cssi/SciSciGPT-SciSciNet huggingface dataset:
Optically based-indentation technique for acute rat brain tissue slices and thin biomaterials

Currently, micro-indentation testing of soft biological materials is limited in its capability to test over long time scales due to accumulated instrumental drift errors. As a result, there is a paucity of measures for mechanical properties such as the equilibrium modulus. In this study, indentation combined with optical coherence tomography (OCT) was used for mechanical testing of thin tissue slices. OCT was used to measure the surface deformation profiles after placing spherical beads onto submerged test samples. Agarose-based hydrogels at low-concentrations (w/v, 0.3–0.6%) and acute rat brain tissue slices were tested using this technique over a 30-min time window. To establish that tissue slices maintained cell viability, allowable testing times were determined by measuring neuronal death or degeneration as a function of incubation time with Fluor-Jade C (FJC) staining. Since large deformations at equilibrium were measured, displacements of surface beads were compared with finite element elastic contact simulations to predict the equilibrium modulus, μ∞. Values of μ∞ for the low-concentration hydrogels ranged from 0.07 to 1.8 kPa, and μ∞ for acute rat brain tissue slices was 0.13 ± 0.04 kPa for the cortex and 0.09 ± 0.015 kPa for the hippocampus (for Poisson ratio = 0.35). This indentation technique offers a localized, real-time, and high resolution method for long-time scale mechanical testing of very soft materials. This test method may also be adapted for viscoelasticity, for testing of different tissues and biomaterials, and for analyzing changes in internal structures with loading. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
EFFECT OF EXCHANGE-CORRELATION FUNCTIONALS AND SYMMETRY CONSTRAINTS OF ELECTRONIC STRUCTURE ON THE TRAJECTORIES OF REACTIVE MOLECULAR COLLISIONS

Two computationally efficient implementations of first-principles molecular dynamics are examined using the reactive scattering of two linear ozone molecules to yield three molecules of oxygen. These methods are based on Kohn-Sham density-functional theory in which the charge density is fitted variationally. The linear combination of Gaussian-type orbitals approach is used to construct the orbital and local-potential basis sets. The first method is a completely general approach requiring variational fitting of the exchange-correlation energy density on a grid of points. The second method avoids the grid of points, but is restricted to the $X\ensuremath{\alpha}$ functional. Key elements of the dynamics calculation include self-consistent-field convergence at each time step, use of fractional occupation numbers to model the configurational mixing that occurs upon bond formation or dissociation, and accurate analytic evaluation of the appropriate forces acting upon the nuclei. Trajectories computed using modern local-density and gradient-corrected functionals, as well as $X\ensuremath{\alpha}$ $(\ensuremath{\alpha}$ = 0.6667) treated analytically, are compared. It is found that reactive trajectories obtained using analytic $X\ensuremath{\alpha}$ and the generalized gradient approximation are very similar when the initial kinetic energy is well above threshold for reaction. Under similar conditions, trajectories resulting from use of modern local-density functionals exhibit somewhat distinctive behavior. These results suggest that the particularly efficient analytic $X\ensuremath{\alpha}$ approach is suitable for preliminary investigations of chemical reactions using first-principles molecular dynamics based on density-functional theory.
The Role of Body Weight in Oral Contraceptive Failure: Results from the 1995 National Survey of Family Growth

Purpose Many unintended pregnancies occur in women who use contraception. We conducted this study to determine if increasing body weight is associated with oral contraceptive (OC) failure. Methods This retrospective cohort study consists of the 1916 women who reported using OCs in January 1993 and provided complete covariate information on the 1993 National Health Interview Survey and 1995 National Survey of Family Growth. Body weight and body mass index (BMI) were self-reported in 1993. The outcome was defined to be any conception occurring in women reporting OC use during the month of conception. Cox proportional hazards models were used to model the body weight/BMI–OC failure association. Results Women with a BMI ≥ 30 had a statistically significant increased risk of having an OC failure as compared to women with BMIs of 20 to 24.9 (HR = 1.80, 95% CI, 1.01, 3.20). However, after adjustment for age, marital status, education, poverty, race/ethnicity, parity, and dual method use, this increased risk was attenuated and no longer statistically significant (HR = 1.51, 95% CI, 0.81, 2.82). Increasing body weight was not associated with an increased risk of OC failure in the unadjusted or adjusted models. Conclusions We did not find a strong or statistically significant association between increasing body weight/BMI and OC failure among this population of women. Prospective studies specifically designed to examine this association are needed to determine if heavier women should be advised to use a contraceptive method other than OCs to prevent pregnancy.
Out-of-home placement for young children with developmental and medical conditions

Abstract The impact of the developmental and health problems of young children on child welfare outcomes is studied using 1999 AFCARS data that reports on children in foster care throughout the United States. Study findings indicate that developmental and health problems are associated with higher numbers of out-of-home placements, longer stays in foster care, decreased likelihood of return to parental care, and higher foster care costs. Study findings are interpreted as indicating a need for more research on how young children with developmental and medical conditions are managed within the child welfare system.
DOPA-Mediated Self-Assembled Biocompatible Plasmonic Nanocrystals

