cssi/SciSciGPT-SciSciNet huggingface dataset:
Disciplinary Authority and Accountability in Scientific Practice and Learning

This article explores the relation between how scientific knowledge is created and the reasoning involved in learning content with understanding. Although an asserted parallel between these underpins reform, little is actually known about this relation. This article offers a model of this relation that draws coherent connections between the science studies literature, which suggests ways of conceiving how scientific knowledge is created; and sociocultural learning theory, which suggests ways of conceiving scientific reasoning. This model highlights a dialectic between construction and critique of claims in both scientific reasoning and practice. A “grasp” of scientific practice as such is instrumental to learning because informational content of scientific knowledge lies not only on the level of facts, but also on the levels of methods and values, and coordinating information across these levels is crucial for understanding. In contrast to prevailing constructivist ideas that highlight student authority to construct knowledge as scientists do, this model emphasizes the importance of knowing how to hold claims accountable. Thus, the ideal vision of students making their own sense of content is superceded by a more defensible ideal vision of students learning how to make scientific sense of content. © 2008 Wiley Periodicals, Inc. Sci Ed92:404–423, 2008
Synaptic plasticity: Going through phases with LTP

Early and late expressing components of synaptic plasticity may underlie the temporal phases of behavioral memory. New studies argue that a balance between kinase and phosphatase activity regulates the transition between different phases of synaptic plasticity and memory.
The Fiber-Optics Hypodermic Microscope

This paper presents the prototype of a hypodermic fiber-optics microscope. The instrument permits the researcher to observe tissues beneath the skin of the living animal or human, microscopically, through a hypodermic needle. The device utilizes fiber optics for image transmission, making it possible to observe through needles with inside diameters of 0.81 mm. Special features of this device include a self-contained illumination system within the same needle as the imaging bundle, and a unique microscope eyepiece which corrects for distortion caused by the necessary bevel at the far end of the needle. The resolving power of the present system is about 10 μ. A major problem is the definition of structures from each other within living tissue. Experiments are under way with various vital stains to improve this definition. Successful observations to date have been made of blood vessels and muscle fibers. Possible applications of the instrument are discussed.
A hierarchical data structure for multidimensional digital images

A tree data structure for representing multidimensional digital binary images is described. The method is based on recursive subdivision of the d-dimensional space into 2d hyperoctants. An algorithm for constructing the tree of a d-dimensional binary image from the trees of its (d - 1 )-dimensional cross sections is given. The computational advantages of the data structure and the algorithm are demonstrated both theoretically and in application to a three-dimensional reconstruction of a human brain.
Nanometer-scale interface engineering boosts the thermoelectric performance of n-type Ti0.4Hf0.6Ni1+zSn0.975Sb0.025 alloys

Engineering the internal structure of bulk semiconductors through the introduction of nanometer-scale interfaces affords opportunities for simultaneous optimization of electronic and thermal transport properties, enabling the fabrication of nanocomposite materials with superior thermoelectric performance. Several compositions of n-type Ti0.4Hf0.6Ni1+zSb0.975Sn0.025 half-Heusler (HH)/full-Heusler (FH) composites were synthesized by a high temperature solid state reaction of the elements. Polycrystalline powders of the resulting HH(1 − z)/FH(z) composites were further processed by mechanical alloying using high-energy ball milling. Transmission electron microscopy (TEM) studies revealed the presence of small (∼20 nm) FH precipitates coherently embedded in micron-scale grains of HH/FH composites obtained after the solid state reaction, whereas nanometer-scale grains (∼20 nm) of the HH/FH composites containing very small (<10 nm) FH precipitates were observed in mechanically alloyed samples (SS-MA). The as-synthesized HH(1 − z)/FH (z) samples (SS) showed similar electrical conductivity, thermopower and thermal conductivity at all temperatures regardless of the fractions of FH inclusions. This suggests that the FH inclusions are electronically inert with regard to the matrix. Interestingly, drastic alterations of all three properties were observed on mechanically alloyed samples and the magnitude of change in various properties increases with the mole fractions of FH inclusions. For example, large reductions in the thermal conductivity (8.5 W K−1 m−1 to 4.0 W K−1 m−1 at 300 K) as well as electrical conductivity (4750 S cm−1 to 1750 S cm−1 at 300 K) were observed in all SS-MA samples compared to SS samples with similar compositions. This behavior is attributed to enhanced scattering of phonons and electrons at multiple grain boundaries generated by the mechanical alloying process. Remarkably, the magnitude of the reduction in the electrical and thermal conductivities increases with the mole fraction of FH inclusions in the samples suggesting (1) reduction in the carrier density due to trapping of low-energy carriers and (2) additional phonon scattering at nanometer-scale HH/FH interfaces. This results in large increases in the thermopower (−60 μV K−1 to −92 μV K−1 at 300 K) of SS-MA samples, which mitigates the drop in the electrical conductivity leading to large improvement of the figures of merit of mechanically alloyed Ti0.4Hf0.6Ni1+zSb0.975Sn0.025 samples.
Leucocytes at a molecular level

