cssi/SciSciGPT-SciSciNet huggingface dataset:
Hafnium in peralkaline and peraluminous boro-aluminosilicate glass and glass sub-components: a solubility study

A relationship between the solubility of hafnia (HfO2) and the host glass composition was explored by determining the solubility limits of HfO2 in peralkaline and peraluminous borosilicate glasses in the system SiO2-Al2O3-B2O3-Na2O, and in glasses in the system SiO2-Na2O-Al2O3 in air at 1450 C. The only Hf-bearing phase to crystallize in the peralkaline borosilicate melts is hafnia, while in the boron-free melts sodium-hafnium silicates crystallize. All peraluminous borosilicate melts crystallize hafnia, but the slightly peraluminous glasses also have sector-zoned hafnia crystals that contain Al and Si. The more peraluminous borosilicate glasses also crystallize a B-containing mullite. The general morphology of the hafnia crystals changes as peralkalinity (Na2O/(Na2O+Al2O3)) decreases, as expected in melts with increasing viscosity. In all of the glasses with Na2O > Al2O3, the solubility of hafnia is linearly and positively correlated with Na2O/(Na2O + Al2O3) or Na2O - Al2O3 (excess sodium), despite the presence of 5 to 16 mol% B2O3. The solubility of hafnia is higher in the sodium-aluminum borosilicate glasses than in the sodium-aluminosilicate glasses, suggesting that the boron is enhancing the effect that excess sodium has on the incorporation of Hf into the glass structure. The results of this solubility study are compared to other studiesmore » of high-valence cation solubility in B-free silicate melts. From this, for peralkaline B-bearing glasses, it is shown that, although the solubility limits are higher, the solution behavior of hafnia is the same as in B-free silicate melts previously studied. By comparison, also, it is shown that in peraluminous melts, there must be a different solution mechanism for hafnia: different than for peralkaline sodium-aluminum borosilicate glasses and different than for B-free silicate melts studied by others.« less
Polarization of laser-induced fluorescence in OH in an atmospheric pressure flame

Measurements have been made of the polarization of the laser-induced fluorescence in OH in the burnt gases of a CH4/O2 flame diluted with N2, Ar, or He. A significant degree of polarization is observed for the lines emitted by the pumped level. Although elastic depolarizing collisions occur, they must compete with rapid quenching, resulting in a freezing of the coherence generated by the polarized laser. The variation of apparent line strength ratios with pump line and J is in agreement with theoretical expectations. The coherence is preserved to a small degree following collisional transfer to nearby rotational levels. The implications concerning relative collision rates and for flame diagnostic measurements are discussed.
Properties of purified folate-binding proteins from chronic myelogenous leukemia cells.

Abstract Folate-binding protein(s) from chronic myelogenous leukemia cells have been purified using acid dialysis, ammonium sulfate fractionation and affinity chromatography. The purified preparation which migrates as a single band on disc electrophoresis could be separated by DEAE agarose chromatography into two folate-binding proteins (binders I and II) which bind molar equivalents of folic acid. One binder (I) eluted from DEAE at 1 mM sodium phosphate, pH 6.0, and the other (II) at 100 mM sodium phosphate, pH 7.4. Analysis of the purified mixture, which contained more than 90% binder II, by sedimentation equilibrium centrifugation indicated a homogeneous protein with a calculated molecular weight of 44000. Antiserum raised against the purified mixture gave a single precipitin line by immunodiffusion against a preparation of partially purified cell lysate. Hydrolysis of the more acidic binder (II) with neuraminidase converted it to a weakly acidic protein similar to binder I suggesting that these binders are glycoproteins which differ in sialic acid content. With isoelectric focusing, the binding of folic acid would be demonstrated at pH 6.7, 7.3, 7.8 and 8.2 for binder I, and at pH 5.1, 5.8 and 6.5 for binder II. Binders I and II had equally high affinity for folic acid and dihydroflate, lower affinity of N 5 -methyl-tetrahydrofolate, and no apparent affinity for N 5 -formytetrahydrofolate or methotrexate.
Comparison of prostate biopsy schemes by computer simulation.

Objectives. To compare the ability of different biopsy schemes to detect cancer and predict tumor volume using our previously described prostate biopsy simulation system. In addition, we used the simulation system to evaluate the optimal location of transition zone biopsies. Methods. Digital reconstructions of 180 radical prostatectomy specimens were used. Forty simulations were performed on each prostate for 10 biopsy schemes, including a previously reported five-region peripheral zone biopsy pattern and a new 11-core multisite-directed scheme consisting of sextant, two transition zone, one midline, and two anterior horn biopsies. For simulation of the transition zone biopsies, paired near-midline biopsies were simulated, with needle insertion points from the apex to the base of the prostate and with needle advances of 1 to 4 cm before firing. A total of 1,180,800 individual biopsy tracks were simulated. Results. The 11-core multisite-directed biopsy scheme had the highest detection rate for cancers greater than 0.5 cc. This scheme reliably detected cancer in 94% (138 of 147) of the cases. These results were significantly better than those of the sextant biopsy scheme (P <0.001) and the five-region 18-core peripheral zone scheme (P = 0.03). Compared with other schemes, there were increases in small-volume (0.5 cc or less) cancer detection by both the 11-core multisite-directed and five-region schemes, but they were not statistically significant. The multisite and the sextant plus four transition zone biopsy schemes had the best correlation of mean total core cancer length with total cancer volume. In the simulation of the transition zone biopsies, the highest detection rate was observed when the biopsies were initiated at the most apical section and inserted for a depth of 3 cm before firing. Conclusions. Our simulation results suggest that the detection rate of prostate biopsies is not related solely to the number of cores taken. Core placement (the regions of the prostate from which samples are taken) is also important. The 11-core multisite-directed biopsy scheme performed the best, with improved cancer detection rates and tumor volume correlation over other schemes. On the basis of our simulations, this scheme has been chosen for clinical evaluation.
The effects of enriching Sargasso sea water on the production and species composition of the phytoplankton