Biocompatible plasmonic nanocrystals provide scattering, absorptive, and luminescent contrast for bioimaging, and act as photothermal therapeutic agents. We report DOPA-mediated self-assembly and surface stabilization of gold and silver nanoparticles with potentially functionalized PEG polymers.
Blood chemistry of healthy, nephrocalcinosis-affected and ozone-treated tilapia in a recirculation system, with application of discriminant analysis

Blood chemistry parameters of Nile tilapia (pure strain Oreochromis niloticus) raised in a recirculation system were studied. Plasma samples were collected from 30 healthy tilapia every 3 months during a 1-year period. An additional 30 tilapia affected with nephrocalcinosis, and 30 fish from a system treated with ozone were also examined. Significant differences among healthy groups were observed in all parameters except for plasma magnesium, iron, albumin-to-globulin ratio, glucose, cholesterol, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphotase (AP) and creatine kinase (CK) activities. Nephrocalcinosis-affected tilapia differed significantly from healthy fish in most electrolyte and metabolite concentrations, as well as in ALT, AST and AP activities. Ozone-treated fish showed significant differences in electrolyte concentrations and ALT, AST and AP activities. Discriminant analysis revealed good separation of these groups. Evaluation of the data set indicated that the number of blood chemistry parameters could be reduced from 23 to 9 without losing the ability to separate the groups (90% and 92% correct, respectively). Most of the incorrect prediction came from less satisfactory separation of ozone-treated fish from healthy fish, due to the lack of apparent adverse impact on health of this treatment. Thirty tilapia from the same facility that were experiencing a low mortality rate were also used to test the model; individuals with abnormal blood chemistry profiles were identified.
1083 DIFFUSION OF MOXALACTAM INTO CSF OF CHILDREN WITH BACTERIAL MENINGITIS

Moxalactam (MOX), a new oxa-β-lactam antibiotic,is active against an expanded spectrum of gram negative organisms including Haemophilus influenzae. It has also been reported to diffuse into cerebrospinal fluid. We administered IV MOX to children (6 wks-4½ yrs) receiving conventional antimicrobial therapy for bacterial meningitis. Plasma and CSF specimens were collected 2 to 3 hours after a dose and assayed for MOX concentration by HPLC (capable of detecting 1 μg/ml of MOX). Eight patients received single doses of 15 or 25 mg/kg. In 11 determinations the plasma levels ranged between 4.7 and 29.4 μg/ml but MOX was detected in the CSF in only one instance. Eight patients received 50 mg/kg of MOX every 8 hours for 3 doses, and in 5 patients the drug diffused into CSF. MOX was detectable in 3/5 of CSF specimens early in the course of illness (2nd or 3rd day) and averaged 20% (range 2.5 to 30%) of plasma concentration. It was detectable in 5/11 of CSF specimens obtained later in the illness (13th to 22nd day) and averaged 15.7% (6 to 36%) of plasma concentration. There was no correlation between the diffusion of MOX into CSF and the CSF white cell count, however MOX diffused to a greater extent in patients with higher CSF protein content. In summary, MOX diffuses into CSF but such diffusion is unpredictable. Caution must be exercised in using MOX alone in the treatment of meningitis.
The Psychophysiology of the DSM-IV Classification of Attention Deficit Hyperactivity Disorder in Children - A Pilot Study 53

ABSTRACT. Background: According to the DSM-IV there are three subtypes of Attention Deficit Hyperactivity Disorder (ADHD): ADHD, Predominantly Inattentive Type (ADHD-I), ADHD, Combined Type (ADHD-C), and ADHD, Predominantly Hyperactive-Impulsive Type (ADHD-H/I). The central nervous system physiological distinctions between these categories remain unclear.
Comparison of tidal ventilation and high-frequency jet ventilation before and after cardiopulmonary bypass in dogs using two-dimensional transesophageal echocardiography

This study compared the use of high-frequency jet ventilation (HFJV) and tidal ventilation (TV) in a group of dogs with induced global myocardial ischemia before and after cardiopulmonary bypass. Transesophageal echocardiography was used to determine whether HFJV with its lower airway pressures could improve cardiac performance. The surgical procedure was separated into four study periods: closed chest before bypass, open chest before bypass, open chest after bypass, and closed chest after bypass. During each of these study periods, the dogs were randomly ventilated with alternate periods of TV and HFJV to maintain the PaCO2 at 34.3 +/- 3.3 mm Hg (mean +/- SEM). Cardiac output, stroke volume, systemic mean blood pressure, left ventricular ejection fraction, left ventricular end-diastolic volume, left ventricular dP/dt, left ventricular stroke work, and expiratory volumetric flows were higher during HFJV, whereas airway pressures and pulmonary vascular resistance were lower. Increases in cardiac output and stroke volume during HFJV were due to a combination of improved left ventricular contractility indicated by increased LV dP/dt and increased left ventricular end-diastolic volume accompanying decreased airway pressures. These data indicate that HFJV with its lower airway pressure is associated with significantly less impairment of cardiovascular function than TV in dogs with induced global myocardial ischemia.
Wedged geomembrane tubes as temporary flood-fighting devices