Molecular biologists have left their imprint on almost every aspect of immunology investigation; one notable exception is the study of macrophage differentiation and activation. Few cells have as many interesting responses as the monocyte; and as most of the differentiation-activation responses occur without cellular proliferation, mononuclear phagocytes are excellent subjects in which to study environmental responses at the molecular level. Participants in a recent meeting(∗) considered how the techniques of molecular biology, often focused on problems of nerve-cell differentiation and fibroblast growth responses, could be used to address what many perceive to be the central question of macrophage biology: how are the many and diverse differentiation pathways regulated and can differentiation be described in distinct molecular terms from the state of activation?
A Markovian approach for optimizing highway life-cycle with genetic algorithms by considering maintenance of roadside appurtenances

Roadside appurtenances, such as guardrails, signs, and luminaries form a major portion of highway features whose upkeep and timely maintenance is very critical to maximize highway life-cycle. Their life-expectancy is largely reduced by poor maintenance. While significant work has been done in pavement and bridge maintenance roadside appurtenances have received limited attention. In this paper we develop a Markovian model for maximizing highway life-cycle by considering optimal maintenance strategies for roadside appurtenances over a given planning horizon. A genetic algorithm is developed to solve the developed optimization model since the resulting Markov tree tends to be clustered and relatively complex. Due to this complexity traditional approaches, such as dynamic programming seem to be computationally inefficient. Separate formulations under deterministic and probabilistic approaches to be undertaken for different maintenance conditions are developed. A probabilistic deterioration function for roadside appurtenances is also developed. An illustrative example to investigate the effectiveness of the deterministic approach is presented. The paper concludes with directions for future research.
Differential Roles of Arrestin-2 Interaction with Clathrin and Adaptor Protein 2 in G Protein-coupled Receptor Trafficking *

The non-visual arrestins, arrestin-2 and arrestin-3, play a critical role in regulating the signaling and trafficking of many G protein-coupled receptors (GPCRs). Molecular insight into the role of arrestins in GPCR trafficking has suggested that arrestin interaction with clathrin, beta(2)-adaptin (the beta-subunit of the adaptor protein AP2), and phosphoinositides contributes to this process. In the present study, we have attempted to better define the molecular basis and functional role of arrestin-2 interaction with clathrin and beta(2)-adaptin. Site-directed mutagenesis revealed that the C-terminal region of arrestin-2 mediated beta(2)-adaptin and clathrin interaction with Phe-391 and Arg-395 having an essential role in beta(2)-adaptin binding and LIELD (residues 376-380) having an essential role in clathrin binding. Interestingly, arrestin-2-R169E, an activated form of arrestin that binds to GPCRs in a phosphorylation-independent manner, has significantly enhanced binding to beta(2)-adaptin and clathrin. This suggests that receptor-induced conformational changes in the C-terminal tail of arrestin-2 will likely play a major role in mediating arrestin interaction with clathrin-coated pits. In an effort to clarify the role of these interactions in GPCR trafficking we generated arrestin mutants that were completely and selectively defective in either clathrin (arrestin-2-DeltaLIELD) or beta(2)-adaptin (arrestin-2-F391A) interaction. Analysis of these mutants in COS-1 cells revealed that arrestin/clathrin interaction was essential for agonist-promoted internalization of the beta(2)-adrenergic receptor, while arrestin/beta(2)-adaptin interaction appeared less critical. Arrestin-2 mutants defective in both clathrin and beta(2)-adaptin binding functioned as effective dominant negatives in HEK293 cells and significantly attenuated beta(2)-adrenergic receptor internalization. These mutants should prove useful in better defining the role of arrestins in mediating receptor trafficking.
Understanding stability and change in fields

Abstract In the literature on organizations, there are two very different views of social change. One emphasizes piecemeal change and actor learning. The other views change as more revolutionary resulting in entirely novel forms of organizations. On the surface, these two conceptions of social change seem incompatible. But, I argue that by situating organizations in field analysis, we can make sense about the conditions under which both can occur. This paper offers a framework for understanding strategic action in organizational fields. Embedded in this framework is the idea that these different theories of change operate under quite different structural conditions of fields. The emergence or transformation of a field implies radical change precisely because all elements of the structuring of the field are in flux. If one is observing an already existing field, then the dynamics of interaction are likely to be quite different. Actors in existing fields will work to maintain their position in the field. They will engage in strategic action to make changes in response to what others are doing in the field. Thus, in a stable field where the game for position is ongoing, we expect change to be more incremental, more imitative, and often, in reaction to the moves of others. I end by presenting an example of stability and suggesting a research agenda.
Unhealthy cities: corporate medicine, community economic underdevelopment, and public health.

