cssi/SciSciGPT-SciSciNet huggingface dataset:
Interaction of GM2 Activator Protein with Glycosphingolipids

GM2 activator protein is a protein cofactor that stimulates the hydrolysis of the GalNAc and the NeuAc in GM2 by β-hexosaminidase A and sialidase, respectively. To understand the mechanism of action of GM2 activator, the interaction of this protein with GM2 and/or β-hexosaminidase A has been the subject of interest since the purified GM2 activator became available. Numerous techniques including ultracentrifugation, isoelectric focusing, polyacrylamide gel electrophoresis, gel filtration, thin layer chromatogram overlay, and fluorescence dequenching assay have been used to investigate the binding and the affinity of GM2 activator to various glycosphingolipids. It has been generally accepted that GM2 activator must have a very weak binding with the enzyme, because they can be easily separated GM2 activator protein is a protein cofactor that stimulates the hydrolysis of the GalNAc and the NeuAc in GM2 by β-hexosaminidase A and sialidase, respectively. To understand the mechanism of action of GM2 activator, the interaction of this protein with GM2 and/or β-hexosaminidase A has been the subject of interest since the purified GM2 activator became available. Numerous techniques including ultracentrifugation, isoelectric focusing, polyacrylamide gel electrophoresis, gel filtration, thin layer chromatogram overlay, and fluorescence dequenching assay have been used to investigate the binding and the affinity of GM2 activator to various glycosphingolipids. It has been generally accepted that GM2 activator must have a very weak binding with the enzyme, because they can be easily separated from each other by gel filtration. Therefore, the interaction of GM2 and GM2 activator has been the focus for most of the study. Although preferential association of GM2 activator with GM2 was detected by some methods, GM2 activator was found also to bind other glycosphingolipids. Isolation of the specific complex that consists of only GM2 activator and GM2 from an incubation mixture containing the activator protein and mixed glycosphingo-lipids has not been successfully carried out.
The ocs element in the soybean GH2/4 promoter is activated by both active and inactive auxin and salicylic acid analogues.

The octopine synthase (ocs or ocs-like) element has been previously reported to be responsive to the plant hormones, auxin, salicylic acid, and methyl jasmonate. Using transient assays with carrot protoplasts, we have demonstrated that an ocs element from the soybean auxin-inducible GH2/4 promoter is not only activated by strong auxins (i.e, 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, α-naphthalene acetic acid) and salicylic acid, but also by weak auxin analogues (β-naphthalene acetic acid), inactive auxin analogs (i.e., 2,3-dichlorophenoxyacetic acid, 2,4,6-trichlorophenoxyacetic acid), and inactive salicylic acid analogs (3-hydroxybenzoic acid and 4-hydroxybenzoic acid). Our results indicate that the ocs element in the GH2/4 promoter is not selectively induced by plant hormones and might function similarly to tandem AP-1 sites in some animal glutathione S-transferase (GST) genes. The ocs element, like the AP-1 sites in animal GST promoters, may be induced not only by certain hormones but also by some non-hormonal stress-inducing or electrophilic agents.
Observations of Anisotropic Electron Scattering on Graphite with a Low-Temperature Scanning Tunneling Microscope

Low-temperature scanning tunneling microscopy was used to observe anisotropic (3-fold) scattering from point defects on a graphite surface. Such scattering from defects was theoretically predicted ...
Advanced transport structures and materials technology.

A program was undertaken regarding the economic benefits attainable through the application of advanced technologies to the next generation of long-range transport aircraft in the Mach number range from 0.85 to 1.0. In addition to airframe studies, two parallel engine systems studies contracts are also in progress. The manufacturability of composites promises structural concepts which can take forms very similar to those employed in conventional structures or forms very different from conventional approaches. It is pointed out that the findings of the studies discussed justify a considerably expanded effort not only in composite materials but also in other technologies.
Shear gradient dependence of the viscosity of critical mixtures

Abstract We present a theory of the nonlinear shear viscosity of fluids near the critical point, and suggest that the experimentally observed leveling off (cusplike behavior) of the excess viscosity may be due to shear gradient effects.
Identification of Staphylococci in Nonfat Dry Milk by the Fluorescent Antibody Technique

Summary An investigation was made of the applicability of the fluorescent antibody technique to the detection of staphylococci in nonfat dry milk. Procedures are given for the preparation of milk films and the staining of these films by the indirect fluorescent antibody procedure. Qualitative studies revealed that Staphylococcus aureus cells could be specifically identified in the presence of cells of Streptococcus lactis, Lactobacillus casei, Bacillus subtilis , and other organisms which might occur normally in milk. Additional studies showed that cells of staphylococci could be quantitatively determined in milk films by this procedure, and that direct microscopic counts of these organisms correlated extremely well with numbers of S. aureus cells known to be present. The quantitative detection of staphylococci from nonfat dry milk which had been inoculated with S. aureus before spray-drying demonstrated that the heating and desiccation occurring during spray-drying did not affect the results of our tests. Advantages of the fluorescent antibody technique over conventional procedures are presented.
Open surgical inferior vena cava filter retrieval for caval perforation and a novel technique for minimal cavotomy filter extraction

