cssi/SciSciGPT-SciSciNet huggingface dataset:
Mesquite and grass relationships at two spatial resolutions

Relationships between woody plants and grass are typically described at either the stand (≥100 m2) or plant (≤10 m2) spatial resolutions. Descriptions of the Prosopis velutina (mesquite)–grass relationships in the North American Desert Grassland differ between spatial scales: P. velutina often inhibits grass at the stand scale compared to facilitation or neutral relations at the plant scale. We use simultaneous measures of grass density at both spatial resolutions (made at 3 y intervals from 1997 to 2003) to evaluate the influence of the spatial resolution on detecting P. velutina–grass relationships. We confine our observations to the parsimonious conditions of (1) two distinct P. velutina age classes that are exclusive occupants of study sites and (2) total cover of P. velutina was not different between study sites in 2000 and 2003. Thus, total P. velutina cover is constant in those 2 years but P. velutina ages contributing to that cover differed between the study sites. We confirmed the importance of spatial scale because no grass species was related to P. velutina age at the stand scale, but 2 of 5 species were significantly related at the plant scale. Aristida spp. was greater under young than old P. velutina, and Muhlenbergia porteri was greater under old P. velutina. These results suggest that the influence of old P. velutina on grass abundance is restricted to the area under the canopy and does not extend into inter-canopy areas, and therefore the observations at the stand scale may not detect the P. velutina–grass relationships at the plant scale.
Exploring the HTLV-1 Gag Membrane-Trafficking Pathway with Fluorescence Fluctuation Spectroscopy and Total Internal Reflection Fluorescence Microscopy

The use of biophysical fluorescence-based techniques for the study of proteins in living cells has significantly advanced in recent years. A particularly challenging aspect of fluorescence measurements conducted in live cells is in the study of protein systems which exhibit complex and varying behaviors in different regions of the cell. An example of such a system is retroviral Gag structural proteins, which play a prominent role in viral assembly and are known to have cytoplasmic and membrane-bound states with low-order and high-order oligomeric states, respectively. The presence of high-order, fluorescently-labeled Gag oligomers at the membrane can impact fluorescence monitoring of the cytoplasmic fraction of Gag. In addition, cytoplasmic species can confuse the study of membrane-bound Gag complexes. Our work focuses on the use of fluorescence fluctuation spectroscopy (FFS) and total internal reflection fluorescence (TIRF) microscopy to investigate retroviral Gag species, both at the membrane and in the cytoplasm. A focus of the study is the relationship between cytoplasmic Gag concentration and the formation of Gag assembly sites at the plasma membrane. FFS monitors Gag cytoplasmic concentration, while TIRF monitors the biogenesis of HTLV-1 virus-like particles. Comparison of results from HTLV-1 and HIV-1 Gag reveals intriguing differences in their assembly pathways. This work is supported by NIH Grant AI81673, NIH Grant GM064589, a Cancer Center Cancer Biology Training Grant (T32CA09138), and an American Cancer Society Postdoctoral Fellowship (PF-11-159-01-MPC).
Growth of Ce-Nb oxide films: A test of oxidation theory

Experiments on the oxidation, at room temperature, in 5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ Torr oxygen, of vapor deposited films of cerium, niobium, and niobium covered by some monolayers of cerium are reported. The valence-band structure was studied by ultraviolet photoemission spectroscopy (UPS), the surface potential due to chemisorbed oxygen was measured by measuring work-function change by UPS, and oxide growth was followed by x-ray photoelectron spectroscopy. The energy level ${\ensuremath{\epsilon}}_{a}$ of oxygen chemisorbed on ${\mathrm{CeO}}_{2}$ was determined from UPS difference spectra and found to be at 4 eV below the Fermi level ${\ensuremath{\epsilon}}_{F}$. Comparing this with measured values of the surface potential (${V}_{S}$=-0.6 V) we conclude that contrary to earlier predictions, the entire value of the Mott potential ${V}_{M}$\ensuremath{\equiv}${e}^{\mathrm{\ensuremath{-}}1}$(${\ensuremath{\epsilon}}_{F}$-${\ensuremath{\epsilon}}_{a}$) does not materialize as a surface potential in the course of oxidation. We found, that for the oxidation of Nb the incorporation of oxygen ions at the surface is the rate-limiting step, while in case of cerium, and niobium covered by some monolayers of cerium, the first stage of oxidation is limited by oxygen-ion diffusion, and the second stage of oxidation is limited by electron tunneling.
Morphologically heterogeneous met-enkephalin terminals form synapses with tyrosine hydroxylase-containing dendrites in the rat nucleus locus coeruleus.