Abstract Sandbags are often used to hold back floodwaters. Recently, water-filled tubes have been introduced as an alternative temporary flood barrier. Some failures have occurred due to rupture or excessive movements. The results of a numerical investigation of these tubes are presented here, along with some test results. The two-dimensional analysis uses the finite-difference program FLAC. The cross-section of the tube is modeled with beam elements, and the Mohr–Coulomb soil model is adopted. External water of varying heights is applied on one side of the tube, and a wedge is placed on the downstream side to inhibit rolling or sliding. The cross-sectional deformations, underseepage flow rates, and pore pressure beneath the tube are determined, along with the critical floodwater height. The numerical results compare well with those from the experiments. This research demonstrates that water-filled tubes can provide an effective alternative to sandbags for holding back floodwaters.
The paths to rain forest destruction: Crossnational patterns of tropical deforestation, 1975–1990

Abstract Recently published, crossnational data on tropical deforestation vary in quality, but with appropriate safeguards they can be used to analyze the causes of tropical deforestation. We use these data to assess the major explanations for tropical deforestation during 1975–1990. One set of explanations, which we label frontier theory, identifies entrepreneurs, companies, and small farmers, working in concert, as the chief agents of deforestation. A second set of explanations, which we call immiserization theory, attributes most deforestation to expanding peasant populations who have few other economic opportunities and therefore decide to clear additional land for agriculture. The quantitative analysis suggests that frontier theory described deforestation in places with large forests and immiserization theory describes deforestation in plates with small forests. Policies to reduce deforestation should vary in their effectiveness depending on which of these two processes predominates in a place.
Linearization of families of vector fields

(3) Thus a,(O) = 0, and at the origin the Jacobian matrix of a, can be found from (3), ai. = A*-‘(O) A&,(O). 0 ne may take A,(O) = Z and ai* = Ai. Let L = {A,,***,Ak}LA, the real Lie algebra generated by the matrices A i, and 9 = {a, ,..., ukILA, the Lie algebra of vector fields on R” generated by the a,. Correspondence (3) preserves the Lie bracket, so that A i -+ a, gives an algebra isomorphism of the generated Lie algebras. In this case 9 is said to be faithful to its linear Lie algebra
Interaction of aromatic hydrocarbons and drugs with adrenal microsomal cytochrome P-450 in the guinea pig.

Abstract Addition of simple aromatic hydrocarbons (benzene, ethylbenzene, naphthalene) to guinea pig adrenal microsomes produced typical Type I difference spectra (ΔOD 385-420 ). Spectral dissociation constants ( K s ) for each indicated a far higher affinity for adrenal than hepatic cytochrome P-450. Hydrocarbon affinities for adrenal cytochrome P-450 were similar to that for progesterone, an endogenous steroid substrate. Ethylmorphine and aniline produced Type I and Type II spectral changes respectively in adrenal microsomes. The K s , and magnitude of spectrum for each in adrenals was similar to that in livers. Nonetheless, demethylation of ethylmorphine proceeded far more rapidly in adrenal than hepatic tissue. The Michaelis constants ( K m ) for ethylmorphine metabolism in both tissues were similar. Although the aniline-induced difference spectra in adrenal and hepatic microsomes did not differ substantially, aniline hydroxylase activity was far greater in liver. Pretreatment of guinea pigs with phenobarbital or 3-methylcholanthrene increased hepatic but not adrenal ethylmorphine metabolism. Spironolactone pretreatment, in contrast, did not affect hepatic metabolism, but significantly lowered adrenal demethylase activity. The results indicate a relative non-specificity of guinea pig adrenal microsomal cytochrome P-450 and suggest that the adrenal cortex may represent a significant site for the extra-hepatic metabolism of foreign compounds in the guinea pig.
Secreted Gaussia luciferase as a biomarker for monitoring tumor progression and treatment response of systemic metastases.