Abstract The technique of artificial enrichment of sea water has been used in an attempt to define nutrients critically limiting the growth of phytoplankton in the Sargasso Sea. It is shown that final population growth achieved with different enrichment is a function of time. In 3-day experiments, iron appeared essential while in 7-day experiments nitrogen and phosphorus alone produced large populations. It is postulated that the influence of iron may be catalytic since enrichment with aluminium produced identical growth curves. In addition the final population resulting from enrichment in terms of species composition was shown to be a function of the addition of specific nutrients.
The Aurora Project Square Mirror Arrays

Simple low cost methods are discussed for obtaining 96-mirror arrays using closely packed square mirrors and commercially available linear actuators. Advantages and disadvantages of orthogonal-kinematic and gimbaled-pivot-flexure designs that have been employed in the Aurora Project are addressed.
Dangerous liaisons? Critical international theory and constructivism

The 1990s have seen the emergence of a new `constructivist' approach to international theory and analysis. This article is concerned with the relationship between constructivism and critical intern...
Correlation of Si wafer FTIR spectra with wafer temperatures and resist durability variations in plasma etching processes

The temperatures that wafers reach in plasma etching processes result from a balance of several factors including energetic particle bombardment heating, exothermic chemical reactions, radiative cooling, and gas phase viscous and molecular cooling. The radiative cooling depends on the emittance of the particular wafers and can vary considerably from wafer to wafer. As a result, the heating rate of and peak temperatures reached by different wafers can vary in the identical plasma etching process. This can lead to variations in the etch rates and reticulation thresholds of resists coated onto those wafers. A simple means of estimating the emittance of a silicon wafer below 200 degree(s)C could improve our ability to predict the peak temperatures that wafers reach in plasma etching processes. This could improve the reproducibility of resist etch rate and reticulation threshold measurements in plasma environments. Much of the energy radiated by a black or gray body in the range between room temperature and 200 degree(s)C is in the wavelength range scanned by commercially available FTIR spectrometers. Consequently, the magnitudes of transmitted and reflected IR signals provide an indication of IR absorption by silicon wafers and therefore of the emittance of the wafers in the wavelength range of interest for radiative cooling in plasma etching processes. In this paper we present resist etch rate and reticulation threshold measurements on wafers with differing FTIR transmission and reflection spectra. The data show that variations in etch rates and reticulation thresholds do correlate with differences in the wafers' IR transmittance and reflectance, suggesting that the wafers' peak temperatures also correlate with the FTIR spectra.
The effect of mono(2-ethylhexyl) phthalate on Sertoli cell transferrin secretion in vitro

We have examined the effect of mono(2-ethylhexyl) phthalate (MEHP) on the secretion of rat transferrin (rTf) by Sertoli cells (SC) in the presence and absence of FSH. Significant decreases in rTf secretion were observed in SC cultures exposed to 50 and 75 microM MEHP, in the absence of FSH. Treatment of SC with FSH (300 ng/ml) obviated this suppression of rTf secretion by MEHP. These findings indicate an effect of MEHP on rTf secretion by SC in vitro which could account for the testicular toxicity of MEHP in vivo.
The topography of tip growth in a plant cell.

Tips of young Phycomyces sporangiophores were dusted with starch grains, and growth photographically recorded. Rates of longitudinal displacement from the cell tip of individual markers were determined, also corresponding rates of change of cell diameter. From these the magnitude and spatial distribution of "relative elemental growth rates" along both longitudinal and circumferential axes of the cell were obtained. Growth rates in these two directions are functions of distance from the cell apex, and have different spatial distributions. In particular, rates of growth in cell circumference are complexly patterned. Relative elemental growth rates in length and in girth are approximately equal and maximal at the cell's apex, with a value of 2.4 mm. mm.–1 hr.–1. The characteristic shape of the tip is maintained constant in the face of its changing substance and position. This shape reflects a steady state of the cell's constituent growth patterns. At every point the growing membrane simultaneously expands in the two dimensions of its surface. The degree of polarization or directional preference of growth is measured by the ratio of longitudinal to circumferential relative elemental growth rate at any point. The ratio is not constant, but changes with position along the tip. This fact does not support the idea that membrane growth is based upon a quantal "growth event." Possible causal factors in oriented membrane growth are discussed.
Efficacy of screening mammography. A meta-analysis.

