cssi/SciSciGPT-SciSciNet huggingface dataset:
IT training for students, who needs it?

This presentation will be a discussion of two Information Technology training programs at the university/college level. The two programs are ”The Student Peer Trainers” (SPT) and “The Freshman Year Seminar Technology Lab” (FYS). Both are charged with the duty of providing computer-training classes that will help students learn the skills they need to complete their academics, including instruction on basic computer comprehension, Internet tools and popular software. The focus of our discussion will center around an evaluation of both programs which was conducted in order to determine the efficacy of IT training programs. To do this, we will attempt to answer three key research questions: Do students need Information Technology training to complete the tasks required by their academic programs; Do students use the learned skills for their academic work; Do the students find the training valuable? We'll begin with a description of the Student Peer Training program, detailing the types of students who utilize the service by gender, major, grade level and computer experience level. We’ll outline those courses that are the most and least popular, comparing course attendance rates and other factors that influence student attendance rates. In addition, students’ comments about why they attend IT training sessions and if they find them useful will be discussed. The second part of the presentation will examine The Freshman Year Seminar Technology Lab. We will provide a history of how and why the program came into existence, and what the future holds for this type of Information Technology training. We’ll also examine characteristics of the students who completed the program by gender and experience level, the comments they had for the program including the programs’ strengths and weaknesses. The data will provide us with a complete picture of computer-training programs, an accurate evaluation of their worth, and the students who use them. This information is perhaps most useful for administrators at institutions of higher education who are faced with meeting students’ need for acceptable Information Technology training. However, it is applicable to all persons interested in the role of computer training.
Prediction of adsorption equilibrium using a modified D–R equation: organic–water vapor mixtures on BPL carbon

Abstract Methods to describe and predict adsorption equilibrium using the D–R equation are presented in this paper. We focus on adsorption of organic–water vapor binary mixtures on BPL activated carbon. By adjusting the partial pressure of the organic component in the binary mixture, the effects of the presence of water vapor on adsorption of the organic component are quantitatively expressed using one term in a modified form of the D–R equation. The developed models have broad application ranges that are not limited by organic type and the loadings of the organic and water vapor. They can be used for coadsorption of water-immiscible or water-miscible organic compounds with water vapor on BPL activated carbon in the cases of small or large organic loading with low or near-saturation relative humidity. Compared with other methods for the adsorption of organic–water vapor binary mixtures, our models are simple and do not require iteration.
Single molecule photobleaching: increasing photon yield and survival time through suppression of two-step photolysis

Abstract Irreversible photobleaching imparts the unavoidable limitation on single-molecule spectroscopy: when the fluorescent probe molecule becomes nonfluorescent, the experiment is over. A detailed study of the photobleaching rate for rhodamine 6G under vacuum reveals that low excitation rates yield long photochemical survival times and unprecedented numbers of emitted photons. A four-level system is used to model the photobleaching rate, reproducing the experimental bleaching rate and photon yield from single molecule and ensemble experiments. A higher triplet excited state Tn is found to be the predominant reactive state for photobleaching. This model produces a calculated quantum yield for photobleaching on the order of 7×10−7 bleaching events per excitation to Tn.
Evidence for involvement of multiple iron species in DNA single-strand scission by H2O2 in HL-60 cells

Some of the properties of cellular iron species which react with H2O2 to cause DNA single-strand breaks in HL-60 cells were characterized in control cells and in cells made deficient of iron using 4,7-phenylsulfonyl-1,10-phenanthroline (bathophenanthroline disulfonic acid or BPS) and ascorbate. Single-strand breaks were measured using alkaline elution of DNA of cells treated at 4 degrees to minimize repair during treatment. Strand breakage in the presence of 10% serum was only 40% of that in the absence of serum. This effect was traced to reaction of H2O2 with metals, most likely iron, in serum. Dimethyl sulfoxide (Me2SO) inhibited a maximum of 65% of breaks in control cells. The diffusion distance from the site of generation of hydroxyl radicals to the site of reaction with DNA for the Me2SO-inhibitable fraction was 6.9 nm. There was no significant alteration in the fraction of Me2SO-inhibitable strand breaks or in diffusion distance in iron-deficient cells, though total strand breaks decreased by 70%. When the effect of extracellular iron in serum was taken into account, 60 microM orthophenanthroline (OP) inhibited a maximum of 85% of strand breaks. In cells pretreated with 60 microM OP, the Me2SO-inhibitable fraction of the remaining strand breaks decreased to 32%, while the diffusion distance decreased to 4.1 nm. These data indicate the existence of a number of different iron species, as characterized by overlapping but not coincidental inhibition by OP and Me2SO, and by differing diffusion distances.
THE FAMILY LAW EDUCATION REFORM PROJECT FINAL REPORT

