cssi/SciSciGPT-SciSciNet huggingface dataset:
Class Incorporated: Stratified Patterns of Academic Engagement at a Highly Selective University:

This research examines the influence of social class stratification on students’ self-reported academic engagement. Drawing from 44 interviews with students from the three major class groups at an ...
Impact of anti-anaerobic antibiotic activity on graft-versus-host disease in allogeneic hematopoietic stem cell transplant (HSCT) recipients at an institution that utilizes antibiotic cycling

BACKGROUND At our institution, antibiotic cycling for febrile neutropenia is utilized to increase heterogeneity of antibiotic exposure in patients who have undergone an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Development of acute graft-versus-host disease (aGVHD) has been associated with low diversity within stool microbiota. To date, discordant outcomes have been reported implicating anti-anaerobic antibiotic use with the development of aGVHD, and there is currently a lack of published data available in an antibiotic cycled environment. The objective of this study was to determine if there is a difference in the rate of aGVHD in patients who receive anti-anaerobic cycled antibiotics compared with other cycled antibiotics. METHODS This was a retrospective, observational study evaluating rates of aGVHD in patients who received antibiotics with anaerobic vs non-anaerobic coverage post-allo-HSCT from January 2008 to January 2018. Univariate and multivariable analyses were performed to assess associations with aGVHD. Secondary outcomes include rate of all stages of aGVHD, progression-free survival, overall survival, 100-day treatment-related mortality (TRM), and 1-year TRM. RESULTS A total of 273 patients were included in the study. Baseline characteristics were similar between groups, except patients who received anti-anaerobic antibiotics had more unrelated donors (P = .002), were more likely to get myeloablative preparatory regimens (P = .009), had less subtherapeutic calcineurin inhibitor serum concentrations (P = .001), and more often received T-cell depletion (P = .004). The incidence of grades II-IV aGVHD post-HSCT in patients who received anti-anaerobic antibiotics was 32.6% compared with 18.8% in patients who received other antibiotics (P = .015). Multivariable analysis showed that the occurrence of grades II-IV aGVHD was associated with cytomegalovirus reactivation (OR = 2.1, 95% CI = 1.0-4.5, P = .047), unrelated donors (OR = 6.1, 95% CI = 2.3-16.6, P < .001), and use of anti-anaerobic antibiotics (OR = 2.3, 95% CI = 1.1-4.8, P = .021). A 100-day TRM in patients who received anti-anaerobic antibiotics was 9.6% compared with 3.6% in patients who received other antibiotics (P = .046). One-year TRM in patients who received anti-anaerobic antibiotics was 25.2% compared with 13.8% in patients who received other antibiotics (P = .017). There was no statistically significant difference seen between groups in progression free survival or overall survival. CONCLUSION Variability in baseline characteristics limits ability to make strong conclusions, but patients who received antibiotics with anaerobic coverage during the first 30 days after an allogeneic HSCT appeared to be at an increased risk of developing aGVHD and TRM. Larger well-controlled trials are warranted to further clarify these relationships.
Economic Growth in Croatia: Potential and Constraints

This paper examines the factors and constraints that affect recent and potential growth in Croatia, as well as policies that can influence it. On current productivity trends, it estimates Croatia's potential growth rate at 4-4½ percent, a result reasonably robust to different methodologies. To sustain growth at a higher rate in line with the authorities' aspirations, the analysis highlights the critical need to improve the business environment through further measures to reduce the administrative burden, legal uncertainties, and corruption. It also emphasizes the importance of attracting more greenfield foreign direct investment, and reforms to reduce the role of the state in the economy through fiscal consolidation and faster privatization.
Modelling of particle capture by expanding droplets

Froth flotation by small air bubbles has been traditionally used in industry to capture fine minerals and other hydrophobic particles. This method, however, is not efficient for capturing very small particles. The present work is motivated by a new agglomeration process that overcomes this lack of efficiency. It consists of mixing a particle suspension and saltwater-filled droplets covered with semi-permeable oil layers. This paper investigates the two-particle dynamics of a solid particle and a semi-permeable spherical drop that expands due to osmosis in an external, pure extensional flow field. A dimensionless engulfment parameter measures the relative effects of droplet growth and convective flow. The computational results from numerical integration determine a transient collision efficiency, which describes the influence of hydrodynamic interactions and osmotic flow on particle capture. The results show that drop expansion, which decays slowly with time, greatly increases particle capture rates, especially for small particles. Moreover, as the engulfment parameter increases, there is a transition from flow-dominated capture to expansion-dominated capture. For the case of a non-expanding droplet, we provide a numerical solution for the transient pair distribution function, which enables us to explain the transient particle-capture rate in terms of the microstructure of the suspension. Furthermore, we derive an analytical expression for the initial collision efficiency at zero times, which agrees with our numerical data. The numerical results for non-expanding droplets at long times show increasing collision efficiency as the permeability increases and when the size ratio is near unity, in agreement with previous steady-state calculations.
Optical engineering education with curriculum mapping for ABET accreditation