The growing corporate dominance in U.S. medical care has been a major factor in the increasingly inequitable distribution of health care resources and the declining public health conditions in poor...
Frequency and buckling eigenvalues of anisotropic cylinders subjected to nonuniform lateral prestress

Abstract Solutions are developed herein for the evaluation of frequency and stability eigenvalues of macro-scopically fully anisotropic circular cylindrical shells subjected to nonuniform lateral prestress. Included in the analysis is the presence of torsional prestress. The results obtained are applicable to any type of prestress which satisfy Dirichlet's conditions for Fourier series. Furthermore, in the manner of Kalnins [3], using the procedure outlined herein, similar results could be obtained for general anisotropic shells of revolution.
Serotonin Infusion in Rats with Experimental Renovascular Hypertension

Simultaneous, constant infusion of serotonin (100 mcg./kg./min.) and angiotensin (2 mcg./kg./min.) for 2 hr. in normotensive rats resulted in a diminution of the pressor response noted with angiotensin alone. A more marked depression occurred following infusion of serotonin in rats with established renovascular hypertension and this agent failed to influence blood pressure in rats with unilateral renal artery constriction that did not develop hypertension. Serotonin and/or angiotensin in the doses employed did not affect the degree of granularity of renal juxtaglomerular cells in these situations. These findings fail to support the view relating some instances of hypertension in man to the combined effects of serotonin and subpressor amounts of angiotensin II.
Synthesis and Properties of CaAl2O4-Coated AI2O3 Microcomposite Powders

Novel microcomposite powders, consisting of inert cores (αAL-Al2O3) surrounded by reactive cement-based coatings (CaAl2O4), were synthesized by a modified Pechini process. The evolution of the crystalline CaAl2O4 phase during calcination was studied using multiple analytical techniques, including DRIFTS,13C and 27AlMAS FT-NMR, and XRD, for both pure CaAl2O4 and CaAl2O4-coated Al2O3 precursor powders. In both powders, decomposition proceeded via hydrocarbon chain scission and removal of ester groups at low temperatures (T 450°C). These decomposition processes were accelerated by the underlying Al2O3 cores. Transmission electron microscopy (TEM) of the fully calcined powders showed that the inert αAL-Al2O3 particles were surrounded by relatively uniform CaAl2O4 coatings ranging in thickness from approximately 10 to 100 nm.
Influence of the superior colliculus on responses of lateral geniculate neurons in the cat

The superior colliculus (SC) projects to all layers of the cat's lateral geniculate nucleus (LGN) and thus is in a position to influence information transmission through the LGN. We investigated the function of the tecto-geniculate pathway by studying the responses of cat LGN neurons before, during, and after inactivating the SC with microinjections of lidocaine. The LGN cells were stimulated with drifting sine-wave gratings that varied in spatial frequency and contrast. Among 71 LGN neurons that were studied, 53 showed a statistically significant change in response during SC inactivation. Control experiments with mock injections indicated that some changes could be attributed to slow waxing and waning of responsiveness over time. However, this could not account for all of the effects of SC inactivation that were observed. Forty cells showed changes that were attributed to the removal of tecto-geniculate influences. About equal numbers of cells showed increases (22 cells) and decreases (18 cells) in some aspect of their response to visual stimuli during SC inactivation. The proportion of cells that showed tecto-geniculate influences was somewhat higher in the C layers (68% of the cells) than in the A layers (44% of the cells). In addition, among cells that showed a significant change in maximal response to visual stimulation, the change was larger for cells in the C layers (64% average change) than in the A layers (26% average change) and it was larger for W cells (61% average change) than for X and Y cells (29% average change). Nearly all of the X cells that showed changes had an increase in response, and nearly all of the Y cells had a decrease in response. In addition, across all cell classes, 80% of the cells with receptive fields 15 deg from the area centralis had a decrease in response. None of the LGN cells had significant changes in spatial resolution, and only three cells had changes in optimal spatial frequency. Ten cells had a change in contrast threshold, 25 cells had a change in contrast gain, and 29 cells had a change in the maximal response to a high-contrast stimulus. Thus, our results suggest that the tecto-geniculate pathway has little or no effect on spatial processing by LGN neurons. Rather, the major influence is on maximal response levels and the relationship between response and stimulus contrast. Several hypotheses about the role of the tecto-geniculate pathway in visual behavior are considered.
Nature of group Ib metal films deposited on polymer surfaces photooxidized with far-ultraviolet (185 nm) radiation

Abstract Solid samples of three polymers (polymethyl methacrylate, polycarbonate, and polyimide), whose surfaces were photooxidized with far-ultraviolet (185 nm) radiation in air, were used as substrates for the deposition of gold, silver, and copper films in vacuo. The electrical conductivities of the films were studied in situ as a function of the film thickness (0–15 nm). At a thickness of 10 nm, silver films showed 10 4 greater conductivities when deposited on the treated surfaces of all three polymers. Gold films showed no detectable differences between treated and untreated surfaces. Copper behaved similar to gold on PMMA but showed somewhat greater sensitivity (
The diode laser in atomic physics

Abstract Over the past fiie years the use of diode lasers in physics research has expanded rapidly. In part, this has occurred because the diode laser is a highly monochromatic and tunable light source that, when compared to other laser systems, is quite inexpensive and easy to operate. These characteristics make the diode laser ideal for multi-laser experiments, or small scale/high quality research projects in general. In this article a brief introduction to the AlGaAs single-mode diode laser's characteristics and operation is presented, along with an overview of this laser's contributions to atomic physics research to date. It is hoped that this review will facilitate the further use of diode lasers in all aspects of physics, and in particular will aid the small scale researcher in attaining a more active place in mainstream physics.
Effects of fish predation on larval chironomid ( Diptera: Chironomidae ) communities in an arctic ecosystem

