cssi/SciSciGPT-SciSciNet huggingface dataset:
Novel chemical and biological fiber optic sensor

Effective response to potentially dangerous environmental situations that can arise requires accurate and real time data on the environment that is being monitored. The ability to respond in an appropriate time frame is determined by the sensitivity and response time of the method used for monitoring. Fiber optic sensors have been used and are capable of detecting chemical compounds within an environment; however the sensitivity and response time of this detection method needs to be improved for many sensing applications. Improving these characteristics can be accomplished by designing the structure of the optical fiber sensor to allow increased response time and sensitivity. Through the introduction of new structures and control of these structures, the sensitivity and response time can be designed for a specific application. We have developed a novel porous optical fiber that has potential applications in chemical and biological agent sensing systems. Sensing capabilities of the optical fiber are a result of the structure that is designed into the fiber. The structure of the fiber developed, results of characterization of the fiber and the methods of analysis employed are presented. Methods used to analyze this new fiber optic sensor include nitrogen absorption porosity data, scanning electron microscopy and optical microscopy, and optical characterizations. The structure of the optical fiber is produced by controlling the processing parameters during the fiber draw as well as post processing stages. Fabrication methods and the processing steps that are used during the fiber optic production are also presented. Effect of altering processing conditions on the sensor structure is detailed and how this affects the performance of the fiber.
Scanning electron microscopy of the subarachnoid space in the dog: Inflammatory response after injection of defibrinated chicken erythrocytes

The leptomeningeal reaction and the cerebrospinal fluid reaction of the canine inflammatory response were investigated concurrently. One-half milliliter cerebrospinal fluid (CSF) was withdrawn from the cisterna magna of 17 anesthetized mongrel dogs and analyzed. Using this same spinal tap, control and experimental animals were injected with 0.5 ml sterile saline and 0.5 ml defibrinated chicken erythrocytes, respectively. A second spinal tap was performed 2 to 168 hr later. The CSF from the first spinal tap contained less than 1 WBC/mm3. The cell population was unchanged in the second spinal tap of control animals. In experimental animals, the WBC population increased more than 100-fold by 24 hr. Polymorphonuclear cells (PMNs) appeared in the CSF first, followed by lymphocytes and monocytes. Injected erythrocytes seemed trapped in the subarachnoid space (SAS), especially in the inner sheet of the arachnoid mater. The leptomeninges had a substantial increase in free cells without fibrosis. Pial and leptomeningeal cells of the arachnoid trabeculae appeared swollen. Two hours after injection, chicken erythrocytes were phagocytosed by pial cells, macrophages, and free cells adherent to the leptomeninges. The epiplexus cell populations for saline-control and erythrocyte-experimental animals were similar, suggesting that the choroid plexuses were not a gateway for PMN, lymphocyte, or monocyte infusion into the SAS.
Calibration of Chemical Kinetic Models Using Simulations of Small-Scale Cookoff Experiments

Establishing safe handling limits for explosives in elevated temperature environments is a difficult problem that often requires extensive simulation. The largest influence on predicting thermal cookoff safety lies in the chemical kinetic model used in these simulations, and these kinetic model reaction sequences often contain multiple steps. Several small-scale cookoff experiments, notably Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), One-Dimensional Time-to-Explosion (ODTX), and the Scaled Thermal Explosion (STEX) have been performed on various explosives to aid in cookoff behavior determination. Past work has used a single test from this group to create a cookoff model, which does not guarantee agreement with the other experiments. In this study, we update the kinetic parameters of an existing model for the common explosive 2,4,6-Trinitrotoluene (TNT) using DSC and ODTX experimental data at the same time by minimizing a global Figure of Merit based on hydrodynamic simulated data. We then show that the new kinetic model maintains STEX agreement, reduces DSC agreement, and improves ODTX and TGA agreement when compared to the original model. In addition, we describe a means to use implicit hydrodynamic simulations of DSC experiments to develop a reaction model for TNT melting.
Living Arrangements, Knowledge of Health Risks, and Stress as Determinants of Health-Risk Behavior Among College Students

The association of knowledge of health risks, living arrangements, and perceived stress with health-risk behaviors was examined in a sample of college students included in the Health Promotion and Disease Prevention Supplement of the National Health Interview Survey. Regressions of each health-risk behavior (dependent variable) were performed on the predicted correlates. Although knowledge was not associated with participation in physical activity or smoking, the study found that students who knew more about the harmful effects of alcohol drank less, and those with greater knowledge of health risks practiced fewer risky behaviors. Students living independently were more likely to smoke, and those living in residence halls were less like to do so. Drinking, however, was more common among students living in residence halls or independently than among those living at home. Hall residents engaged in more group physical activity than other students did, but their physical activity was unrelated to health-risk behaviors. Stress was associated with smoking but not with other health practices. The findings suggest that smoking may be less influenced by health knowledge and more associated than drinking is with a response to stress. Drinking appears to be a social activity associated with living among peers and is potentially modifiable by increased knowledge about the effects of alcohol on health.
Control of Filament Formation in Candida albicans by the Transcriptional Repressor TUP1