Objective. —To determine the efficacy of screening mammography by age, number of mammographic views per screen, screening interval, and duration of follow-up. Design. —Literature review and meta-analysis. Data Identification and Analysis. —Literature search of English-language studies reported from January 1966 to October 31, 1993, using MEDLINE, manual literature review, and consultation with experts. A total of 13 studies were selected, and their results were combined using meta-analytic techniques based on the assumption of fixed effects. Main Results. —The overall summary relative risk (RR) estimate for breast cancer mortality for women aged 50 to 74 years undergoing screening mammography compared with those who did not was 0.74 (95% confidence interval [CI], 0.66 to 0.83). The magnitude of the benefit in this age group was similar regardless of number of mammographic views per screen, screening interval, or duration of follow-up. In contrast, none of the summary RR estimates for women aged 40 to 49 years was significantly less than 1.0, irrespective of screening intervention or duration of follow-up. The overall summary RR estimate in women aged 40 to 49 years was 0.93 (95% CI, 0.76 to 1.13); the summary RR estimate for those studies that used two-view mammography was 0.87 (95% CI, 0.68 to 1.12) compared with 1.02 (95% CI, 0.73 to 1.44) for those studies that used one-view mammography, and for those studies with 7 to 9 years of follow-up, the summary RR estimate was 1.02 (95% CI, 0.82 to 1.27) compared with 0.83 (95% CI, 0.65 to 1.06) for those studies with 10 to 12 years of follow-up. Conclusion. —Screening mammography significantly reduces breast cancer mortality in women aged 50 to 74 years after 7 to 9 years of follow-up, regardless of screening interval or number of mammographic views per screen. There is no reduction in breast cancer mortality in women aged 40 to 49 years after 7 to 9 years of follow-up. Screening mammography may be effective in reducing breast cancer mortality in women aged 40 to 49 years after 10 to 12 years of follow-up, but the same benefit could probably be achieved by beginning screening at menopause or 50 years of age. (JAMA. 1995;273:149-154)
Phagocytic Cell-Derived Inflammatory Mediators and Lung Disease

T he critical role that phagocytic cells play in the initiation, propagation, and resolution of both acute and chronic inflammatory lung disease is well established. A number ofdistinct effector mechanisms of phagocytic cells have been identified and characterized in terms of their bactericidal and cytolytic activity. 1.2 In addition, specific mediators released by stimulated inflammatory cells have been shown to alter structural components of the lung and modulate both immunologic responses to antigenic challenge and vascular and fibroblast cell functions.34 A detailed description of the recent investigations of these mediator systems and how they effect physiologic and pathologic alterations of the lung in specific human disease processes is beyond the scope of this discussion. Therefore, we will focus on describing the recent insights that have been provided regarding those factors involved in activation of inflammatory cells, in particular phagocytic cells, following exposure to a chemotactic or phagocytic stimulus, the mechanisms responsible for the production of biologically active lipid mediators and the biologic reactivity of one of the effector mechanisms of stimulated phagocytic cells: the generation of reactive oxygen metabolites.
Adjacent vertices on transportation polytopes

To solve linear fixed charge problems with Murty's vertex ranking algorithm, one uses a simplex algorithm and a procedure to determine the vertices adjacent to a given vertex. In solving fixed charge transportation problems, the simplex algorithm simplifies to the stepping-stone algorithm. To find adjacent vertices on transportation polytopes, we present a procedure which is a simplification of a more general procedure for arbitrary polytopes.
Inhibition of bleomycin-induced [3H] thymidine 5'-triphosphate incorporation into liver and hepatoma nuclei by N-ethyl maleimide and daunomycin.

The addition of bleomycin to a nuclear incorporating system results in an increased incorporation of 3H-thymidine 5'-triphosphate (3H-TTP) into the DNA of liver and hepatoma nuclei. Bleomycin added to the nuclear incorporating system also produces scissions of DNA as determined by sucrose density gradient centrifugation of the extracted DNA. The action of bleomycin is dependent on the presence of sulfhydryl agents in the incubation mixture.Two compounds, N-ethyl maleimide and daunomycin, inhibit the bleomycin-induced incorporation of 3H-TTP preferentially. N-Ethyl maleimide inhibits bleomycin-induced activity in liver and hepatoma 7777 nuclei equally. Lower levels of daunomycin inhibit the bleomycin-induced activity in the hepatoma 7777 nuclei than are required to inhibit the activity in liver nuclei. The two compounds inhibit the bleomycin effect by different mechanisms. The addition of N-ethyl maleimide to bleomycin in the incubation system prevents bleomycin from causing breaks in the DNA. The addition of daunomycin, despite inhibition of bleomycin-induced 3H-TTP incorporation, does not affect the bleomycin-produced breaks in the DNA. N-Ethyl maleimide acts by binding to the DNA and by competing with a sulfhydryl agent for bleomycin-sensitive sites on the DNA. Daunomycin apparently inhibits a repair enzyme that is responsible for the increased incorporation following bleomycin treatment.
Refiguring American film genres : history and theory