Chironomid communities were analyzed in systems with three types of predator regimes to determine hierarchical effects of predation; ponds without fish present, lakes with slimy sculpin (Cottus cognatus) present, and lakes with slimy sculpin present along with burbot (Lota lota) and lake trout (Salvelinus namaycush). Samples were collected by coring bare sediment habitats in 4 systems of each type near the Toolik Lake field station in northern Alaska. Lakes with burbot and lake trout present in addition to slimy sculpin displayed significantly higher (P ‘ 0.05) biomass, density, richness, and diversity. This is likely due to the increased complexity of the predator regime. Ponds without fish had a significantly greater percentage of predacious chironomids present.
PROTECTIVE AND OPSONIC ACTIVITY OF IgG SUBCLASS ANTIBODIES (Ab) AGAINST HAEMOPHILUS INFLUENZAE TYPE B (Hib)

Ab to the capsular antigen of Hib is considered protective in humans, but the role of Ab of various immunoglobulin classes and subclasses is not well known. We evaluated the protective nature of sera from 13 children, 3 of whom were immunized with polyribosylribitol phosphate (PRP) and 4 with PRP conjugated to diphtheria toxgid (PRP-D); 6 were immunized with PRP conjugated to outer membrane protein of N. meningitidis. Each serum was used to passively immunize a series of 5-day-old rats, followed by subcutaneous inoculation of virulent Hib, The dose of total PRP Ab (Farr technique) required to prevent bacteremia and/or meningitis in 50% of rats (PD50) ranged from 13-916 ng/rat. Sera were also tested for in vitro opsonic activity. Neither protection nor opsgnic activity correlated with total PRP Ab. Analysis of anti-PRP IgG, IgG subclass and IgM Ab suggested that high IgG and IgM Ab were associated with protection. A drop in protection was associated with low Ab of two or more IgG subclasses. No single subclass response was consistently protective. High levels of IgG4 and IgM Ab were present in the most opsonic and protective sera. Anti-PRP IgM alone did not compensate for low levels of two or more IgG subclass Ab's. Full protection probably cannot be realized when there are low levels of Ab of 2 or more of the heavy chain genotypes tested (IgM, IgG1-4).
Employment opportunity can decrease adolescent childbearing within the underclass

Abstract Data from the evaluation of the Youth Incentive Entitlement Pilot Projects are used to test for a negative effect of economic opportunity upon adolescent childbearing among black youths from low-income households. We find that economic opportunity has a significant effect upon fertility, but that the direct effect of fertility upon school dropout is insignificant. The observed connection between fertility and dropout appears to reflect unmeasured factors for adolescent women which drive both variables. Methodological and policy implications of this finding are discussed.
Monomer diffusion and polymer alignment in domains of sickle hemoglobin.

We have used polarized absorbance to observe the process of monomer accretion and polymer alignment which occurs in domains of sickle hemoglobin that are formed and maintained by laser photolysis. These diffusion and alignment processes have been studied as a function of initial concentration and temperature (initial and final), as well as beam size and domain number. Monomers are found to diffuse into growing polymer domains with a rate that is essentially temperature and concentration independent, but which depends on the size of the final domain boundaries, and the number of domains within a boundary. The final concentrations achieved are very close to those found in packed centrifugation experiments (50–55 g/dl) and are approximately independent of starting temperature and concentration. The influx of monomers is accompanied by polymer alignment, and the amount aligned is proportional to the amount diffused throughout the process. We propose that polymer alignment controls the influx of added monomers into the growing domain.
Issues in Multigenerational Families: Adolescents’ Perceptions of Grandparents’ Declining Health

The impact of declining health in grandparents on grandchildren is largely overlooked in the literature. Similar to their parents, grandchildren may feel pressured between their responsibilities to grandparents while also negotiating their own social and psychological needs (Baranowski (1982). Adolescents25(67), 575–584). Limited attention is paid to the impact on children’s development when grandparents’ health declines (Baranowski (1982). Adolescents25(67), 575–584; Mead (1970). Grandparents as educators. In Leichter H. J. (Ed.), The family as educators. Teacher College Press: New York). Narrative themes of adolescents reveal multi-determined reactions to grandparents’ illness through identifications with family members, cultural roles, and individual development. The authors will identify these relevant themes and discuss new interventions with multigenerational families who provide care for older adults in declining health.
Effect of protamine on heparin-antithrombin III complexes. In vitro studies

Abstract In vitro, when protamine sulfate (salmine) is added to heparinized human plasma, the activated heparin-antithrombin III complex which had been formed is broken, freeing the antithrombin and reestablishing its slowly progressive antithrombin activity. The “freed” antithrombin can be reactivated to an immediate inhibitor of thrombin by the addition of excess heparin to the “neutralized” plasma. In its interaction with commercial porcine mucosal heparin, protamine forms complexes only with the higher molecular weight, biologically active fractions of the heparin.
Recent Demographic Trends in Armenia: Results of the 2001 Census and Update to 2006