The pathogenic yeast Candida albicans regulates its cellular morphology in response to environmental conditions. Ellipsoidal, single cells (blastospores) predominate in rich media, whereas filaments composed of elongated cells that are attached end-to-end form in response to starvation, serum, and other conditions. The TUP1 gene, which encodes a general transcriptional repressor in Saccharomyces cerevisiae, was isolated from C. albicans and disrupted. The resulting tup1 mutant strain of C. albicans grew exclusively as filaments under all conditions tested. TUP1 was epistatic to the transcriptional activator CPH1, previously found to promote filamentous growth. The results suggest a model where TUP1 represses genes responsible for initiating filamentous growth and this repression is lifted under inducing environmental conditions.
Diminished ingestive behavior of Fischer 344 rats following treatment with polyethylene glycol

Fluid and food intakes of Fischer 344 and Sprague-Dawley rats were compared in the 24 h after treatment with polyethylene glycol (PEG), and subjects were presented with drinking supplies of physiological saline or tap water. As in previous investigations, Fischer rats displayed relatively lower levels of ingestive behavior, a pattern that remained evident even in the longer post-PEG interval when animals drank copious amounts of the saline solution. These data therefore confirmed again that Fischer rats are more “economical” in their behavioral responsiveness, and that strain differences may exert noteworthy influences on research into the physiological controls of ingestive behavior.
Recessions and social classes: Economic impacts and political opinions

Economic classes represent groupings of individuals in terms of some long-run distribution of economic advantages. Recessions and inflations impose unequal short-run costs which may or may not be congruent with class inequalities. This paper begins with the hypothesis that the class structure channels the personal impacts of macroeconomic fluctuations and helps to explain the opinion formation process which underlies any observed political response. The empirical puzzle involves properly specifying and implementing a test of this hypothesis.
Serum lactate as a predictor of mortality in patients with infection

To determine the utility of an initial serum lactate measurement for identifying high risk of death in patients with infection. Post-hoc analysis of a prospectively compiled registry in an urban academic hospital. Patients with (a) a primary or secondary diagnosis of infection and (b) lactate measurement who were admitted over the 18 months following hospital-wide implementation of the Surviving Sepsis Campaign guideline for lactate measurement in patients with infection and possible severe sepsis. There were 1,177 unique patients, with an in-hospital mortality of 19%. Outcome measures included acute-phase (≤ 3 days) death and in-hospital death. We defined lactate ranges a priori (low, 0.0–2.0; intermediate, 2.1–3.9; high, 4.0 mmol/l or above)—and tested for linear associations with mortality by one-way analysis of variance. We determined sensitivity/specificity, odds ratios, and likelihood ratios for a lactate ≥ 4.0 mmol/l and performed a Bayesian analysis to determine its impact on a full range (0.01–0.99) of hypothetical pretest probability estimates for death. In-hospital mortality was 15%, 25%, and 38% in low, intermediate, and high lactate groups, respectively. Acute-phase deaths and in-hospital deaths increased linearly with lactate. An initial lactate ≥ 4.0 mmol/l was associated with sixfold higher odds of acute-phase death; however, a lactate level less than 4 mmol/l had little impact on probability of death. When broadly implemented in routine practice, measurement of lactate in patients with infection and possible sepsis can affect assessment of mortality risk. Specifically, an initial lactate ≥ 4.0 mmol/l substantiallyincreases the probability of acute-phase death.
Wavelength dependence of high-performance AlGaAs/GaAs waveguide phase modulators

The wavelength dependence of doped, reverse-biased channel waveguide phase modulators with very high efficiencies are reported between 1.06 ?m and 1.53 ?m. Figures-of-merit ranging from 61°/V mm and 40°/V mm to 27°/V mm and 16°/V mm for the TE and TM modes, respectively, have been obtained. By deducting the easily calculated linear electro-optic and free-carrier plasma effects, the data gives the first real measure of the dispersion associated with the shift in the absorption edge. This dispersion, which is the primary contribution to the quadratic electro-optic effect in semiconductors, accounts for more than half of the measured phase shift at 1.06 ?m with the doping level used.
Redox stratification and anoxia of the early Precambrian oceans: Implications for carbon isotope excursions and oxidation events

Abstract An updated compendium of δ13C data offer compelling evidence that δ13C positive excursions of unsurpassed magnitude in the recorded Earth history (>8‰, and up to 18‰ PDB) occurred in the early Proterozoic (the Lomagundi event). Questions whether or not these unprecedented positive δ13C shifts were contemporaneous in various basins and represent local or global events remain unresolved. The framework of major geologic events that occurred in the Paleoproterozoic argues against a Snowball Earth scenario as a backdrop to these exceptional 13C-enrichments. Substantial increases of carbon flux ratio (Fo/Fc, eight times the Phanerozoic average) and organic carbon burial rate (Fo, three times the Phanerozoic average) are required to account for the observed 13C-enrichments under steady-state and dynamic equilibrium modes, respectively. These enhanced ratios and rates are conditional on the availability of a flux of nutrients to the contemporaneous biota producers in excess of the riverine flux, and a decoupling of the P and C cycles. It is argued that these two conditions were met between 2.25 and 2.11 Ga in a redox-stratified ocean with weak upwelling and sluggish meridional surface circulation. The alternative, that the major disturbance in the terrestrial carbon cycle occurred in a rapidly ventilated ocean, is assessed as being unlikely. A large pulse of O2 equivalent to six to seven times the present terrestrial oxygen budget was rapidly scavenged and spent in the oxidation of reduced Fe and S transported to the shelves by rivers. This contention is consistent with data inferring low oxygen levels (10−5 to 10−2 PAL) in the Paleoproterozoic atmosphere and the occurrence of ocean anoxia until the late Precambrian.
A quantitative assessment of TPP-induced delayed neuropathy in the retina and lateral geniculate nucleus of the European ferret (Mustela putorius furo).

