cssi/SciSciGPT-SciSciNet huggingface dataset:
The minimum latency problem

We are given a set of points p1, . . . , pn and a symmetric distance matrix (dij) giving the distance between pi and pj . We wish to construct a tour that minimizes ∑n i=1 `(i), where `(i) is the latency of pi, defined to be the distance traveled before first visiting pi. This problem is also known in the literature as the deliveryman problem or the traveling repairman problem. It arises in a number of applications including diskhead scheduling, and turns out to be surprisingly different from the traveling salesman problem in character. We give exact and approximate solutions to a number of cases, including a constant-factor approximation algorithm whenever the distance matrix satisfies the triangle inequality. ∗School of Computer Science, CMU. Supported in part by NSF National Young Investigator grant CCR9357793. †School of Computer Science, CMU. ‡IBM T.J. Watson Research Center.
Unlocking the mysteries of iron homeostasis and of the anemia of chronic disease: is hepcidin the key?

![Figure][1] When the long and difficult search for the HLA-linked gene was finally brought to a conclusion by the cloning of HFE, it was generally thought that the discovery of this elusive molecule would provide us with true insight into how body iron is regulated. After all, mutation of
Effect of a magnetic field on phospholipid membranes

Abstract The paramagnetic resonance and optical properties of phospholipid bilayer membranes indicate that the phospholipid molecules can be oriented by a magnetic field whose direction lies in the plane of the membrane.
Axoplasmic transport of labeled proteins in rat ventral motoneurons.

Axoplasmic transport was studied in lumbar ventral motor neurons of adult rats by injecting l-leucine3-H directly into the spinal cord and subsequently analyzing the distribution of the incorporated label in the nerve roots and peripheral nerve. Very little of the label was found in the dorsal roots at distances in excess of 10 mm from the spinal cord during the period 1–40 days after injection, suggesting that the label was not carried into the nerve by diffusion in the endoneurial spaces. On the other hand, the rapid entry of the label into the ventral root and peripheral nerve conforms with the concept that axoplasmic proteins are synthetized in the neuron cell body and transported into the axon. It is suggested that the labeled axoplasmic protein was transported into the axon in possibly three sectors of the axoplasm: (a) a slowly moving sector which is transported at approximately 1 mm/day; (b) a sector which has a net somatofugal transport velocity of a few mm/day; and (c) a rapidly moving sector of the axoplasm in which components are transported at velocities in excess of 100 mm/day.
Systematic techniques for solving nonlinear communications

An explanation of differences of individuals in engineering communications skills places common problems in several psychological contexts. Individual and corporate personality types are examined along with standard approaches to improving communications. Group communication patterns are analyzed and systematic techniques are presented which add behavioural psychological considerations to the mechanics of generating valuable communications.
Active surveillance vs. treatment for low-risk prostate cancer: A cost comparison

Abstract Objective Radical prostatectomy (RP) and radiation therapy are standard curative approaches for low-risk prostate cancer (PC). Active surveillance (AS) is becoming an increasingly accepted management alternative for low-risk PC. Our aim is to compare the cumulative medical costs of treatment vs. AS. Methods and materials We collected data on the cumulative medical costs of open radical retropubic prostatectomy (RRP), robotic-assisted radical prostatectomy (RARP), external beam radiotherapy (EBRT), brachytherapy (BT), and AS at our institution. For physicians' reimbursements, Medicare values of our region were used to maintain uniformity. For inpatient costs other than reimbursements, we used the mean cost at our institution. The costs of RRP and RARP involve preoperative investigations, medical clearance, physicians' fees, inpatient costs, and pathologic examination of prostatectomy specimen and follow-up. The inpatient costs include the operating room, disposable equipment, anesthesia, post-anesthesia care, transfusion, and hospital stay. The cost of EBRT involves the cost of consultation, planning, simulation and treatment sessions, and follow-up. BT costs involved radiotherapy planning as well as inpatients costs. AS protocol involves regular visits, transrectal ultrasound guided biopsies, prostate specific antigen (PSA) testing. To evaluate the cost of treating complications, treatment after AS, and treatment for recurrence, we created a Markov model based on recent studies and our experience. Results The cumulative costs of RRP are $9,732 (1 year), $10,360 (2 years), $12,209 (5 years), and $15,084 (10 years). While for RARP, the costs are $17,824 (1 year), $18,308 (2 years), $20,117 (5 years), and $22,762 (10 years). The costs of EBRT are $20,730 (1 year), $20,969 (2 years), $22,043 (5 years), and $23,953 (10 years). BT costs are $14,061 (1 year), $14,300 (2 years), $15,374 (5 years), and $17,284 (10 years). The costs of AS are $1,154 (1 year), $2,308 (2 years), $8,761 (5 years), and $13,116 (10 years). Conclusions The cumulative medical costs of RARP and EBRT are much higher than BT, RRP, and AS. AS is associated with a different cost distribution in which the initial cost is low and relatively higher cost of follow-up. Despite the higher follow-up cost, AS remains the most cost effective alternative for low-risk PC.
Active phase of a nickel phosphide (Ni2P) catalyst supported on KUSY zeolite for the hydrodesulfurization of 4,6-DMDBT