Physiological and anatomical studies have suggested that the endogenous opioid peptide, methionine-enkephalin (ENK), may directly modulate noradrenergic neurons. Additionally, chronic opiate administration has been shown to increase the levels of a number of G-proteins and phosphoproteins including the catecholamine synthesizing enzyme, tyrosine hydroxylase (TH). We combined immunogold-silver localization of tyrosine hydroxylase and immunoperoxidase labeling for ENK in single sections through the nucleus locus coeruleus (LC) in the rostral pons to determine potential substrates for the divergent actions of this opioid peptide. Light microscopic analysis of ENK immunoreactivity in the LC area indicated that ENK fibers are dense and highly varicose. In coronal sections, ENK-immunoreactive processes were punctate and appeared to envelop LC-cell bodies. More rostrally, in the region of catecholamine-immunoreactive extranuclear dendrites, ENK-immunoreactive varicose processes were interdigitated with TH-labeled processes. Electron microscopy of this rostral region revealed that ENK-immunoreactive axon terminals contained small clear as well as large dense core vesicles. The large dense core vesicles (1-10/terminal) were consistently the most immunoreactive and were identified toward the periphery of the axon terminal distal to the active zone of the synapse. Unlabeled axon terminals and glial processes were the most commonly observed elements located adjacent to the plasmalemma of axons containing the labeled dense core vesicles. Axon terminals containing ENK immunoreactivity varied in size (0.3 micron to 2.0 microns) as well as formation of synaptic specializations (i.e., asymmetric versus symmetric). The ENK-labeled terminals formed synapses with dendrites with and without detectable TH immunoreactivity. These results provide the first direct ultrastructural evidence that morphologically heterogeneous terminals containing ENK immunoreactivity form synapses with catecholamine dendrites within the LC. The formation of asymmetric and symmetric synaptic specializations suggests that the opioid peptide, ENK, may be colocalized with other neurotransmitters. Furthermore, the distribution of ENK immunoreactivity in axon terminals apposed to other unlabeled afferents or astrocytic processes suggests that actions of ENK may also include presynaptic modulation of other transmitters and/or effects on astrocytes.
Star arboricity of graphs

Abstract We develop a connection between vertex coloring in graphs and star arboricity which allows us to prove that every planar graph has star arboricity at most 5. This settles an open problem raised independently by Algor and Alon and by Ringel. We also show that deciding if a graph has star arboricity 2 is NP-complete, even for 2-degenerate graphs.
Effect of dietary supplements on hemostasis: a case of bleeding in context of research and surveillance.

The hemostatic implications of dietary supplements are best understood after review of the regulatory context of dietary supplements, and a review what dietary supplements are — and moreover — what they are not. Dietary supplements are a highly diverse collection of substances including herbals and other botanicals, enzymes and other proteins, peptides and amino acids; lipids and polysaccharides; colloidal metals, metalloids, trace elements, vitamins as well as whole glands and other tissues. Dietary supplements are regulated, and under the law, they are foods, not drugs. The 1994 Dietary Supplement Health and Education Act (DSHEA) [1] defines dietary supplements by their intent of use to bsupport the structure and function of the body.Q Industry can only make claims that fit that intent but they cannot promote
Host-specific effects of the korA-korB operon and oriT region on the maintenance of miniplasmid derivatives of broad host-range plasmid RK2

Two genetic determinants are sufficient for small derivatives of broad host-range plasmid RK2 to replicate in different Gram-negative bacteria: trfA, which encodes a replication initiator, and oriV, the origin of replication. In this study, nonessential RK2 determinants in the region encoding oriT, the origin of conjugative transfer, and the korA-korB operon, whose products regulate trfA expression, were tested for their effects on the stability of mini-RK2 plasmids in eight different hosts. We found that determinants of both regions can substantially alter plasmid stability, but the effects are not uniform in all hosts. The results also indicate that the effects of the korA-korB operon extend beyond that of the regulation of trfA transcription. This study further illustrates the different requirements for stable plasmid maintenance in diverse bacteria and the ability of wild-type RK2 to adapt to a variety of intracellular environments. The data also provide further evidence for the involvement of different regions of RK2 for stable maintenance in various hosts.
Convergent synthesis of an inner core GPI of sperm CD52

An inner core of the GPI anchor of sperm CD52 antigens was synthesized by a highly convergent process using specially modified inositol, glucosamine and phospholipid as key building blocks. This paper also presents a new and efficient procedure to prepare 1,2,6-differentiated derivatives of inositol for GPI syntheses.
GLEAM/1130-a production system base for computer-aided design

The partitioned computing system, operating several tasks concurrently, is an effective tool for computer-aided design. Such a system offers a high-performance man-machine interface and at the same time operates the low-speed graphic devices (such as plotters) continuously with small drain upon the system. The concept of queueing tasks for devices, instead of queueing users for the system, improves user-access and maintains a reasonably constant load upon the system's hardware. Strong resident support eases programming and extends the computing power by efficiently utilizing the resources of the small computer. The communications connection to a larger computer greatly expands the system's capability.
Single-molecule analysis of nucleotide-dependent substrate binding by the protein unfoldase ClpA.