Abstract Triphenyl phosphite (TPP) has been examined extensively in our lab to assess its degenerative effects on the visual pathway of the European ferret. Tanaka et al. [Fundam. Appl. Toxicol. 22 (1994) 577; J. Toxicol. Environ. Health 58 (1999) 215] reported an age-related pattern of fiber and cell body degeneration progressing from retinal axons and lateral geniculate nucleus (LGN) neurons to the visual cortex. These studies, however, did not address whether TPP exposure results in retinal ganglion cell (RGC) degeneration, nor did they quantify the degenerative effects in the LGN. The purpose of this study was to quantify the effects of TPP on RGCs and LGN neurons. We administered single subcutaneous injections of TPP (1184 mg/kg) to 13 ferrets for histological analysis. The retinae were examined as whole-mounts and the brains sectioned parasagittally (50 μm). RGC counts from matched areas of nasal retina showed significantly fewer (21%) neurons in the TPP-treated ferrets (5d = 282 ± 52 S.D.; 7d = 284 ± 12 S.D.) compared with control (359 ± 42 S.D.). No significant difference in cell number was found in temporal retina, even though this region contained, on average, 13% fewer ganglion cells in TPP-treated ferrets (5d = 334 ± 44 S.D.; 7d = 357 ± 39S.D. versus control = 394 ± 72S.D.). The mean soma sizes and RGC cell size distributions for nasal and temporal retinae were not significantly different for any group. LGN neurons were significantly smaller (28%) than control in the TPP-treated ferrets (5d = 155 μm 2 ± 23 S.D.; 7d = 152 μm 2 ± 28 S.D. versus control = 214 μm 2 ± 9 S.D.). Cell size distributions for LGN neurons were shifted toward smaller cell sizes in both TPP-treated groups compared to control.
Long-term follow-up of aortic coarctation in infants, children and adults

We have studied 140 patients undergoing corrective surgery for aortic coarctation between 1952 and 1972, following them for a mean period of 23 years. Of the patients, 19 underwent surgery in infancy (age range 15 days to 190 days, mean 84 days), 52 during childhood, with a mean age of 11.8 years (range 1 years), and 69 as adults (age range 18−50 years, mean 30.5 years). All infants were symptomatic at presentation and fared poorly because of associated cardiac lesions. Their operative mortality was 11%, and mortality prior to discharge from hospital was 21%. Of the survivors, 38% required surgery for recurrent coarctation. There were three late deaths. Of the survivors, 90% were asymptomatic at long-term follow-up. Only six children (11%) were symptomatic at presentation. There was no operative or early postoperative mortality, and only three late deaths (6%). Of the 49 survivors, 96% were asymptomatic, and only six required antihypertensive medication. The recoarctation rate was 9% (four patients). In the group undergoing surgery as adults, 42% were symptomatic at presentation with 90% being hypertensive. There were two postoperative deaths and a late mortality of 22%, which was mainly related to the cardiovascular complications. None of the adults had suffered recoarctation, but 48% remained hypertensive. Our study confirms that the prognosis of patients with aortic coarctation presenting in infancy is related to presence of associated cardiac anomalies and operative complications. The prognosis in older patients, and particularly adults, is related to residual hypertension and resultant cardiovascular disease. Surgical correction reduces symptoms and improves life expectancy, regardless of the age at operation, with the best overall prognosis being obtained for those undergoing surgery as children.
Promoting the “Social” in the Examination of Social Stigmas

This review highlights the value of empirical investigations examining actual interactions that occur between stigmatizers and targets, and is intended to stimulate and help guide research of this type. We identify trends in the literature demonstrating that research studying ongoing interactions between stigmatizers and targets is relatively less common than in the past. Interactive studies are challenging, complex, and have variables that are sometimes more difficult to control; yet, they offer unique insights and significant contributions to understanding stigma-related phenomena that may not be offered in other (e.g., self-report) paradigms. This article presents a conceptual and empirical overview of stigma research, delineates the unique contributions that have been made by conducting interactive studies, and proposes what can be further learned by conducting more of such research.
New mode tracking methods in aeroelastic analysis