The Family Law Education Reform Project (the FLER Project) is co-sponsored by the Association of Family and Conciliation Courts and the Center for Children, Families and the Law at Hofstra Law School. This Final Report is based on a series of dialogues between family law academics and practitioners from many disciplines, a FLER Project survey, and research conducted by law students at Hofstra University and Northeastern University.2
Percolation Induced Heat Transfer in Deep Unsaturated Zones

Subsurface temperature data from a borehole located in a desert wash were measured and used to delineate the conductive and advective heat transfer regimes, and to estimate the percolation quantity associated with the 1997–1998 El Nino precipitation. In an arid environment, conductive heat transfer dominates the variation of shallow subsurface temperature most of the time, except during sporadic precipitation periods. The subsurface time-varying temperature due to conductive heat transfer is highly correlated with the surface atmospheric temperature variation, whereas temperature variation due to advective heat transfer is strongly correlated with precipitation events. The advective heat transfer associated with precipitation and infiltration is the focus of this paper. Disruptions of the subsurface conductive temperature regime, associated with the 1997–1998 El Niono precipitation, were detected and used to quantify the percolation quantity. Modeling synthesis using a one-dimensional coupled heat and unsaturated flow model indicated that a percolation per unit area of 0.7 to 1.3 m height of water in two weeks during February 1998 was responsible for the observed temperature deviations down to a depth of 35.2 m. The reported study demonstrated quantitatively, for the first time, that the near surface temperature variation due to advective heat transfer can be significant at a depth greater than 10 m in unsaturated soils and can be used to infer the percolation amount in thick unsaturated soils.
Group Work and Electronic Meeting Systems: From Boardroom to Classroom

In the business community, collaborative efforts of work teams have led to a dramatic increase in the number of group meetings. Business managers, seek ing more efficient and effective methods of managing diverse contributions, have increasingly used information technology to supportgroup work. The same need to improve group communication is relevant to today's classroom, where new technologies can transform the classroom from a traditional instructor-centered environment to a student-centered environment where stu dents actively participate in intellectual discourse. Results from field and labo ratory studies about business usage of electronic meeting systems (EMS) can be applied to the classroom setting. We offer an overview of available tools and suggest some classroom activities. EMS-supported courses provide many new opportunities to foster learning. Students participate, participate more equally, and report a highly satisfying experience.
Intercalate ionization in graphite—halogen compounds☆

Abstract There has been considerable disagreement in the literature concerning the extent of intercalate ionization in the graphite—halogen compounds. Some experiments have been interpreted in terms of complete molecular dissociation and ionization, others on the basis of intermediate ionization, and yet others under the assumption of little or no ionization. We summarize the experimental evidence related to halogen ionization in the graphite—halogen compounds and show this evidence to be consistent with a low intercalate ionization and the preservation of the molecular identity of the halogen intercalate.
A comparison of (−)-deoxybenzomorphans devoid of opiate activity with their dextrorotatory phenolic counterparts suggests role of σ2 receptors in motor function

Abstract Three novel benzomorphans, (+)-N-benzylnormetazocine, (−)-deoxy-N-benzylnormetazocine, and (−)-deoxypentazocine were tested for their ability to produce circling behavior in rats following intranigral microinjections. Dose studies revealed the following rank order of potency: (−)-deoxypentazocine > (−)-deoxy-N-benzylnormetazocine > (+)-N-benzylnormetazocine. This rank order approximates that for affinities for σ2 receptors but not σ1 receptors. It is very unlikely that the effects of the (−)-deoxybenzomorphans were mediated by opiate receptors for the following reasons: (1) consistent with the known requirement for the phenolic hydroxyl group for opiate activity, both (−)-deoxy compounds showed very low affinity for opiate receptors; (2) naloxone (4 μg) co-administered with (−)-deoxy-N-benzylnormetazocine failed to reduce its efficacy; (3) both (−)-deoxy compounds failed to produce marked analgesic effects in the tail flick test following systemic injections of 20 mg/kg s.c. These findings suggest that σ2 receptors mediate the motor effects of σ ligands in rats.
Gas Chromatographic Isolation of Individual Compounds from Complex Matrices for Radiocarbon Dating

This paper describes the application of a novel, practical approach for isolation of individual compounds from complex organic matrices for natural abundance radiocarbon measurement. This is achieved through the use of automated preparative capillary gas chromatography (PCGC) to separate and recover sufficient quantities of individual target compounds for 14C analysis by accelerator mass spectrometry (AMS). We developed and tested this approach using a suite of samples (plant lipids, petroleums) whose ages spanned the 14C time scale and which contained a variety of compound types (fatty acids, sterols, hydrocarbons). Comparison of individual compound and bulk radiocarbon signatures for the isotopically homogeneous samples studied revealed that Δ14C values generally agreed well (±10%). Background contamination was assessed at each stage of the isolation procedure, and incomplete solvent removal prior to combustion was the only significant source of additional carbon. Isotope fractionation was addressed thr...
THE ROLE OF DIETARY FATTY ACIDS IN LIPOPROTEIN OXIDATION AND ATHEROSCLEROSIS