Late complications of retrievable inferior vena cava (IVC) filters resulting from IVC perforation and erosion into adjacent structures is an increasingly frequent phenomena. We describe six cases of open filter explantation for IVC penetration and offer a novel technique for open filter removal without the need for an extensive cavotomy. All patients had radiographic evidence of filter erosion into pericaval structures requiring open surgical filter explant. Four of the six patients underwent minimal cavatomy filter extraction, eliminating the need for caval reconstruction.
A comparison of modeled diurnally varying sea surface temperatures to geostationary satellite data

A subset of modeled diurnally varying sea surface temperatures is compared to geostationary satellite sea surface temperature data in order to evaluate how well the model computes the diurnal cycle. By analyzing the satellite coverage of sea surface temperatures, a small set of grid points are selected to compare the evolution of the diurnal cycle to the model data over the course of a day. Overall, the model overestimates the peak of the diurnal cycle as compared to the satellite data, although the pre-dawn and post-sunset temperatures are fairly similar. Since the difference averaged over all hours of the day is small, the model is believed to estimate the total heat content in the upper layers of the ocean correctly, but needs some adjusting to broaden the heating cycle.
On the bowed out tilt wall model of flow stress and size effects in metal matrix composites

A model of bowed-out tilt-wall array has been recently proposed by the authors to provide a correlation between the flow stress and particle size/spacing of metal matrix composites. Here, the authors elaborate on the tilt-wall model and show that the number of dislocations needed to predict the experimental result, for aluminum alloys reinforced with alumina or TiB[sub 2] particulates, is not affected by the dislocation spacing for realistic pile-ups with 2 < d/[bar d] < 7, where [bar d] is the spacing between two adjacent slip planes. The model is also used to explain new experimental results for an Al-Si alloy with Si particles of different sizes.
Simultaneous optimal parameter and mode transition time estimation

This paper presents a method of simultaneous mode transition time and parameter estimation for hybrid systems based on switching time optimization techniques. A concise derivation of first- and second-order optimality conditions with respect to both mode transition times and parameter values is presented, including cross-derivative terms between the switching times and the parameters. The estimation algorithm is shown to be effective for estimating transition times as well as unknown parameter values from coarsely sampled data for a skid-steered vehicle, which traverses unknown or changing terrain and transitions between discrete dynamic modes. It is shown that second-order optimization methods using the exact Hessian provide far superior convergence, compared to first-or approximate second-order methods, to correct values in simulated and experimental scenarios.
Measurements of fracture strength and Young's modulus of surface-micromachined polysilicon

Polycrystalline silicon (polysilicon) is widely used as a mechanical layer in MicroElectroMechanical Systems (MEMS). Mechanical elements within MEMS structures are, by design, microscopic in size. Because the thickness of the polysilicon layer is typically around 2 micrometers and the width and length of the freed area is a few to hundreds of micrometers, standard techniques and apparatus for measurements of mechanical properties are not applicable. Furthermore, the deposition techniques for polysilicon cannot be adapted to make specimens big enough to test by conventional techniques. Therefore, special structures were designed to facilitate measurements of Young's modulus and fracture strength: cantilever beams and dog-bone tensile specimens. Here we report first experiences with these structures. These experiences include successes and failures in manipulating and testing the special structures. While no definitive results for either fracture strength or Young's modulus are reported here, some plausible values for both quantities were obtained. Test methods and preliminary results to date are discussed.
The influence of sympathetic nervous activity on the antiarrhythmic efficacy of diphenylhydantoin.

Abstract The efficacy of diphenylhydantoin as an antagonist for ouabain induced ventricular rhythm disorders was determined in spinal cats exhibiting signs of low and high adrenergic neural activity. In cats with high heart rates and blood pressures, diphenylhydantoin was effective in increasing the lethal dose of ouabain. On the other hand, in animals with slow heart rates and low blood pressures, diphenylhydantoin produced no increase in the lethal dose of ouabain. After diphenylhydantoin administration both groups of ouabain intoxicated animals behaved similarly with respect to heart rates, blood pressures, rate of ventricular tachycardia and lethal dose. These data indicate that diphenylhydantoin produces a reduction in adrenergic activity and that this reduction may account for the drug's antiarrhythmic activity.
Rethinking Avian Response to Tamarix on the Lower Colorado River: A Threshold Hypothesis