An American geographer and specialist on population change in the former Soviet republics presents a study of the first post-Soviet census of Armenia. The author reviews major national- and regional-level changes in population size, urban/rural distribution, and ethnic affinity, by focusing on disruptive effects of the 1988 earthquake on the last Soviet census enumeration (1989), which hinders temporal comparisons. Also included in his study is the largely economically based mass migration to other former Soviet republics (chiefly to Russia) and the United States; an internal territorial reorganization in 1995; and migration streams of Armenian displaced persons and refugees as well as emigration of Azeris as a consequence of the Nagorno-Karabakh conflict noted in some detail. Journal of Economic Literature, Classification Numbers: J11, O18, R23. 3 figures, 2 tables, 60 references.
Northern Eurasia Earth Science Partnership Initiative: evolution of scientific investigations to applicable science

The letters collected in this focus issue of Environmental Research Letters on ‘Environmental, socio-economic and climatic changes in Northern Eurasia and their feedbacks to the global Earth system’ represent the third special issue based on the results of research within the Northern Eurasia Earth Science Partnership Initiative (NEESPI: http://neespi.org) program domain. Through the years, NEESPI researchers have presented a diverse array of articles that represent a variety of spatial scales and demonstrate the degree to which abrupt climatic and socio-economic changes are acting across Northern Eurasia and feed back to the global Earth system.
Effect of Nitrite and Sorbate on Total Number of Aerobic Microorganisms in Chicken White and Dark Meat Patties

The effects of nitrite, sorbate and combinations of these two ingredients plus salt on the number of aerobic microorganisms in chicken white and dark meat patties were examined. All patties were stored at 4–5°C for 12 days. Nitrite concentrations of 400 and 2500 ppm were effective in preventing bacterial growth in chicken white meat patties while 2500 ppm was required to prevent growth in dark meat. A reduction in bacterial growth (4–10 days) was demonstrated with 100 and 150 ppm nitrite in chicken white meat patties. Four hundred ppm nitrite reduced bacterial growth in dark meat patties for 6 days. In white meat patties, the use of sorbate (0.26%) in combination with nitrite (40 ppm) was as effective in reducing bacterial growth as higher concentrations of nitrite, salt (2.5%) alone or in combination with sorbate (0.26%) or nitrite (40 ppm) inhibited bacterial growth in both white and dark meat patties during the first 4–6 days of storage.
TWinner: understanding news queries with geo-content using Twitter

In the present world scenario, where the search engines wars are becoming fiercer than ever, it becomes necessary for each search engine to realize the intent of the user query to be able to provide him with more relevant search results. Amongst the various categories of search queries, a major portion is constituted by those having news intent. Seeing the tremendous growth of social media users, the spatial-temporal nature of the media can prove to be a very useful tool to improve the search quality. In our work we examine the development of such a tool that combines social media in improving the quality of web search and predicting whether the user is looking for news or not. We go one step beyond the previous research by mining Twitter messages, assigning weights to them and determining keywords that can be added to the search query to act as pointers to the existing search engine algorithms suggesting to it that the user is looking for news. We conduct a series of experiments and show the impact that TWinner has on the results.
Abrasive wear of silicon carbide particulate- and whisker- reinforced 7091 aluminum matrix composites

Abstract The abrasive wear behavior of silicon carbide particulate- and whisker-reinforced aluminum matrix composites was investigated under two-body abrasion conditions utilizing a pinon-disk apparatus. Both SiC particulate- and SiC whisker-reinforced composites exhibited greater wear resistance than the unreinforced 7091 alloy. The whisker reinforcement was more effective than the particulate reinforcement in improving the wear resistance of the matrix alloy. Further, whisker reinforcements oriented normal to the contact surface were, at small abrasive sizes, more effective than whiskers oriented within the contact surface. At larger abrasive sizes the opposite effect was observed. It was found that, at constant reinforcement volume fraction, the ratio of the average abrasive penetration depth to the characteristic size of the reinforcement was the critical parameter controlling the relative abrasive wear resistance of composites reinforced with SiC.
Precontoured plating of clavicle fractures: decreased hardware-related complications?

Background Operative treatment of displaced midshaft clavicle fractures reportedly decreases the risk of symptomatic malunion, nonunion, and residual shoulder disability. Plating these fractures, however, may trade these complications for hardware-related problems. Low-profile anatomically precontoured plates may reduce the rates of plate prominence and hardware removal.
Volleyball and the hitting shoulder: is it time to institute a ‘pitch count’?