Within the context of analysis of finite element models, a methodology is developed for the tracking of complex eigenvalues and eigenvectors through changes in aeroelastic eigenvalue problems. The goal is to eliminate difficulties caused by mode switching (i.e., frequency crossing). Two new methods for mode tracking are presented and compared with an existing method. The first new method, the complex higher order eigenpair perturbation algorithm, is based on a perturbation expansion of the eigenproblem. It iteratively computes changes in the eigenpairs due to parameter perturbations with the important feature of maintaining the correspondence between the baseline and perturbed eigenpairs. The second new method is the complex cross-orthogonality check method which uses mass biorthogonality of the left and right eigenvectors to re-establish correspondence after a standard reanalysis. Applications of mode tracking technology are presented in V-g and/?^fc subsonic aeroelastic analyses. Each application procedure is outlined and examples are given. Recommendations are made based on method ease of use and robustness in the example problems.
Bile acids (BA) induce heparin‐binding EGF‐LIKE growth factor (HB‐EGF) expression in human gastroesophageal (GE) adenocarcinoma cells

Background HB-EGF, a member of the EGF family associated with tumor growth, is induced in GE cancers. BAs associated with GE reflux is a principle etiologic factor driving intestinal metaplasia and adenocarcinoma at the GE junction (GEJ). Recent studies revealed that HB-EGF is a target gene of Cdx2, a transcription factor central to the development of differentiated intestinal cells. Here, the ability of BAs to regulate HB-EGF expression in OE19 GEJ adenocarcinoma cells was examined. Methods HB-EGF expression in OE19 cells was quantified by RT-PCR, and immunoblot and promoter analyses. Results Exposure of OE19 cells to deoxycholic acid (DCA) increased HB-EGF mRNA and protein expression. DCA transcriptionally regulated HB-EGF expression, since it enhanced HB-EGF promoter-luciferase activity. Further, DCA increased Cdx2 mRNA and protein expression in OE19 cells, reflecting transcriptional regulation by NF-kB. Indeed, DCA increased NF-kB binding to and transcriptional activation of the Cdx2 promoter, while deletion of the NF-kB binding site in the Cdx2 promoter prevented these effects. Conclusions BAs promote intestinal metaplasia and neoplasia at the GEJ by activating NF-kB, inducing the ectopic expression of Cdx2 which, in turn, drives the expression of HB-EGF. Clinical Pharmacology & Therapeutics (2005) 77, P15–P15; doi: 10.1016/j.clpt.2004.11.062
Ion beam synthesis of CdS, ZnS, and PbS compound semiconductor nanocrystals

Sequential ion implantation followed by thermal annealing has been used to form encapsulated CdS, ZnS, and PbS nanocrystals in SiO{sub 2} and Al{sub 2}O{sub 3} matrices. In SiO{sub 2}, nanoparticles are nearly spherical and randomly oriented, and ZnS and PbS nanocrystals exhibit a bimodal size distribution. In Al{sub 2}O{sub 3}, nanoparticles are faceted and coherent with the matrix. Initial photoluminescence (PL) results are presented.
Reinforced thermoplastic polyimide with dispersed functionalized single wall carbon nanotubes.

Molecular π-complexes were formed from pristine HiPCO single- wall carbon nanotubes (SWCNTs) and 1-pyrene- N-(4-N′-(5-norbornene-2,3-dicarboxyimido)phenyl butanamide, 1. Polyimide films were prepared with these complexes as well as uncomplexed SWCNTs and the effects of nanoadditive addition on mechanical, thermal, and electrical properties of these films were evaluated. Although these properties were enhanced by both nanoadditives, larger increases in tensile strength and thermal and electrical conductivities were obtained when the SWCNT/1 complexes were used. At a loading level of 5.5 wt %, the Tg of the polyimide increased from 169 to 197 °C and the storage modulus increased 20-fold (from 142 to 3045 MPa). The addition of 3.5 wt % SWCNT/1 complexes increased the tensile strength of the polyimide from 61.4 to 129 MPa; higher loading levels led to embrittlement and lower tensile strengths. The electrical conductivities (DC surface) of the polyimides increased to 1 × 10−4 Scm−1 (SWCNT/1 complexes loading l...
Songs and the analysis of algorithms

In teaching a course that includes the analysis of algorithms, songs can be used as teaching examples. Multiple examples can be done at one time, or in one homework set, without the background explanation required to analyze real algorithms. Many components of algorithm analysis can be introduced using an analysis of songs. This is particularly useful at gaining experience extracting summations from "word problems."
Chloramine-T induced binding of monoclonal antibody B72.3 to Concanavalin-A

Abstract The effects of chloramine-T (CT) on monoclonal antibody B72.3 were studied with particular reference to Con-A lectin binding. After exposure to chloramine-T concentrations from 0.8 to 4.0 mg/mL (115–574 mol CT/mol B72.3), B.72.3 showed progressive binding to agarose-linked Con-A. This behavior was paralleled by decreasing immunoreactivity and increasing fragmentation and aggregation of B72.3 demonstrated by SDS-PAGE and size exclusion HPLC.
Parallel algebraic modeling for stochastic optimization

We present scalable algebraic modeling software, StochJuMP, for stochastic optimization as applied to power grid economic dispatch. It enables the user to express the problem in a high-level algebraic format with minimal boiler-plate. StochJuMP allows efficient parallel model instantiation across nodes and efficient data localization. Computational results are presented showing that the model construction is efficient, requiring roughly one percent of solve time. StochJuMP is configured with the parallel interior-point solver PIPS-IPM but is sufficiently generic to allow straight forward adaptation to other solvers.
THE UNCERTAIN FUTURE OF IDEOLOGY: Rereading Marx