Background Currently, only few techniques are available for quantifying systemic metastases in preclinical model. Thus techniques that can sensitively detect metastatic colonization and assess treatment response in real-time are urgently needed. To this end, we engineered tumor cells to express a naturally secreted Gaussia luciferase (Gluc), and investigated its use as a circulating biomarker for monitoring viable metastatic or primary tumor growth and their treatment responses. Methodology/principal findings We first developed orthotopic primary and metastatic breast tumors with derivative of MDA-MB-231 cells expressing Gluc. We then correlated tumor burden with Gluc activity in the blood and urine along with bioluminescent imaging (BLI). Second, we utilized blood Gluc assay to monitor treatment response to lapatinib in an experimental model of systemic metastasis. We observed good correlation between the primary tumor volume and Gluc concentration in blood (R(2) = 0.84) and urine (R(2) = 0.55) in the breast tumor model. The correlation deviated as a primary tumor grew due to a reduction in viable tumor fraction. This was also supported by our mathematical models for tumor growth to compare the total and viable tumor burden in our model. In the experimental metastasis model, we found numerous brain metastases as well as systemic metastases including bone and lungs. Importantly, blood Gluc assay revealed early growth of metastatic tumors before BLI could visualize their presence. Using secreted Gluc, we localized systemic metastases by BLI and quantitatively monitored the total viable metastatic tumor burden by blood Gluc assay during the course of treatment with lapatinib, a dual tyrosine kinase inhibitor of EGFR and HER2. Conclusion/significance We demonstrated secreted Gluc assay accurately reflects the amount of viable cancer cells in primary and metastatic tumors. Blood Gluc activity not only tracks metastatic tumor progression but also serves as a longitudinal biomarker for tumor response to treatments.
An Application of Concomitant Measurements for Two-Phase Flow of Air-Water Mixture in Minichannels

The complex nature of two-phase flow itself creates obstacles in detecting, monitoring and description of flow patterns, which are directly related to spatial and temporal distributions of concentration in the mixture. In addition to this, difficulties in comparing results and noticed differences in reported results generated in different experiments require more extensive research toward finding a satisfactory explanation. Because of both high significance and difficulties in measurement of in-situ parameters including concentration measurements and existence of significant differences in the published results, one possible approach to reduce the differences is to conduct a comparative study of the measurement properties of the concomitant measurement systems for the same flow conditions (identical time and space). This reported experimental study focuses on the comparison of two different concentration measurement methods (capacitive and conductive system) including the determination of concomitancy for those two systems. In this investigation, a Computer Aided Experimentation System (CAES) is used to generate a broad range of flow conditions and flow patterns, where the in-situ concentrations are measured simultaneously in the same time and space for air-water heterogeneous mixture flow. Based on the in-situ concentration measurements (full range of concentration) from both capacitive and conductive systems, a direct comparison between the results is presented and the concomitancy between the two systems is determined.Copyright © 2005 by ASME
The Digital Divide and Managing Workforce Diversity: A Commentary

Aux Etats-Unis, les minorites sont nettement en-dessous de la moyenne nationale dans l’occupation des emplois relevant des technologies de l’information et autres industries high-tech. D’un point de vue plus global, l’embauche de gens de couleur provenant d’Afrique, du Pakistan, d’Inde ou du Bengladesh pose egalement probleme au Royaume Uni et dans les autres pays de l’union europeenne. En clair, il faut inverser ces patriques. Les auteurs examinent ces faits et d’autres donnees de partage numerique dans une perspective de diversiteelargie de la main-d’œuvre et proposent un modele de croissance lente destinea centrer l’attention du lecteur sur les moyens de traiter les inegalites dans la hierarchic des technologies de l’information. In the US, minorities lag far behind the national average in holding jobs in the information technology and other high-tech industries. On a broader global perspective, employment of persons of color of African, Pakistani, West Indian, and Bangladeshi origin in the United Kingdom and elsewhere in the European Union countries is also problematic. Clearly, these trends need to be reversed. The authors examine these and other digital divide issues from a global workforce diversity perspective and propose a trickle-up model to focus the reader's attention on ways to address inequities in the information technology value chain.
The extinction of slowly-varying nonadiabatic flames

Abstract Using the techniques of large activation energy asymptotics, we observe that a slowly-varying planar nonadiabatic flame will extinguish (1) as the burning rate approaches zero, rather than at finite burning rate as predicted by the steady theory, and (2) at a finite position, when subjected to a wide class of external stimuli. An example is given in which the external stimuli arises from either fuel or concentration variations ahead of the flame.
Alternative Strategies for Transitioning to Organic Production in Direct-Seeded Grain Systems in Eastern Washington I: Crop Agronomy

Organic grain production is not common to eastern Washington, but offers attractive market opportunities if systems can be developed that are compatible with regional production constraints. Erodible soils make tillage-intensive systems unsustainable, and there are limited alternative fertility options. Given these constraints, the objective of this study was to evaluate nine cropping systems during the transition to organic grain production under reduced tillage and relying on legumes as the primary source of crop nitrogen. The experimental transition systems ranged in the degree in which legume grain crops or legume green manures/forages were present in the rotation. We found that spring pea grown for grain to be a poor choice for organic production due to the susceptibility of this crop to insect pests and weeds, which generally resulted in crop failure. Likewise, bell bean was poorly suited as a legume green manure crop due to its low productivity in our region. In contrast, alfalfa and winter pea-bas...
Self-assembly of a semi-fluorinated diblock copolymer in a selective solvent