Many of the world’s large river systems have been greatly altered in the past century due to river regulation, agriculture, and invasion of introduced Tamarix spp. (saltcedar, tamarisk). These riverine ecosystems are known to provide important habitat for avian communities, but information on responses of birds to differing levels of Tamarix is not known. Past research on birds along the Colorado River has shown that avian abundance in general is greater in native than in non-native habitat. In this article, we address habitat restoration on the lower Colorado River by comparing abundance and diversity of avian communities at a matrix of different amounts of native and non-native habitats at National Wildlife Refuges in Arizona. Two major patterns emerged from this study: (1) Not all bird species responded to Tamarix in a similar fashion, and for many bird species, abundance was highest at intermediate Tamarix levels (40–60%), suggesting a response threshold. (2) In Tamarix-dominated habitats, the greatest increase in bird abundance occurred when small amounts of native vegetation were present as a component of that habitat. In fact, Tamarix was the best vegetation predictor of avian abundance when compared to vegetation density and canopy cover. Our results suggest that to positively benefit avian abundance and diversity, one cost-effective way to rehabilitate larger monoculture Tamarix stands would be to add relatively low levels of native vegetation (;20– 40%) within homogenous Tamarix habitat. In addition, this could be much more cost effective and feasible than attempting to replace all Tamarix with native vegetation.
EARLY VERSUS DELAYED CORD CLAMPING AT BIRTH; IN SICKNESS AND IN HEALTH

Third stage practice, including the timing of cord clamping and its impact on neonatal health, has been comprehensively reviewed previously by Downey and Bewley, and this opinion will focus on the evidence about neonatal transition which has been published since. Many professional organisations and experts recommend at least a 30-second delay before clamping the umbilical cord, especially after preterm births.
Factors affecting judgements of how much another likes us: A signal detection approach

Investigated the effects of subjects' self-concept and the attractiveness of the other on subjects' estimates of how much the other liked them. The use of a signal detection paradigm allowed the measurement of both the criteria and discriminability of subjects' decisions. Eighty mule and 80 female subjects participated in a computer match where they received either somewhat positive or somewhat negative feedback from their match. Besides sex and type of feedback, the factorial design included dating self-concept (high vs. low) and other-attractiveness (high vs. low). Results indicate that high dating self-concept subjects had a lower criterion than low dating self-concept subjects for saying that another liked them (p < .0l), and that the former group was superior to the latter at discriminating between the two types of feedback (p < .03). Also, males were more willing to say that the attractive match liked them than that the unattractive match liked them, while among females the direction of these differences reversed (p < .03). fie results were explained in terms of differential attention to pay-off matrices and prior odds.
Catalytic reaction. 1. catalytic 1,4-hydrogenation of α,β-unsaturated aldehydes and ketones using SC-1 nickel boride

Abstract Ex-situ generated SC-1 nickel boride (SC-1 Ni 2 B), prepared by refluxing nickel chloride and sodium borohydride in methanol, is used in the selective 1,4-hydrogenation of α, β-unsaturated ketones and aldehydes at one atmospheric pressure. Previous studies of in-situ generated Ni 2 B have had the disadvantage of the undesirable side reaction of sodium borohydride with the various functional groups. In contrast, our catalyst cleanly gives the corresponding saturated aldehyde or ketone with no detectable amounts of saturated alcohol. Furthermore, the degree of substitution of the double bond plays a significant role in the rate of hydrogenation. While unsaturated carbonyl compounds containing di- and tri- substituted double bonds are readily hydrogenated, tetrasubstituted double bond containing carbonyl compounds are highly unreactive.
Pith Autolysis in Herbaceous Dicotyledonous Plants. A Physiological Ecological Study of Pith Autolysis under Native Conditions with Special Attention to the Wild Plant Impatiens capensis Meerb.

Pith autolysis, in the past studied only in herbaceous cultivated dicotyledonous plants, commonly occurs in wild plants. A survey of pith autolysis in wild plants was conducted in several different biomes in both North Carolina, USA and in Belgium. An objective method and a subjective method were developed and used to estimate the amount of pith autolysis in the internodes of bean (Phaseolus vulgaris L.) and the wild plant jewelweed (Impatiens capensis Meerb.) under experimental conditions. A ranking system also was used to quantify pith autolysis in other wild plants. In the field, a positive correlation was found between the rate of internode elongation and pith autolysis. Injections of sucrose solution were found to reduce the amount of pith autolysis developed in the upper internodes of jewelweed when compared to injections of control solution. Extracts from the nodal tissues of jewelweed increased the amount of pith autolysis developed by both jewelweed in the field and bean in the greenhouse. This increase in pith autolysis may be due to a principle present in the jewelweed nodes that signals or causes the supertending internodes to become hollow.
Insertion-Duplication Mutagenesis in Streptococcus pneumoniae: Targeting Fragment Length Is a Critical Parameter in Use as a Random Insertion Tool

To examine whether insertion-duplication mutagenesis with chimeric DNA as a transformation donor could be valuable as a gene knockout tool for genomic analysis in Streptococcus pneumoniae, we studied the transformation efficiency and targeting specificity of the process by using a nonreplicative vector with homologous targeting inserts of various sizes. Insertional recombination was very specific in targeting homologous sites. While the recombination rate did not depend on which site or region was targeted, it did depend strongly on the size of the targeting insert in the donor plasmid, in proportion to the fifth power of its length for inserts of 100 to 500 bp. The dependence of insertion-duplication events on the length of the targeting homology was quite different from that for linear allele replacement and places certain limits on the design of mutagenesis experiments. The number of independent pneumococcal targeting fragments of uniform size required to knock out any desired fraction of the genes in a model genome with a defined probability was calculated from these data by using a combinatorial theory with simplifying assumptions. The results show that efficient and thorough mutagenesis of a large part of the pneumococcal genome should be practical when using insertion-duplication mutagenesis.
Parameter estimation in non-Gaussian noise