A travers son histoire, l' « ideologie » (le concept et la theorie) a servi de repoussoir a la sociologie, comme un standard oppose contre lequel elle a defini son propre savoir-verite. Des lors que la science du social a entrepris depuis le milieu du siecle de changer son idee d'elle-meme et de ses methodes d'investigations, la theorie de l'ideologie a tenu lieu de registre rendant compte de ces changements. Les travaux des structuralistes et des post-structuralistes, en particulier Foucault et Althusser, ont pousse les sociologues a un profond reexamen du pouvoir et de ses effets et ont deplace la notion d'ideologie de la theorie de la fausse conscience vers une position de pratique culturelle. Pour certains, la theorie de l'ideologie est obsolete (en raison precisement de ses racines de « fausse conscience » ) ou redondante (en raison de ses liens avec la « culture » ). Malgre les merites de ces arguments, un argument provisoire en faveur de la theorie de l'ideologie est avance, et une relecture de Marx a la lumiere des evenements actuels est preconisee
Aequorin mutants with increased thermostability

Bioluminescent labels can be especially useful for in vivo and live animal studies due to the negligible bioluminescence background in cells and most animals, and the non-toxicity of bioluminescent reporter systems. Significant thermal stability of bioluminescent labels is essential, however, due to the longitudinal nature and physiological temperature conditions of many bioluminescent-based studies. To improve the thermostability of the bioluminescent protein aequorin, we employed random and rational mutagenesis strategies to create two thermostable double mutants, S32T/E156V and M36I/E146K, and a particularly thermostable quadruple mutant, S32T/E156V/Q168R/L170I. The double aequorin mutants, S32T/E156V and M36I/E146K, retained 4 and 2.75 times more of their initial bioluminescence activity than wild-type aequorin during thermostability studies at 37 °C. Moreover, the quadruple aequorin mutant, S32T/E156V/Q168R/L170I, exhibited more thermostability at a variety of temperatures than either double mutant alone, producing the most thermostable aequorin mutant identified thus far.
Protection afforded by intranasal immunization with the neuraminidase-lacking mutant of influenza A virus in a ferret model

Protective efficacy of the intranasal immunization with the neuraminidase (NA)-deficient mutant of the influenza A virus was investigated in ferrets. Despite the highly attenuated replication in vivo, the mutant completely protected the animals against the wild type virus challenge. When challenge was done with antigenic drift variants, significant reductions in the viral titers, inflammatory cell counts, and protein concentrations were observed in the nasal washes of the immunized animals. The genetically engineered NA-deficient mutant also protected animals against the challenge and induced humoral immune response against the foreign protein that replaced the NA. We conclude that the NA as antigen is dispensable in the live attenuated influenza virus vaccine and that the NA-lacking mutant can be used as a virus vector.
Results of lung volume reduction surgery in patients meeting a National Emphysema Treatment Trial high-risk criterion

Abstract Objectives A report from the National Emphysema Treatment Trial indicated that lung volume reduction candidates with a forced expiratory volume in 1 second and a diffusing capacity of carbon monoxide of 20% or less of predicted value were at high risk for mortality and were unlikely to benefit from surgical intervention. This article examines the applicability of the National Emphysema Treatment Trial findings to our own patients. Methods We reviewed 280 patients who underwent bilateral lung volume reduction surgery at our institution between January 1993 and December 2001. All patients met our selection criteria, including heterogeneous distribution of emphysema. Of these 280 patients, 20 patients had both a preoperative forced expiratory volume in 1 second and a diffusing capacity of carbon monoxide of less than or equal to 20% of the predicted normal values, thus meeting one National Emphysema Treatment Trial criterion for high risk. Outcomes of the 20 patients were assessed through 5 years after the operation. The survival of the 20 patient cohort was compared with that of the 260 patients not meeting the National Emphysema Treatment Trial high-risk criterion. Results Ninety-day operative mortality included 1 (5%) patient. In all patients the forced expiratory volume in 1 second increased from 0.46 L (17%) to 0.78 L (32%), a 73% change; the diffusing capacity of carbon monoxide increased from 16% to 27%, a 70% improvement; residual volume decreased from 6.33 L (305%) to 4.26 L (205%), a 33% improvement; and room air arterial partial pressure of oxygen increased from 55 mm Hg to 64 mm Hg. Kaplan-Meier 5-year survivals did not differ between the high-risk and non–high-risk groups. Conclusions Patients with a forced expiratory volume in 1 second and a diffusing capacity of carbon monoxide of 20% or less of predicted value might experience improvements in lung function, exercise tolerance, and quality of life with acceptable morbidity and mortality after lung volume reduction surgery.
An economic valuation of water connections under different approaches of service governance

Abstract This study investigates how households value different water sources which include in-house and yard connections to water systems. Differentials in the value of in-house and yard connections across governance approaches (municipal, private and community-managed services) are also investigated. The empirical analysis involves estimating hedonic models of stated rental prices for a large sample of urban and rural households in Guatemala. Findings indicate that urban households value municipal and private services. Conversely, urban households do not value piped water when provided by a community-managed system. Rural households seem to be more concerned about the distance of their primary source than about the type of water source.
Determination of FeCO geometry and heme rigidity in carbonmonoxyhemoglobin using femtosecond IR spectroscopy