The self-assembly of a highly incompatible siloxane containing semi-fluorinated diblock copolymer, polytrifluoro propyl methylsiloxane-b-polystyrene (SiF-PS), in toluene, a selective solvent for polystyrene, was studied using Small Angle Neutron Scattering. Incompatibility is often enhanced by inserting fluorinated segments into one of the blocks and as a result not only the interchain interactions are changed but also the rigidity of the blocks. Herein the incorporation of siloxane into the backbone of a semi-fluorinated block maintains its flexibility and allows separation of the effects of direct interactions due to fluorine atoms from those of rigidity. Measurements were carried out in dilute solutions below 1 wt%, at volume fractions ϕSiF ranging from 0.0 to 0.5. The high incompatibility of the SiF block drives aggregation at low volume fractions of the SiF block, where spherical core–Gaussian shell aggregates are detected at ϕSiF = 0.16. In the symmetric SiF-PS complex fluid, elongated micelles were observed. The micelles exhibited unique temperature stability in comparison with the aggregates formed by diblock-copolymers in the lower segregation regime. As the temperature increases the micelles dissociate into free chains to form unimolecular micelles.
What Do People Want to Feel and Why? Pleasure and Utility in Emotion Regulation

It is typically assumed that people always want to feel good. Recent evidence, however, demonstrates that people want to feel unpleasant emotions, such as anger or fear, when these emotions promote the attainment of their long-term goals. If emotions are regulated for instrumental reasons, people should want to feel pleasant emotions when immediate benefits outweigh future benefits, but when future benefits outweigh immediate benefits, people may prefer to feel useful emotions, even if they are unpleasant. In this article, I describe an instrumental account of emotion regulation, review empirical evidence relevant to it, and discuss its implications for promoting adaptive emotional experiences.
Activation of constitutive nitric-oxide synthase activity is an early signaling event induced by ionizing radiation.

Ionizing radiation at clinical dose levels activates both pro- and anti-proliferative signal transduction pathways, the balance of which determines cell fate. The initiating and amplifying mechanisms involved in the activation are poorly understood. We demonstrate that one mechanism involves stimulation of constitutive nitric-oxide synthase (NOS) activity. NOS activity of Chinese hamster ovary cells was measured by the arginine → citrulline conversion assay. Irradiation stimulated a transient activation of NOS with maximal activity at 5 min of post-irradiation. Western blot analysis and genetic manipulation by overexpression of wild type or dominant negative NOS mutant identify the radiation-induced isoform as NOS-1. Further evidence that NOS-1 is activated by radiation was the demonstration of radiation-induced cGMP formation in cells transiently transfected with the NO-dependent soluble guanylate cyclase. Protein Tyr nitration, a footprint of peroxynitrite formation, followed radiation exposure and was inhibited by expression of a dominant negative NOS-1 mutant. Radiation-induced ERK1/2 kinase activity, a cytoprotective response to radiation, was also blocked by inhibiting NOS activity. These experiments establish NO-dependent signal transduction pathways as being radioresponsive. Given the lipophilic and relatively stable properties of NO, these results also suggest a possible mechanism by which ionization events in one cell may activate signaling processes in adjacent cells.
Rate adaptation in visual MIMO

We propose a rate adaptation scheme for visual MIMO camera-based communications, wherein parallel data transmissions from light emitting arrays are received by multiple receive elements of a CCD/CMOS camera image sensor. Unlike RF MIMO, multipath fading is negligible in the visual MIMO channel. Instead, the channel is largely dependent on receiver perspective (distance and angle) and visibility issues (partial line-of-sight availability and occlusions). This allows for slower adaptation but requires the adaptation algorithm to choose among a more complex set of modes. In this paper, we define a set of operating modes for visual MIMO transmitters and propose a rate adaptation scheme to switch between these modes. Our Visual MIMO Rate Adaptation (VMRA) is a packet based rate adaptation protocol that bases its rate selection decisions on the packet error rate feedback. Using trace-based simulation results for a vehicle-to-vehicle communication scenario, we illustrate how our VMRA algorithms can adapt over distance as well as visibility variations in an optical link and achieve a higher average throughput.
Distinct mycorrhizal communities on new and established hosts in a transitional tropical plant community

The extent to which interspecific plants share mycorrhizal fungal communities depends on the specificity of the symbiosis. For tropical forest tree seedlings, colonization by mycorrhizal fungi associated with established vegetation could have important consequences for survival and growth. I used a novel molecular technique to assess the potential for sharing of mycorrhizas in forest and pasture in southern Costa Rica, by identifying arbuscular mycorrhizal (AM) fungi in roots of the forest canopy tree species Terminalia amazonia, pasture grasses Urochloa ruziziensis and U. decumbens, and seedlings of T. amazonia planted into experimental reforestation plots. I tested the hypotheses that experimental seedlings were colonized either by the AM fungal community of the forest T. amazonia (suggesting host specificity) or of Urochloa (suggesting absence of specificity/importance of local environment). After two years, pasture-grown T. amazonia seedlings were colonized by neither community, but rather by a species of Glomus that was rarely observed on the other plants. These results suggest that conspecific seedlings planted into existing vegetation generate a distinct mycorrhizal community that may influence competitive interactions and the relative costs and benefits of the AM fungal symbiosis at early stages in the life cycle of tropical trees.
Pre- and postexposure protection against human immunodeficiency virus type 1 infection mediated by a monoclonal antibody