Abstract Ni2P catalysts supported on potassium ion-exchanged ultrastable Y zeolites (KUSY) were prepared by temperature-programmed reduction (TPR), and the effect of Ni2P loading and initial Ni/P ratios on the hydroprocessing performance was studied. X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS) were used to obtain structural parameters. Transmission electron microscopy (TEM) analysis showed that the KUSY-supported Ni2P samples consisted of nanoparticles, which were likely situated in the mesoporous cavities or the external surfaces of the zeolite crystals. The catalytic activity was measured at 613 K and 3.1 MPa in a three-phase fixed bed reactor for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) using a model liquid feed containing 500 ppm S as 4,6-dimethyldibenzothiophene (4,6-DMDBT), 500 ppm N as quinoline, and 3000–6000 ppm S as dimethyldisulfide (DMDS). Partial exchange with K enhanced the catalytic activity for the HDS of 4,6-DMDBT and resistance to N-compound inhibition. The Ni2P/KUSY had high activity with an HDS conversion of 99%, and an HDN conversion of 100%, which were much higher than those of a commercial Ni–Mo–S/Al2O3 catalyst with an HDS conversion of 80% and HDN conversion of 100%, based on equal sites (240 μmol) loaded in the reactor. The sites were counted by CO chemisorption for the phosphide and by low-temperature O2 chemisorption for the sulfide. Deficiency of P in the Ni2P resulted in deactivation, probably due to susceptibility to sulfidation. EXAFS analysis of the catalysts showed that the addition of extra P led to an increase in Ni–P coordination with lengthening of Ni–Ni bond distances, resulting in a high and stable catalytic activity.
Endogenous Growth in a Dependent Economy with Traded and Nontraded Capital

The equilibrium growth path for this economy depends upon the relative sectoral capital intensities of the two production functions. If the nontruded sector is relatively intensive in traded capital, both the relative price of nontraded output and the price of installed capital always remain at their respective steady-state levels. Traded capital and aggregate wealth are always on their respective steady-state growth paths. Nontraded capital undergoes transitional dynamics, ultimately converging to the growth rate of traded capital and an equilibrium ratio of traded to nontraded capital. If the sectoral intensities are reversed, both asset prices will follow transitional adjustment paths.
Optimization of particle image velocimeters. I, Double pulsed systems

The spatial resolution, detection rate, accuracy and reliability of a particle image velocimeter (PIV) depend critically upon the careful selection of a number of parameters of the PIV system and the fluid motion. An analytical model and a Monte Carlo computer simulation have been developed to analyse the effects of experimental parameters and to optimize the system parameters. A set of six nondimensional parameters that are the most significant in optimizing PIV performance are identified. They are the data validation criterion, the particle image density, the relative in-plane image displacement, the relative out-of-plane displacement, a velocity gradient parameter, and the ratio of the mean image diameter to the interrogation spot diameter. These parameters are studied for the case of interrogation by autocorrelation analysis. By a single transformation, these results can be applied to interrogation by two-dimensional Fourier transform analysis of the Young's fringes.
Using denoising to improve image fusion performance

We applied an image fusion approach that uses different wavelet transforms for the forward and reconstruction transforms to efficiently compact energy for improved reconstruction. In addition, we used denoising to reduce the error induced by this approach. We found that using such an approach generally increases the Average Relative Entropy (ARE) of the fused result when compared to a conventional image fusion method.
Prophylactic antibiotics with intracranial pressure monitors and external ventricular drains: a review of the evidence.

BACKGROUND The role of prophylactic antibiotics (PABs) in preventing infections associated with intracranial pressure (ICP) monitors and external ventricular drains (EVD) is not well defined. METHODS This study includes an analysis of published reports and a survey of current practices regarding the use of PABs with ICP monitors and EVDs. A computerized data search and a review of the abstracts from two major national neurosurgical meetings over the past decade yielded 85 related articles. Three independent investigators, blinded to the title, author(s), institution(s), results, and conclusions of the articles used predetermined inclusion criteria to select studies for meta-analysis. Thirty-six responses were returned from 98 questionnaires (37%) mailed to university neurosurgical programs. RESULTS Among the articles reviewed, only two studies met the predetermined inclusion criteria for the meta-analysis, and they were of insufficient size to produce statistically significant results. Among the 36 programs that responded to the survey, 26 (72%) used PABs, mainly cephalosporins (46%) and semisynthetic penicillins (38%), with ICP monitors and EVDs. Twenty-two (85%) used one drug, and 4 (15%) used two drugs. Twenty-two (61%) of the total group reported intra-institutional variation in practices among individual staff neurosurgeons. Nineteen (53%) expressed interest in a retrospective study, and 27 (75%) expressed interest in a prospective study on the role of PABs in minor neurosurgical procedures. CONCLUSION No consensus regarding the use of PABs with ICP monitors and EVDs is noted. Randomized controlled trials of sufficiently large size with appropriate blinding are needed to address this issue.
The relationship between social stratification and all-cause mortality among children in the United States: 1968-1992.