Single-molecule fluorescence experiments on the ClpA ATPase component of the ClpAP protease demonstrate that ClpA binds its peptide substrates in discrete high- and low-affinity conformations. Thes...
Alfven waves in a two-fluid model of the solar wind

A two-fluid model for the solar wind is presented that includes the presence of Alfven waves which originate at the sun. The effective pressure of these Alfven waves is considered, as well as a model representation for proton heating through nonlinear Alfven wave damping. The effects of rotation in the solar equatorial plane are allowed for. The implications of the computational results obtained are discussed.
Recanalization of the Left Atrial Appendage Demonstrated by Transesophageal Echocardiography

Closure of the fibrillating left atrial appendage has been recommended during mitral valve operations to help prevent thrombus formation and systemic embolization postoperatively. We report recanalization of the appendage orifice in 6 patients after surgical closure by pursestring suturing at the time of mitral valve replacement. Transesophageal echocardiography demonstrated disruption of the closure line and partial recanalization of the sutured orifice with relatively high velocity flow between the left atrial body and the appendage.
Injuries caused by personal violence.

Abstract Injury is the leading cause of death for Americans from infancy to middle age. Thirty-seven per cent of injuries admitted to this faculty are the result of personal violence. A prospective pilot study sought to elucidate the circumstances of such injuries. Medical records of all admissions for gunshot wounds, stab wounds or assault during a 30-day period were reviewed ( N = 105). A subset ( N = 32) were interviewed and given psychometric tests. Distribution by mode of injury was assault, 46 per cent; stabbing, 42 per cent; shooting, 12 per cent. Single, black males aged 18–44 dominated the sample. Injuries tended to occur in or near bars (82 per cent), between 1800 and 0600 hours (79 per cent) and were accompanied by alcoholic intoxication (63 per cent). Un- or underemployment was prevalent (56 per cent). Thirty-eight per cent of incomes were below the official poverty level. Some victims were illiterate. Histories of previous violent encounters (mean number = 22) during the year before the injury and hospital treatment for previous injury were common (56 per cent). Those interviewed reported high frequencies of recent and developmental stresses. The yearly cost of the acute care of patients with injuries caused by violence and treated at this hospital is estimated to be $8 000 000. Of this 80 per cent is paid for with public funds. Personal violence is a serious but neglected part of public health.
Instability and Impingement in the Athlete’s Shoulder

The competitive athlete who participates in a sport requiring overhead motion depends on a shoulder with optimal function. An acute episode of injury or a gradual onset of symptoms in the shoulder can affect the athlete's ability to perform. An understanding of shoulder anatomy and function is essential, and an accurate diagnosis of the underlying pathology is critical for planning treatment options. The correct diagnosis may be less clear when the athlete presents with an insidious onset of shoulder pain. A detailed history and physical examination, as well as an evaluation of the overhead motion and onset of pain, is important when the diagnosis of instability or impingement is considered. Rehabilitation of the rotator cuff often succeeds in alleviating symptoms and restoring function. Surgery is considered when symptoms and diminished function persist despite appropriate nonoperative treatment. Operative repair or reconstruction must be anatomical in nature. Postoperative rehabilitation is equally important in this setting, and a motivated athlete helps to ensure success.
Accurate composition determination of Be‐Ti alloys by electron energy loss spectroscopy

SUMMARY Accurate quantification of the Be content in Be-Ti alloys on a submicrometre scale can be accomplished with electron energy loss spectroscopy in an analytical electron microscope. The three major steps required to ensure the accuracy of the numerical results are analysed. The first step is the choice of the specimen thickness which should be such that the influence of the specimen surface effects can be ignored yet thin enough so that deconvolution of the spectra is unnecessary. The second step is the background extrapolation under the ionization edge of interest. In this study, a direct least-squares fit with a progressive weighting is used to avoid the drawbacks of the conventional linear least-squares fit. The third step is the calibration of the partial ionization cross-section ratio with the use of a standard specimen. Without this calibration step, the error in the final microanalysis result could be excessive, as demonstrated. With all these precautions taken into consideration, we are able to show that the intermetallic phase TiBe12 exhibits a great deviation from its nominal stoichiometry.
Ultramicroanalysis of biological fluids with energy dispersive X-ray spectrometry

The use of an energy dispersive spectrometer (EDS) X-ray analyser on a standard scanning electron microscope (SEM) is described and evaluated for the elemental analysis of ultramicrosamples on the order of 10−10 1. volumes of biological fluids. The method incorporates several modifications in the preparation of ultramicro fluid samples as previously described for diffractive microprobe X-ray analysis which extend the sensitivity of EDS quantitation and facilitate the routine preparation of such samples. The method provides quantitation of most elements of biological interest present in concentrations of about 1mM or more, and demonstrates good linearity (r > 0.99) throughout a wide range of commonly encountered biological concentrations. When not limited statistically by count rate, the reproducibility of the analysis is on the order of 2%. In the presence of 150mM NaCl, the minimal determinable concentration (MDC) is between 0.5mM and 1.0mM for S, P, K, and Ca and slightly more than 1.0mM for Mg. The MDC for all elements is approximately 0.3 weight percent of total desiccated sample solute. The validity of the method was verified by comparing results of EDS analysis of diluted and undiluted samples of sweat, saliva, and urine with the results of analyses of the same samples performed by conventional methods. Except for C1 in concentrated urines and Mg in low concentrations, good agreement was found between the methods.
Changes in Venice Lagoon dynamics due to construction of mobile barriers