Abstract The anisotropy of carbon monoxide hemoglobin at ambient temperatures following photolysis with 350 fs (fwhm) visible pulses was followed by monitoring the bound CO absorption bleach from 30 fs to 1 ns delays. The anisotropy was modeled assuming the porphyrin undergoes small damped harmonic oscillations about in-plane axes along and perpendicular to the projection of the CO bond onto the heme plane and expressed in terms of the protein rotational diffusion constant, the angle between the CO and the heme plane normal, the moment of inertia of the porphyrin ring, and the diffusion coefficient of the porphyrin within the protein. The anisotropy within the first 20 ps is constant at −0.170 ±0.003, while the average anisotropy from delays of 30 fs to 1 ns is nearly identical at −0.169 ±0.002 and hence it appears that the heme plane is rigidly held within the protein. The magnitude of the angle between the CO and the normal to the heme plane containing the absorption dipoles was calculated considering the fact that the heme is not a perfect circular absorber at the excitation wavelength, and was found to be 17.5° ±2.5°.
Deaf Children’s Acquisition of the Passive Voice

Ten each severely prelingually deaf boys and girls at the ages of nine–10, 11–12, 13–14, 15–16, and 17–18 years were tested for their comprehension and production of the passive voice. The comprehe...
Performance of initial full-length RHIC dipoles

The successful performance of four full-length research and development (R&D) dipole magnets for the proposed Relativistic Heavy Ion Collider (RHIC) is reported. A review is given of the dipole design, and the performance of initial prototypes is recounted. These magnets were built by a cooperative arrangement between Brookhaven National Laboratory and an industrial vendor in West Germany. The magnets reached a quench plateau of approximately 4.5 T with very reasonable 'training'. Quench data are presented along with the results of field-quality measurements. Measured field multipoles are considered to be quite acceptable for this series of R&D magnets. >
Role of oxygen radicals in phorbol myristate acetate-induced glomerular injury

Role of oxygen radicals in phorbol myristate acetate-induced glomerular injury. Phorbol myristate acetate (PMA) is known to be a potent activator of neutrophils and macrophages resulting in the generation of large amounts of oxygen-free radicals by these cells. When injected into the left renal artery of 250 to 300g male Sprague-Dawley rats, PMA caused significant proteinuria compared to control rats which received normal saline (35.4 ± 4mg/24hr in PMA treated vs. 14.1 ± 0.9mg/24hr in saline control, P 2 O 2 and/or its metabolites derived from neutrophils were important in the PMA-induced proteinuria. In contrast, superoxide dismutase (SOD) had no effect. We conclude that, following the intra-arterial injection of PMA, neutrophil-derived hydrogen peroxide and/or its metabolic products are capable of causing acute proteinuria in association with morphological alterations in glomeruli of rats. Role des radicaux oxygene sur les lesions glomerulaires induites par le phorbol myristate acetate. Le phorbol myristate acetate (PMA) est connu pour etre un activateur puissant des neutrophils et des macrophages entrainant la production de grandes quantites de radicaux libres oxygene par ces cellules. Apres injection dans l'artere renale gauche de rats mâles Sprague-Dawley de 250 a 300 g, le PMA entrainait une proteinurie significative par rapport aux rats controles qui recevaient du solute physiologique (35,4 ± 4mg/hr chez les traites au PMA contre 14,1 ± 0,9 mg/24hr chez les controles au solute sale, P 2 O 2 et/ou ses metabolites provenant des neutrophiles sont importants pour la proteinurie induite par le PMA. A l'oppose la superoxyde dismutase (SOD) etait sans effet. Nous concluons qu'apres injection intra-arterielle de PM, le peroxyde d'hydrogene provenant des neutrophiles et/ou ses metabolites sont capables d'entrainer une proteinurie aigue associee a des alterations morphologiques des glomerules de rats.
Endophyte-mediated tritrophic interactions between a grass-feeding caterpillar and two parasitoid species with different life histories

Plant secondary chemicals can alter herbivore suitability for parasitoids by weakening or stunting the host, delaying its development, or when larval parasitoids encounter ingested phytotoxins in the body of their host. Experiments with different parasitoids that exploit the same host species feeding on the same plant may provide insight about how parasitoid life history affects the strength of such interactions. The encyrtid wasp Copidosoma bakeri, a slow-developing polyembryonic egg-larval parasitoid, and the tachinid fly Linnaemya comta, a fast-developing solitary species, both parasitize Agrotis ipsilon, a generalist noctuid. We tested the hypothesis that of the two parasitoid species, the encyrtid, because of its more prolonged developmental association with the host, would suffer greater fitness costs when A. ipsilon feeds on perennial ryegrass containing an alkaloid-producing fungal endophyte. Indeed, fewer parasitized cutworms yielded C. bakeri broods, and those host mummies were smaller, formed more slowly, and contained fewer adults when the hosts fed on endophytic as opposed to endophyte-free grass. In contrast, L. comta fitness parameters were similar regardless of the type of grass upon which their host fed. Our results highlight that the outcome of endophyte-mediated tritrophic interactions may differ for different parasitoid species. Implications for integrating the use of endophytic grasses and biological control are discussed.
Regio- and stereoselective cycloadditions of dichloroketene to bridged bicyclic olefins