The Physics and Optical Engineering department at Rose-Hulman Institute of Technology offers three degrees at the undergraduate level; physics, optical engineering, and engineering physics. The department recently transitioned a science-based applied optics degree into a B.S (Optical Engineering) degree. With this transition we began the process of seeking accreditation for the optical engineering program through the Accreditation Board of Engineering and Technology (ABET). This paper describes several assessment components of the accreditation process which includes a detailed curriculum mapping exercise to meet engineering standards. We discuss the overall outcome based optical engineering education.
Optical model for tubular hollow light guides (1415-RP)

Tubular hollow light guides are found in many lighting and daylighting systems to transport collected light into deep spaces of building interiors. Linear straight guides are popularly used due to their high optical efficiency, but non-linear guides with bent sections are sometimes required to fulfill some installation restrictions. The optical performance of such bent guides is, however, unknown. This article presents the development, validation, and application of an optical model to compute the transmittance of light guides with and without bends. The model is based on the ray-tracing technique and can handle segmented guides with connection elbows. Measurement of the light transmittance of a light guide with two connection elbows is conducted using an outdoor large integrating box to benchmark the model. The model predictions are in good agreement with the measurement and public data for vertical light guides without bends. The model predictions for bent light guides installed in a northern mid-latitu...
Relationship between Cell Surface Properties and Transport of Bacteria through Soil

A study was conducted to relate the properties of Enterobacter, Pseudomonas, Bacillus, Achromobacter, Flavobacterium, and Arthrobacter strains to their transport with water moving through soil. The bacteria differed markedly in their extent of transport; their hydrophobicity, as measured by adherence to n-octane and by hydrophobic-interaction chromatography; and their net surface electrostatic charge, as determined by electrostatic interaction chromatography and by measurements of the zeta potential. Transport of the 19 strains through Kendaia loam or their retention by this soil was not correlated with hydrophobicities or net surface charges of the cells or the presence of capsules. Among 10 strains tested, the presence of flagella was also not correlated with transport. Retention was statistically related to cell size, with bacteria shorter than 1.0 μm usually showing higher percentages of cells being transported through the soil. We suggest that more than one characteristic of bacterial cells determines whether the organisms are transported through soil with moving water.
Estimation of Employee Stock Option Exercise Rates and Firm Cost: Methodology

Investors have become increasingly concerned about the cost of executive stock options to shareholders. Because executives face hedging constraints, standard option theory does not apply. The valuation problem reduces to accurately characterizing the option payoff. This paper develops a methodology for estimating option exercise and cancellation rates as a function of the stock price path, time to expiration, and firm and option holder characteristics. Our estimation accounts for correlation between exercises by the same executive. Valuation proceeds by using the estimated exercise rate function to describe the option's expected payoff along each stock price path and then computing the present value of the payoff. The estimation of empirical exercise rates also allows us to test the predictions of theoretical models of option exercise behavior. The paper not only illustrates an ideal valuation method for a large dataset, but also shows how to evaluate the usefulness of some of the approximations proposed in the literature.
The nature of the deep lens survey fast transients

The discovery and study of highly transient sources, especially those that rise to high brightness and then fade to obscurity, has been a major part of modern astrophysics. Well-known examples include supernovae and novae. A by-product of the Deep Lens Survey was the discovery of three transients that varied on a timescale of less than an hour. All three had faint and red counterparts, the brightest of which was identified with an M star. However, the remaining two showed hints of an extragalactic origin; one had a spatially extended counterpart, and the other appeared in projection on the outskirts of a bright elliptical galaxy. If these two sources were really of extragalactic origin, then the two events represent a new class of exotic explosive transients. We undertook spectroscopic observations with the Keck telescope and find that the two counterparts are also late-type Galactic dwarfs. Our main conclusion is that flares from M dwarfs constitute a dense foreground fog and dominate over any plausible class of extragalactic fast transients by at least 2 orders of magnitude. Overcoming this fog will likely require dedicated surveys with careful optimization of target field location, filter(s), and cadence, presearch imaging to filter out late-type dwarfs, and a well-planned rapid follow-up plan.
Abstract 37: Refining of the Association of Fever with Functional Outcome in SAH

Background: Fever has been associated with worse clinical outcomes in aneurysmal subarachnoid hemorrhage (aSAH). However, the impact of the cause, severity, and duration of fever is not clear. We conducted this study to evaluate the impact of fever and subfebrile load and fever characteristics on functional outcome. Methods: We collected detailed information on fever onset, cause, severity, and duration during the ICU stay in a cohort of 586 consecutive patients with aSAH. Fever was defined as core body temperature ≥ 38.3°C. Subfebrile measurements were those between 37 and 38.2°C. Febrile and subfrebile loads were defined as number of hours with fever or subfebrile measurements. Poor outcome was defined as modified Rankin score (mRS) > 2. Univariate and multivariate logistic regression models were developed to define predictors of outcome using various categorizations of fever cause, severity, and duration. Results: 532/586 patients (90.9%) had fever for a mean of 2.1±3.0 days. Fever started within 24 ho...
ALLERGENIC PROPERTIES OF MILK AND MILK PROTEINS. A STUDY OF ANAPHYLAXIS IN GUINEA PIGS.

