated as well. Neither saccharin nor water intake in a second group of animals was significantly affected by the inactive isomer, d-NAME, suggesting a stereospecific action. These data suggest that a taste factor might contribute to the well-documented hypophagic action of NOS inhibitors in a number of animal species. The possibility that such effect might be mediated through a serotonergic mechanism is considered.
Toward University Modeling Instruction—Biology: Adapting Curricular Frameworks from Physics to Biology

University Modeling Instruction (UMI) is an approach to curriculum and pedagogy that focuses instruction on engaging students in building, validating, and deploying scientific models. Modeling Instruction has been successfully implemented in both high school and university physics courses. Studies within the physics education research (PER) community have identified UMI's positive impacts on learning gains, equity, attitudinal shifts, and self-efficacy. While the success of this pedagogical approach has been recognized within the physics community, the use of models and modeling practices is still being developed for biology. Drawing from the existing research on UMI in physics, we describe the theoretical foundations of UMI and how UMI can be adapted to include an emphasis on models and modeling for undergraduate introductory biology courses. In particular, we discuss our ongoing work to develop a framework for the first semester of a two-semester introductory biology course sequence by identifying the essential basic models for an introductory biology course sequence.
Introduction to biostatistics: Part 3, sensitivity, specificity, predictive value, and hypothesis testing

Diagnostic tests guide physicians in assessment of clinical disease states, just as statistical tests guide scientists in the testing of scientific hypotheses. Sensitivity and specificity are properties of diagnostic tests and are not predictive of disease in individual patients. Positive and negative predictive values are predictive of disease in patients and are dependent on both the diagnostic test used and the prevalence of disease in the population studied. These concepts are best illustrated by study of a two by two table of possible outcomes of testing, which shows that diagnostic tests may lead to correct or erroneous clinical conclusions. In a similar manner, hypothesis testing may or may not yield correct conclusions. A two by two table of possible outcomes shows that two types of errors in hypothesis testing are possible. One can falsely conclude that a significant difference exists between groups (type I error). The probability of a type I error is alpha. One can falsely conclude that no difference exists between groups (type II error). The probability of a type II error is beta. The consequence and probability of these errors depend on the nature of the research study. Statistical power indicates the ability of a research study to detect a significant difference between populations, when a significant difference truly exists. Power equals 1-beta. Because hypothesis testing yields "yes" or "no" answers, confidence intervals can be calculated to complement the results of hypothesis testing. Finally, just as some abnormal laboratory values can be ignored clinically, some statistical differences may not be relevant clinically.
Arnfried Antonius, coral diseases, and the AMLC

The study of coral diseases, coral pathogens, and the effects of diseases on tropical and subtropical coral reefs are all current, high-profile research areas. This interest has grown steadily since the first report of a coral disease in 1973. The author of this report was Arnfried Antonius and the publication was an abstract in the proceedings of a scientific meeting of the Association of Marine Laboratories of the Caribbean, or AMLC (then known as the Association of Island Marine Laboratories of the Caribbean). Since Antonius’ pioneering communication he continued working on coral diseases on reefs throughout the world, often documenting the first observation of a novel pathology in a novel location. Each of the coral diseases Antonius first described, in particular black band disease, is the subject of current and ongoing investigations addressing pathogens, etiology, and their effects on coral reefs. Many of the points and observations he made in his early papers are highly relevant to research today. This paper reviews aspects of Antonius’ early work, highlighting contributions he made that include the first in situ experimental studies aimed at discerning coral epizootiology and the first quantitative assessments of the role of environmental factors in coral disease. Antonius’ early findings are discussed in terms of relevant current controversies in this research area.
On calibrating measurements of packet transit times

We discuss the problem of detecting errors in measurements of the total delay experienced by packets transmitted through a wide-area network. We assume that we have measurements of the transmission times of a group of packets sent from an originating host, A, and a corresponding set of measurements of their arrival times at their destination host, B, recorded by two separate clocks. We also assume that we have a similar series of measurements of packets sent from B to A (as might occur when recording a TCP connection), but we do not assume that the clock at A is synchronized with the clock at B, nor that they run at the same frequency. We develop robust algorithms for detecting abrupt adjustments to either clock, and for estimating the relative skew between the clocks. By analyzing a large set of measurements of Internet TCP connections, we find that both clock adjustments and relative skew are sufficiently common that failing to detect them can lead to potentially large errors when analyzing packet transit times. We further find that synchronizing clocks using a network time protocol such as NTP does not free them from such errors.
Engineering evaluation of geothermal reservoirs

Reservoir engineering evaluation of geothermal systems attempts to provide answers on the extent of the reserves, their probable longevity and the deliverability and production rate of the reservoir. Economic decisions on the desirability of the exploitation of the particular reservoir hinge on these findings. This paper presents a set of calculational procedure and thinking sequences available to the geothermal reservoir engineer that would aid in an appropriate management decision. An exploitable geothermal system consists of a fluid as well as a heat reservoir. Since much of the heat is stored in the confining rock, reinjection strategies are outlines for the efficient mining of heat.
Pressure-Volume-Temperature Relationships for Normal Deuterium Between 18.7 and 21.0 K.

Analytical expressions are derived for the melting line and liquid equation of state of normal deuterium near the triple point. Melting pressures were measured between the triple point and 20.4 K. These results combined with existing pressure measurements along the saturated liquid-vapor curve fix an accurate value, T /SUB tp/ =/18.723 K, for the triple-point temperature. Data for the isothermal compressibility and thermal expansion coefficients of the liquid were taken over the temperature and pressure ranges 18.8 to 21.0 K and 4 to 70 bar, respectively. The liquid molar volume was measured at nine points below 20.4 K. All liquid PVT data are shown to be internally consistent. Measurements of the volume changes on melting are also presented. The heat of fusion and the solid molar volume at melting are deduced from these data. Also included are detailed comparisons of our results with existing data. A critical appraisal is given of all measured thermodynamic quantities in this regime.