CONTRIBUTORS: Rick Altman Leo Braudy Carol J. Clover George Lipsitz Michael Rogin David J. Russell Thomas Schatz Vivian Sobchack Linda Williams
The taxonomic position of the coccidian genus Crystallospora (Protozoa, Apicomplexa)

The genus Crystallospora was established by Labbe (1896) for a coccidium that Thelohan (1893) had found in the Atlantic Ocean off France. Dogel’ (1948) later found it in Peter the Great Gulf (Pacific Ocean) off Japan. It was transferred to Eimeria by Doflein (1909) and remained there until Dykova & Lom (1981) revived it because of its unique sporocyst structure. Actually, its structure necessitates its removal from the family Eimeriidae and placement in the family Barrouxiidae (see Levine [1983] for a review of this family). The pertinent taxa and their diagnoses therefore become:
Use of hypothermia in the intensive care unit

Used for over 3600 years, hypothermia, or targeted temperature management (TTM), remains an ill defined medical therapy. Currently, the strongest evidence for TTM in adults are for out-of-hospital ventricular tachycardia/ventricular fibrillation cardiac arrest, intracerebral pressure control, and normothermia in the neurocritical care population. Even in these disease processes, a number of questions exist. Data on disease specific therapeutic markers, therapeutic depth and duration, and prognostication are limited. Despite ample experimental data, clinical evidence for stroke, refractory status epilepticus, hepatic encephalopathy, and intensive care unit is only at the safety and proof-of-concept stage. This review explores the deleterious nature of fever, the theoretical role of TTM in the critically ill, and summarizes the clinical evidence for TTM in adults.
Miami in the 1990s: “City of the future” or “City on the edge”?

No city in the United States, and few in the world, have been as profoundly affected by immigration in as short a period of time as Miami, Florida. The result is a complex pattern of ethnoracial politics among the city’s Hispanics, Blacks and Anglos–a pattern that defies conventional models of ethnic relations and immigrant adaptation. This article focuses on the latinization of Miami and the implications for ethnoracial relations of an immigrant group that achieves rapid economic and political ascendancy while challenging conventional assumptions about ethnic assimilation. The article also examines the role of local government structures in both shapping or responding to the dynamics of ethnoracial politics.
Strength reduction for division and modulo with application to accessing a multilevel store

A method for replacing certain division and modulo operations by additions and subtractions is presented. This optimization allows efficient and easy use of partitioned arrays to access a multilevel store.
Tyrosine kinase inhibitors potentiate the induction of low density lipoprotein receptor gene expression by hepatocyte growth factor

Abstract The role of tyrosine kinase, protein kinase C, cyclic nucleotide- and Ca 2+ -calmodulin-dependent protein kinase second messenger pathways in the induction of LDL receptor gene expression by hepatocyte growth factor (HGF) was studied in the human hepatoma cell line Hep-G2. Incubation with media containing HGF increased the level of LDL receptor mRNA by 6.5-fold. Co-incubation with HGF and either of two tyrosine kinase inhibitors genistein (2.0–20.0 μg/ml) and herbimycin A (0.5–500.0 ng/ml) increased the level of LDL receptor mRNA above that observed with HGF alone by 40–60%. Incubation with HGF in the presence of the calmodulin antagonist W7 (10–30 μM) also super-induced the level of LDL receptor mRNA by nearly 230%. The protein kinase C and A inhibitors chelerythrine (0.1–10.0 μM) and H8 (0.5–5.0 μM), respectively, had no significant effects on the induction of LDL receptor mRNA by HGF. Taken together, these data suggest that tyrosine kinase, protein kinases C and A, and Ca 2+ -calmodulin dependent protein kinase activities are not essential for activation of LDL receptor gene expression in Hep-G2 cells by HGF.
Interaction of the vesicular-arbuscular mycorrhizae of maize with extractable soil phosphorus levels and nitrogen-potassium fertilizers

A field experiment was conducted for 3 years to determine whether increasing extractable soil P levels would affect vesicular-arbuscular mycorrhizae (VAM) of maize (Zea mays L.) and the subsequent uptake of P and production of dry matter. Five levels of extractable soil P were established on an Aquic Dystrochrept soil with high and low NK fertilization. The results show that as extractable soil-P levels increase the vesicular-arbuscular mycorrhizae of maize decrease, but P concentrations in both leaf and root tissue increase. There was a significant interaction between the extractable soil-P levels and NK treatment. At the low soil-P level NK fertilization increased mycorrhizae, while at the high soil-P levels NK fertilization reduced mycorrhizae. Dry-matter production generally paralleled extractable soil-P levels from 1.0 mg P kg−1 to a maximum at 10 mg P kg−1 soil (by ammonium acetate, pH 4.8). The reduction in vesicular-arbuscular mycorrhizae at the highest levels of extractable soil P apparently was not critical to either P uptake or dry-matter production.
Comparison between equations-of-motion and green's function methods for the particle-hole response function

Abstract We show that, apart from a few differences, the equations-of-motion method of McKoy et al. provides the leading correction to the random phase approximation (with exchange) in the fully renormalized response function (density-density correlation function). Thus, their equations-of-motion method is shown to be equivalent to a partial summation of infinite sets of terms in the perturbation expansion of the response function.
Neonatal exposure to parathion alters lipid metabolism in adulthood: Interactions with dietary fat intake and implications for neurodevelopmental deficits.