Monoclonal antibody BAT123 was passively transferred into SCID mice reconstituted with human peripheral blood lymphocytes (hu-PBL-SCID) to study passive antibody protection against human immunodeficiency virus type 1 (HIV-1) infection. BAT123 is specific for the third variable loop of the gp120 of HIV-1LAI. Animals were protected against subsequent infection with LAI strain, but not other virus strains, when BAT123 (1 mg/kg; 25 micrograms/mouse) was given 1 h before virus inoculation. This resulted in a peak serum concentration of 16 micrograms/mL of the antibody, which should be easily attainable in humans. In addition, postexposure protection was observed when the antibody was given within 4 h of virus inoculation. No therapeutic effect was observed, however, when BAT123 was administered after infection had been established. These results indicate that passive antibody prophylaxis against HIV-1 infection may be possible in certain clinical situations.
The state of research within managed care plans: 1997 survey

The growing need for information about managed care and for the use of managed care organization (MCO) members in clinical and health services research requires research capability within MCOs. To learn the extent to which such capability exists, we conducted a survey of readily identifiable MCO research programs. Responses were obtained from twenty of twenty-three eligible organizations. Although there is great variability in size, these organizations have a collective budget of $93 million, more than 158 career researchers, and extensive research infrastructure and applied research activities.
Noncontact electro-optic sampling with a GaAs injection laser

30 ps pulses from a diode laser have been used to perform noncontact electric field measurements using a versatile `finger probe? electro-optic sampling technique.
Tseitin's tautologies and lower bounds for Nullstellensatz proofs

We use the known linear lower bound for Tseitin's tautologies for establishing linear lower bounds on the degree of Nullstellensatz proofs (in the usual boolean setting) for explicitly constructed systems of polynomials of a constant (in our construction 6) degree. It holds over any field of characteristic distinct from 2. Previously, a linear lower bound was proved for an explicitly constructed system of polynomials of a logarithmic degree.
Polymerization and copolymerization of α‐methacrylophenone

Under a variety of conditions it has not been possible to induce the free-radical-initiated homopolymerization of α-methacrylophenone (α-MAP). The only product isolated from such efforts was the Diels-Alder dimer of the monomer. A Mayo-Lewis plot of the free-radical copolymerization of α-MAP and styrene shows considerable scatter but the copolymer composition indicates that an α-MAP unit can add to itself. These results have been ascribed to a penultimate effect. α-MAP is homopolymerized by dimsylsodium or n-butyllithium. Attempted copolymerization of α-map and styrene with n-butyllithium produces >95% α-MAP. Unexpectedly, α-MAP does not homopolymerize with lithium dispersion, but does react in the presence of styrene to give product containing a relatively small amount of α-MAP.
Self-Sensitivity in Fetal Development

It is an inconvenient truth that the onset of behavior is before birth. In all the mammalian species, for example, behavior begins in utero, hidden within the mother’s body. This simple bit of biology has made it difficult to observe or to access fetuses, leaving the beginnings of behavior to the imagination or, even worse, allowing it to be forgotten or ignored. Such truncation of perspective probably helped many to consider behavioral capabilities first seen at birth in a separate, special category termed inborn or “innate.” Gradually, however, behavioral embryologists began to accrue observations of fetal behavior (e.g., Narayanan, Fox, & Hamburger, 1971). They learned how to probe into fetal behavior with questions and methods to obtain rudimentary answers. The early pioneers were joined by some developmental psychobiologists, who brought other traditions to the area (Krasnegor & Lecanuet, 1995; Smotherman & Robinson, 1995). When studying behavioral embryology in oviparous (egg-laying) species, the living embryo is virtually presented to the investigator, who can cut a window into the eggshell or gain direct access to the embryo within it (e.g., Gottlieb, 1985; Kuo, 1967). With viviparous species, investigators bring the fetus out of the mother’s body, carefully preserving the umbilical and placental connections. These dramatic preparations allow researchers to see directly, manipulate directly, and measure more directly, which effectively gave birth to a new field of study. My comments here are inspired mostly by the impressive and important report by Robinson, Kleven, and Brumley (this issue). This research is a contribution to a continuing literature on rat behavioral embryology and, indeed, to developmental studies in general.
Why Does Language Interfere with Vision-Based Tasks?

Conversation with a remote person can interfere with performing vision-based tasks. Two experiments tested the role of general executive resources and spatial attentional resources in this interference. Both experiments assessed performance in vision-based tasks as participants engaged in a language task involving a virtual remote speaker. In both experiments, the language task interfered with the vision task more when participants were speaking or planning what to say next than when they were listening. In Experiment 1, speaking or planning what to say next were also associated with higher interference from a visual distractor than listening, indicating that preparing to speak and speaking pose higher executive requirements than listening. In both experiments, localizing the voice of the remote speaker to the front of participants slightly reduced interference in comparison to other directions. This suggests that remote conversation requires spatial attention resources for representing the position of the remote person.
Transformation of signals by interneurones in the barnacle's visual pathway.