SUMMARY Least squares (LS) estimation of model parameters is widely used in geophysics. If the data errors are Gaussian and independent the LS estimators will be maximum likelihood (ML) estimators and will be unbiased and of minimum variance. However, if the noise is not Gaussian, e.g. if the data are contaminated by extreme outliers, LS fitting will result in parameter estimates which may be biased or grossly inaccurate. When the probability distribution of the errors is known it is possible, using the maximum likelihood method, to obtain consistent and efficient (minimum variance) estimates of parameters. In some cases the distribution of the noise may be determined empirically, and the resulting distribution used in the ML estimation. A procedure for doing this is described here. Hourly values of geomagnetic observatory data are used to illustrate the technique. These data sets contain a number of periodic components, whose amplitudes and phases are geophysically interesting. Geomagnetic storms and other phenomena in the record make the noise distribution long-tailed, asymmetric and variable with location. Using an iterative procedure, one can model the form of these distributions using smoothing splines. For these data ML estimation yields quite different results from standard robust and LS procedures. The technique has the potential for widespread application to other problems involving the recovery of a known form of signal from non-Gaussian noise.
Modeling robustness tradeoffs in yeast cell polarization induced by spatial gradients.

Cells localize (polarize) internal components to specific locations in response to external signals such as spatial gradients. For example, yeast cells form a mating projection toward the source of mating pheromone. There are specific challenges associated with cell polarization including amplification of shallow external gradients of ligand to produce steep internal gradients of protein components (e.g. localized distribution), response over a broad range of ligand concentrations, and tracking of moving signal sources. In this work, we investigated the tradeoffs among these performance objectives using a generic model that captures the basic spatial dynamics of polarization in yeast cells, which are small. We varied the positive feedback, cooperativity, and diffusion coefficients in the model to explore the nature of this tradeoff. Increasing the positive feedback gain resulted in better amplification, but also produced multiple steady-states and hysteresis that prevented the tracking of directional changes of the gradient. Feedforward/feedback coincidence detection in the positive feedback loop and multi-stage amplification both improved tracking with only a modest loss of amplification. Surprisingly, we found that introducing lateral surface diffusion increased the robustness of polarization and collapsed the multiple steady-states to a single steady-state at the cost of a reduction in polarization. Finally, in a more mechanistic model of yeast cell polarization, a surface diffusion coefficient between 0.01 and 0.001 µm2/s produced the best polarization performance, and this range is close to the measured value. The model also showed good gradient-sensitivity and dynamic range. This research is significant because it provides an in-depth analysis of the performance tradeoffs that confront biological systems that sense and respond to chemical spatial gradients, proposes strategies for balancing this tradeoff, highlights the critical role of lateral diffusion of proteins in the membrane on the robustness of polarization, and furnishes a framework for future spatial models of yeast cell polarization.
Determining the involvement and therapeutic implications of host cellular factors in hepatitis C virus cell-to-cell spread.

Hepatitis C virus (HCV) infects 180 million people worldwide and is a leading cause of liver diseases such as fibrosis, cirrhosis, and hepatocellular carcinoma. It has been shown that HCV can spread to naive cells using two distinct entry mechanisms, “cell-free” entry of infectious extracellular virions that have been released by infected cells and direct “cell-to-cell” transmission. Here, we examined host cell requirements for HCV spread and found that the cholesterol uptake receptor NPC1L1, which we recently identified as being an antiviral target involved in HCV cell-free entry/spread, is also required for the cell-to-cell spread. In contrast, the very low density lipoprotein (VLDL) pathway, which is required for the secretion of cell-free infectious virus and thus has been identified as an antiviral target for blocking cell-free virus secretion/spread, is not required for cell-to-cell spread. Noting that HCV cell-free and cell-to-cell spread share some common factors but not others, we tested the therapeutic implications of these observations and demonstrate that inhibitors that target cell factors required for both forms of HCV spread exhibit synergy when used in combination with interferon (a representative inhibitor of intracellular HCV production), while inhibitors that block only cell-free spread do not. This provides insight into the mechanistic basis of synergy between interferon and HCV entry inhibitors and highlights the broader, previously unappreciated impact blocking HCV cell-to-cell spread can have on the efficacy of HCV combination therapies. IMPORTANCE HCV can spread to naive cells using distinct mechanisms: “cell-free” entry of extracellular virus and direct “cell-to-cell” transmission. Herein, we identify the host cell HCV entry factor NPC1L1 as also being required for HCV cell-to-cell spread, while showing that the VLDL pathway, which is required for the secretion of cell-free infectious virus, is not required for cell-to-cell spread. While both these host factors are considered viable antiviral targets, we demonstrate that only inhibitors that block factors required for both forms of HCV entry/spread (i.e., NPC1L1) exhibit synergy when used in combination with interferon, while inhibitors that block factors required only for cell-free spread (i.e., VLDL pathway components) do not. Thus, this study advances our understanding of HCV cell-to-cell spread, provides mechanistic insight into the basis of drug synergy, and highlights inhibition of HCV spread as a previously unappreciated consideration in HCV therapy design.
Generalized matching from theory to application