Background. US childhood poverty rates have increased for most of the past 2 decades. Although overall mortality among children has apparently fallen during this interval, these aggregate mortality rates may hide a disproportionate burden imposed on the least advantaged. This study assessed the impact of social stratification on long-term US childhood mortality rates and examined the temporal relationship between mortality attributable to social stratification and childhood poverty rates. Methods. Using US childhood mortality data obtained from the Compressed Mortality File (National Center for Health Statistics) and a county-level measure of social stratification (residential telephone availability), I evaluated the impact of social stratification on long-term trends (1968–1992) in age-adjusted mortality and compared the resulting attributable proportions to trends in childhood poverty rates. Results. Between 1968 and 1987 the proportion of US childhood deaths attributable to social stratification decreased from .22 to .17. Subsequently, it increased to .24 in 1992, despite continuous declines in overall childhood mortality rates. These proportions correlated strongly with earlier childhood poverty rates, taking into account an apparent 9-year lag. Among black children comparable trends were not observed, although throughout this time period their mortality rates were far higher than among the rest of the population and declined more slowly. Conclusions. Despite declining childhood mortality rates between 1968 and 1992, children living in the least advantaged counties continued to die at higher rates than those living in the most advantaged counties. This differential worsened considerably after 1987, and by 1992 had a substantive impact on US life expectancy at birth, resulting in perhaps the most significant (in terms of years of life lost) reversal in the health of the US public in the 20th century.
Pinocytosis by epithelium associated with lymphoid follicles in the bursa of fabricius, appendix, and Peyer's patches. An electron microscopic study

The fine structure and micropinocytotic capabilities of epithelial cells closely associated with lymphoid follicles in the chicken bursa of Fabricius, rabbit appendix, and mouse Peyer's patch were compared. Epithelial cells capable of transporting ferritin and India ink tracers from the lumen were demonstrated in all three locations. Epithelial cells not associated with lymphoid follicles in the bursa and appendix did not express pinocytotic activity. Lymphoid cells were identified in bursal epithelium of chick embryos as early as the twelfth day of incubation. These lymphoid cells were smaller than typical bursal lymphocytes, had dense cytoplasm, numerous cytoplasmic projections, and prominent nucleoli. The small lymphoid cells were first demonstrable at a time in incubation during which lymphoid stem cells have been shown to migrate into the bursal epithelium. Lymphoid cells were seen earlier than the specialized follicle-associated epithelium. It is concluded that specialized pinocytotic follicle-associated epithelium does not induce initial migration of stem cells into areas along the intestinal tract, but that this transepithelial pinocytotic flow of intestinal contents after birth may provide a significant stimulus for attraction, proliferation and egression of lymphocytes.
A computational model to protect patient data from location-based re-identification

Objective: Health care organizations must preserve a patient's anonymity when disclosing personal data. Traditionally, patient identity has been protected by stripping identifiers from sensitive data such as DNA. However, simple automated methods can re-identify patient data using public information. In this paper, we present a solution to prevent a threat to patient anonymity that arises when multiple health care organizations disclose data. In this setting, a patient's location visit pattern, or ''trail'', can re-identify seemingly anonymous DNA to patient identity. This threat exists because health care organizations (1) cannot prevent the disclosure of certain types of patient information and (2) do not know how to systematically avoid trail re-identification. In this paper, we develop and evaluate computational methods that health care organizations can apply to disclose patient-specific DNA records that are impregnable to trail re-identification. Methods and materials: To prevent trail re-identification, we introduce a formal model called k-unlinkability, which enables health care administrators to specify different degrees of patient anonymity. Specifically, k-unlinkability is satisfied when the trail of each DNA record is linkable to no less than k identified records. We present several algorithms that enable health care organizations to coordinate their data disclosure, so that they can determine which DNA records can be shared without violating k-unlinkability. We evaluate the algorithms with the trails of patient populations derived from publicly available hospital discharge databases. Algorithm efficacy is evaluated using metrics based on real world applications, including the number of suppressed records and the number of organizations that disclose records. Results: Our experiments indicate that it is unnecessary to suppress all patient records that initially violate k-unlinkability. Rather, only portions of the trails need to be suppressed. For example, if each hospital discloses 100% of its data on patients diagnosed with cystic fibrosis, then 48% of the DNA records are 5-unlinkable. A naive solution would suppress the 52% of the DNA records that violate 5-unlinkability. However, by applying our protection algorithms, the hospitals can disclose 95% of the DNA records, all of which are 5-unlinkable. Similar findings hold for all populations studied. Conclusion: This research demonstrates that patient anonymity can be formally protected in shared databases. Our findings illustrate that significant quantities of patient-specific data can be disclosed with provable protection from trail re-identification. The configurability of our methods allows health care administrators to quantify the effects of different levels of privacy protection and formulate policy accordingly.
Accurate polarization within a unified Wannier function formalism