Although it is well established that dietary saturated fatty acid intake is an important risk factor for coronary heart disease, there remains substantial controversy regarding whether these dietary fatty acids should be replaced with either carbohydrates, monounsaturated fatty acids, polyunsaturated fatty acids or a combination of these. This review highlights recent studies evaluating the role of dietary fatty acids in atherosclerosis, with a particular emphasis on their roles in lipoprotein oxidation and other potential proatherogenic processes.
Simple high-performance liquid chromatographic method for determination of pentoxifylline in human plasma

A simple high-performance liquid chromatographic method using ultraviolet detection was developed for the determination of pentoxifylline in human plasma. Prior to analysis, pentoxifylline and the internal standard (chloramphenicol) were extracted from plasma sample using dichloromethane. The mobile phase comprised 0.02 M phosphoric acid adjusted to pH 4, methanol and tetrahydrofuran (55:45:1, v/v). Analysis was run at a flow-rate of 1.4 ml/min with the detector operated at a wavelength of 273 nm. The method was specific and sensitive with a detection limit of approximately 3.0 ng/ml at a signal to noise ratio of 3:1, while the limit of quantification was 12.5 ng/ml. Mean recovery value of the extraction procedure was about 99.9%, while the within-day and between-day coefficient of variation and percent error values of the assay method were all less than 10.0%. The calibration curve was linear over a concentration range of 12.5-400.0 ng/ml.
Growth-dependent subcellular redistribution of protein kinase C in cultured porcine aortic endothelial cells

We have previously observed major differences in the phosphorylation of membrane proteins in sparse, proliferating versus confluent, quiescent pig aortic endothelial cells (EC) (Kazlauskas and DiCorleto, 1987). In the present study we examined whether EC growth state can influence the activity of a specific phosphorylating enzyme, protein kinase C (PKC) in cytosolic and membrane fractions of pig aortic EC. Levels of PKC were measured using two methods: (1) Ca2+ and phospholipid-dependent phosphorylation of exogenous histones using gamma-labeled [32P]ATP, and (2) [3H]phorbol-12, 13-dibutyrate (PDBu) binding activity. The total amount of PKC activity in the quiescent versus proliferating cells was similar but the percentage of PKC activity in the membrane fraction correlated with the proliferative index of the cells: confluent, quiescent cultures exhibited a majority of PKC activity in the cytosolic fraction (67%), whereas sparse, proliferating cultures contained principally membrane-bound PKC (70%). We also examined the role of PKC in the mitogenic response of pig aortic EC to fetal calf serum. Following serum stimulation of sparse, serum-deprived pig aortic EC, PKC activity redistributed from the cytosolic to the membrane fraction in a rapid process that correlated with subsequent DNA synthesis. A potent activator of PKC, 12-O-tetradecanoylphorbol-13-acetate (TPA), induced a minimal mitogenic response in pig aortic EC when added alone but acted synergistically with low concentrations of fetal calf serum to greatly stimulte DNA synthesis. Furthermore, pig aortic EC treated with TPA for 24 h to down-regulate PKC exhibited only 25% of the serum-stimulated mitogenic activity of control cultures. These results suggest a role for PKC activation and translocation in the proliferation of pig aortic EC.
Optimal morphological peak classification

ABSTRACT The morphological top-hat transform is often used to locate bright peaks in a gray-scale image. Themethod can be problematic when there are two classes of peaks, one corresponding to valid objects and the other to noise. The present paper employs Bayesian estimation in conjunction with a multinomial distribution corresponding to levels of peak heights in the top-hat image to arrive at anoptimal conditional-expectation estimator for the number of images in a random sample of images thatcontain a given number of valid peaks.Keywords: Morphology, Bayesian Estimation, Top-hat transform. 1. INTRODUCTION Detection of bright peaks is a common problem in image processing and the morphological top-hattransform is often applied to isolate peaks irrespective of their local background gray level [1 -4]. Fora fixed structuring set D, the top-hat transform is defined by 'P(f) = f — (f o D), where f o D is themorphological opening. Following the top-hat transform, a global threshold is applied to produce a
Peroxynitrite-induced p38 MAPK pro-apoptotic signaling in enterocytes.