We present a novel approach for post-mapping optimization. We exploit the concept of generalised matching, a technique that finds symbolically all possible matching assignments of library cells to a multi-output network specified by a Boolean relation. Several objectives are targeted: area minimization under delay constraints; power minimization under delay constraints; and unconstrained delay minimization. We describe the theory of generalized matching and the algorithmic optimization required for its efficient and robust implementation. A tool based on generalized matching has been implemented and tested on large examples of the MCNC'91 benchmark suite. We obtain sizable improvements in: speed (6% in average, up to 20.7%); area under speed constraints (13.7% an average, up to 29.5%); and power under speed constraints (22.3% in average, up to 38.1%).
the burden of visions amidst reform: peasant relations to law in the Peruvian Andes

Passage of the 1969 Agrarian Reform Law in Peru became a critical moment in which various sectors of Andean society invoked distinct principles and deployed particular strategies in order to defend their rights to land and their visions of just labor relations and legitimate political authority. The principles they invoked and the strategies they used were careful responses to the new face and character of the state, the legal content of the reform law, and the dynamics of interethnic and class relations. Using archival evidence and field research from one rural district, this article argues that an examination of the ways Quechua-speaking peoples interpret legal principles and use laws reveals the complex ideological and socio-economic relationships between the nation-state and local communities, the bases for establishing and defending cultural autonomy, and the efforts of rural inhabitants to transform the structure and content of legal principles themselves. [highland Peru, Quechua, law and anthropology, agrarian reform, states and agrarian societies]
STUDIES ON THE MECHANISM OF THE FORMATION OF THE PENICILLIN ANTIGEN III. THE N-(D-α-BENZYLPENICILLOYL) GROUP AS AN ANTIGENIC DETERMINANT RESPONSIBLE FOR HYPERSENSITIVITY TO PENICILLIN G

An excess of D-benzylpenicillenic acid (BPE) was reacted with human gamma-globulin, human serum albumin, gelatin, and poly-L-lysine in aqueous solution buffered at pH 7.5-8.0. Under these conditions, BPE reacted predominantly with lysine epsilon-amino groups of the proteins to form the mixture of diastereomers of epsilon-N-(D-alpha-benzylpenicilloyl)-lysine groups (Di-BPO-Lys). BPE reacted also, but to a considerably smaller extent, with cystine disulfide linkages of human gamma-globulin and human serum albumin to form D-benzylpenicillenic acid-cysteine mixed disulfide groups (BPE-SS-Cys). Conjugates containing large numbers of BPE or D-penicillamine mixed disulfide groups were prepared by reaction of BPE or D-penicillamine with thiolated human gamma-globulin under mild oxidizing conditions. Anti-penicillin antibodies were produced in rabbits by immunization with either potassium penicillin G (PG) or a preincubated mixture of PG with normal rabbit serum (PG-NRS) in complete Freund's adjuvant. Specific precipitation analyses in aqueous and gel media (Ouchterlony), PCA analyses, and specific inhibition of these reactions with haptens were carried out on the rabbit anti-PG and anti-(PG-NRS) sera, using the above conjugates as antigens. The anti-penicillin antibodies were found to be directed against the diastereomeric mixture of N-(D-alpha-benzylpenicilloyl) groups, predominantly the Di-BPO-Lys groups. By these techniques, no antibodies directed against the BPE-mixed disulfide or the D-penicillamine mixed disulfide groups were detected. Three out of six patients with histories of allergic reactions to PG responded with wheal-and-erythema reactions to the N-(D-alpha-benzylpenicilloyl) (BPO) groups contained in BPE-human gamma globulin conjugate. Another such patient exhibited serum antibodies specific for the BPO group. One patient being treated with 25 gm per day of PG showed the presence of non-dialyzable antigenic BPO-conjugates in his serum. These results demonstrate that the diastereomeric BPO groups (predominantly Di-BPO-Lys groups) are major antigenic determinant groups responsible for PG hypersensitivity in rabbits and human beings. The possible clinical usefulness of multivalent Di-BPO conjugates and univalent Di-BPO haptens is discussed.
Correlation of critical heat flux in hybrid jet impingement/micro-channel cooling scheme

Experiments were performed to investigate the two-phase cooling characteristics of a new hybrid cooling scheme combining the cooling attributes of slot jets and micro-channel flow. A test module was constructed in which dielectric PF-5052 liquid was introduced through five 0.48 mm wide and 12.7 mm long slot jets, each leading to a 1.59 mm wide and 1.02 mm deep channel. Increases in flow rate and subcooling yielded similar trends of delaying the inception of boiling and increasing critical heat flux (CHF). A previous channel flow correlation predicted CHF values far smaller than measured, while those for slot jets yielded closer predictions. This proves the cooling performance of the hybrid configuration is dominated more by jet impingement than by micro-channel flow. By dividing the test surface into a portion that is dominated by jet impingement and another by micro-channel flow, and applying the appropriate CHF correlation for each portion, the CHF data for this hybrid cooling configuration are predicted with a mean absolute error of 8.42%.
Global Biogeochemical Cycling of Mercury: A Review