We review the pertinent literature and survey 31 collegiate women's volleyball programme athletic trainers estimating the prevalence of shoulder pain among participants, particularly the ‘hitters’....
MAXIM x-ray interferometry mission

The MicroArcsecond Imaging Mission (MAXIM) will resolve the event horizons of black holes with 0.1 microarcsecond imaging in the X-ray bandpass. In the NASA "Beyond Einstein" roadmap, MAXIM takes it place as the "Black hole Imager." In this paper, we will outline the scientific goals for this mission. We will describe the current state of the technology -- including a discussion of several laboratory demonstrations of X-ray interferometry. We will describe some engineering studies we have performed over the past two years.
On the Classical Radiation of Accelerated Electrons

This paper is concerned with the properties of the radiation from a high energy accelerated electron, as recently observed in the General Electric synchrotron. An elementary derivation of the total rate of radiation is first presented, based on Larmor's formula for a slowly moving electron, and arguments of relativistic invariance. We then construct an expression for the instantaneous power radiated by an electron moving along an arbitrary, prescribed path. By casting this result into various forms, one obtains the angular distribution, the spectral distribution, or the combined angular and spectral distributions of the radiation. The method is based on an examination of the rate at which the electron irreversibly transfers energy to the electromagnetic field, as determined by half the difference of retarded and advanced electric field intensities. Formulas are obtained for an arbitrary charge-current distribution and then specialized to a point charge. The total radiated power and its angular distribution are obtained for an arbitrary trajectory. It is found that the direction of motion is a strongly preferred direction of emission at high energies. The spectral distribution of the radiation depends upon the detailed motion over a time interval large compared to the period of the radiation. However, the narrow cone of radiation generated by an energetic electron indicates that only a small part of the trajectory is effective in producing radiation observed in a given direction, which also implies that very high frequencies are emitted. Accordingly, we evaluate the spectral and angular distributions of the high frequency radiation by an energetic electron, in their dependence upon the parameters characterizing the instantaneous orbit. The average spectral distribution, as observed in the synchrotron measurements, is obtained by averaging the electron energy over an acceleration cycle. The entire spectrum emitted by an electron moving with constant speed in a circular path is also discussed. Finally, it is observed that quantum effects will modify the classical results here obtained only at extraordinarily large energies.
Vertical strain determination in the Antarctic ice sheet using optical fibers

As part of a program to measure and model vertical strain in the West Antarctic ice Sheet, we developed a new sensor to accurately and stably record displacements. The sensors consist of optical fibers, encased in thin-walled stainless steel tubes, frozen into hot-water drilled boreholes, and stretched from the surface to various depths in the ice sheet ranging to 1000 m. An EDM (electronic distance meter) connected annually to the fibers read out their absolute lengths with a precision of about 2 mm. An initial elongation of about 0.15% of the optical fibers allowed them to follow an ice thinning rate of 300 ppm per year for up to five years. Two sets of five sensors were installed in the 1997-1998 field season: one set was near the Siple Dome core hole (an ice divide) and a second set was on the flank 7 km to the north (the ice thickness at both sites is approximately 1000 m).
Modulation of endogenous antioxidant enzymes by nitric oxide in rat C6 glial cells.

To understand the possible mechanism of nitric oxide (NO)-mediated cytotoxicity, we investigated the effect of NO on the endogenous antioxidant enzymes (AOEs) catalase, glutathione peroxidase (GPX), and CuZn- and Mn-superoxide dismutases (SODs) in rat C6 glial cells under conditions in which these cells expressed oligodendrocyte-like properties as evidenced by the expression of 2',3'-cyclic-nucleotide 3'-phosphohydrolase. The 24-h treatment with S-nitroso-N-acetylpenicillamine (SNAP), a NO donor, decreased the activities and the protein levels of catalase, GPX, and Mn-SOD in a dose-dependent manner. Alternatively, the activity and the protein level of CuZn-SOD were increased. 2-Phenyl-4,4, 5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a NO scavenger, blocked the effect of SNAP. Moreover, the treatment of C6 cells with sodium nitroprusside, another NO donor, or with a combination of lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), which induce excessive production of NO, also significantly modulated the AOE activities in a manner similar to that seen with SNAP treatment. The compounds/enzymes that inhibit the production of NO (e.g., N-nitro-L-arginine methyl ester hydrochloride, arginase, and PTIO) blocked the effects of LPS and IFN-gamma on the activities of AOEs. Treatment with SNAP and a combination of LPS and IFN-gamma also modulated the mRNA levels of AOEs, parallel to the changes in their protein levels and activities, except for Mn-SOD where the combination of LPS and IFN-gamma markedly stimulated the mRNA expression. In spite of the stimulation of mRNA level, LPS and IFN-gamma significantly inhibited the activity of Mn-SOD within the first 24 h of incubation; however, Mn-SOD activity gradually increased with the increase in time of incubation. These results suggest that alterations in the status of AOEs by NO may be the basis of NO-induced cytotoxicity in disease states associated with excessive NO production.
Defining Gendered Oppression in U.S. Newspapers: The Strategic Value of " Female Genital Mutilation"