Enterocyte apoptosis in necrotizing enterocolitis is partly due the elaboration of toxic intermediates of nitric oxide (NO), such as peroxynitrite (PN). Because p38 mitogen-activated protein kinase (MAPK) and serine-threonine kinase (AKT) are well-characterized pro- and anti-apoptotic mediators respectively, we hypothesized that PN could induce enterocyte apoptosis via activation of p38 and deactivation of AKT. To test this hypothesis, the rat intestinal cell line, IEC-6, was treated with PN. PN caused phosphorylation of p38, its upstream activator, MKK3/6, and downstream effector, transcription factor ATF2. PN-induced apoptosis was inhibited by the p38 inhibitor, SB202190, and by p38 siRNA. PN decreased AKT phosphorylation; this effect was abrogated by pre-treatment with SB202190 or p38 siRNA. PN exposure also increased the activity of the protein phosphatase 2A (PP2A). These data demonstrate that PN-mediated apoptosis depends on the p38 pathway and that p38 mediates deactivation of AKT survival pathways possibly by the involvement of PP2A.
Population of Nuclei Via 7Li-Induced Binary Reactions

The authors have investigated the population of nuclei formed in binary reactions involving {sup 7}Li beams on targets of {sup 160}Gd and {sup 184}W. The {sup 7}Li + {sup 184}W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si {Delta}E-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies.
Teaching Bioeconomics: A Political Scientist's Experience Teaching Evolutionary Psychology

When the European colonial powers were slicing up Africa during the late 19th century, they paid little or no attention to ethnic, historical or cultural divisions; each power grabbed what it could, and fought whatever boundary skirmishes were necessary in order to retain whatever it believed was rightfully its own. The result (after World War I shook things down somewhat) was the political and ethnic incoherence that continues to cripple African economic and social development, and is likely to do so for the foreseeable future. In a fairly close analogy, when the structure of American universities was being decided about the same time, each discipline—or nascent discipline—grabbed whatever intellectual territory it could, paying close attention to defining and defending its own unique mandate, while eschewing any effort to identify common intellectual concerns. The result, replicated in universities across the US and now the world, is the intellectual incoherence that continues to cripple the social sciences as cumulative, empirically based endeavor. And it appears to be an equilibrium. Periodic attempts by isolated universities to create integrated social science programs are at a serious competitive disadvantage in placing their graduates, thus in attracting strong applicants; and they are at a comparable disadvantage in the discipline-based ratings game to which deans pay close attention. Similarly, periodic attempts by members of one discipline to intrude their own concepts and analytics into the subject matters claimed by others produce, at best, nicely quarantined ‘sub-fields’ with their own specialized journals and academic meetings, a process strikingly similar to that by which the immune system isolates and renders harmless invading pathogens. The yawning gap between the methods and concepts of the several social sciences and those of the life sciences—notably Biology, Cognitive Neuroscience, Evolutionary Psychology, Ethology—has proved an even more formidable divide, one that is particularly distressing at the present time, given the major advances in those fields during the past forty or so years. Professional training in, say, Political Science (my own discipline), can and often does involve concepts and methods from Economics, Psychology, Sociology, and even Anthropology, thus ensuring at least a modicum of cross-disciplinary literacy among future disciplinary
REACT: intelligent authoring of social skills instructional modules for adolescents with high-functioning Autism

Difficulties in social skills are generally considered defining characteristics of High-functioning Autism (HFA). These difficulties interfere with the educational experiences and quality of life of individuals with HFA, and interventions must be highly individualized to be effective. For these reasons, we are interested in exploring the way technologies may play a role in assisting individuals with the acquisition of social skills. In this article we present an approach to developing an authoring tool designed to help parents and other caregivers to create social problem solving skills instructional modules. The authoring tool, which we call REACT, will help non-experts create interactive social scenarios personalized to individual adolescents with HFA. The technology will assist by advising the author on instructional strategies, and on scenario creation.
Localization and capacitance fluctuations in disordered Au nanojunctions

Nanojunctions, containing atomic-scale gold contacts between strongly disordered leads, exhibit different transport properties at room temperature and at low temperature. At room temperature, the nanojunctions exhibit conductance quantization effects. At low temperatures, the contacts exhibit Coulomb blockade. We show that the differences between the room-temperature and low-temperature properties arise from the localization of electronic states in the leads. The charging energy and capacitance of the nanojunctions exhibit strong fluctuations, with applied magnetic field at low temperature, as predicted theoretically.
Nocturnal feeding pattern in the prepubertal rat: influence of the ventromedial hypothalamus (VMH).

Abstract Daily feeding patterns, food intake and changes in body weight of male and female prepubertal rats were observed across a period from 21 to 50 days of age. Light/dark differences in feeding were found for both males and females throughout the recorded period, with feeding occurring predominantly during the dark period. The light/dark difference in feeding behavior gradually increased as the animals developed. Bilateral lesions placed in the VMH of female rats at 21 days of age disrupted the light/dark differences in feeding behavior primarily by decreasing dark period feeding. These lesions further resulted in a period of hypophagia and retarded body weight gain as well as a delay in pubertal onset. These data indicate that prepubertal rats regulate their feeding behavior so that food intake occurs principally during the dark period and that the integrity of the VMH is necessary for this regulation.
A MULTI-DIMENSIONAL TUNNELING THEORY WITH APPLICATION TO SCANNING TUNNELING MICROSCOPE