Mercury pollution poses global human health and environmental risks. Although mercury is naturally present in the environment, human activities, such as coal burning, have increased the amount of mercury cycling among the land, atmosphere, and ocean by a factor of three to five. Emitted to the atmosphere in its elemental form, mercury travels worldwide before oxidizing to a form that deposits to ecosystems. In aquatic systems, mercury can convert into methylmercury, a potent neurotoxin. People and wildlife are exposed to methylmercury as it bioaccumulates up the food chain. Mercury continues to circulate in the atmosphere, oceans, and terrestrial system for centuries to millennia before it returns to deep-ocean sediments. Areas of uncertainty in the global biogeochemical cycle of mercury include oxidation processes in the atmosphere, land-atmosphere and ocean-atmosphere cycling, and methylation processes in the ocean. National and international policies have addressed direct mercury emissions, but further...
Improving the thermoelectric properties of half-Heusler TiNiSn through inclusion of a second full-Heusler phase: microwave preparation and spark plasma sintering of TiNi1+xSn

Half-Heusler thermoelectrics offer the possibility to choose from a variety of non-toxic and earth-abundant elements. TiNiSn is of particular interest and – with its relatively high electrical conductivity and Seebeck coefficient – allows for optimization of its thermoelectric figure of merit, reaching values of up to 1 in heavily-doped and/or phase-segregated systems. In this contribution, we used an energy- and time-efficient process involving solid-state preparation in a commercial microwave oven and a fast consolidation technique, Spark Plasma Sintering, to prepare a series of Ni-rich TiNi1+xSn with small deviations from the half-Heusler composition. Spark Plasma Sintering plays an important role in the process by being a part of the synthesis of the material rather than solely a densification technique. Synchrotron powder X-ray diffraction and microprobe data confirm the presence of a secondary TiNi2Sn full-Heusler phase within the half-Heusler matrix. We observe a clear correlation between the amount of full-Heusler phase and the lattice thermal conductivity of the samples, resulting in decreasing total thermal conductivity with increasing TiNi2Sn fraction. This trend shows that phonons are scattered effectively as a result of the microstructure of the materials with full-Heusler inclusions in the size range of microns to tens of microns. The best performing samples with around 5% of TiNi2Sn phase exhibit maximum figures of merit of almost 0.6 between 750 K and 800 K which is an increase of ca. 35% compared to the zT of the parent compound TiNiSn.
Fingerprint-based location tracking with Hodrick-Prescott filtering

Conventional location fingerprint techniques usually require a prebuilt training set of fingerprints sampled at known locations, so that locations of future fingerprints can be determined by comparing to this set. For good accuracy, the training set should be large enough to appropriately cover the area. However, it is not always feasible to obtain a quality training set in practice, and so recent studies have resorted to utilizing fingerprints that are available but without location information. This paper investigates how these so-called unlabeled fingerprints can be useful for location tracking of a mobile device as it is moving. Specifically, we propose a fingerprint-based tracking approach based on Hodrick-Prescott filtering and substantiate its potential via an evaluation study.
Infrastructure and interpretation: Meters, dams, and state imagination in Scotland and India

The technical infrastructures of modern life—energy, communications, transport—stand at the juncture between material orderings of society and collective meaning. Public utilities are both material and symbolic, and both aspects require maintenance—and anthropological understanding. However, recent anthropological approaches building from science studies have tended to pursue “flat” descriptions that replace mystical or hypostatizing concepts of “social forces” with material associations and have focused on micrological discipline rather than ritual sites where collective identity is formed. By contrast, I identify an “aporetic relation” between material ordering and symbolic form as the site of ritual, and hermeneutic, processes by which large-scale political collectives are built up—and infrastructures are shaped to serve collective projects. I analyze examples of contemporary and historical infrastructural politics from India and Scotland to develop insights into how collectivities and states are formed, interpreted, and challenged in symbolic contests over their infrastructures.
Preparation of SiO2 Glass from Model Powder Compacts: III, Enhanced Densification by Sol Infiltration

Highly ordered powder compacts were formed using spherical, nearly monosized, amorphous SiO2 particles. Some of these compacts were subsequently infiltrated with a “silica’sol. After drying, the powder compact interstices contained small, porous xerogel particles, thereby increasing the green relative density of the compact. Sintering studies showed a significant enhancement in densification for the sol-infiltrated samples.
The low-ball compliance procedure: a meta-analysis

Practitioners of the low-ball compliance procedure allow individuals to agree to a request and then raise the cost of agreement slightly. When successful, the tactic results in more compliance than a condition in which people are presented only with the higher price. A meta-analysis of published low-ball studies found that the procedure is a reliable and effective method for increasing compliance. The procedure appears to be most effective when participants state their initial agreement publicly and when the second request is only slightly more costly than the first. Three psychological processes are identified that may explain the low-ball effect—commitment to the action, commitment to the person, and self-presentation. It is likely that all three contribute to the effectiveness of low-ball manipulations.
Gastrostomy for Prematures: Erudition for Pediatricians