According to the logic of the gendered modernity/tradition binary, women in traditional societies are oppressed and women in modern societies liberated. While the binary valorizes modern women, it potentially erases gendered oppression in the West and undermines feminist movements on behalf of Western women. Using U.S. newspaper text, I ask whether female genital cutting (FGC) is used to define women in modern societies as liberated. I find that speakers use FGC to both uphold and challenge the gendered modernity/ tradition binary. Speakers use FGC to denigrate non-Western cultures and trivialize the oppressions that U.S. women typically encounter, but also to make feminist arguments on behalf of women everywhere. I argue that in addition to examining how culturally imperialist logics are reproduced, theorists interested in feminist postcolonialism should turn to the distribution of such logics, emphasizing the who, where, when, and how of reinscription of and resistance to such narratives.
t-Covering Arrays: Upper Bounds and Poisson Approximations

A k×n array with entries from the q-letter alphabet {0, 1, …, q − 1} is said to be t-covering if each k × t submatrix has (at least one set of) qt distinct rows. We use the Lovasz local lemma to obtain a general upper bound on the minimal number K = K(n, t, q) of rows for which a t-covering array exists; for t = 3 and q = 2, we are able to match the best-known such bound. Let Kλ = Kλ(n, t, q), (λ ≥ 2), denote the minimum number of rows that guarantees the existence of an array for which each set of t columns contains, amongst its rows, each of the qt possible ‘words’ of length t at least λ times. The Lovasz lemma yields an upper bound on Kλ that reveals how substantially fewer rows are needed to accomplish subsequent t-coverings (beyond the first). Finally, given a random k × n array, the Stein–Chen method is employed to obtain a Poisson approximation for the number of sets of t columns that are deficient, i.e. missing at least one word.
Time-domain reconstruction for thermoacoustic tomography in a spherical geometry

Reconstruction-based microwave-induced thermoacoustic tomography in a spherical configuration is presented. Thermoacoustic waves from biological tissue samples excited by microwave pulses are measured by a wide-band unfocused ultrasonic transducer, which is set on a spherical surface enclosing the sample. Sufficient data are acquired from different directions to reconstruct the microwave absorption distribution. An exact reconstruction solution is derived and approximated to a modified backprojection algorithm. Experiments demonstrate that the reconstructed images agree well with the original samples. The spatial resolution of the system reaches 0.5 mm.
Chilean Clitic Reduplication: Implications for Morphology and Syntax

This paper explores the phenomenon of clitic duplication in Spanish as seen in the sentence Te voy a pegarte (‘I’m going to hit you’). Structures like these have several interesting implications for the Spanish language and generativist syntax. Neverthelesss, clitic duplication has not been extensively examined in the generativist literature. This working paper will critically review the small body of existing work on clitic reduplication. Furthermore, based on data gathered from native speakers of Chilean Spanish, it will provide some preliminary evidence for strengthening the argument that Spanish clitics are object agreement morphemes. Ultimately, this paper aims to provide a base to further pursue the topic of Chilean clitic reduplication to make more theoretically sound claims, provide more robust empirical data, and to propose a more formalized argument of the phenomena. Pedagogical implications of the argument are also considered.
Mechanotransduction in Musculoskeletal Tissue Regeneration: Effects of Fluid Flow, Loading, and Cellular-Molecular Pathways

While mechanotransductive signal is proven essential for tissue regeneration, it is critical to determine specific cellular responses to such mechanical signals and the underlying mechanism. Dynamic fluid flow induced by mechanical loading has been shown to have the potential to regulate bone adaptation and mitigate bone loss. Mechanotransduction pathways are of great interests in elucidating how mechanical signals produce such observed effects, including reduced bone loss, increased bone formation, and osteogenic cell differentiation. The objective of this review is to develop a molecular understanding of the mechanotransduction processes in tissue regeneration, which may provide new insights into bone physiology. We discussed the potential for mechanical loading to induce dynamic bone fluid flow, regulation of bone adaptation, and optimization of stimulation parameters in various loading regimens. The potential for mechanical loading to regulate microcirculation is also discussed. Particularly, attention is allotted to the potential cellular and molecular pathways in response to loading, including osteocytes associated with Wnt signaling, elevation of marrow stem cells, and suppression of adipotic cells, as well as the roles of LRP5 and microRNA. These data and discussions highlight the complex yet highly coordinated process of mechanotransduction in bone tissue regeneration.
Acute increases in monoamine release in the rat prefrontal cortex by the mGlu2/3 agonist LY379268 are similar in profile to risperidone, not locally mediated, and can be elicited in the presence of uptake blockade.

Abstract Our recent work (Cartmell et al., Journal of Neurochemistry, 75 (2000) 1147–1154) demonstrated that systemic injection of the potent, selective mGlu2/3 receptor agonist, LY379268, acutely increased extracellular levels of dopamine, its metabolites DOPAC and HVA, and the 5-HT metabolite, 5-HIAA, in rat medial prefrontal cortex (mPFC). Here, we compared the acute effects of LY379268 with those of clozapine and risperidone (atypical antipsychotics) on extracellular levels of both dopamine and 5-HT in the mPFC of freely-moving rats. Uptake blockers were included to minimize metabolism of monoamines near the probe area. One hour after injection, LY379268 (10 mg/kg s.c.), clozapine (10 mg/kg s.c.) or risperidone (1 mg/kg s.c.) maximally increased dopamine by 224, 257 and 234% of basal levels. These effects were followed by maximal increases in DOPAC and HVA levels 2 to 3.5 hours after administration. LY379268, at 3 and 10 mg/kg s.c., and risperidone (1 mg/kg s.c.) also increased dialysate 5-HT to 169, 179 and 140% of basal levels and 5-HIAA to 144, 154 and 121% of basal levels, respectively. These neurochemical changes in the mPFC could not be mimicked when LY379268 (3 or 30 μM) was administered locally via the microdialysis probe. These data demonstrate that increases in extracellular monoamines in the rat prefrontal cortex evoked acutely by the mGlu2/3 agonist, LY379268, are similar in profile to risperidone, not locally mediated, and can be elicited in the presence of uptake blockade.
Implementation of a hypersonic rarefied flow particle simulation on the connection machine