Abstract The MoSE project (construction of mobile barrier to safeguard the Lagoon of Venice) entails changes to the structure of the lagoon's inlets. This could have consequences for the areas near the inlets and for the dynamics of the lagoon ecosystem as a whole. In order to predict the effects of the proposed alterations on the hydrodynamics of the lagoon, a well-tested hydrodynamic-dispersion model was applied. Simulations were carried out considering both idealised and realistic tide and wind scenarios. The results show that with the new structures the Lido sub-basin tends to increase its extension due the southward movement of the watershed, at the expense of the Chioggia sub-basin, whereas the Malamocco sub-basin changes its relative position, but not its extension. The residence time shows variations in agreement with this trend, decreasing in the southern part of the Lido sub-basin and increasing in the inner part of the Chioggia sub-basin. The variations in residence time and return flow factor indicate that they are caused by changes in both instantaneous current velocities and sea–lagoon interaction. In fact the new breakwaters in front of the Malamocco and Chioggia inlets modify the length and direction of the outflow jet (up to 1 ms− 1) and the patterns of the currents around the inlets and the nearby coast. The new artificial island in the Lido inlet changes the current pattern and increases the current velocity on the southern side of the channel propagating this effect up to the Venice city. The risks and benefits individuated from our conclusion are that the Lido sub-basin can improve its renewal time, but the more intense current speeds can be a risk for the conservation of habitats and infrastructures. Finally the micro-circulation between the breakwater and the coast in Chioggia and Malamocco inlets can be a trap for pollutants or suspended sediment.
Hubble Space Telescope/Advanced Camera for Surveys Narrowband Imaging of the Kepler Supernova Remnant

We present narrowband images of the Kepler supernova remnant obtained with the Advanced Camera for Surveys aboard the Hubble Space Telescope. The images, with an angular resolution of 0.05'', reveal the structure of the emitting gas in unprecedented detail. Radiative and nonradiative shocks are found in close proximity, unresolvable in ground-based spectra, indicating that the pre-shock medium is highly clumped. The ionization structure, traced by differences in the [O III] to [N II] flux ratio, varies on subarcsecond scales. The variation is due to both differences in shock velocity and gradients in the evolutionary stage of the shocks. A prominent complex of knots protruding beyond the boundary of the remnant in the northwest is found to consist of bright radiative knots, connected by arcuate nonradiative filaments. Based on the coincidence of the optical emission with a bright isolated knot of X-ray emission, we infer that this feature is due to a Rayleigh-Taylor finger that formed at the contact discontinuity and overtook the primary blastwave.
Shortest bayes credibility intervals for the lognormal failure model

Abstract The lognormal distribution with density function f(x|λ,δ 2 )= (2π) 1 2 δx −1 exp − ( In x−λ) 2 2δ 2 , for x>0,δ>0,−∞ is considered as a failure model from the Bayesian point of view. The shortest Bayesian confidence intervals for the parameters and reliability function are obtained for two cases. First, it is assumed that σ2 is known and that γ has a normal prior distribution. Then, the case that γ is known and σ2 has an inverted gamma prior distribution is considered. Some computer simulations are given to demonstrate the advantage of the shortest Bayesian confidence intervals over the ordinary Bayesian confidence intervals in terms of their length ratios.
Neurologic recovery after out-of-hospital cardiac arrest

Abstract A retrospective cohort study of the neurologic sequelae of out-of-hospital cardiac arrest was done using 459 consecutive patients resuscitated and admitted to a teaching hospital over 10 y...
Single toxin detection is inadequate to diagnose Clostridium difficile diarrhea in pediatric patients

Abstract Background & Aims: Clostridium difficile is an important cause of symptomatic diarrhea in pediatric patients. The bacterium produces two toxins, although many laboratories assay for only one. We questioned this diagnostic approach when patients had positive results for C. difficile at our institution, but initially had tested negative at outside laboratories. Methods: We retrospectively analyzed relative frequencies of C. difficile toxin A alone, toxin B alone, and toxins A and B from pediatric patients with diarrhea. Results were stratified according to toxin detection and patient age. Results: Of 1061 specimens, 276 (26.8%) were positive for C. difficile toxin(s). Fifty-one (18.5%) were positive for toxin A alone, 133 (48.2%) for toxin B alone, and 92 (33.3%) for both toxins. Assaying for toxin B identified C. difficile infection more frequently than did assaying for toxin A ( P Conclusions: Testing for C. difficile toxin A or toxin B alone will result in more frequent misdiagnosis than testing for both toxins. This practice may lead to inappropriate further invasive investigations in children, although this finding may not be applicable to adults. GASTROENTEROLOGY 1998;115:1329-1334
Meso-scale measurement of the electrical spreading resistance in highly anisotropic media