1. The photoreceptors of the median eye of the giant barnacle drive decrementally-conducting neurones in the supraoesophageal ganglion termed ‘inverting cells’ (I-cells) which in turn drive impulse-producing neurones termed ‘amplifying cells’ (A-cells). Using intracellular recording techniques we have studied the role of I-cells in visual processing. 2. Horseradish peroxidase injections show that I-cells are interneurones whose processes are confined to the regions of the photoreceptor terminals on both sides of the bilaterally symmetrical ganglion. 3. In the dark, I-cell membrane potentials (-45 mV) are considerably less negative than those of other ganglion cells (-60 to -70 mV). At the onset of a maintained light, I-cells undergo a transient peak hyperpolarization which declines to a steady-state response. Both response components are graded with light intensity. 4. The reversal potential of the peak of the I-cell light response depends on the external K+ concentration more strongly than does the dark resting potential (3-30 m m-K+). This evidence indicates that the hyperpolarization results from an increase in the cell's permeability to K+ ions. 5. At the offset of light an I-cell undergoes a transient depolarization that overshoots the dark membrane potential. Dimming of a background light can also cause the I-cell membrane potential to overshoot its dark resting value. This overshoot is associated with a large depolarizing synaptic potential in A-cells. 6. An overshoot of the dark resting potential can also be elicited by the break of a hyperpolarizing pulse of current injected into an I-cell. The amplitude of this overshoot increases with pulse duration over a time course of seconds. 7. In the presence of external tetraethylammonium ion (TEA) and tetrodotoxin, (TTX), the break of a hyperpolarizing pulse or the onset of a depolarizing pulse can evoke in an I-cell an action potential whose rate of rise and amplitude depend on the external Ca concentration. This action potential can be maintained by replacement of external Ca with Ba, or blocked by addition of 15 m m-Co to the saline. These observation's indicate that depolarizing potential changes in this cell activate a voltage-sensitive Ca conductance. 8. When hyperpolarizing current pulses are injected into an I-cell, the voltage during the pulse sags back slowly towards the dark resting potential. Thus, during hyperpolarization with light or current an I-cell's membrane properties change over a time course of seconds. 9. The onset of a depolarizing pulse or the offset of a hyperpolarizing pulse of current injected into an I-cell leads to a transient depolarization of a simultaneously impaled A-cell. Synaptic transmission occurs when the I-cell is depolarized to the vicinity of the dark resting potential. The amplitude of the response in an A-cell depends on the rate of change of the I-cell voltage.
A Human Umbilical Cord with Four Arteries

An unusual case of a newborn infant with four umbilical arteries is presented. Multiple catheterizations revealed that triplication of the right umbilical artery was responsible. There were no associated malformations, and follow-up at 9 months of age revealed age-appropriate growth and development. This case extends the spectrum of observable umbilical artery anomalies.
An approach to facilitating communication of expert arguments through visualisation

Many public issues, such as environmental actions, involve a large number of diverse stakeholders such as governments, corporations, organizations (e.g. NGOs), and concerned citizens. Discussions frequently become contentious as the stakeholders defend their potentially conflicting goals with various assumptions, views, and expert testimony. These issues also tend to involve a range of fields. For example, the disposition of nuclear waste includes issues of economics, science, engineering, politics, and intergenerational justice, each with large uncertainties due to dependences on indirect estimations and the long time periods involved. At the same time that these complex issues might increase in number, due to applications of new technologies, tools are being developed on the Internet to enable flexible learning, visualization, collaborative conferencing, distributed computing, and meaning‐based (semantic) context. These tools might enable improved techniques for debating and discussing these complex issues. A technique that might facilitate orderly discussion of various arguments would include explicit recording and visualization of the evidence, its assumptions and uncertainties, their relationships in constructing the overall argument, and the ways the evidence needs to be generalized to support the argument. A simple argument visualization approach is explored based on a combination of an argument logic framework and techniques for fusing generalized data that are similar to kriging in spatial analysis. This approach is then applied to a recently contested risk analysis of nuclear waste disposition that was debated in a peer‐reviewed journal, involving concerns about uses of data, complex computational models, uncertainty analysis, and expert judgment. The need for wider understanding of such complex issues might be addressed by a convergence of techniques to facilitate greater understanding and the advanced Internet technologies to lower barriers to their adoption.
On Non-linearities Separate Modeling Method and State Feedback Control