Experiments employing anaphylaxis in guinea pigs, in which skim milk, evaporated milk, a proprietary formula of equal parts of casein and demineralized whey (S-26), and individual milk proteins were used as sensitizing and challenge agents, showed all of these substances to be antigenic for guinea pigs in varying degrees.
THE USEFULNESS OF SIPP FOR CHILD CARE RESEARCH AND POLICY FORMULATION

This paper outlines the types of information needed to evaluate and formulate Federal child care policy and reports on the utility of the Survey of Income and Program Participation (SIPP) for providing this information. It highlights SIPP's usefulness as currently designed and describes some of SIPP's limitations. It concludes with recommendations for changes with a discussion of relative importance and estimated degree of difficulty to change to increase SIPP's utility to Federal child care policy analysts and other child care researchers.
Effects of High-Intensity Training on Anaerobic and Aerobic Contributions to Total Energy Release During Repeated Supramaximal Exercise in Obese Adults.

Studying relative anaerobic and aerobic metabolism contributions to total energy release during exercise may be valuable in understanding exercise energetic demands and the energetic adaptations that occur in response to acute or chronic exercise in obese adults. The aim of the present study is to evaluate the effects of 6 weeks of high-intensity training (HIT) on relative anaerobic and aerobic contributions to total energy release and on peak power output during repeated supramaximal cycling exercises (SCE) in obese adults. Twenty-four obese adults (body mass index = ± 33 kg.m−2) were randomized into a control group (n = 12) and an HIT group (n = 12). Accumulated oxygen deficits (ml.min−1) and anaerobic and aerobic contributions (%) were measured in all groups before and after training via repeated SCE. In addition, the peak power output performed during SCE was determined using the force-velocity test. Before HIT, anaerobic contributions to repeated SCE did not differ between the groups and decreased significantly during the third and fourth repetitions. After HIT, anaerobic contributions increased significantly in the HIT group (+11 %, p < 0.01) and were significantly higher than those of the control group (p < 0.01). Moreover, the peak power obtained during SCE increased significantly in the HIT group (+110 W.kg−1, p < 0.01) and correlated positively with increases in anaerobic contributions (r = 0.9, p < 0.01). In obese adults, HIT increased anaerobic contributions to energy release which were associated with peak power enhancement in response to repeated SCE. Consequently, HIT may be an appropriate approach for improving energy contributions and muscle power among obese adults.
Remote Subpaging Across a Fast Network

While improvements in semiconductor technology have made it possible to accommodate a large physical memory in today's machines, the need for supporting an even larger virtual address space continues unabated. Improvements in disk access times have however lagged improvements in both processor and memory speeds. Recent advances in networking technology has made it possible to go out on the network and access the physical memory on other machines at a cost lower than accessing the local disk. This paper describes a system implemented for such a remote paging environment. This system allows us to use a fine grain (a subpage) data transfer unit for remote memory paging and to employ different algorithms for determining when and how to transfer these units. The novelty of our implementation is that all the policy decisions about the subpage size and the subpaging algorithm are made at the user level, thus letting applications choose their own set of parameters. Performance results indicate that applications can benefit significantly from this flexibility.
NONSPECIFIC JEJUNAL ULCERATION: IN SEARCH OF AN ETIOLOGY

Summary Nine cases of unequivocal nonspecific jejunal ulceration have been presented, representing all such cases encountered at the Columbia-Presbyterian Medical Center from 1922 through 1965. Detailed microscopic examination of the submucosal and mesenteric vasculature has shown arteriolar narrowing or occlusion, or both, to be present in eight of the cases. Current literature, indicating a causal relationship between the ingestion of KCl- thiazide drugs and small intestinal ulceration, has been critically reviewed and challenged. Further documentation is necessary to prove this alleged relationship. Although this study has not demonstrated a consistent etiology for primary, nonspecific jejunal ulceration, the presence of hypertensive cardiovascular disease or mesenteric vascular changes, or both, is remarkable.
On Racial Speculation and Racial Science: A Response to Shiao et al.

In June 2012, Sociological Theory published “The Genomic Challenge to the Social Construction of Race” by Jiannbin Lee Shiao, Thomas Bode, Amber Beyer, and Daniel Selvig. The article argues that “r...
Enhanced detection of sphingoid bases via divalent ruthenium bipyridine complex derivatization and electrospray ionization tandem mass spectrometry.

Sphingoid bases, such as unsaturated sphingosine (So) and its corresponding dihydro-saturated species sphinganine (Sa), are present in cell samples in low abundance. This fact combined with their low-to-moderate electrospray ionization (ESI) potential, compared to other sphingolipids such as sphingomyelins, limits their detection and quantitation by liquid chromatography−tandem mass spectrometry (LC−MS2). To enhance the ESI efficiency of sphingoid bases, a novel procedure to generate stably derivatized analytes that enhance the LC−MS2 detection of sphingoid bases when analyzed using LC−MS2 was developed. In this method, a ruthenium complex, [4-(N-succimidyloxycarbonyl propyl)-4′-methyl-2,2′-bipyridine] bis(2,2′-bipyridine) Ru(II) dihexafluorophosphate, is added directly to a cell extract. This complex reacts with and covalently binds to an amino group within the sphingoid bases. The dicationic nature of the ruthenium ion enhances the compound’s ionization efficiency resulting in increased LC−MS2 signals f...
Treatment Implications for Young Adult Users of MDMA