May I endorse wholeheartedly Dr. Keitel9s objection to the use of gastrostomy for the feeding of prematures. The possible shortening of the stay in the hospital by a few days surely does not justify the additional risk inherent to a surgical procedure—even in the hands of the most skilled and experienced— which it will not be if taken up indiscriminately. I cannot, however, subscribe to his criticism of the editorial management of "Experience and Reason—Briefly Recorded.
The Xtrican Co-Promotion Team: Everyday Decision Making in a Strategic Alliance

This case describes the everyday decisions made by an alliance team. The case focuses on a budgetary decision where the two parties are $100 million apart, and describes the prior decisions of which each partner is clearly aware. Weighing partnership needs against individual company needs is one of the critical concerns manifested.
What Really Determines Whether a Manufacturing Firm Locates and Remains in California

Manufacturing provides high paying jobs for nearly 10 percent of working Californians. Compared to the 2004 California median income of slightly more than $37,000, the average annual income earned in manufacturing was $57,000. Based upon a complex, but well accepted method of shift-share analysis for the periods 1999 to 2001 and 2002 to 2005, we find that much of these losses in California's manufacturing activity are tied to national and international economic trends that are beyond the control of the State's policymakers. So there is statistically based evidence that although things still remain bad in many manufacturing sectors in California, they are not as bad as in these same sectors in the United States as a whole. Nevertheless, some (especially many in the business community) believe that a significant portion of California's loss in manufacturing base is attributable to statewide public policies that raise the cost of doing business in the State. This paper explores this concern in detail by examining: (1) Is It in California's Best Interest to Pursue Manufacturing Jobs? (2) Factors Cited in Policy and Business Discussions as Being Important to Why California is Losing Manufacturing. (3) What Previous Empirical Studies Have Found As Important Determinants of Intra-State Manufacturing Location. (4) The Effect of Current California Business Climate on Manufacturing Investment. (5) Suggested Policies to Retain/Increase Manufacturing Investment.
Team Self Assessment

This note invites students to assess their work teams in terms of characteristics shown in the current literature that describe highly effective teams. The references for these characteristics are shown at the end of the note.
On the comparison of filter magnetographs and the advanced stokes polarimeter

Liteset al. (1994) (hereafter LMS) have recently published a comparison of the response of their magnetograph (the Advanced Stokes Polarimeter (ASP)) to that they expect from filter-based magnetographs (FM). Not surprisingly, they conclude the ASP is better. They claim that only their instrument is ″quantitative,″ and others are not, and that the transverse field strength and azimuth measured by filter magnetographs may be in error by up to 50%. While the calculation is formally correct it ignores the high sensitivity attained by real FM's accumulating thousands of difference frames. Further, FM's have been cross-compared and tested empirically, without any such errors appearing. We point out that the two instruments have different roles, but the functional use of the FM is far superior to the ASP for solar research. The ASP may give accurate results for unresolved unipolar fields; it gives totally erroneous results when the field rapidly changes direction within its resolution element, as occurs in delta spots.
SIMILARITY OF AMINO ACIDS IN NECTAR AND LARVAL SALIVA: THE NUTRITIONAL BASIS FOR TROPHALLAXIS IN SOCIAL WASPS

Larvae of social wasps of the family Vespidae produce an oral exudate that is imbibed by attendant adults. Passage of this liquid from larvae to adults is the key feature of trophallaxis behavior (Wheeler, 1918), which has recently been reviewed by Wilson (1971), Spradbery (1973), and Jeanne (1980). Exchange of alimentary liquid among adults is also generally viewed as a component of trophallaxis, but this exchange is distinct from the larva-adult exchange (Hunt, 1982), and we will not consider it here. Maschwitz (1966) showed that the larval exudate in Vespula vulgaris is chemically identical to the labial gland secretion. Morimoto (1960) fed larvae of Polistes chinensis antennalis a radioactively labeled solution, and he noted that no label appeared in the trophallactic liquid after 30 min, but at 3 h and thereafter label did appear. In another experiment Morimoto (1960) used radiotracers to confirm the uptake of larval liquid by the adults. Nutritive value of the liquid has been demonstrated by several studies (Table 1). Attractiveness of the liquid for the attendant adult wasps has been widely reported. Roubaud (1916) proposed, in fact, that adult attraction to the larval secretion was the raison d'etre of wasp sociality. This extreme position has been challenged by West-Eberhard (1978), who argues that polygynous social groupings of wasps antedate the monogynous social species, and so the attraction to larval secretions is not necessary to explain group living in wasps. While we feel that this may be true, it does not fully dismiss the potential importance of the larval secretions in the evolution of wasp sociality. Hunt (1982) has specified larva-adult trophallaxis as one of five varied feeding behaviors that may have affected social evolution in Hymenoptera. In this paper we will present new data on the nutritive value of the larval trophallactic secretion, propose an hypothesis on the origin of larva-adult trophallaxis, and briefly discuss the significance of such trophallaxis in the social evolution of wasps.
Uncomplicated Pregnancies and Ultrasounds for Fetal Growth Restriction: A Pilot Randomized Clinical Trial.