We present an alternative formalism for calculating the maximally localized Wannier functions in crystalline solids, obtaining an expression which is extremely simple and general. In particular, our scheme is exactly invariant under Brillouin zone folding, and therefore it extends trivially to the $\ensuremath{\Gamma}$-point case. We study the convergence properties of the Wannier functions, their quadratic spread and centers as obtained by our simplified technique. We show how this convergence can be drastically improved by a simple and inexpensive ``refinement'' step, which allows for very efficient and accurate calculations of the polarization in zero external field.
Initiation, ablation, precursor formation, and instability analysis of thin foil copper liners

Summary form only given. Solid liners are an attractive load design for use with magnetized liner inertial fusion (MagLIF) and for possible replacement of wire-array Z-pinches on large pulsed-power drivers. Experiments have been conducted on COBRA, our 1 MA, 100 ns rise time pulsed power generator, to investigate three aspects that can affect liner performance: initiation; ablation and precursor formation; and instability development.
Atomic-step rearrangement on Si(100) by interaction with arsenic and the implication for GaAs-on-Si epitaxy

The lowest-energy configuration of a class of vicinal Si(100) surfaces has equally spaced steps, each with a height of two atomic units. This results in a single-domain surface with the surface Si-Si dimers being aligned parallel to the step edges. The interaction of As with vicinal Si(100) surfaces is crucial for GaAs growth on Si and there have been several studies of this system, but results from several groups appear to be in contradiction. The results described here, which combine scanning tunneling microscopy, low-energy electron diffraction, and x-ray photoemission, yield a consistent picture of the interaction of As with vicinal Si(100). It is found that depending on the time order of (i) exposure to As and (ii) raising the surface temperature, the directions of the As-As dimers can reproducibly be made perpendicular or parallel to the step edge. In the latter case the step array on the Si substrate is completely rearranged. GaAs grown on one type of dimer arrangement is controllably oriented 90\ifmmode^\circ\else\textdegree\fi{} with respect to that on the other type.
The Effect of Epoxidized Safflower Oil on the Properties of Polyvinyl Chloride Films

Polyvinyl chloride (PVC) is among the top three most widely used plastics globally. Di(2-ethylhexyl) phthalate (DEHP) is often added as a plasticizer by up to 40 wt% to impart flexibility. DEHP, a toxin and carcinogen, can leach into the atmosphere to cause environmental contamination. This study investigates the suitability of epoxidized safflower oil, namely Carthamus tinctorius oil (ECTO), as a PVC plasticizer. PVC films with DEHP and ECTO were compared in resilience, elastic modulus, toughness, and glass transition temperature. ECTO films displayed statistically similar physical properties of resilience, elastic modulus, and toughness at up to 30 wt%. ECTO films of 0 to 40 wt% all displayed significantly lower glass transition temperature.
A New Amazonian Species of Micronycteris (Chiroptera: Phyllostomidae) with Notes on the Roosting Behavior of Sympatric Congeners

Abstract Micronycteris sensu stricto is a diverse group of small to medium-sized phyllostomid bats characterized by large rounded pinnae that are connected at the base by an interauricular band of skin. Eight species are currently recognized, including three with dark venters (hirsuta, megalotis, microtis) and five with pale venters (brosseti, sanborni, schmidtorum, minuta, homezi). As many as seven species can occur sympatrically at Amazonian localities. In this paper we describe a new dark-bellied species from the lowlands of northeastern Peru and document its diagnostic external and craniodental characters. We also summarize information about diurnal roosting habitats for the new species and its Amazonian congeners, and we emphasize the importance of nonconventional collecting methods for future studies of phyllostomine diversity in Neotropical rainforests.
The determination of organotins (TBT) in fish and shellfish via gas chromatography flame photometric detection and direct current plasma emission spectroscopy (GC-FPD/DCP)

Gas chromatography (GC) has been interfaced very simply and inexpensively with a flame photometric detector (FPD) and a direct current plasma (DCP) atomic emission spectrometer in order to perform highly specific and selective determination of organotins in fish and shellfish samples. GC–FPD studies employed a fused-silica, megabore column with a thin, immobilized stationary phase of DB-17 (1 μm thickness), with a commercially available GC–FPD instrument. No prior alkylation or hydridization reactions were performed on the organotins; rather they were separated as the original, native species. Separate GC–FPD and GC–DCP injections and quantitative determinations have been performed, though simultaneous FPD/DCP detection on a single injection is suggested. This permitted routine qualitative and quantitative determinations of organotin species in complex food matrices (fish/shellfish) via both element selective detectors. Isothermal GC–FPD/DCP conditions permitted baseline resolution of all four tin species of interest today: monobutyl-, dibutyl-, tributyl- (TBT), and tetrabutyl-tin. Optimization of the GC–DCP interface was accomplished, followed by a determination of detection limits and linearity of the calibration plots, and a comparison of the results with those obtained by the newer GC–FPD approach (which was also developed here). In three sample instances, qualitative and quantitative results for naturally occurring and spiked levels agreed for both the GC–FPD and GC–DCP approaches. Improved sample preparation and extraction procedures have been developed for organotins from fish samples involving extraction with an organic solvent, concentration, saponification, back-extraction, and injection of the eluent onto the GC column. Quantitative levels of organotins (solely TBT) in fish and shellfish are reported for samples from Europe, Korea, Scandinavia, and the USA.
Biographical Objects: How Things Tell the Stories of People's Lives