We have developed a formal general approach for evaluating the WKB wave function in a forbidden region of a non-separable potential in a three-dimensional space. The wave function is described by two sets of orthogonal wave-fronts, the equi-phase and equiamplitude surfaces, or equivalently by two sets of paths defined to be normal to these surfaces respectively. We have extended a Huygens type construction to the forbidden region to obtain the multi-dimensional wave function. The construction determines the wave-fronts and the paths. It is found that the equations for the paths obtained from the construction are coupled to each other and do not reduce to a set of ordinary differential equations. However, if the incident wave is normal to the turning surface, the equations satisfied by the paths can be de-coupled. These equations are found to be equivalent to Newton's equations of motion for the inverted potential and energy. This characteristics has been used to calculate the current density distribution for an STM. In this paper, we use the same approach to derive the expressions for the lateral resolutions and corrugations for a model STM.
Valence force constants for the P2O74− ion in MIVP2O7 and M2IIP2O7 solids

Abstract A set of valence force constants is calculated for the P 2 O 7 4− ion in β-Mg 2 P 2 O 7 and a group of M IV P 2 O 7 compounds typified by ZrP 2 O 7 . The results agree generally with the relationships between bond orders and stretching force constants suggested by Cruickshank and Robinson. Bond distances calculated from the stretching force constants are in excellent agreement with observed PO bond distances in the M IV P 2 O 7 compounds, but not in β-Mg 2 P 2 O 7 . The values of the bending force constants support Lazerev's contention that the bridging oxygen is not firmly fixed in a linear POP configuration.
Sa1535 Dual Modality Drainage of Infected Walled off Pancreatic Necrosis Is Associated With Reduction in Resource Utilization Over Standard Percutaneous Drainage

Dual Modality Drainage of Infected Walled off Pancreatic Necrosis Is Associated With Reduction in Resource Utilization Over Standard Percutaneous Drainage Michael Gluck*, Andrew S. Ross, Shayan Irani, S. Ian Gan, Richard a. Kozarek Digestive Disease Institute, Virginia Mason Medical Center, Seattle, WA Background: Infected walled off pancreatic necrosis (IWOPN) is generally considered an absolute indication for drainage and/or debridement. Our group has previously demonstrated superior clinical outcomes and decreased resource utilization with combined endoscopic and percutaneous drainage (DMD) of infected and symptomatic walled off pancreatic necrosis in comparison to standard percutaneous drainage (SPD). We sought to compare our experience with DMD to that with SPD for patients with IWOPN alone. Methods: We reviewed an IRB-approved, prospective database of all patients with WOPN treated with either SPD or DMD between 1/1/2006 to 11/24/2012. If the initial gram stain and culture at the time of drainage was positive, patients were labeled as having IWOPN and included in this analysis. Results: During the study period, 98 patients were treated with DMD and 44 with SPD for WOPN of whom 47 (48%) and 19 (41%) had IWOPN respectively. Mean age, male preponderance, majority with gallstone etiology and computed tomographic severity indices (CTSI) were statistically identical (See Table). DMD treated patients with IWOPN had statistically reduced length of hospitalizations (LOH) (24 v 63 days, p 0.004), use of radiological resources (p 0.002), and ERCP’s (p 0.01). Removal of drains was achieved earlier in the DMD cohort (83 v 158 days, p 0.05). There were 4 patients who bled from pseudoaneurysms in the SPD cohort (21%) and 1 in the DMD treated group (2%, p 0.001). Three patients had surgery for either fistulae or debridement (16%) in the SPD group versus none in the DMD cohort. Two patients with DMD had surgery for chronic pain over one year after removal of external drains. There were 2 deaths in each cohort in patients who had external drains in place (not completed therapy). Conclusions: In patients with IWON, DMD resulted in decreased length of hospitalization as well as decreased utilization of radiologic, surgical and endoscopic resources as compared to SPD. These data further support DMD as the treatment of choice for patients undergoing percutaneous drainage of IWOPN.
Representation of architectural concepts in the study of precedents: a concept-learning system

Learning architectural concepts through the study of precedents is a common activity in design studio. Traditionally, an instructor presents a design concept by showing selected examples using slides, photographs, drawings, texts and verbal analyses. This method relies on a linear mode of conveying design knowledge and is time bound. It emphasizes information retention and recall of facts rather than an understanding of information. If information on architectural precedents are represented digitally in a system designed to promote understanding of the material rather than just presentation of facts, then some disadvantages of the traditional method may be overcome and additional advantages may be achieved. This paper describes a computer-assisted lesson system designed to represent architectural concepts related to spatial composition in design by using graphic images and text and reports on its development, implementation and testing. The system relies on many characteristics, such as accessibility, interactivity, flexibility, rapid feedback, etc., which are known to foster effective concept learning. The paper also evaluates the viability and effectiveness of this system from a technological and logistical viewpoint as well as from a concept learning viewpoint, and concludes with a discussion on other potential applications.
INTERRELATIONSHIP OF PHYSICAL, PERCEPTUAL-MOTOR, AND ACADEMIC ACHIEVEMENT VARIABLES IN ELEMENTARY SCHOOL CHILDREN