Abstract Organophosphates are developmental neurotoxicants but recent evidence also points to metabolic dysfunction. We determined whether neonatal parathion exposure in rats has long-term effects on regulation of adipokines and lipid peroxidation. We also assessed the interaction of these effects with increased fat intake. Rats were given parathion on postnatal days 1–4 using doses (0.1 or 0.2 mg/kg/day) that straddle the threshold for barely detectable cholinesterase inhibition and the first signs of systemic toxicity. In adulthood, animals were either maintained on standard chow or switched to a high-fat diet for 7 weeks. We assessed serum leptin and adiponectin, tumor necrosis factor-α (TNFα) in adipose tissues, and thiobarbituric acid reactive species (TBARS) in peripheral tissues and brain regions. Neonatal parathion exposure uncoupled serum leptin levels from their dependence on body weight, suppressed adiponectin and elevated TNFα in white adipose tissue. Some of the effects were offset by a high-fat diet. Parathion reduced TBARS in the adipose tissues, skeletal muscle and temporal/occipital cortex but not in heart, liver, kidney or frontal/parietal cortex; it elevated TBARS in the cerebellum; the high-fat diet again reversed many of the effects. Neonatal parathion exposure disrupts the regulation of adipokines that communicate metabolic status between adipose tissues and the brain, while also evoking an inflammatory adipose response. Our results are consistent with impaired fat utilization and prediabetes, as well as exposing a potential relationship between effects on fat metabolism and on synaptic function in the brain.
Heterospecific interactions and the proliferation of sexually dimorphic traits

Sexual selection is expected to promote speciation by fostering the evolution of sexual traits that minimize reproductive interactions among existing or incipient species. In species that compete for access to, or attention of, females, sexual selection fosters more elaborate traits in males compared to females. If these traits also minimize reproductive interactions with heterospecifics, then species with enhanced risk of interactions between species might display greater numbers of these sexual dimorphic characters. We tested this prediction in eight families of North American birds. In particular, we evaluated whether the number of sexually dimorphic traits was positively associated with species richness at a given site or with degree of sympatry with congeners. We found no strong evidence of enhanced sexual dimorphism with increasing confamilial species richness at a given site. We also found no overall relationship between the number of sexually dimorphic traits and overlap with congeners across these eight families. However, we found patterns consistent with our prediction within Anatidae (ducks, geese and swans) and, to a lesser degree, Parulidae (New World warblers). Our results suggest that sexually selected plumage traits in these groups potentially play a role in reproductive isolation.
Moving boundary problems governed by anomalous diffusion.

Anomalous diffusion can be characterized by a mean-squared displacementx 2 (t)� that is proportional to t a where a �= 1. A class of one-dimensional moving boundary problems is investigated that involves one or more regions governed by anomalous diffusion, specifically subdiffusion (a < 1). A novel numerical method is developed to handle the moving interface as well as the singular history kernel of subdiffusion. Two moving boundary problems are solved: the first involves a subdiffusion region to the one side of an interface and a classical diffusion region to the other. The interface will display non-monotone behaviour. The subdiffusion region will always initially advance until a given time, after which it will always recede. The second problem involves subdiffusion regions to both sides of an interface. The interface here also reverses direction after a given time, with the more subdiffusive region initially advancing and then receding.
Imaging Evidence and Recommendations for Traumatic Brain Injury: Advanced Neuro- and Neurovascular Imaging Techniques

SUMMARY: Neuroimaging plays a critical role in the evaluation of patients with traumatic brain injury, with NCCT as the first-line of imaging for patients with traumatic brain injury and MR imaging being recommended in specific settings. Advanced neuroimaging techniques, including MR imaging DTI, blood oxygen level– dependent fMRI, MR spectroscopy, perfusion imaging, PET/SPECT, and magnetoencephalography, are of particular interest in identifying further injury in patients with traumatic brain injury when conventional NCCT and MR imaging findings are normal, as well as for prognostication in patients with persistent symptoms. These advanced neuroimaging techniques are currently under investigation in an attempt to optimize them and substantiate their clinical relevance in individual patients. However, the data currently available confine their use to the research arena for group comparisons, and there remains insufficient evidence at the time of this writing to conclude that these advanced techniques can be used for routine clinical use at the individual patient level. TBI imaging is a rapidly evolving field, and a number of the recommendations presented will be updated in the future to reflect the advances in medical knowledge. ABBREVIATIONS: BOLD blood oxygen level– dependent; FA fractional anisotropy; MD mean diffusivity; MEG magnetoencephalography; TBI traumatic brain injury
Developmental Exposure to the Potent Aryl Hydrocarbon Receptor Agonist 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Impairs the Cell-Mediated Immune Response to Infection with Influenza A Virus, but Enhances Elements of Innate Immunity