Abstract Dichloroketene cycloadditions to selected bridged bicyclic compounds are described. The regio- and stereochemical course of these cycloadditions is discussed.
Soil phosphorus dynamics during 17 years of continuous cultivation: A method to estimate long-term P availability

Abstract The ability to predict long-term plant-availability of soil P provides an additional management tool for sustainable agriculture. Our objective is to present a methodology using P fractionation data for predicting long-term plant-availability of soil P. Soil samples were collected (0–30 cm) in 1975, 1985, and 1992 from two continually cropped field trials. Soils were a Norfolk loamy sand and a Davidson clay loam, two Ultisols from North Carolina, USA. Four rates of P were applied from 1975 to 1986, and subsequently discontinued. The relationships between the resin and inorganic NaHCO3 fractions, and between the inorganic NaHCO3 and NaOH fractions, indicated that some level of equilibrium appeared to exist between these three fractions of soil P. Given this equilibrium condition, removal of resin P, as the most plant-available fraction, would subsequently reduce the levels of P in the inorganic NaHCO3 and NaOH fractions. Conversely, adding P as fertilizer would increase P in the resin fraction with a subsequent increase in the inorganic NaHCO3 and NaOH fractions. Although P applied as fertilizer was not completely accounted for in crop removal or net change in soil P, estimated numbers of crops based on our model for predicting available P reflected trends in yields at these two field sites. Sixteen and five crops were estimated for the Norfolk and Davidson soils, respectively. Both corn and soybean yields continued to be high on the Norfolk soil through 1992, while corn yields had declined after 1985 on the Davidson soil. Quantifying the long-term availability of soil P provides some measure of potential return on a capital investment of P fertilization in low-input agriculture.
The Reinterpretation of Political Tradition: The Catholic Roots of Jurassian Nationalism

The timing of the rise of and spatial variation in popular support for Jurassian nationalism cannot be explained by existing theories of nationalism or proposed explanations of the Jurassian case. The article argues that support for Jurassian nationalism has its roots in Catholic political traditions of antagonism toward Berne and develops an explanation grounded in a theory of discursive change. The timing of Jurassian nationalism can be explained by the decline of the salience of the religious axis of conflict in Jurassian politics, and the variation in support for nationalism can be explained by the existence within Catholic communities of discursive content that, upon the decline of religious conflict, was susceptible to reinterpretation within a nationalist frame.
Natural history of potentially lethal ventricular arrhythmias in patients treated with long-term antiarrhythmic drug therapy☆

Abstract To examine the natural history of long-term antiarrhythmic therapy in patients with benign and potentially lethal ventricular premature complexes (VPCs), 28 patients with initial efficacy with moricizine (>75% suppression of baseline mean VPCs/hr and >90% suppression of repetitive VPCs) were prospectively followed for 1 to 56 (mean ± standard deviation 25 ± 17) months. Patients were examined during baseline placebo, antiarrhythmic drug therapy and intermittent pulsedplacebo reexamination periods. The mean VPCs of all patients at baseline entry were 233 ± 47 VPCs/ hr, and after moricizine therapy 14 ± 4 VPCs/hr. Follow-up demonstrated that antiarrhythmic efficacy decreased to 75% at 12 months and to 62% at 24 months. Loss of antiarrhythmic drug efficacy most commonly occurred as a “transient” event (10 patients [36%]), and efficacy was spontaneously reestablished without a change in antiarrhythmic therapy. In contrast, increased dose titration of moricizine was necessary to reestablish antiarrhythmic suppression efficacy in 4 patients (14%), and 4 patients (14%) lost antiarrhythmic drug responsiveness during follow-up. Spontaneous decrease in baseline VPCs resulted in discontinuation of antiarrhythmic therapy in 3 patients, and increase in baseline VPCs was associated with a loss of antiarrhythmic response in 2 patients. Late proarrhythmic effects (2 patients, 7%), delayed side effects necessitating drug withdrawal (6 patients, 21%) and medical events (4 patients, 14%) occurred during 56 months of follow-up. Individual serum moricizine levels remained in the therapeutic range throughout the study and did not correlate with changes in antiarrhythmic efficacy. Both the development of time-dependent changes in spontaneous variability of VPCs and the occurrence of late clinical and arrhythmic events confound the evaluation of long-term antiarrhythmic drug therapy.
Energetic Cost and Stability during Human Walking at the Preferred Stride Frequency

The possibility that preferred modes of locomotion emerge from dynamical and optimality constraints and the energetic and dynamical constraints on preferred and predicted walking frequency are explored in this article. Participants were required to walk on a treadmill at their preferred frequency, at a frequency predicted as the resonance of a hybrid pendulum-spring model of the legs, and at frequencies +/-15%, +/-25%, +/-35% of the predicted frequency. Walking at the preferred and predicted frequencies resulted in minimal metabolic costs and maximal stability of the head and joint actions. Mechanical energy conservation was constant across conditions. The head was more stable than the joints. The joints appeared to be in service of the head in maintaining a stable trajectory. The major findings of this study suggest a complementary relationship between energetic (physiological) and stability constraints in the adoption of a preferred frequency of walking. Multiple subsystems may be involved in constraining observed macroscopic behavior in intact biological systems. The approach and results of the study imply that a useful tack in understanding how dynamical control structures arise is to study the potential criteria that serve to act as constraints on skilled movement patterns in unimpaired and impaired populations.
Functionalization of polyesters with maleic anhydride by reactive extrusion