Young adults' 3,4-methylenedyoxymethamphetamine (MDMA) use is a national public health concern. Although research on the epidemiology of MDMA use has increased, inquiry into intervention and treatment is needed. The authors examine results from an epidemiological investigation from a clinical perspective and provide suggestions for clinicians working with MDMA users.
Metal-catalyzed living radical graft copolymerization of butyl methacrylate and styrene initiated from the structural Defects of narrow molecular weight distribution poly(vinyl chloride)†

Poly(vinyl chloride) (PVC) prepared by the radical polymerization of vinyl chloride (VC) contains allyl chloride and tertiary chloride structural defects. The graft copolymerization initiated from the structural defects of PVC should eliminate the structural defects of PVC and, therefore, should provide novel graft copolymers that will exhibit both new physical properties and higher thermal stability than the parent PVC. The preliminary graft copolymerization experiments reported previously from our laboratory were performed with PVC with broad molecular weight distribution and did not allow kinetic experiments to be performed. Model compounds for the allyl chloride defects in PVC were used as initiators and gave almost quantitative initiation in the case of styrene (0.99), while for methacrylates the maximum initiator efficiency was only 0.40. Based on these data, the successful grafting of PVC with butyl methacrylate (BMA) and the less successful grafting of PVC with styrene were difficult to be explained. This publication reports the metal catalyzed living radical graft copolymerization experiments initiated from the structural defects of PVC with narrow molecular weight distribution. These experiments demonstrate that, contrary to the results obtained using model compounds as initiators, the structural defects of PVC provide an excellent initiation efficiency for the graft copolymerization of BMA and a less efficient initiation for the case of styrene. Under suitable reaction conditions, the initiation efficiency from the structural defects of PVC for the graft copolymer- ization of BMA can be considered to be quantitative.
Synthesis of 2-deoxy-D-arabino-(6-13C)hexose.

Abstract 2-Deoxy- d - arabino -[6- 13 C]hexose ( 10 ), to be used to test the stability of 2-deoxy- d - arabino -hexose 6-phosphate in brain tissue, was prepared. 2-Deoxy- d - arabino -hexose was labeled at C-6 because of the large difference in chemical shift between C-6 in the free sugar and C-6 in the 6-phosphate. The synthetic scheme resembled that used for the synthesis of d -[6- 13 C]glucose that involved the removal of C-6 from d -glucose followed by its replacement with 13 C. The protected derivative methyl 2-deoxy-α- d - arabino -hexofuranoside was prepared, using trifluoroacetic acid in methanol. This was treated with periodate, which cleaves only between C-5 and C-6, to afford an aldehyde which reacted directly with K 13 CN to give a mixture of the d - arabino and l - xylo nitriles. The enriched nitriles were reduced with hydrogen in the presence of 5% Pd-carbon catalyst to a mixture of 6- aldehydo sugars. These were reduced with NaBH 4 to a mixture of the two labeled methyl furanosides. Acid hydrolysis followed by ion-exchange chromatography on AG-50(Ca 2+ ) resin at 65° gave 10 in an overall yield of 16% from K 13 CN.
Factors affecting the seasonal abundance, composition and diversity of fishes in a Southeastern New England estuary

Abstract Fish communities in the Slocum River, Buzzards Bay, Massachusetts were sampled over a 2-year period. Physical variables were measured when each of the 221 seine hauls were taken. A total of 54 species representing 36 families and comprising 18 913 individuals was collected. The measures of species diversity were computed for each month and the physical and biological data were subjected to factor analysis. The Slocum River estuary is dominated by a few resident species that are common in similar habitats along the northern mid-Atlantic states. The number of individuals increased with seasonal increase of temperature but this relationship was only approximate. The mean number of species per seine haul per month was more closely associated with temperature. The reciprocal of Simpson's index, SI′, peaked during the spring and fall. The low diversity during the summer was probably due to the invasion of large numbers of a few anadromous species. The high autumn diversity is caused by invasion of a small number of several expatriate tropical species. Within the estuary salinity influences the composition and diversity of the fishes. Station 1, which was an essentially freshwater habitat, produced all of the freshwater species and station 4, which was an essentially saltwater habitat, produced mostly stenohaline saltwater species. The diversity indices were lowest at these two stations. In contrast, stations 2 and 3 varied most in salinity and tended to be the most diverse. Factor analysis further reduced the large quantity of data and somewhat simplified the handling and the interpretation of the information. The loadings per year were reasonable associations of physical and biological parameters. Temperature was overall the most important physical factor while salinity was most important within seasons. The other physical variables measured were generally intercorrelated with temperature or with salinity and had by themselves no discernible effect on the abundance, composition, or diversity of the fishes.
Reduced Fatty Acid Synthesis and Desaturation Due to Exogenous trans10, cis12-CLA in Cows Fed Oleic or Linoleic Oil