A very efficient direct particle simulation algorithm for hypersonic rarefied flows is presented and its implementation on a Connection Machine is described. The implementation is capable of simulating up to 4 x 106 hard sphere diatomic molecules using 64k processors with a performance better than that of a similar, fully vectorized implementation using a single processor of the Cray 2. Results from flow calculations are presented to demonstrate both the validity of the implementation and the range afforded by the method in solving hypersonic rarefied flow problems. Finally, a breakdown of the calculation time is given to identify a bottleneck which must be resolved for further improvement in performance.
Individual–Group Discontinuity in Group–Individual Interactions: Does Size Matter?

The consistent fi nding that interactions involving groups are more competitive than interactions between individuals is known as the discontinuity effect. We investigated the effects of group size in order to determine whether the effect is a true discontinuity or a continuous function of group size. We also asked whether dyads behave like larger groups. Four hundred and eighty seven students volunteered for the experiment. Individuals played 10 trials of two-choice prisoner’s dilemmas against other individuals or against groups of sizes two through eight. Major fi ndings included (a) individual–individual interactions were more cooperative than individual–group interactions, but there were no differences among group sizes; (b) dyads were indistinguishable from larger groups; and (c) data on expectations revealed that, before interacting, groups were not only distrusted by individuals but also distrusted the individuals. The discontinuity between individuals and groups—including dyads—appears to be a true discontinuity.
Acquisition of the Japanese Reflexive "Zibun" and Movement of Anaphors in Logical Form.

Several recent accounts of crosslinguistic variation in the properties of anaphors have rejected Manzini and Wexler's (1987) parameterized binding principles. Pica (1987), Battistella (1989), Cole et al. (1990) and Katada (1991), among others, claim that anaphors move in Logical Form (LF) such that 'long-distance' binding can be reduced to a series of local relationships. This article looks at research on adult second language learning in the light of the proposal that reflexives move in LF. A first approach to the issue reanalyses data from earlier research on the acquisition of the Japanese long-distance anaphor zibun, research conducted under the assumption that the binding principles are parameterized. Secondly, a new study of 58 adult learners of Japanese is presented, showing that learners' knowledge of zibun at a high-proficiency level is largely consistent with a key prediction of the movement in LF approach. Although relatively few high-proficiency learners in the subject pool seem to have arrive...
Concurrent inflammatory bowel disease (IBD) and celiac disease (CeD): an aggressive form of IBD?

Concurrent inflammatory bowel disease (IBD) and celiac disease (CeD): an aggressive form of IBD?
Unique Features of the Crystallization Kinetics of FeCrBSi Thin Films Obtained by Laser Ablation Deposition

Pulsed laser deposition was used to obtain a metallic glass in thin film form using a Fe77Cr2B16Si5 amorphous ribbon as a target. The as-deposited films were annealed under the same conditions as the parent ribbon samples in order to compare their crystallization behaviors. Transmission Mossbauer measurements were performed to determine the crystallization products formed due to annealing of the Fe77Cr2B16Si5 ribbon. Conversion electron Mossbauer spectroscopy was used to obtain structural and magnetic information from the thin films as well as from the surface layers of the ribbons. Our Mossbauer study showed that crystallization behavior of the FeCrBSi thin films differs from both the surface and bulk crystallization of the ribbon. Crystallization occurs at lower annealing temperature for the thin film than for the bulk ribbon. Annealed films also contain iron oxides which are not observed in the crystallized ribbons. A formation of a very thin, protective oxide film at the surface of the ribbon is taken into account to explain the differences in the crystallization behavior of the films and ribbons.
Gender, Work-Family Responsibilities, and Sleep:

This study adds to a small but growing literature that situates sleep within gendered work— family responsibilities. We conducted interviews with 25 heterosexual dual-earner working-class couples with children, most of whom had one partner (usually the mother) who worked at night. A few men suffered disrupted sleep because of their commitment to being a coparent to their children, but for most their provider status gave them rights to longer and more continuous sleep. By contrast, as they were the primary caregiver during sentient hours, women’s sleep was curtailed and interrupted by responding to the needs of family members at night and at the beginning of each day, and this was true for women who worked nights as well as days. Furthermore, in struggling to meet their daily employment and familial obligations while tired and sleepy, women further stressed their bodies in ways that can cause cumulative sleep debt. This article demonstrates that sleep deficits are another manifestation of gender inequality...