Based on demonstrated effects on functional immunity in rodent models and supportive evidence from epidemiological studies, it is apparent that developmental exposure to ligands for the aryl hydrocarbon receptor (AhR) has the potential to impair immunity in human populations. Furthermore, due to the high levels of these compounds detected in human breast milk, and the fact that they cross the placenta, it is clear that humans are exposed to AhR ligands during fetal and neonatal development. The current studies were conducted to further characterize the relationship between developmental exposure to TCDD, the most potent AhR agonist, and defects in immune function later in life. Impregnated C57Bl/6 mice were treated with 4 doses of 1 mircog/kg TCDD, given on days 0, 7, and 14 of pregnancy, and 2 days after parturition. Functional immunity was assessed by challenging the adult offspring with influenza virus. Both male and female offspring of the TCDD-treated dams demonstrated impairment of the adaptive immune response, as evidenced by suppressed numbers of T cells and IFNgamma-producing cells in the draining lymph nodes and reduced T cell recruitment to the lung. In contrast, the inflammatory response, including infection-associated pulmonary neutrophilia and IFNgamma levels, was significantly elevated in the developmentally-exposed mice. These functional defects in immunity were not correlated with defects in hematopoeisis, as immune cells in the bone marrow, spleen, and thymus were phenotypically normal in uninfected mice. These results support the idea that immune alterations that arise during development cause persistent and significant changes in immune function.
Current Vitality of Ziegler’s Monumental Discovery of Zirconium Catalysis in Olefin Polymerization: Metallocene and Nonmetallocene Catalysts via Reductive Dimerization

Although the avalanche of technical advances unleashed by Ziegler’s discovery of the low-pressure polymerization of ethylene is most often associated with the use of titanium procatalysts, it is well to recall that the key initial experiment leading to the formation of polyethylene was achieved in 1953 with zirconium(IV) acetylacetonate.1 Titanium salts maintained their superiority in the heterogeneous Ziegler-Natta catalysts used for olefin polymerization during the next two decades. With the reawakening of interest in homogeneous, single-site metallocene polymerization catalysts in the late 1970s, the zirconocene(IV) derivatives have regained a marked ascendancy, because they undergo deactivating reduction much less readily than titanocene(IV) derivatives.
Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization

Background: Although the system for producing yellow corn grain is well established in the US, its role among other biofeedstock alternatives to petroleum-based energy sources has to be balanced with its predominant purpose for food and feed as well as economics, land use, and environmental stewardship. We model land usage attributed to corn ethanol production in the US to evaluate the effects of anticipated technological change in corn grain production, ethanol processing, and livestock feeding through a multi-disciplinary approach. Seven scenarios are evaluated: four considering the impact of technological advances on corn grain production, two focused on improved efficiencies in ethanol processing, and one reflecting greater use of ethanol co-products (that is, distillers dried grains with solubles) in diets for dairy cattle, pigs, and poultry. For each scenario, land area attributed to corn ethanol production is estimated for three time horizons: 2011 (current), the time period at which the 15 billion gallon cap for corn ethanol as per the Renewable Fuel Standard is achieved, and 2026 (15 years out). Results: Although 40.5% of corn grain was channeled to ethanol processing in 2011, only 25% of US corn acreage was attributable to ethanol when accounting for feed co-product utilization. By 2026, land area attributed to corn ethanol production is reduced to 11% to 19% depending on the corn grain yield level associated with the four corn production scenarios, considering oil replacement associated with the soybean meal substituted in livestock diets with distillers dried grains with solubles. Efficiencies in ethanol processing, although producing more ethanol per bushel of processed corn, result in less co-products and therefore less offset of corn acreage. Shifting the use of distillers dried grains with solubles in feed to dairy cattle, pigs, and poultry substantially reduces land area attributed to corn ethanol production. However, because distillers dried grains with solubles substitutes at a higher rate for soybean meal, oil replacement requirements intensify and positively feedback to elevate estimates of land usage. Conclusions: Accounting for anticipated technological changes in the corn ethanol system is important for understanding the associated land base ascribed, and may aid in calibrating parameters for land use models in biofuel life-cycle analyses.
Airspace Statistical Proximity Maps Based on Data-Driven Flow Modeling

This paper presents a new methodology that aims to rapidly generate 3-D sector proximity maps, which indicate the probability of presence of at least one or two aircraft at any given point in a considered sector. The maps are generated using an aircraft flow model driven from historical data. Time-varying flow characteristics such as routes, speed, probability density function of the inter-arrival time between two consecutive aircraft, were determined using ETMS data. The maps are intended to be a predictive tool for traffic flow management in order to anticipate for a given time period how different flows may interact together and to predict which “critical” regions may be subject to possible conflict between aircraft.
Learning procedures: the role of working memory in multimedia learning experiences

SUMMARY The ubiquitous label ‘some assembly required’ signals the appearance of instructions for assembly procedures. These instructions come in various formats, some of which may be more effective than others. Previous research has demonstrated advantages for multimedia as compared to single-format presentations. The current study sought to outline the cognitive processes contributing to this advantage. Specifically, two experiments examined the working memory and source monitoring processes involved with remembering procedural instructions presented in three different formats. Participants learned procedural instructions while undertaking one of a variety of selective interference tasks targeting working memory subcomponents. Results, while supporting a multimedia advantage for learning, demonstrated selective working memory subsystem involvement with different instruction formats. Further, despite the multimedia advantage, participants often misremembered multimedia presentations as picture-based ones. These results provide further insight into the cognitive processes that underlie comprehension and memory for multimedia experiences. Copyright # 2006 John Wiley & Sons, Ltd.
Property-based testing: a new approach to testing for assurance