Objective The purpose of this multicenter pilot study was to determine the feasibility of randomizing uncomplicated pregnancies (UPs) to have third trimester ultrasonographic exams (USE) versus routine prenatal care (RPNC) to improve the detection of small for gestational age (SGA; birth weight Material and Methods At three referral centers, 50 UPs were randomized after gestational diabetes was ruled out. Women needed to screen, consenting, and loss to follow-up was ascertained, as was the detection rate of SGA in the two groups. Results During the study period at the three centers, there were 7,680 births, of which 64% were uncomplicated. Of the 234 women approached for randomization, 36% declined. We recruited 149 women and had follow-up delivery data on 97%. The antenatal detection rate of SGA in the intervention group was 67% (95% confidence intervals 31–91%) and 9% (0.5–43%) in control. Conclusion The pilot study provides feasibility data for a multicenter randomized clinical trial to determine if third trimester USE, compared with RPNC, improves the detection of SGA and composite neonatal morbidity.
Experimental granulomatous lung disease in guinea pigs. Morphology and collagen analysis.

Chronic granulomatous lung disease was produced in immunized guinea pigs using aerosol exposure to pigeon serum at intervals of four weeks. Initially, animals developed a hemorrhagic alveolitis with polymorphonuclear leukocytes. After the second exposure, animals had a mononuclear alveolitis with ill-defined granulomata. Animals sacrificed after the third or fourth aerosol exposure had well-defined granulomata with varying degrees of interstitial fibrosis. Chemical estimates of total lung collagen showed increased lung collagen after the third and fourth exposure. Whereas animals sacrificed within one week after the second or third exposure had no increase in collagen concentration, animals sacrified 4 weeks after these exposures did. There was also a correlation between the morphologic and chemical estimates of lung collagen. These data suggest that repeated aerosol exposure of guinea pigs to a soluble antigen at intervals can result in chronic granulomatous lung disease that is characterized by morphologic and chemical increases in lung collagen. This model may be of value in defining immune and connective tissue alterations in granulomatous lung disease.
Oxidation of polychlorinated biphenyls by liver tissue slices from phenobarbital-pretreated mice is congener-specific and atropselective.

Mouse models are powerful tools to study the developmental neurotoxicity of polychlorinated biphenyls (PCBs); however, studies of the oxidation of chiral PCB congeners to potentially neurotoxic hydroxylated metabolites (OH-PCBs) in mice have not been reported. Here we investigate the atropselective oxidation of chiral PCB 91 (2,2',3,4',6-pentachlorobiphenyl), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 132 (2,2',3,3',4,6'-hexachlorobiphenyl), PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl) and PCB 149 (2,2',3,4',5',6-hexachlorobiphenyl) to OH-PCBs in liver tissue slices prepared from female mice. The metabolite profile of PCB 136 typically followed the rank order 5-OH-PCB > 4-OH-PCB > 4,5-OH-PCB, and metabolite levels increased with PCB concentration and incubation time. A similar OH-PCB profile was observed with the other PCB congeners, with 5-OH-PCB:4-OH-PCB ratios ranging from 2 to 12. More 5-OH-PCB 136 was formed in liver tissue slices obtained from animals pretreated with phenobarbital (P450 2B inducer) or, to a lesser extent, dexamethasone (P450 2B and 3A enzyme inducer) compared to tissue slices prepared from vehicle-pretreated animals. The apparent rate of 5-OH-PCBs formation followed the approximate rank order PCB 149 > PCB 91 > PCB 132 ~ PCB 136 > PCB 95. Atropselective gas chromatography revealed a congener-specific atropisomeric enrichment of major OH-PCB metabolites. Comparison of our results with published OH-PCB patterns and chiral signatures (i.e., the direction and extent of the atropisomeric enrichment) from rat liver microsomal revealed drastic differences between both species, especially following induction of P450 2B enzymes. These species differences in the metabolism of chiral PCBs should be considered in developmental neurotoxicity studies of PCBs.
Bridging the gap between graphical arguments and verbal-symbolic proofs in a real analysis context

We examine a commonly suggested proof construction strategy from the mathematics education literature—that students first produce a graphical argument and then work to construct a verbal-symbolic proof based on that graphical argument. The work of students who produce such graphical arguments when solving proof construction tasks was analyzed to distill three activities that contribute to students’ successful translation of graphical arguments into verbal-symbolic proofs. These activities are called elaborating, syntactifying, and rewarranting. We analyze how engaging in these activities relates to students’ success in proof construction tasks. Additionally, we discuss how each individual activity contributes to the translation of a graphical argument into a verbal-symbolic proof.
Seminoma associated with crossed fused renal ectopia.

Abstract We report a case of seminoma associated with crossed fused renal ectopia and a duplicated vena cava. The impact of these congenital anomalies on the treatment of testicular seminoma is discussed. (J. Urol, 143: 1015–1016, 1990)