Biographical Objects: How Things Tell the Stories of People's Lives. JANET HOSKINS. New York: Routledge, 1998. + 213 pp., photographs, references, index.
Genetic information for chronic disease prediction

Type 2 diabetes and coronary artery disease are commonly occurring polygenic diseases, which are responsible for significant morbidity and mortality. The identification of people at risk for these conditions has historically been based on clinical factors alone. Advances in genetics have raised the hope that genetic testing may aid in disease prediction, treatment, and prevention. Although intuitive, the addition of genetic information to increase the accuracy of disease prediction remains an unproven hypothesis. We present an overview of genetic issues involved in polygenic diseases, and summarize ongoing efforts to use this information for disease prediction.
Ecosystem Services from Keystone Species: Diversionary Seeding and Seed‐Caching Desert Rodents Can Enhance Indian Ricegrass Seedling Establishment

Seeds of Indian ricegrass (Achnatherum hymenoides), a native bunchgrass common to sandy soils on arid western rangelands, are naturally dispersed by seed-caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available on or beneath plants and recover most of their caches for consumption during the remainder of the year. Unrecovered seeds in caches account for the vast majority of Indian ricegrass seedling recruitment. We applied three different densities of white millet (Panicum miliaceum) seeds as “diversionary foods” to plots at three Great Basin study sites in an attempt to reduce rodents' over-winter cache recovery so that more Indian ricegrass seeds would remain in soil seedbanks and potentially establish new seedlings. One year after diversionary seed application, a moderate level of Indian ricegrass seedling recruitment occurred at two of our study sites in western Nevada, although there was no recruitment at the third site in eastern California. At both Nevada sites, the number of Indian ricegrass seedlings sampled along transects was significantly greater on all plots treated with diversionary seeds than on non-seeded control plots. However, the density of diversionary seeds applied to plots had a marginally non-significant effect on seedling recruitment, and it was not correlated with recruitment patterns among plots. Results suggest that application of a diversionary seed type that is preferred by seed-caching rodents provides a promising passive restoration strategy for target plant species that are dispersed by these rodents.
A Surface Mooring for Air–Sea Interaction Research in the Gulf Stream. Part II: Analysis of the Observations and Their Accuracies

AbstractA surface mooring was deployed in the Gulf Stream for 15 months to investigate the role of air–sea interaction in mode water formation and other processes. The accuracies of the near-surface meteorological and oceanographic measurements are investigated. In addition, the impacts of these measurement errors on the estimation and study of the air–sea fluxes in the Gulf Stream are discussed. Pre- and postdeployment calibrations together with in situ comparison between shipboard and moored sensors supported the identification of biases due to sensor drifts, sensor electronics, and calibration errors. A postdeployment field study was used to further investigate the performance of the wind sensors. The use of redundant sensor sets not only supported the filling of data gaps but also allowed an examination of the contribution of random errors. Air–sea fluxes were also analyzed and computed from both Coupled Ocean–Atmosphere Response Experiment (COARE) bulk parameterization and using direct covariance mea...
The constitution of difference: Space and psyche in landscapes of exclusion

Abstract Negative reactions to the siting of group homes for persons with disabilities have at their center a public intolerance of ‘difference’. We can better understand these reactions by exploring the connection between the organization of social space and the structure of the psyche. Drawing from psychoanalytic theory, I suggest that because people internalize social norms as a condition for subjective becoming, their own sense of identity is to some extent dependent upon the maintenance of surrounding social and spatial order. This link helps to explain the anxiety underlying opposition to group homes and analogous facilities. The transgression implied by the siting threatens not only the social order, but also the bases of residents' own identities. A case-study involving the recent siting of an AIDS hospice is used to illustrate this theoretical discussion.
Mine detection with the Cauchy beam-forming signal-processing approach

Real life sonar applications exist in which impulsive ocean channels tend to produce large- amplitude, short-duration interferences more frequently than Gaussian channels do. The stable law has been shown to successfully model noise over certain impulsive channels. In this paper, we propose new robust techniques for target detection and localization in the presence of noise modeled as a complex isotropic stable process. We develop optimal in the maximum likelihood sense approaches to the direction-of-arrival problem and we introduce the Cauchy Beamformer. We show that the Cauchy Beamformer provides better bearing estimates than the Gaussian Beamformer in a wide range of impulsive noise environments and for very low signal-to-noise ratio values. In addition, we derive the Cramer-Ratio bound on the estimation error covariance for the case of deterministic incoming signals retrieved in the presence of additive complex Cauchy noise. Finally, we demonstrate the robustness of the Cauchy Beamformer via simulation experiments.
Kv3 channels: voltage-gated K+ channels designed for high-frequency repetitive firing