The spreading resistance of circular contacts with a radius in the range from 60 nm to 500 nm has been measured in highly oriented pyrolytic graphite which is known to exhibit an extremely large electrical conductance anisotropy due to the layered structure. The experimental data are compatible with a diffusive transport model characterized by an inverse scaling of the spreading resistance with contact radius with an effective resistivity of ρeff = 5.7 ± 0.3 × 10−5 Ω m. Based on a scaling theory of the conduction in anisotropic media, we infer a ratio of the in-plane to out-of-plane conductance of 3.6 × 104 in agreement with literature. Accordingly, the radius of the effective area probed is on the order of 100 μm, which is much larger than the radius of contact, whereas the penetration depth into the sample is around 1 nm to 5 nm corresponding to 3–15 graphite layers. Remarkably, no deviation from the scaling model is observed despite the fact that only a small number of graphite layers are involved in t...
Integrating a Hybrid Electric Drive Propulsion System With the Existing DDG 51 Class Machinery Control System

The destroyers of the USS Arleigh Burke Class all have 4 propulsion gas turbines and 3 gas turbine generators (GTGs). A typical at-sea “condition 3” operating profile consists of having 2 gas turbine generators running at approximately 50% capacity, and one propulsion gas turbine online at low to intermediate ship speeds. Having 2 GTGs online at all times at 50% load each provides the obvious advantage of maintaining all electric loads should one GTG shut down unexpectedly. This luxury does come at the cost of fuel efficiency, as gas turbines efficiency improves continuously as they move away from idle. On the propulsion end, a single gas turbine is capable of generating enough horsepower to propel the ship at speeds in excess of 20 knots. Depending upon the specific mission that the destroyer may be on, however, quite a bit of operating profile may be at speeds below 15 knots where the LM2500 is operating at less than 20% capacity. In this range of operation specific fuel consumption ratios are also relatively low. The proposed Hybrid Electric Drive (HED) system has the potential to address both of these inefficient ranges of operation. By installing one 2000 horsepower electric motor on each shaft, the electric motors can be used to propel the ship at speeds below 14 knots (projected) while running the GTGs up to 90% operating range where they are most efficient. The LM2500 is shut down completely at this range, and the potential fuel savings in this configuration is substantial. While there are many engineering challenges with installing such a HED system on board an in-service DDG, the focus of this paper is on how to integrate HED with the existing Machinery Control System (MCS). Such challenges include interfacing MCS to the HED supervisory controller, developing a new HED control interface for the propulsion control operator, integrating HED into the existing shaft speed control algorithm, transitioning to and from HED propulsion, and updating data logging to include HED. Managing the interface between current electric load, changing electric loads, and current available HED power will also be addressed.
Distributed Photorefractometer Using The Total Reflective Phenomena Of An Optical Fiber

Recently, research and development in optical fibers has made rapid progress. Many studies of the application of optical fibers to the analysis of liquid or monitoring sensors in fields of chemical processing plant have been carried out. Formerly, for measuring a liquid refractive index, Abbe's refractometer and others have been used. The authors have developed an optical fiber photorefractometer as a compact measuring method of a refractive index 1,2) and have made studies of its application and its improvements.
Trapping and release of citrate-capped gold nanoparticles

Abstract An electrical method to trap and release charged gold nanoparticles onto and from the surface of gold electrodes modified by an alkanethiol self-assembled monolayer (SAM) is presented. To form electrodes coated with gold nanoparticles (GNPs), amine-terminated SAMs on gold electrodes were immersed in a solution of negatively charged citrate-capped GNPs. Accumulation of GNPs on the electrode surface was monitored by a decrease in the impedance of the SAM-modified electrode and by an increase in the electrochemical activity at the electrode as shown through cyclic voltammetry (CV). Electrostatic interactions between the GNPs and the amine-terminated SAM trap the GNPs on the electrode surface. Application of a subsequent negative bias to the electrode initiated a partial release of the GNPs from the electrode surface. Impedance spectroscopy, cyclic voltammetry, ultraviolet–visible (UV–Vis) spectroscopy and atomic force microscopy (AFM) were used to monitor and confirm the attraction of GNPs to and release from the aminealkanethiolated gold electrodes. This work describes a method of trapping and release for citrate-capped GNPs that could be used for on-demand nanoparticle delivery applications such as in assessing and modeling nanoparticle toxicology, as well as for monitoring the functionalization of gold nanoparticles.
Gasification of cellulosic chars in oxygen and in nitrogen oxides

Abstract Rates of gasification of celluose char (HTT 1,000°C) have been determined in the temperature range 400–600°C in 0.1 atm of oxygen, nitrous oxide (N2O), and nitric oxide (NO) respectively. The results show that the overall reactivity in gasification reactions decreases in the order O2 >NO >N2O.
Interaction of stimulus and contextual information during reading: Identifying words within sentences.