Abstract To determine effects of an elevated supply of cis 9, trans 11-18:2 (9/11CLA) or trans 10, cis 12-18:2 (10/12CLA) on de novo synthesis and desaturation of long-chain fatty acids, four Holstein cows fed high-oleic sunflower (OLE) or high-linoleic safflower oil (LIN) at 2.5% of DM were infused (0.625g/h) with 9/11CLA or 10/12CLA for 48h via the abomasum. Treatments were assigned in a 2×2 factorial design. The assigned diets were fed for 11 d before each 48-h infusion period. Milk samples were obtained at 12 and 0h before infusion and at 12-h intervals from 0 to 96h. Concentrations of trans 11-18:1 and 18:2n-6 in arterial plasma phospholipid, triglyceride, and FFA fractions were greater due to feeding LIN compared with OLE. Infused 9/11CLA and 10/12CLA were incorporated into plasma triglycerides and FFA primarily. Exogenous 10/12CLA also was found in plasma phospholipids. Milk yield and DMI were not affected by treatments. Percentages and yields of protein, lactose, and SNF in milk also were not affected by treatments. Milk fat percentage and yield, however, decreased 25% from 0 to 96h in response to infusion of 10/12CLA compared with 9/11CLA. Yields of trans 11-18:1, 9/11CLA and 18:2n-6 in milk fat before infusion were higher when LIN was fed compared with OLE. Infusion of 9/11CLA, regardless of diet, increased 9/11CLA in milk fat by 44%. Although 10/12CLA was not detectable in milk fat before infusion, it averaged 6mg/g of total fatty acids and 2g/d after 48h. At 48h, recovery in milk of infused 9/11CLA was 16% compared with 8% for 10/12CLA. Yields of saturated 6:0 to 16:0, cis 9-18:1, 9/11CLA, and 20:4n-6 were reduced by 10/12CLA infusion. Due to a 40% increase in the concentration of 18:0 by 48h of 10/12CLA infusion, however, yield of 18:0 was not affected. Ratios of cis 9-18:1/18:0, 9/11CLA/ trans 11-18:1, and 20:4n-6/18:2n-6 in milk fat decreased in response to infusion of 10/12CLA, regardless of diet. At peak concentration of 10/12CLA, reductions in cis 9-18:1 and saturated 4:0-16:0 yields accounted for 36% and 53% of the decrease in total fatty acid yield. Results indicated 10/12CLA alters lipid metabolism in the bovine mammary gland by simultaneously reducing de novo synthesis and desaturation. Furthermore, milk triglyceride synthesis may have a stringent requirement for endogenously synthesized oleic acid.
Generalized pseudospectral methods with mappings for bound and resonance state problems

Abstract Several extensions of the pseudospectral method are made and applied to the solution of bound and resonance state problems. First, an algebraic mapping is introduced to remove the singularity and the domain truncation error common to Coulomb problems. In addition, the conventional procedure is modified, leading to a more desirable symmetric eigenvalue problem instead of an unsymmetric or generalized one. The simplicity, efficiency, and accuracy of the procedures are illustrated by solving the one-electron Dirac equation. Finally a new complex-scaling pseudospectral method is introduced for resonance state problems and applied to the determination of the complex resonance energies for an anharmonic oscillator.
Infrared reflection polarizers using uniform and diffuse low-index layers buried in high-index substrates

The extinction ratio ER and the reflectance, or throughput, for the unextinguished s polarization Rs are calculated for infrared reflection polarizers that consist of a low- index transparent layer embedded in a high-index transparent substrate. Iso-ER and iso-Rs contours illustrate the dependence of the ER and Rs for a specific IR polarizer on the depth and width of a buried layer of SiO2 in Si at 3.5-micrometers wavelength and 80 degree(s) angle of incidence. Both cases of a uniform layer with sharp boundaries and a diffuse Gaussian layer are considered. The diffuse-layer model employs Bruggeman's effective medium theory and is intended to simulate devices that are fabricated by the oxygen-ion implantation of Si. The angular and wavelength sensitivities of these polarizers are determined.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Promoting Disaster-resilient Communities: The Great Sumatra–Andaman Earthquake of 26 December 2004 and the Resulting Indian Ocean Tsunami

The human casualties and socio-economic damage associated with the Great Sumatra–Andaman Earthquake of 26 December 2004 and the resulting Indian Ocean tsunami are discussed. The Sumatra–Andaman earthquake was the largest earthquake to occur since the advent of global digital seismometry and it produced the most devastating tsunami in recorded history (and the largest humanitarian response). A reliable Indian Ocean Tsunami Warning and Mitigation System is shown to require an improved seismographic network, a real-time sea-level observing network covering the entire Indian Ocean basin, and the deployment of deep-ocean pressure sensors. It is concluded that Indian Ocean governments can achieve more tsunami-resilient communities by addressing poverty, promoting education, harnessing technological advances, investing in emergency medical and rescue services, and empowering stakeholders.
Role of Glycine in the N‐Methyl‐d‐Aspartate‐Mediated Neuronal Cytotoxicity

: Current evidence indicates that glutamate acting via the N-methyl-d-aspartate (NMDA) receptor/ion channel complex plays a major role in the neuronal degeneration associated with a variety of neurological disorders. In this report the role of glycine in NMDA neurotoxicity was examined. We demonstrate that NMDA-mediated neurotoxicity is markedly potentiated by glycine and other amino acids, e.g., d-serine. Putative glycine antagonists HA-966 and 7-chlorokynurenic acid were highly effective in preventing NMDA neurotoxicity, even in the absence of added glycine. The neuroprotective action of HA-966 and 7-chlorokynurenic acid, but not that of NMDA antagonists 3-(2-carboxypiperazine-4-yl)propylphosphonate and MK-801, could be reversed by glycine. These results indicate that glycine, operating through a strychnine-insensitive glycine site, plays a central permissive role in NMDA-mediated neurotoxicity.
Subsampling Unit Root Tests for Heavy-Tailed Observations