Analysis of the Kv3 subfamily of K(+) channel subunits has lead to the discovery of a new class of neuronal voltage-gated K(+) channels characterized by positively shifted voltage dependencies and very fast deactivation rates. These properties are adaptations that allow these channels to produce currents that can specifically enable fast repolarization of action potentials without compromising spike initiation or height. The short spike duration and the rapid deactivation of the Kv3 currents after spike repolarization maximize the quick recovery of resting conditions after an action potential. Several neurons in the mammalian CNS have incorporated into their repertoire of voltage-dependent conductances a relatively large number of Kv3 channels to enable repetitive firing at high frequencies - an ability that crucially depends on the special properties of Kv3 channels and their impact on excitability.
An updated estimate of the body dimensions of US children

Anthropometric data from children are important for product design and the promulgation of safety standards. The last major detailed study of child anthropometry in the USA was conducted more than 30 years ago. Subsequent demographic changes and the increased prevalence of overweight and obesity render those data increasingly obsolete. A new, large-scale anthropometric survey is needed. As an interim step, a new anthropometric synthesis technique was used to create a virtual population of modern children, each described by 84 anthropometric measures. A subset of these data was validated against limited modern data. Comparisons with data from the 1970s showed significant changes in measures of width and circumference of the torso, arms and legs. Measures of length and measurements of the head, face, hands and feet exhibited little change. The new virtual population provides guidance for a comprehensive child anthropometry survey and could improve safety and accommodation in product design. Practitioner Summary: This research reviews the inadequacies of available sources of US child anthropometry as a result of the rise in the rates of overweight and obesity. A new synthesised database of detailed modern child anthropometry was created and validated. The results quantify changes in US child body dimensions since the 1970s.
Finestructure and Microstructure Observations During the Passage of a Mild Storm

Abstract Finestructure and microstructure observations of temperature and salinity were made over a two-week period in late winter at a site in the central North Pacific, during which time a mild storm, maximum winds of 18 kt, passed through the area. The strong initial lateral variability in T and S, but weak vertical stratification, was altered apparently by mixing due to surface cooling and the storm winds to produce several discrete types of water. These began to spread laterally several days after the onset of the storm and resulted in a triple step structure of 50 m thick homogeneous layers at one location. Temperature fluctuations in the mixed layers varied between 10−3 and 10−2°C rms, and χ, the rate of destruction of temperature fluctuations, ranged from 1×10−10 to 4×10−2°C−2 s−1. The lower values occurred early in the storm after the mixed layer reached an equilibrium depth of about 100 m. The 2.5 m thick transition region at the base had a sharp interface, 0.25 m thick, but there was no evidenc...
Interactive Manipulation Of Three-Dimensional Data Via A Two-Dimensional Display Device

The medical motivation for interactive manipulation of 3D data via a 2D display device is presented. Four specific topics are described: (i) interactive orientation specification, (ii) 3D83, a program currently being used in clinical practice, (iii) directed-contour-based display and manipulation, and (iv) binary-array-based display and manipulation. Timings are reported for medical exam-ples. Advantages and disadvantages of the various approaches are discussed.
"Flip-flop" orientation of agarose gel fibers in pulsed alternating electric fields.

The orientation of the agarose gel matrix in pulsed electric fields has been studied by transient electric birefringence. Two types of agarose with different degrees of charge were studied, in addition to agarose solutions and gels containing beta-carrageenan, a stereoisomer of agarose, and polyacrylamide. Agarose gels exhibit normal orientation behavior when short, high voltage pulses are applied to the gel. The sign of the birefringence is positive and the relaxation times are consistent with the orientation of dangling fiber ends parallel to the electric field. When long, low voltage pulses, of the amplitude and duration used for pulsed field gel electrophoresis, are applied to the gel, completely different orientation effects are observed. The amplitude of the birefringence (i.e., extent of orientation) is much larger than expected from the high field results, and the birefringence decay curves contain multiple components of opposite sign. The relaxation times are consistent with the orientation of long agarose chain bundles or fibers, as well as large three-dimensional domains. Chain bundles or fibers of the lengths observed in the agarose gels are also observed in agarose solutions, suggesting that the fibers that are free to orient in the gels had previously formed in the sol phase and are only weakly integrated into the matrix structure. In rapidly reversing low voltage electric fields, the sign of the birefringence of the agarose gels reverses from positive to negative in phase with the reversing electric field. This alternating change in the sign of the birefringence suggests that the agarose fibers "flip-flop" in orientation from parallel to perpendicular every time the electric field reverses its direction. Similar effects are observed for agarose gels with different charge densities. The flip-flop orientation and reorientation of agarose fibers within the matrix in reversing electric fields may decrease the microscopic viscosity of the gel, increasing the mobility of large DNA molecules migrating through the gel during electrophoresis. Polyacrylamide gels do not exhibit an anomalous reversal of the sign of the birefringence in reversing electric fields. Hence, the orienting fibers in these gels do not change their direction of orientation in reversing electric fields. Extensive orientation is observed in beta-carrageenan gels, similar to that observed in agarose gels. However, little orientation occurs in polyacrylamide gels, which are chemically crosslinked.(ABSTRACT TRUNCATED AT 400 WORDS)
Physical characteristics and occurrence rates of meteoric plasma layers detected in the Martian ionosphere by the Mars Global Surveyor Radio Science Experiment