In general, studies on the effects of a sentence context on word identification have focused on how context affects the efficiency of processing a single target word, presented separately from the context. Such studies probably would be incapable of measuring contextual facilitation resulting from cascaded or parallel processing of neighboring words within a sentence. To measure these and other types of facilitation, we presented entire phrases and sentences for subjects to read as fast as possible and to monitor for nonwords. Subjects read at rates representative of natural reading. Experiment 1 demonstrated a large contextual facilitation effect on decision time. Experiment 2 showed that facilitation is caused by specific semantic information and, perhaps to a greater degree, by nonpredictive syntactic information. Experiment 3 showed that the amount of facilitation is greater than could be accounted for by separate contributions from autonomous word level and sentence level processes. These results present difficulties for an autonomous model of reading, but are consistent with interactive models, in which the results of ongoing sentential analyses are combined with stimulus information to identify words.
On estimating efficacy from clinical trials.

We define ‘biologic efficacy’ as the effect of treatment for all persons who receive the therapeutic agent to which they were assigned. It measures the biologic action of treatment among compliant persons. In a randomized trial with one treatment and one placebo control, one can theoretically estimate efficacy by comparing persons who complete the treatment regimen with controls who similarly complete the control regimen. In practice, however, we make this comparison with reservation because a control protocol often presents a different challenge for compliance than does the treatment, so that the compliant subgroups are not comparable. Standard practice employs intent-to-treat comparisons in which one compares those randomized to treatment and control without reference to whether they actually received the treatment. Intent-to-treat comparisons estimate the ‘programmatic effectiveness’ of a treatment rather than its biologic efficacy. This paper introduces and derives the statistical properties of an alternative estimator of biologic efficacy that avoids the potential selection bias inherent in a comparison of compliant subgroups. The method applies to randomized trials with a dichotomous outcome measure, whether or not a placebo is given to the control group. The idea is to compare the compliers in the treatment group to an inferred control subgroup chosen to eliminate selection bias. The methodology was motivated by and is illustrated in the analysis of a randomized community trial of the impact of vitamin A supplementation on children's mortality.
Space-frequency methods in image compression

Recently, a new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with tree-structured quantization has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical representation. This paper addresses the problem of how spatial quantization modes and standard scalar quantization can be applied in a jointly optimal fashion in an image coder. We consider zerotree quantization and the simplest form of scalar quantizations, and we formalize the problem of optimizing their joint application and we develop an image coding algorithm for solving the resulting optimization problem. Despite the basic form of the two quantizers considered, the resulting algorithm demonstrates coding performance that is competitive the very best coding algorithms in the literature.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
PERFORMANCE OF MEN AND WOMEN ON MULTIPLE‐CHOICE AND CONSTRUCTED‐RESPONSE TESTS FOR BEGINNING TEACHERS

Some previous research results imply that women tend to perform better, relative to men, on constructed-response (CR) tests than on multiple-choice (MC) tests in the same subjects. An analysis of data from several tests used in the licensing of beginning teachers supported this hypothesis, to varying degrees, in most of the tests investigated. The hypothesis was strongly supported in Praxis™ Principles of Learning and Teaching tests for secondary school teachers and in subject-knowledge tests for social studies teachers, science teachers, and middle school mathematics teachers. Evidence for the hypothesis was weak in subject-knowledge tests for middle school English teachers and for secondary school mathematics teachers. Subject-knowledge tests for secondary school English teachers did not show the hypothesized relationship. The analysis was based on plots showing the cumulative percentages of men and women attaining each possible score on the MC and CR tests.
Performance Evaluation of Composite Prestressed Concrete Slab Bridges

The results from a research project that evaluated the long-term performance of bridges constructed with composite prestressed concrete panels are summarized. The particular construction system investigated used full-span prestressed concrete panels that would be typical for bridges with spans of 12 m (40 ft) or less. A full-scale bridge specimen was constructed and subjected to 5 million cycles of service loading and 48 weeks of durability exposure cycling. This was done to assess the potential for delamination as well as the resistance to chloride-induced reinforcement corrosion. The exposure cycling greatly accelerated the rate of penetration of chlorides, producing concentrations in the deck that exceeded those from bridges that had been in service for nearly 40 years. The results from this study showed that long-term composite behavior can be achieved in these structures by applying a raked finish to the top surface of the prestressed panels. Corrosion measurements revealed the need to modify the pos...
Ammonia-borane: the hydrogen source par excellence?

Ammonia–borane, H3NBH3, is an intriguing molecule for chemical hydrogen storage applications. With both protic N–H and hydridic B–H bonds, three H atoms per main group element, and a low molecular weight, H3NBH3 has the potential to meet the stringent gravimetric and volumetric hydrogen storage capacity targets needed for transportation applications. Furthermore, devising an energy-efficient chemical process to regenerate H3NBH3 from dehydrogenated BNHx material is an important step towards realization of a sustainable transportation fuel. In this perspective we discuss current progress in catalysis research to control the rate and extent of hydrogen release and preliminary efforts at regeneration of H3NBH3.
History of Sulphur Content Effects on the Thermal Stability of RP-1 under Heated Conditions