Modeling method of non-linearities objects controlled have more problem and difficulty. Based on the increment function observer (IFO-Kx), this paper gives the mathematical conceptions of Increment Function Observer with variable gain IFO-K(T(t)) x and the Increment full dimension State Observer with variable gain ISO-T(t) x, which makes the application of increment observer extending to non-linear slow-time-varying controlled system. In this paper, the sufficient condition of IFO-K(T(t)) x and ISO-T(t) x is presented, and comparing this condition with the sufficient and necessary condition of increment function observer, the useful conclusion for practical engineering can be obtained that the design of increment observer can avoid seeking the solution of Sylvester matrix equation, which provides the more maturity theory foundation for the engineering application of incremental observer.
Relationships Between Chihuahuan Desert Perennial Grass Production and Precipitation

Abstract Perennial grass production on the Chihuahuan Desert Rangeland Research Center in south-central New Mexico was correlated with precipitation characteristics over a 34-year period. Total December through September precipitation was highly correlated (r = +0.77, n = 34) with perennial grass production. Practical generalized indices were developed that could be broadly applied by managers for predicting perennial grass production from precipitation characteristics. Perennial grass production and precipitation data on 3 separate pastures were collected over a 6-year period to evaluate the reliability of models to predict perennial grass production. Simple linear, 2-variable, quadratic, and polynomial regression models gave perennial grass production estimates that were well correlated with actual values (r = +0.85 to +0.91, n = 17) across the 3 pastures. The quadratic regression model (Y = 4.04 − 0.24X + 0.012 X2, X = December through September precipitation, Y = forage production, n = 34, r = 0.85) g...
Units of Measurement

This book is largely targeted toward a mathematical audience, whose grasp and recollection of principles of physics may vary from small to great. It seems prudent therefore that we should adopt a somewhat self-contained approach and proceed along elementary lines. In many cases we shall attempt to complement stated principles with concrete computational examples. Towards this end, one necessity is a review of some of the basic units of measurement. Also towards the end of providing a largely self-contained account we will supply generous amounts of detail at times in the discussion of much of the material.
Estimating the economic impacts of a hub airline serving a tourist destination: the case of america west airlines and las vegas, nevada

Airlines are an important component of regional economies. The economic impact of an airline goes beyond the usual impacts of their payroll and expenditures. Airlines also may affect business productivity and the critical economic base of a regional economy. This article estimates the economic impact of America West Airlines on Las Vegas, Nevada. Key aspects of the study were measurement of the direct impacts, estimation of the associated impact on tourism allowing for the possibility of competing travel alternatives, and the use of a regional economic impact model to derive the total economic impact.
An Effective and Benign Treatment of Rumination

This study reports a simple and effective program for the reduction or elimination of ruminative behavior in school-aged students with multiple handicaps. Four students were treated using a combination of peanut butter, reduced fluid consumption at meals, and fading. In each of the cases, the ruminative behavior was significantly reduced or eliminated. The program is discussed in light of its effects on the student, the staff, and its relation to other treatments for rumination.
Involvement of the extrinsic and intrinsic pathways in ultraviolet B-induced apoptosis of corneal epithelial cells

Abstract The goal of this study was to elucidate the pathway by which UVB initiates efflux of K+ and subsequently apoptosis in human corneal limbal epithelial (HCLE) cells. The initial focus of the study was on the extrinsic pathway involving Fas. HCLE cells transfected with Fas siRNA were exposed to 80–150 mJ/cm2 UVB and incubated in culture medium with 5.5 mM K+. Knockdown of Fas resulted in limited reduction in UVB-induced caspase-8 and -3 activity. Patch-clamp recordings showed no difference in UVB-induced normalized K+ currents between Fas transfected and control cells. Knockdown of caspase-8 had no effect on the activation of caspase-3 following UVB exposure, while a caspase-8 inhibitor completely eliminated UVB activation of caspase-3. This suggests that caspase-8 is a robust enzyme, able to activate caspase-3 via residual caspase-8 present after knockdown, and that caspase-8 is directly involved in the UVB activation of caspase-3. Inhibition of caspase-9 significantly decreased the activation of caspases-8 and -3 in response to UVB. Knockdown of Apaf-1, required for activation of caspase-9, resulted in a significant reduction in UVB-induced activation of caspases-9, -8, and -3. Knockdown of Apaf-1 also inhibited intrinsic and UVB-induced levels of apoptosis, as determined by DNA fragmentation measured by TUNEL assay. In UVB exposed cultures treated with caspase-3 inhibitor, the percentage of apoptotic cells was reduced to control levels, confirming the necessity of caspase-3 activation in DNA fragmentation. The lack of effect of Fas knockdown on K+ channel activation, as well as the limited effect on activation of caspases-8 and -3, strongly suggest that Fas and the extrinsic pathway is not of primary importance in the initiation of apoptosis in response to UVB in HCLE cells. Inhibition of caspase-8 and -3 activation following inhibition of caspase-9, as well as reduction in activation of caspases-9, -8, and -3 and DNA fragmentation in response to Apaf-1 knockdown support the conclusion that the intrinsic pathway is more important in UVB-induced apoptosis in HCLE cells.