For third- and sixth-grade children height, weight, grip strength of the dominant and non-dominant hands, elbow flexion and elbow extension strength, hip flexion and hip extension strength, dynamic balance, ball-throwing accuracy, speed of hand-arm movement, eye-hand coordination, stimulus discrimination and hand speed, perceptual ability, academic achievement, and intelligence were measured. (a) Intercorrelations among variables were low and often not significant for sixth- and third-grade children, (b) correlations were of similar magnitude for the two age groups, and (c) perceptual-motor tasks did not correlate any higher with intelligence tests than did simple motor tasks or physical characteristics.
Estimation of Discretization Errors Using the Method of Nearby Problems

The method of nearby problems is developed as an approach for estimating numerical errors due to insufficient mesh resolution. A key aspect of this approach is the generation of accurate, analytic curve fits to an underlying numerical solution. Accurate fits are demonstrated using fifth-order Hermite splines that provide for solution continuity up to the third derivative, which is recommended for second-order differential equations. This approach relies on the generation of a new problem (and corresponding exact solution) that is "nearby" the original problem of interest, and the nearness requirements are discussed. The method of nearby problems is demonstrated as an accurate discretization error estimator for steady-state Burgers's equation for a viscous shock wave at Reynolds numbers of 8 and 64. A key advantage of using the method of nearby problems as an error estimator is that it requires only one additional solution on the same mesh, as opposed to multiple mesh solutions required for extrapolation-based error estimators. Furthermore, the present results suggest that the method of nearby problems can produce better error estimates than other methods in the preasymptotic regime. The method of nearby problems is also shown to provide a useful framework for evaluating other discretization error estimators. This framework is demonstrated by the generation of exact solutions to problems nearby Burgers's equation as well as a form of Burgers's equation with a nonlinear viscosity variation.
Observations on ordered voids in molybdenum

The present measurements, along with those previously published, indicate a threshold for both void ordering (approximately 2 dpa) and for void superlattice formation (approximately 10 dpa) in molybdenum. Theoretical attempts to deal with the creation of the superlattice in molybdenum are thus constrained not to use either void nucleation on a pre-existing solute atom array or void nucleation in an ordered array. Instead, the voids must first form in random arrays from which void ordering and finally the void superlattice evolve. Presently this sequence can be described to be either selective growth and void motion in response to a void-void interaction or to Foreman's crowdion mechanism but these theories must be formulated on a more quantitative basis before detailed comparison with experiment can be accomplished.
The walls speak: the interplay of quality facilities, school climate, and student achievement

Purpose – A growing body of research connecting the quality of school facilities to student performance accompanies recent efforts to improve the state of the educational infrastructure in the USA. Less is known about the mechanisms of these relationships. This paper seeks to examine the proposition that part of the explanation may be the mediating influence of school climate.Design/methodology/approach – Teachers from 80 Virginia middle schools were surveyed employing measures including the School Climate Index, a seven‐item quality of school facilities scale, as well as three resource support items. Data on student SES and achievement were also gathered. Bivariate correlational analysis was used to explore the relationships between the quality of facilities, resource support, school climate, student SES, and student achievement. In addition, multiple regression was used to test school climate as a mediating variable between the quality of facilities and student achievement.Findings – Results confirmed a...
On the sensitivity of 3-D thermal convection codes to numerical discretization: a model intercomparison

Abstract. Fully 3-D numerical simulations of thermal convection in a spherical shell have become a standard for studying the dynamics of pattern formation and its stability under perturbations to various parameter values. The question arises as to how the discretization of the governing equations affects the outcome and thus any physical interpretation. This work demonstrates the impact of numerical discretization on the observed patterns, the value at which symmetry is broken, and how stability and stationary behavior is dependent upon it. Motivated by numerical simulations of convection in the Earth's mantle, we consider isoviscous Rayleigh–Benard convection at infinite Prandtl number, where the aspect ratio between the inner and outer shell is 0.55. We show that the subtleties involved in developing mantle convection models are considerably more delicate than has been previously appreciated, due to the rich dynamical behavior of the system. Two codes with different numerical discretization schemes – an established, community-developed, and benchmarked finite-element code (CitcomS) and a novel spectral method that combines Chebyshev polynomials with radial basis functions (RBFs) – are compared. A full numerical study is investigated for the following three cases. The first case is based on the cubic (or octahedral) initial condition (spherical harmonics of degree e = 4). How this pattern varies to perturbations in the initial condition and Rayleigh number is studied. The second case investigates the stability of the dodecahedral (or icosahedral) initial condition (spherical harmonics of degree e = 6). Although both methods first converge to the same pattern, this structure is ultimately unstable and systematically degenerates to cubic or tetrahedral symmetries, depending on the code used. Lastly, a new steady-state pattern is presented as a combination of third- and fourth-order spherical harmonics leading to a five-cell or hexahedral pattern and stable up to 70 times the critical Rayleigh number. This pattern can provide the basis for a new accuracy benchmark for 3-D spherical mantle convection codes.
A carbon inventory for Orca Basin brines and sediments