Maleic anhydride (MAn) was grafted onto aliphatic and aromatic/aliphatic copolyesters by reactive extrusion in the presence of a free radical initiator using a twin-screw extruder. The grafting reaction was confirmed by spectroscopic analyses. The presence of succinic anhydride groups was shown by FT-IR spectroscopy, and NMR spectra indicate that the grafts consist of single succinic anhydride units. The 2D 1H-NMR spectra (COSY) indicate that grafting reactions take place at aliphatic dicarboxylic acid units of copolyesters. The graft content was determined by a nonaqueous titration method. The effects of concentration of initiator and monomer and reaction temperature on the graft content and intrinsic viscosity were studied. The low percentage grafting in poly(lactic acid) was observed due to the presence of limited free radical sites in the polymer backbone. Temperature and monomer and initiator concentrations affect the graft content, and the desired graft content with minimal degradation can be obtained by controlling these factors. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1693–1702, 1999
A scatter propagation experiment using an array of six paraboloids

Using an antenna system whose aperture could be varied in four-foot steps between 4 and 24 feet, aperture-to-medium coupling loss measurements have been made on a 2720-msec, 216- mile path. These measurements reveal an intrinsic variability in the scattering mechanism which is not accounted for in most current theories. Diversity and fading-rate measurements were also made. A simple mathematical model of the diffracted field yields calculated values of the normal component of the wind which agree well with the measured wind. Calculated and measured values of fading rate are also seen to be in good agreement. An estimate is made of the turbulent wind velocity.
Drug delivery of antisense oligonucleotides or peptides to tissues in vivo using an avidin–biotin system

AbstractThe pharmacologic efficacy of antisense oligonucleotide- or peptide-based therapeutics in intact organisms is limited by the poor transport of these highly charged molecules across cellular membranes. Since recent studies have shown that avidin, a cationic protein, is taken up by cells via absorptive-mediated endocytosis, the present studies examine whether the avidin-biotin system may be used to develop soluble transport vectors that mediate the organ uptake in vivo of monobiotinylated antisense oligonucleotides or peptides. The model antisense oligonucleotide used is a 21-mer complementary to the bovine GLUT1 glucose transporter mRNA, and the model peptide used is [desamino-Cys1, d-Lys8]lysine vasopressin (DDLVP). The antisense oligonucleotide was bound to avidin with a noncleavable biotin linker using N-hydroxysuccinimidobiotin, and the DDLVP was coupled to the avidin vector with a cleavable biotin linker using sulfosuccinimidyl - 2 - (biotinamido) ethyl -1, 3 - dithiopropionate. Pharmacokineti...
Mechanistic Considerations of Bending‐Strain Effects within Organic Semiconductors on Polymer Dielectrics

The development of organic transistors for flexible electronics requires the understanding of device behavior upon the application of strain. Here, a comprehensive study of the effect of polymer-dielectric and semiconductor chemical structure on the device performance under applied strain is reported. The systematic change of the polymer dielectric results in the modulation of the effects of strain on the mobility of organic field-effect transistor devices. A general method is demonstrated to lower the effects of strain in devices by covalent substitution of the dielectric surface. Additionally, the introduction of a hexyl chain at the peripheries of the organic semiconductor structure results in an inversion of the effects of strain on device mobility. This novel behavior may be explained by the capacitative coupling of the surface energy variations during applied strain.
The Optical Environment Of The Earth As Seen From Space

Space Physics LaboratoryThe Aerospace CorporationThe development of satellites has permitted many optical experimentswhich hitherto were impossible. Our understanding of the world welive in has undergone a rapid and exciting development. It is my purposein this report to discuss certain aspects of the optical radiation whichwould be seen by a satellite, with emphasis on what can be learned bylooking at the earth itself. Illustrations will include a number ofexperiments carried out by members of our laboratory in the AerospaceCorporation.Even though the sun is the brightest source of light near the earth,the solar radiation intercepted by the earth must ultimately be reemittedin order to maintain a heat balance. Hence the earth also is a strongsource of radiation. The mean earth albedo is about 30 %; 70% of theenergy is absorbed, to reappear in a form which is characteristic, notof the sun, but of the earth. We can learn a great deal about the opticalproperties of the earth from studies of the reflected and the emittedradiations. Before considering this, however, it is necessary to brieflyreview the characteristics of the solar irradiance.At various times during the past half century attempts have beenmade to measure the spectral distribution of the solar radiation, and itsintegral, the solar constant. The most recent, and most extensive measure-ment was reported about a year ago by a team from Goddard Space Flight Center.1This group carried out a series of measurements with a battery of instru-ments in a high flying aircraft. The altitude of flight permitted themto be above most of the haze, dust, and moisture which are highly variablein the atmosphere and hence difficult to correct for. The solar spectrum