It is shown that the subsampling methodology can be used to develop unit root tests when the noise sequence is heavy-tailed with infinite variance. Using least-squares residuals, we construct processes which approximately satisfy the null hypothesis and then, using subsampling, we approximate the null distribution of test statistics. We establish the asymptotic validity of this method and demonstrate its applicability in finite samples by means of a simulation study and a data example.
PREPARATION OF ANTIGENS SPECIFIC OF HUMAN BREAST CARCINOMA BY AN IMMUNOCHROMATOGRAPHIC METHOD.

IN spite of a rapidly mounting literature on the problem of specific antigens in human neoplasms, there have been few attempts to separate these antigens in amounts permitting biochemical and immunological analyses of the same. Such analyses not only would shed light on carcinogenic mechanisms, including possibly the serological back-tracking of eventual biological agents, but would make possible a much-desired immunological classification of tumours. Work from this laboratory has been concentrated on such efforts.
Englacial tephrostratigraphy of Erebus volcano, Antarctica

Abstract A tephrostratigraphy for Erebus volcano is presented, including tephra composition, stratigraphy, and eruption mechanism. Tephra from Erebus were collected from glacial ice and firn. Scanning electron microscope images of the ash morphologies help determine their eruption mechanisms The tephra resulted mainly from phreatomagmatic eruptions with fewer from Strombolian eruptions. Tephra having mixed phreatomagmatic–Strombolian origins are common. Two tephra deposited on the East Antarctic ice sheet, ~ 200 km from Erebus, resulted from Plinian and phreatomagmatic eruptions. Glass droplets in some tephra indicate that these shards were produced in both phreatomagmatic and Strombolian eruptions. A budding ash morphology results from small spheres quenched during the process of hydrodynamically splitting off from a parent melt globule. Clustered and rare single xenocrystic analcime crystals, undifferentiated zeolites, and clay are likely accidental clasts entrained from a hydrothermal system present prior to eruption. The phonolite compositions of glass shards confirm Erebus volcano as the eruptive source. The glasses show subtle trends in composition, which correlate with stratigraphic position. Trace element analyses of bulk tephra samples show slight differences that reflect varying feldspar contents.
Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for immune-related molecules by central nervous system mixed glial cell cultures.

Cytokines secreted within the central nervous system (CNS) are important in the development of multiple sclerosis (MS) lesions. The balance between Th1, monocyte/macrophage (M/M) and Th2 cytokines ...
Chloride transport in bullfrog gastric mucosa

Abstract Omeprazole uncouples histamine-stimulated hydrogen and chloride secretion in the frog gastric mucosa. This uncoupling results in a large increase in PD and Isc due to the unmasking of an electrogenic Cl− flux. Using a selective anoxia technique, we have attempted to define the cellular origin of this electrogenic Cl− flux. Sixteen bullfrog gastric mucosas were mounted in Ussing chambers. Under short-circuit conditions, PD, Isc, R, and unidirectional 36Cl flux were determined every 15 min. Acid secretion (10−5M histamine) was measured by hand titration (0.1 N NaOH). With both sides of the mucosas oxygenated, the addition of Omeprazole (10−4M) resulted in cessation of H+ secretion and the unveiling of an electrogenic Cl− flux. Subsequent serosal anoxia (5% CO2-95% N2 nutrient side/30% O2 secretory side) resulted in a drop in JnetCl associated with an appropriate fall in Isc. These changes were reversible with reoxygenation: ∗ . PD ∗ (mV) I sc ∗ (μeq/cm2·hr) J H+ ∗ (μeq/cm2·hr) J net Cl ∗∗ (μeq/cm2·hr) Control 18 ± 5 3.1 ± 1.1 2.0 ± 0.6 4.7 ± 2.4 Omeprazole 57 ± 4 6.5 ± 1.4 0.2 ± 0.5 5.4 ± 2.0 Anoxic GG 27 ± 8 1.2 ± 0.5 0.02 ± 0.1 1.1 ± 2.9 Reoxygenation 55 ± 4 5.2 ± 0.8 0.01 ± 0.1 4.2 ± 2.2 ∗ n = 48 ∗∗ n = 24 ; mean ± SD Bullfrog gastric mucosas which are partially oxygenated on the secretory side only (serosal anoxia) do not secrete acid in response to histamine. Therefore, the JnetCl which is inhibited in these experiments by serosal anoxia may originate in the gastric glands ≈ 3.0 μeq/cm2·hr). The JnetCl which remains during serosal anoxia may originate in the surface epithelial cells (≈ 1.0 μeq/cm2·hr).
Karst landforms and drainage basin evolution in the Obey River basin, north-central Tennessee, U.S.A.