[1] Low-altitude plasma layers are present in 71 of 5600 electron density profiles from the Martian ionosphere obtained by the Mars Global Surveyor Radio Science experiment. These layers are produced by the ablation of meteoroids and subsequent ionization of meteoric atoms. The mean altitude of the meteoric layer is 91.7 ± 4.8 km. The mean peak electron density in the meteoric layer is (1.33 ± 0.25) × 1010 m−3. The mean width of the meteoric layer is 10.3 ± 5.2 km. The occurrence rate of meteoric layers varies with season, solar zenith angle, and latitude. Seasonal variations in occurrence rate are particularly strong, often exceeding an order of magnitude. Meteoric layer altitude, peak electron density, and width are all positively correlated, with correlation coefficients of 0.3–0.4. Other correlation coefficients between the physical characteristics of meteoric layers and atmospheric or observational properties, such as scale height, solar zenith angle, and solar flux, have absolute values that are significantly smaller, indicating lack of correlation. The photochemical lifetime of plasma in meteoric layers is ∼12 days and depends on altitude.
Experimental results for a heat-sink mechanical seal

This work presents experimental results for a heat-sink mechanical seal installed in a 1 x 1.5 x 6 in. ANSI centrifugal water pump. The heat-sink seal is constructed of a stainless steel substrate with an electrodeposited pin fin micro-heat sink located within 3 mm of the end face. Each pin has a ten-sided polygon cross section with a flat-to-flat diameter of 675 μm, a height of 856 μm, and a 300-μm edge-to-edge spacing. The end face is coated with a WC thin film that forms the wear surface for the rotating ring. The heat-sink seal's effectiveness is demonstrated in a significant reduction of both the seal interface and seal chamber temperature when compared to a similar industry standard seal. The heat-sink seal removes 750 W of heat and reduces the stationary ring temperature by 80° C under dead-head conditions using only 1.6 W of coolant pumping power.
Comparison of the effects of propylthiouracil and selenium deficiency on T3 production in the rat.

Selenium deficiency and propylthiouracil (PTU) treatment both decrease hepatic type I T4 5'-deiodinase activity (5'D-I), which is considered to be an important regulator of the serum T3 derived from peripheral T4 to T3 conversion (T3 neogenesis). The effects of PTU treatment or a selenium-deficient diet on T4 and T3 kinetics were compared in thyroid-ablated rats infused with stable T4 to determine whether PTU treatment is a more potent inhibitor of T3 neogenesis than selenium deficiency and to compare the degree of inhibition of T3 production with the degree of inhibition of 5'D-I. PTU treatment and selenium deficiency (Se-) did not affect the T3 MCR (control, 46.0 +/- 2.5; PTU, 41.7 +/- 2.8; Se-, 41.1 +/- 4.0 ml/h.100 g BW), but did reduce serum T3 concentrations by 29% and 25%, respectively (control, 58.7 +/- 2.6; PTU, 41.5 +/- 1.0; Se-, 43.9 +/- 2.7 ng/dl; P < 0.01 for PTU or Se- vs. control) and the T3 production rate by 35% and 32%, respectively (control, 26.6 +/- 1.0; PTU, 17.3 +/- 2.0; Se-, 18.0 +/...
Informing the Research Agenda on Domestic Abuser Intervention Through Practitioner-Researcher Dialogues

Officials in the state of Maryland have adopted the goal of establishing empirically based practice standards for intervention programs that work with domestic abuse perpetrators. This article highlights a set of roundtable discussions between practitioners, policy makers, and researchers, the goal of which was to inform the research agenda on Abuser Intervention Programs (AIPs). Contextual material is provided on the gap between practice and research in mental health disciplines in general and on the need for structured communication between practitioners and researchers to help bridge this gap. Roundtable participants emphasized a number of important research directions that converge and diverge with recent trends in research on domestic abuse perpetrators and AIPs.
Change within a Teacher Education Program and Laboratory: A Reflective Commentary.

Intentional, systemic philosophical change on an educational program level and on an individual level is often a slow and cyclic process. In this article, we reflect on the journey of philosophical change and growth from a traditional philosophy to an inquiry-based, Reggio-inspired one that occurred on both levels in an early childhood teacher education program and laboratory school over a period of 7 years. As an inquiry group, we reflected on the change we experienced in our own teaching methods, our interactions with staff members and each other, and our perceptions of change in interaction with our students. After carefully and systematically reviewing our reflections, five trends in change were identified. They were (a) recasting the image of the teacher and reevaluating the process of teaching and learning, (b) valuing dialogue, (c) cultivating a reflective mindset, (d) valuing outside perspectives, and (e) building meaningful relationships. The process of reflecting on and documenting our journey h...
Neurochemical interactions of cocaine with dopaminergic systems.