Orca Basin, an intraslope depression at a depth or about 2400 m on the continental slope of the north-central Gulf of Mexico, contains an anoxic, hypersaline brine similar in composition to those reported in the Red Sea. Concentrations and stable carbon isotope compositions of various inorganic and organic carbon species have been determined on the brine and sediments in order to gain an understanding of the origin and cycling of carbon in this unique environment. ΣCO 2 in the brine (55 mg C/l) is about twice seawater with δ 13 C PDB = −16.4‰ and Δ 14 C= −501‰.CH 4 has a concentration of 12 mg C/l and δ 13 C= −73.5‰. Dissolved and particulate organic carbon concentrations are seven times higher and have δ 13 C values several permil different than the overlying seawater. ΣCO 2 and CH 4 in the interstitial waters are considerably higher in concentrations and isotopically lighter than the overlying brine. Solution of near-surface salt deposits by seawater with subsequent microbial production and consumption of methane can be used to explain most of the data.
Tax policy and secondary material use

Abstract Legislative interest in policies to stimulate resource recovery has pointed out the need for an analysis of the determinants of materials flows. This paper characterizes the flows of virgin and secondary materials and explores in detail points where the two materials become substitute commodities. Econometric models specified at these points of substitution in the wastepaper and scrap steel industries are used to analyze various policy options being considered by Congress.
RAC2 Regulates the activation of akt and the balance between pro- and anti-apoptotic proteins bad and bcl-xl

Abstract We have previously demonstrated that the hematopoietic cell specific Rho GTPase Rac2 plays not only an essential role in regulating multiple actin-based functions of bone marrow derived mast cells, such as adhesion to fibronectin, migration, and degranulation but is also critical to mast cell survival. To determine the extent of involvement of signaling pathways in increased apoptosis due to Rac2 deficiency, we examined the activation of PI-3Kinase and its downstream effector, Akt, in response to SCF-stimulation. Although, PI-3Kinase activation in response to SCF stimulation was identical in Rac2−/− compared with wild-type (wt) mast cells, the activation of Akt was completely abolished in Rac2−/− mast cells. Unexpectedly, the level of the proapoptotic protein, Bad was significantly elevated (∼10-fold) in Rac2−/− cells in comparison to wt. In contrast, the level of anti-apoptotic protein Bcl-Xl was significantly reduced (∼10-fold) in Rac2−/− cells in comparison to wt. To confirm that enhanced apoptosis in mast cells was the direct result of Rac2 deficiency, Rac2−/− mast cells were transduced with a retrovirus expressing a wt Rac2 cDNA. As expected, Rac2−/− cells expressing Rac2 as a transgene demonstrated complete correction of all actin-based functions and normal survival of mast cells in response to SCF-stimulation. In addition, the activation of Akt and the level of Bad and Bcl-Xl protein were restored to wt levels. In summary, these data demonstrate that Rac2 not only plays an essential role in hematopoietic cell actin-mediated functions, but also plays a critical role in maintaining the survival of these cells by regulating the activation of Akt and the balance between pro- and anti-apoptotic proteins, Bad and Bcl-Xl.
The Future of an Imagined Community: Trailer Parks, Tree Huggers, and Trinational Forces Collide in the Southern Arizona Borderlands

Surviving small towns in southern Arizona have diversified to occupy a variety of specialized niches. Each responds to the needs of the nearby urban centers or to sectors of the broader and more remote public of visitors, vacationers, and transients. Benson, Arizona, a former market town and transportation center located on the San Pedro River, is seeking its niche in the "new economy." Options run the gamut from RV park communities through specialty-crop agricultural markets to psuedo-Western "frontier towns." But Benson's choices are now limited by an array of increasingly powerful public and private interests that see the San Pedro Valley as either a national environmental treasure to be preserved or an exploitable set of resources for international commercial development.
Synthesis of SiO2 Nanowires and CdS/SiO2 Composite Nanowires and Investigation of Their Electron Field Emission Properties

A thermal evaporation method was used to obtain SiO2 and CdS/SiO2 nanowires by heating Si substrates coated with a gold thin film in a quartz tube furnace. During growth, pure CdS powder was placed at the heating zone in the furnace, serving as the CdS source for the CdS/SiO2 composite nanowires. It was found that both non-porous and porous Si substrates served as the Si source for the growth of SiO2 nanowires and the CdS/SiO2 composite nanowires. It was also found that the effect of the temperature gradient in the reaction chamber plays an important role in the density distribution of different nanowires (SiO2 or CdS/SiO2 nanowires). The electron field emission properties of these nanowires were investigated using an electron field emission microscope equipped with a Faraday cup.
Structural and evolutionary divergence of eukaryotic protein kinases in Apicomplexa