The goal of software testing analysis is to validate that an implementation satisfies its specifications. Many errors in software are caused by generalizable flaws in the source code. Property-based testing assures that a given program is free of specified generic flaws. Property-based testing uses property specifications and a data-flow analysis of the program to guide evaluation of test executions for correctness and completeness.
Testing whether survival function is bivariate new better than used

We present statistical procedures to test that a life distribution is bivariate exponential against the alternative that it is bivariate new better than used (BNBU).
A lightweight statistical authentication protocol for access control in wireless LANs

With the increasing performance and dropping price of wireless networking equipments, wireless networking has revolutionized the way people work and play. Wi-Fi hot spots popping up all over the country provides a convenient way of internet connectivity. For the ISPs of hot spots, authentication and accounting have been recognized as two most crucial concerns. For authentication, IETF PANA 1 WG, is working on a transport protocol for authenticating IP hosts for network access. However, PANA does not provide access control and per-packet authentication, which are desirable in accounting and access control. Instead of using high-overhead crypto-based mechanisms, such as IPSec or 802.11i, we propose a lightweight statistical authentication protocol, namely Shepherd2. In Shepherd, the legitimacy of a mobile node is determined by continuously checking a series of random authentication bits where each hit in this stream is piggybacked by a packet. Such authentication bit stream is generated by both mobile node and access point using the same random number generator under the same shared seed as a key. We analyze this protocol under three synchronization schemes. Our analytical results show that this protocol performs well in terms of computational and communication cost, synchronization efficiency, and protocol operation secrecy. We also show that this new protocol is practical for implementation in wireless LANs.
The Concomitance of Learning Disabilities and Emotional/Behavioral Disorders: A Conceptual Model

Although research has documented overlapping and coexisting characteristics of learning disabilities and emotional/behavioral disorders, little attention has been paid to the subset of students who manifest symptoms of both disorders (LD/EBD). This gap in our professional knowledge/research base may be due to (a) exclusive language in federal definitions that promotes differentiation of disabilities rather than recognition of symptom overlap; (b) the lack of a conceptual model of concomitant learning and emotional/behavioral disorders; and (c) the absence of a research focus on this population. In this article, we construct a conceptual model involving six critical domains of relevance to students with LD/EBD. After describing the utility of this interactive and functional model, we highlight critical issues in screening, assessment, and programming for children with concomitant LD/EBD.
ENLARGEMENT OF THE ADRENAL CORTEX IN EXPERIMENTAL UREMIA

The production of an experimental uremia in the albino rat by removal of both kidneys is followed by hypertrophy of the adrenal glands. In the case of male rats 90 days of age this adrenal enlargement amounted to 65 per cent and in the case of female rats 180 days of age 47 per cent. The increase in the size of the whole gland is due entirely to hypertrophy of the cortex. This increase in the volume of cortical tissue amounted to approximately 40 per cent for males and 61 per cent for females and was due in large part to an increase in the size of the cells. The content of water and material soluble in fat solvents was higher in the uremic than the control glands. However after subtraction of such storage materials a true hypertrophy of the cortex still remained. It amounted to 21 per cent. Histologically the stainable fat had a more irregular distribution and was present in lesser amount in the adrenals from the uremic animals. The capillaries of the medulla and reticular cortex were distended. The nuclei of both the cortical and medullary cells were swollen and stained faintly.
The E3 Ubiquitin Ligase Protein Associated with Myc (Pam) Regulates Mammalian/Mechanistic Target of Rapamycin Complex 1 (mTORC1) Signaling in Vivo through N- and C-terminal Domains *

Pam and its homologs (the PHR protein family) are large E3 ubiquitin ligases that function to regulate synapse formation and growth in mammals, zebrafish, Drosophila, and Caenorhabditis elegans. Phr1-deficient mouse models (Phr1Δ8,9 and Phr1Magellan, with deletions in the N-terminal putative guanine exchange factor region and the C-terminal ubiquitin ligase region, respectively) exhibit axon guidance/outgrowth defects and striking defects of major axon tracts in the CNS. Our earlier studies identified Pam to be associated with tuberous sclerosis complex (TSC) proteins, ubiquitinating TSC2 and regulating mammalian/mechanistic target of rapamycin (mTOR) signaling. Here, we examine the potential involvement of the TSC/mTOR complex 1(mTORC1) signaling pathway in Phr1-deficient mouse models. We observed attenuation of mTORC1 signaling in the brains of both Phr1Δ8,9 and Phr1Magellan mouse models. Our results establish that Pam regulates TSC/mTOR signaling in vitro and in vivo through two distinct domains. To further address whether Pam regulates mTORC1 through two functionally independent domains, we undertook heterozygous mutant crossing between Phr1Δ8,9 and Phr1Magellan mice to generate a compound heterozygous model to determine whether these two domains can complement each other. mTORC1 signaling was not attenuated in the brains of double mutants (Phr1Δ8,9/Mag), confirming that Pam displays dual regulation of the mTORC1 pathway through two functional domains. Our results also suggest that although dysregulation of mTORC1 signaling may be responsible for the corpus callosum defects, other neurodevelopmental defects observed with Phr1 deficiency are independent of mTORC1 signaling. The ubiquitin ligase complex containing Pam-Fbxo45 likely targets additional synaptic and axonal proteins, which may explain the overlapping neurodevelopmental defects observed in Phr1 and Fbxo45 deficiency.
An ab initio study of HCuCO