Abstract The psychotropic effects of cocaine are usually attibuted to its ability to block the reuptake of dopamine into mesocortical or mesulimblic neurons, rather than to its ability to block the reuptake of 5-HT and norepinephrine. However, the interactions between cocaine and dopamine receptors have only recently been investigated. In this article , Matthew Galloway reviews new biochemical findings on the site of action of cocaine and its effects on dopamine systems. These support a role of dopamine reuptake inhibition in cocaine addiction, but the exact mechanism of interaction between the cocaine binding site and the dopamine transporter remains to be determined .
Extracellular signal-regulated kinase 1/2-mediated phosphorylation of JunD and FosB is required for okadaic acid-induced activator protein 1 activation.

Previously, we reported that in papilloma-producing 308 mouse keratinocytes, the tumor promoter okadaic acid, a serine-threonine phosphatase inhibitor, increased binding of activator protein 1 (AP-1) to a consensus 12-O-tetradecanoylphorbol-13-acetate-responsive element (Rosenberger, S. F., and Bowden, G. T. (1996) Oncogene12, 2301–2308). In this study, we investigated the correlation between AP-1 DNA binding and transactivation and examined molecular mechanisms involved in this process. Using a luciferase reporter driven by region −74 to +63 of the human collagenase gene, we demonstrated induction of AP-1-mediated transcription following okadaic acid treatment. By performing in vitro kinase assays, we found elevated activities of extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase. The ERK-1/2-specific inhibitor PD 98059 completely abrogated okadaic acid-induced AP-1 transactivation without altering AP-1 expression, DNA binding, or complex composition. Phosphorylation analyses indicated that inhibition of ERK-1/2 decreased okadaic acid-elevated phosphorylation of JunD and FosB. To further examine the role of JunD and FosB in okadaic acid-induced AP-1 transactivation, we generated fusion proteins of the DNA-binding domain of the yeast transcription factor Gal4 and the transactivation domain of either JunD or FosB. Cotransfection experiments of these constructs with a Gal4-luciferase reporter demonstrated that both JunD and FosB are required for okadaic acid-induced transcription. Treatment with PD 98059 reduced JunD/FosB-dependent transactivation, suggesting that ERK-1/2-mediated phosphorylation is a critical component in this process.
Prediction Limits for the Last Failure Time of a (Log) Normal Sample from Early Failures

Sometimes one wants to predict how long a sample of units will run until all fail. This paper presents prediction limits for the last failure time of a sample from a s-normal or lognormal life distribution when one has observed the earliest r failures.
Environmental Education (EE) for the 21st Century: Where Have We Been? Where Are We Now? Where Are We Headed?

When first approached about being a guest editor for this special edition, I had several distinct and separate thoughts. In the final analysis, I felt we should be focused on the present and the fu...
Accurate perspective projection calculation using a pixel-pyramid model for iterative cone beam reconstruction

The calculation of perspective projection is the essential part in either cone-beam projection or realistic volume rendering. In this paper, we propose a pixel-pyramid model to accurately calculate pixel values in flat-panel-based cone-beam reconstruction. This model faithfully portrays the divergent beam projection on a grilled planar detector. It consists of a pyramidal base (detector pixel facet) and an apex (X-ray source). Through spatial clipping by a flat-panel detector (FPD), a cone is tailored into a pyramid with the base at the FPD, called FPD pyramid, which is then spatially decomposed into pyramidal elements (PYREL). During cone-beam projection, a PYREL intersects the 3D object and produces a frustum, wherein the voxels are accumulated to produce a pixel value. In backprojection, the pixel value is imparted to the same contributive voxels. A voxel’s weight (contribution to a PYREL) is determined by spatial overlapping, which is a piecewise linear function. Through iterative algorithm, accurate cone beam reconstruction is achieved. Since the pyrel model portrays the perspective projection geometry and the voxel weight in a more natural fashion, it can be used for accurate calculation of perspective projection, especially in dealing with severe incomplete data. Simulations and comparisons are provided.
Expression and Functional Assessment of an Alternatively Spliced Extracellular Ca2+-Sensing Receptor in Growth Plate Chondrocytes

The extracellular Ca2+-sensing receptor (CaR) plays an essential role in mineral homeostasis. Studies to generate CaR-knockout (CaR−/−) mice indicate that insertion of a neomycin cassette into exon 5 of the mouse CaR gene blocks the expression of full-length CaRs. This strategy, however, allows for the expression of alternatively spliced CaRs missing exon 5 [Exon5(−)CaRs]. These experiments addressed whether growth plate chondrocytes (GPCs) from CaR−/− mice express Exon5(−)CaRs and whether these receptors activate signaling. RT-PCR and immunocytochemistry confirmed the expression of Exon5(−)CaR in growth plates from CaR−/− mice. In Chinese hamster ovary or human embryonic kidney-293 cells, recombinant human Exon5(−)CaRs failed to activate phospholipase C likely due to their inability to reach the cell surface as assessed by intact-cell ELISA and immunocytochemistry. Human Exon5(−)CaRs, however, trafficked normally to the cell surface when overexpressed in wild-type or CaR−/− GPCs. Immunocytochemistry of g...