The Apicomplexa constitute an evolutionarily divergent phylum of protozoan pathogens responsible for widespread parasitic diseases such as malaria and toxoplasmosis. Many cellular functions in these medically important organisms are controlled by protein kinases, which have emerged as promising drug targets for parasitic diseases. However, an incomplete understanding of how apicomplexan kinases structurally and mechanistically differ from their host counterparts has hindered drug development efforts to target parasite kinases. We used the wealth of sequence data recently made available for 15 apicomplexan species to identify the kinome of each species and quantify the evolutionary constraints imposed on each family of apicomplexan kinases. Our analysis revealed lineage-specific adaptations in selected families, namely cyclin-dependent kinase (CDK), calcium-dependent protein kinase (CDPK) and CLK/LAMMER, which have been identified as important in the pathogenesis of these organisms. Bayesian analysis of selective constraints imposed on these families identified the sequence and structural features that most distinguish apicomplexan protein kinases from their homologs in model organisms and other eukaryotes. In particular, in a subfamily of CDKs orthologous to Plasmodium falciparum crk-5, the activation loop contains a novel PTxC motif which is absent from all CDKs outside Apicomplexa. Our analysis also suggests a convergent mode of regulation in a subset of apicomplexan CDPKs and mammalian MAPKs involving a commonly conserved arginine in the αC helix. In all recognized apicomplexan CLKs, we find a set of co-conserved residues involved in substrate recognition and docking that are distinct from metazoan CLKs. We pinpoint key conserved residues that can be predicted to mediate functional differences from eukaryotic homologs in three identified kinase families. We discuss the structural, functional and evolutionary implications of these lineage-specific variations and propose specific hypotheses for experimental investigation. The apicomplexan-specific kinase features reported in this study can be used in the design of selective kinase inhibitors.
A 2*2 fiber optic switch using chiral liquid crystals

A nonchemical 2*2 optical switch for fiber optic applications is described. Using a chiral-nematic liquid-crystal cell and switchable nematic liquid-crystal waveplates, the authors measured -26-dB crosstalk between unselected fibers, a fiber-to-fiber insertion losses of 1.4 dB, and switching times under 40 ms with operation at 1318 nm using 62.5/125- mu m multimode fiber. The device features simple construction, low power requirements, and an optical bandwidth suitable for LED or laser sources, and it works equally well with multimode or single-mode fiber. >
Oligodendrocytes from forebrain are highly vulnerable to AMPA/kainate receptor-mediated excitotoxicity

Little is known of the molecular mechanisms that trigger oligodendrocyte death and demyelination in many acute central nervous system insults. Since oligodendrocytes express functional alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate-type glutamate receptors, we examined the possibility that oligodendrocyte death can be mediated by glutamate receptor overactivation. Oligodendrocytes in primary cultures from mouse forebrain were selectively killed by low concentrations of AMPA, kainate or glutamate, or by deprivation of oxygen and glucose. This toxicity could be blocked by the AMPA/kainate receptor antagonist 6-nitro-7-sulfamoylbenzo(f)quinoxaline-2,3-dione (NBQX). In vivo, differentiated oligodendrocytes in subcortical white matter expressed AMPA receptors and were selectively injured by microstereotaxic injection of AMPA but not NMDA. These data suggest that oligodendrocytes share with neurons a high vulnerability to AMPA/kainate receptor-mediated death, a mechanism that may contribute to white matter injury in CNS disease.
Hormonal modulation of α-fetoprotein gene expression in newborn rat livers

Suppression of serum alpha-fetoprotein (AFP) levels in glucocorticoid treated newborn rats was investigated. Daily intraperitoneal injection of 2 micrograms/g body weight of dexamethasone into newborn rats greatly reduced the concentration of AFP in the serum and liver cytosol. In contrast, this treatment stimulated liver ornithine decarboxylase activity. The reduction in AFP levels is not due to a change of distribution of AFP molecular variants, inhibition of secretion of synthesized AFP by the liver or disruption of liver polysomes. Glucocorticoids decrease the AFP levels in hormone-treated rats by supressing the synthesis of AFP. The size of AFP polysomes isolated from the livers of dexamethasone-treated rats were as large as those from normal rats. However, the amount of AFP-producing polysomes in hormone-treated rat liver is only 14% of the controls. By hybridization assays, it was found that dexamethasone treated livers contained decreased amounts of AFP mRNA sequences in liver cytoplasmic and nuclear RNAs. The decreased amounts of AFP mRNA sequences in hormone-treated liver are caused by both a decrease in the rate of AFP mRNA transcription and in AFP mRNA stability.