Abstract An extensive karst landscape is developed on the Mississippian limestones of the dissected western margin of the Cumberland Plateau. Surface streams rising on the clastic rocks of the Cumberland Plateau flow down the escarpment and sink along its slopes at the upper contact of the Bangor Limestone. Some surface channels are continuous across the karst of the lower slopes while others terminate in blind valleys as swallow holes. At the base of the escarpment is an upland surface of doline karst developed in the Monteagle and St. Louis limestones at an elevation of 300–330 m. It consists of 1–5 km 2 shallow blind valleys and uvala-like closed depressions along with many smaller dolines. The internal drainage from the dolines and from the sinking streams is perched on the impermeable Warsaw Formation and emerges as contact springs on the inner gorges of the rivers which have cut deep narrow valleys below the level of the upland surface. Tributary streams to the Wolf, Obey and Roaring rivers (tributaries of the Cumberland River in north-central Tennessee) were analysed by fitting their longitudinal profiles to exponential and logarithmic functions. Linear segments of semilogarithmic plots permitted extrapolating both active streams and underdrained stream channels through the doline karst. The presently active streams extrapolated through the karst emerge at grade with the present-day base-level streams. Underdrained segments of the tributary valleys extrapolate to the upland surface and suggest that dry karst valleys can be interpreted much like river terraces. The development of interior drainage appears to be a much faster process than is the adjustment of the surface drainage.
The role of gesture in communication and thinking

Abstract People move their hands as they talk – they gesture. Gesturing is a robust phenomenon, found across cultures, ages, and tasks. Gesture is even found in individuals blind from birth. But what purpose, if any, does gesture serve? In this review, I begin by examining gesture when it stands on its own, substituting for speech and clearly serving a communicative function. When called upon to carry the full burden of communication, gesture assumes a language-like form, with structure at word and sentence levels. However, when produced along with speech, gesture assumes a different form – it becomes imagistic and analog. Despite its form, the gesture that accompanies speech also communicates. Trained coders can glean substantive information from gesture – information that is not always identical to that gleaned from speech. Gesture can thus serve as a research tool, shedding light on speakers' unspoken thoughts. The controversial question is whether gesture conveys information to listeners not trained to read them. Do spontaneous gestures communicate to ordinary listeners? Or might they be produced only for speakers themselves? I suggest these are not mutually exclusive functions – gesture serves as both a tool for communication for listeners, and a tool for thinking for speakers.
Elucidation of the Photorhabdus temperata Genome and Generation of a Transposon Mutant Library To Identify Motility Mutants Altered in Pathogenesis

ABSTRACT The entomopathogenic nematode Heterorhabditis bacteriophora forms a specific mutualistic association with its bacterial partner Photorhabdus temperata. The microbial symbiont is required for nematode growth and development, and symbiont recognition is strain specific. The aim of this study was to sequence the genome of P. temperata and identify genes that plays a role in the pathogenesis of the Photorhabdus-Heterorhabditis symbiosis. A draft genome sequence of P. temperata strain NC19 was generated. The 5.2-Mb genome was organized into 17 scaffolds and contained 4,808 coding sequences (CDS). A genetic approach was also pursued to identify mutants with altered motility. A bank of 10,000 P. temperata transposon mutants was generated and screened for altered motility patterns. Five classes of motility mutants were identified: (i) nonmotile mutants, (ii) mutants with defective or aberrant swimming motility, (iii) mutant swimmers that do not require NaCl or KCl, (iv) hyperswimmer mutants that swim at an accelerated rate, and (v) hyperswarmer mutants that are able to swarm on the surface of 1.25% agar. The transposon insertion sites for these mutants were identified and used to investigate other physiological properties, including insect pathogenesis. The motility-defective mutant P13-7 had an insertion in the RNase II gene and showed reduced virulence and production of extracellular factors. Genetic complementation of this mutant restored wild-type activity. These results demonstrate a role for RNA turnover in insect pathogenesis and other physiological functions. IMPORTANCE The relationship between Photorhabdus and entomopathogenic nematode Heterorhabditis represents a well-known mutualistic system that has potential as a biological control agent. The elucidation of the genome of the bacterial partner and role that RNase II plays in its life cycle has provided a greater understanding of Photorhabdus as both an insect pathogen and a nematode symbiont.
End-wall boundary layer prediction for axial compressors

An integral boundary layer procedure was developed for the computation of viscous and secondary flows along the annulus walls of an axial compressor. The procedure is an outgrowth and extension of the pitch-averaged methods of Mellor and Horlock. In the present work secondary flow theory is used to develop approximations for the velocity profiles inside a rotating blade row and for the blade force deficit terms in the momentum integral equations. The computer code based on this procedure was iteratively coupled to a quasi-one-dimensional model for the external inviscid flow. Computed results are compared with measurements in a compressor cascade.
Development of a chemiluminescent enzyme capture immunoassay for the detection of Escherichia coli