HCuCO is studied using a large Gaussian basis set at the coupled cluster singles and doubles level of theory, including a perturbational estimate of the connected triples (CCSD(T)). In contrast with CuCO, HCuCO is linear. The Cu-CO bond in HCuCO is significantly stronger than in CuCO. These differences between HCuCO and CuCO are discussed in terms of theCu-H bond polarizing the Cu 4s electron away from the CO.
Comparison of Continuous Infusion of Fentanyl to Bolus Dosing in Neonates After Surgery

Objective Concern about respiratory depression may lead to underuse of postoperative narcotic analgesia in neonates. The authors compared continuous infusion of fentanyl with bolus dosing in infants after surgery to determine whether continuous infusion is associated with less respiratory depression. Study design In the first phase of the study, 16 patients were randomly assigned to receive fentanyl by continuous infusion (C) or bolus dosing every 2 hours (B) in a double-blinded trial. Respiratory events were recorded. An observational pain score and saliva for cortisol concentration were obtained 2, 8, and 24 hours after beginning treatment to compare efficacy of pain control. In the second phase, 20 additional patients received fentanyl by continuous infusion in an unblinded fashion, with the same data collection, to more accurately determine the incidence of respiratory events. Results In phase 1, apnea occurred in eight of nine B patients (89%) compared with one of seven C patients (14%; P Conclusion Continuous infusion of fentanyl at the doses studied is associated with pain control similar to that with bolus dosing at regular intervals. Although episodes of respiratory depression were less severe and less frequent for C patients, there may be an increased need for ventilator support with continuous infusion of fentanyl to achieve acceptable pain control. Providing adequate pain control to neonates in the immediate postoperative period remains a challenge.
Variance component modeling of attachment level measurements.

Abstract The purpose of this study was to investigate the influence of within subject and within tooth variability of attachment-level measurements on hypothesis testing. Full-mouth attachment-level measurements were obtained at 4 sites per tooth in early onset periodontitis subjects (both localized N= 89 and generalized N= 139) and adult periodontitis subjects (N= 309). Variance component models utilizing iterative generalized least squares were employed to estimate the % of variance distributed at the level of the site, tooth and subject in the 3 subject populations. The data indicate that a significant % of the variance is distributed within the tooth and the subject. Ignoring the variance attributable to teeth or subjects can result in inappropriately low type I error rates for hypothesis testing. Thus, both the subjects and the tooth must be considered in the modeling of attachment level measurements. Also in studies in which a limited number of samples are taken, data analysis would be simplified if these samples were taken from different teeth.
GATA2 is required for the generation of V2 interneurons

During embryogenesis, transcription factor GATA2 is expressed in a variety of distinct cell types, and earlier experiments showed that GATA2 is a vital regulator of both hematopoiesis and urogenital development. Despite the fact that GATA2 is expressed early and abundantly in the nervous system, there has been no demonstration of its direct participation in neurogenesis. We show here that GATA2 is expressed in the ventral spinal cord exclusively in newly generated V2 interneurons, suggesting that GATA2 might be required for the generation of this discrete neuronal population. Proof for this hypothesis was provided by showing that the number of cells expressing V2 neuronal markers was drastically diminished in gata2 null mutant embryos. The tissue-specific enhancer that directs gata2 transcription specifically in V2 neurons was localized to a 190 bp intragenic element lying within gata2 intron 5, and this element is both necessary and sufficient to confer GATA2 spinal cord expression. The identification of a V2-specific enhancer should allow fundamental new insight into the genetic hierarchy of regulatory events that govern neurogenesis in a well-defined cell lineage.
Spatial variations in endothelial barrier function in disturbed flows in vitro

Hindered barrier function has been implicated in the initiation and progression of atherosclerosis, a disease of focal nature associated with altered hemodynamics. In this study, endothelial permeability to macromolecules and endothelial electrical resistance were investigated in vitro in monolayers exposed to disturbed flow fields that model spatial variations in fluid shear stress found at arterial bifurcations. After 5 h of flow, areas of high shear stress gradients showed a 5.5-fold increase in transendothelial transport of dextran (molecular weight 70,000) compared with no-flow controls. Areas of undisturbed fully developed flow, within the same monolayer, showed a 2.9-fold increase. Monolayer electrical resistance decreased with exposure to flow. The resistance measured during flow and the rate of change in monolayer resistance after removal of flow were lowest in the vicinity of flow reattachment (highest shear stress gradients). These results demonstrate that endothelial barrier function and permeability to macromolecules are regulated by spatial variations in shear stress forces in vitro.