As technologies advance in the aerospace industry, a strong desire has emerged to design more efficient, longer life, reusable liquid hydrocarbon fueled rocket engines. To achieve this goal, a more complete understanding of the thermal stability and chemical makeup of the hydrocarbon propellant is needed. Since the main fuel used in modern liquid hydrocarbon systems is RP-1, there is concern that Standard Grade RP-1 may not be a suitable propellant for future-generation rocket engines due to concern over the outdated Mil-Specification for the fuel. This current specification allows high valued limits on contaminants such as sulfur compounds, and also lacks specification of required thermal stability qualifications for the fuel. Previous studies have highlighted the detrimental effect of high levels of mercaptan sulfur content (^50 ppm) on copper rocket engine materials, but the fuel itself has not been studied. While the role of sulfur in other fuels (e.g., aviation, diesel, and automotive fuels) has been extensively studied, little has been reported on the effects of sulfur levels in rocket fuels. Lower RP-1 sulfur concentrations need to be evaluated and an acceptable sulfur limit established before RP-1 can be recommended for use as the propellant for future launch vehicles. (5 tables, 8 figures, 9 refs.)
Modulation of myocardial L-triiodothyronine receptors in normal, hypothyroid, and hyperthyroid rats

Abstract To characterize the nuclear receptor believed to mediate the thyroid hormones' actions on the heart, binding of L-[ 125 I]T3 to extracts of myocardial cell nuclei from normal, propylthiouracil, and T4-treated rats has been investigated. Analysis of in vitro iodothyronine binding to this solubilized nuclear preparation revealed multiple saturable, specific binding sites for T3. High affinity binding for T3 (Kd = 4.2 ± 1.0 × 10 −10 mol/L), and lower affinity (Kd ∼ 10 −8 mol/L) binding activity appeared to be independent (Hill plot slope = 1). The mean maximal binding capacity of the high affinity binding site for T3 in euthyroid rats (84 ± 8 fmol/mg DNA) was increased by approximately 50% in hypothyroidism (120 ± 6 fmol/mg DNA) and unchanged in hyperthyroidism (88 ± 25 fmol/mg DNA). The molecular weight of this T3 binding site is estimated to be 50,000–55,000 daltons. The properties of this solubilized binding activity from rat myocardial nuclei are consistent with its putative role as the biologic thyroid hormone receptor. The increase in binding capacity with hypothyroidism suggest regulation by thyroid hormone of its nuclear receptor in myocardium.
Syphilis Serology in Blood Donors: A Possible Surrogate Marker for Human Immunodeficiency Virus Risk

We report a preliminary study on whether syphilis serology might be reactive in some blood donors at risk for human immunodeficiency virus (HIV) infection. We retrospectively analyzed voluntary blood donations with reactive Treponema pallidum antibody (TPA) tests according to the type of donation, the presence of other safety markers, confidential unit exclusion, syphilis diagnosis, and HIV risk factors. Over 2 years (1987-1988), 1 in 8,900 regular homologous donations (n = 258,610) was TPA positive as compared with 1 in 2,200 directed donations (n = 6,685) and 1 in 300 autologous donations (n = 8,870; p less than 0.05 for both). The rate in directed donations was not significantly higher than in first-time regular donors (1 in 4,800; n = 57,000). TPA-positive donations had higher rates of antibody to hepatitis B core antigen and confidential unit exclusion than TPA-negative donations. Ten TPA-positive homologous or directed donors had latent or previously treated syphilis (1 in 26,500 such donations), and 2 of these had HIV risk factors. None of the autologous donors were determined to have active syphilis. Syphilis serology in blood donors bears further scrutiny as a possible surrogate marker for HIV risk.
Special issue: managing and adapting to global change in tourism places

The focus of the articles in this special issue of Tourism Geographies is global change. Global change incorporates social and economic globalization, which is arguably the most important process to have shaped the development of modern tourism since the nineteenth century, and climate change, which is likely to be the most significant factor influencing human behavior and livelihood in the coming decades. The organization of these articles reflects a traditional geography approach, emphasizing the physical geography foundation of the human condition, especially through the issue of climate change. This is broadened by a series of insightful comparative studies of how communities relate to their changing natural and social environments through tourism.
Fecal chymotrypsin in alcoholic liver disease

Fecal chymotrypsin assays were done on 34 patients with alcoholic liver disease. Only one such patient had low fecal activity. Correlation of fecal chymotrypsin with fat malabsorption and duodenal drainage tests was undertaken. Although fat malabsorption was frequently encountered (13 of 34), the low incidence of abnormal fecal chymotrypsin suggests that severe pancreatic exocrine insufficiency is an unusual occurrence in this population. Six patients had pancreozymin-secretin tests and Lundh test meals and one showed abnormal results, but fecal chymotrypsin assays were uniformly normal in this small subgroup.
LiDAR forest inventory with single-tree, double-, and single-phase procedures.