There has been increasing demand for rapid, sensitive and specific detection of Escherichia coli as an indicator of possible pathogen contamination in foods and water. Approximately 97% of E. coli strains produce ?- glucuronidase (GUS), which could permit the use of a specific microbial enzyme as an alternative approach for detection of E. coli. A procedure was developed for chemiluminometric measurement of GUS using a 1,2-dioxetene derivative as substrate, and was compared to the fluorescent assay for GUS detection. The chemiluminescent assay was found to be 10 times more sensitive than the fluorescent assay. Induction of GUS production in E. coli was maximum when p-nitropheny 1-?-D-glucuronide was used in the growth medium at 0.3 mM concentration after 8 h. GUS was isolated from the growth medium with a 30 minute immunocapture method at 37°C. Anti E. coli GUS antibodies were covalently immobilized on magnetic beads and used for the immunocapture assay. GUS from E. coli culture was captured using the prepared magnetic-beads. Compared to the chemiluminescent assay of GUS in culture filtrate, immunomagnetic capture of GUS provided signal increases up to 81x. The method permitted the detection of 1 CPU/ml of E. coli within 8 hours incubation in growth medium. The chemiluminescent enzyme capture immunoassay developed for the detection of GUS could serve as a quantitative indicator for the presence ofviable E. coli cells. The total assay time including growth, immunocapture and enzyme assay was 9 h.
The Knowledge-Shaping Process: Elite Mobilization and Environmental Policy:

Both using and contributing to power structure research, this article presents evidence that corporate and military elites form networks and mobilize resources to influence the development of environmental policy. This influence may be achieved when elites form and utilize knowledge-shaping processes, which involve four principle exercises of power. First, elites suppress information that may threaten their interests. Second, elites organize and fund institutions to produce and promote research that may be useful in efforts to secure their goals. Third, elites fund experts willing to attack and discredit potentially damaging research. Finally, they attempt to exert influence in knowledge administration, or in selecting what information counts as knowledge and what does not. Archival evidence is used to construct a case study of a knowledge-shaping process created to influence the national policy debate over ammonium perchlorate, the primary constituent of solid rocket fuel and a widespread water contamina...
The effect of debt for equity swaps when equity is valued as an option

Several researchers have found that the value of stock declines at the announcement of a debt for equity swap. This decline is attributed to an information effect: the firm’s financial condition is worse than the market expected. Our research develops an alternative explanation. Using the theory that equity can be valued as an option on the firm, it is shown that, depending on the exchange ratio, a debt for equity swap will cause the price of the stock to decline. This theory is tested using a sample of firms that announced debt for common equity swaps. The theoretically predicted stock price reactions are consistent with the actually observed stock price reactions. Furthermore, the contingent claims model has better explanatory power than a simple model of dilution. Tests on the sensitivity to the assumptions of the option pricing model show that only the assumption of the time to expiration of the option significantly affects the results.
Antipsychotic Treatment and Functional Connectivity of the Striatum in First-Episode Schizophrenia

Importance Previous evidence has implicated corticostriatal abnormalities in the pathophysiology of psychosis. Although the striatum is the primary target of all efficacious antipsychotics, the relationship between its functional connectivity and symptomatic reduction remains unknown. Objective To explore the longitudinal effect of treatment with second-generation antipsychotics on functional connectivity of the striatum during the resting state in patients experiencing a first episode of psychosis. Design, Setting, and Participants This prospective controlled study took place at a clinical research center and included 24 patients with first-episode psychosis and 24 healthy participants matched for age, sex, education, and handedness. Medications were administered in a double-blind randomized manner. Interventions Patients were scanned at baseline and after 12 weeks of treatment with either risperidone or aripiprazole. Their symptoms were evaluated with the Brief Psychiatric Rating Scale at baseline and follow-up. Healthy participants were scanned twice within a 12-week interval. Main Outcomes and Measures Functional connectivity of striatal regions was examined via functional magnetic resonance imaging using a seed-based approach. Changes in functional connectivity of these seeds were compared with reductions in ratings of psychotic symptoms. Results Patients had a median exposure of 1 day to antipsychotic medication prior to being scanned (mean [SD] = 4.5 [6.1]). Eleven patients were treated with aripiprazole and 13 patients were treated with risperidone. As psychosis improved, we observed an increase in functional connectivity between striatal seed regions and the anterior cingulate, dorsolateral prefrontal cortex, and limbic regions such as the hippocampus and anterior insula (P Conclusions and Relevance Our results indicated that corticostriatal functional dysconnectivity in psychosis is a state-dependent phenomenon. Increased functional connectivity of the striatum with prefrontal and limbic regions may be a biomarker for improvement in symptoms associated with antipsychotic treatment.
Theory and laboratory demonstrations on the use of a nematic liquid-crystal phase modulator for controlled turbulence generation and adaptive optics

We discuss the use of liquid-crystal phase modulators (LCPM's) both as a repeatable disturbance test source and as an adaptive optics corrector. LCPM's have the potential to induce controlled, repeatable, dynamic aberrations into optical systems at low cost, low complexity, and high flexibility. Because they are programmable and can be operated as transmissive elements, they can easily be inserted into the optical path of an adaptive optics system and used to generate a disturbance test source. When used as wave-front correctors they act as a piston-only segmented mirror and have a number of advantages. These include low operating power requirements, relatively low cost, and compact size. Laboratory experiments with a Meadowlark LCPM are presented. We first describe use of the LCPM as a repeatable disturbance generator for testing adaptive optics systems. We then describe a closed-loop adaptive optics system using the LCPM as the wave-front corrector. The adaptive optics system includes a Shack-Hartmann wave-front sensor operated with a zonal control algorithm.