Light Detection and Ranging (LiDAR) data at 0.5–2 m postings were used with double-sample, stratified procedures involving single-tree relationships in mixed, and single species stands to yield sampling errors ranging from ±2.1% to ±11.5%. LiDAR samples were selected with focal filter procedures and heights computed from interpolated canopy and DEM surfaces. Tree dbh and height data were obtained at various ratios of LiDAR, ground samples for DGPS located ground plots. Dbh-height and ground-LiDAR height models were used to predict dbh and compute Phase 2 estimates of basal area and volume. Phase 1 estimates were computed using the species probability distribution from ground plots in each strata. Phase 2 estimates were computed by randomly assigning LiDAR heights to species groups using a Monte Carlo simulation for each ground plot. There was no statistical difference between volume estimates from 0.5 m and 1 m LiDAR densities. Volume estimates from single-phase LiDAR procedures utilizing existing tree attributes and height bias relationships were obtained with sampling errors of 1.8% to 5.5%.
The abandonment of latent variables: Philosophical considerations

Cramer et al.'s critique of latent variables implicitly advocates a type of scientific anti-realism which can be extended to many dispositional constructs in scientific psychology. However, generalizing Cramer et al.'s network model in this way raises concerns about its applicability to psychopathology. The model could be improved by articulating why a given cluster of symptoms should be considered disordered.
Reproductive performance of the desert pupfish ( Cyprinodon n. nevadensis ) in relation to salinity

The reproductive performance of the desert pupfish, Cyprinodon n. nevadensis, was tested by exposing breeding pairs to a range of salinities from 0.1 to over 40‰ In terms of eggs g−1 body weight day−1 , eggs per spawning and embryo viability. reproductive performance was optimal at 10‰ Performance decreased above and below 11 producing a plateau of statistically equivalent reproductive performance from 0.2 to 20‰ The upper salinity limit placed on reproduction is the tolerance of the eggs, since a few eggs are laid above 20but they do not hatch. These small fish probably never experience the upper salinity limit for reproduction in their native habitat. The tolerance limits for reproduction are compared with a lethal range from less than 0.1 to 53in a 96 h LD-50 test.
Use of x-ray scattering functions in Kramers-Kronig analysis of reflectance

Kramers-Kronig analysis is commonly used to estimate the optical properties of new materials. The analysis typically uses data from far infrared through near ultraviolet (say 40--$40\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ or 5 meV--5 eV) and uses extrapolations outside the measured range. Most high-frequency extrapolations use a power law, 1/${\ensuremath{\omega}}^{n}$, transitioning to $1/{\ensuremath{\omega}}^{4}$ at a considerably higher frequency and continuing this free-carrier extension to infinity. The midrange power law is adjusted to match the slope of the data and to give pleasing curves, but the choice of power (usually between 0.5 and 3) is arbitrary. Instead of an arbitrary power law, it is better to use x-ray atomic scattering functions such as those presented by Henke and co-workers. These basically treat the solid as a linear combination of its atomic constituents and, knowing the chemical formula and the density, allow the computation of dielectric function, reflectivity, and other optical functions. The ``Henke reflectivity'' can be used over photon energies of 10 eV to 34 keV, after which a $1/{\ensuremath{\omega}}^{4}$ continuation is perfectly fine. The bridge between experimental data and the Henke reflectivity as well as two corrections made to the latter are discussed.
Cognition and Vocation

The Mind at Work is a book that is so pleasurable to read, so gentle and genial in tone, it is occasionally easy to forget how ambitious it is as well. In its quiet way, the book offers a challenge to traditional boundaries between "blue-collar" and "white-collar" work, describing the (often complex) cognitive demands of the for mer and the hands-on, manual dimension of the latter. In the process, author Mike Rose (a professor in the Graduate School of Education at the University of Califor nia, Los Angeles) manages to explode a variety of stereotyped portraits of the pro fessions-but as it happens, the explosions are beneficial to all concerned. The book thus heralds that rarest of revolutions in which no one gets hurt. The Mind at Work is primarily a discussion of the cognitive demands of profes sions whose cognitive dimension is often overlooked. Rose writes of the way in which plumbers understand complex systems of pipes, materials, and dynamic pro cesses; how the perceptions of young carpentry students are made more acute and re sponsive as they learn their profession; how hair stylists exercise creativity within the constraints set by their tools (and their customers' demands); and how a welding teacher instructs her students to combine theory and practice by developing an un derstanding of the principles behind their instruments. The book begins on a note closer to home, as Rose describes his mother's lifelong work as a waitress and shows in detail how her day-to-day work included highly practiced skills of planning, con flict resolution, and self-taught heuristics to aid visual and spatial memory. (These last skills, by the way, would appear familiar to students of the memory-enhancing
Quantum theory: the classical theory of nonlinear electromagnetics

Abstract This paper combines a classical electrodynamic base, adaptive electrons, and reactive radiation reaction energy effects and obtaines atomic stability, the Schrodinger equation, and quantized radiation. Electrons are assigned intrinsic parameter values and modeled as dynamic distributions of charge and current densities, bound together in a soliton-like way, with a form that alters in response to local force fields: not as waves or rigid spheres. The result is a deterministic view of quantum theory. Its postulatory base is replaced with derived results. The statistical interpretation of the wave function is that of standard quantum mechanics. When combined with classical electrodynamics, the theory completely describes quantum radiation.