cssi/SciSciGPT-SciSciNet huggingface dataset:
Hepatitis A vaccine in the last-minute traveler

Current recommendations state that travelers should receive hepatitis A vaccine 2 to 4 weeks before departure. Such recommendations, however, may dissuade last-minute travelers from receiving the vaccine. A preponderance of evidence exists to support hepatitis A vaccination of the imminent-departure traveler and therefore suggests that these guidelines merit reconsideration. In examining this issue, one of the most important elements to determine is the amount of time required for seroconversion following vaccination. Clinical trials of hepatitis A vaccines measured antibody response at 2 and 4 weeks after vaccination. However, studies investigating early seroconversion found that the vast majority of vaccinees develop antibodies within 2 weeks of vaccination, some as early as 12 days after vaccination. This is relevant information, given that the hepatitis A virus has an average incubation period of 28 days. Seroconversion is predicated on achieving a "protective" antibody level. However, levels of antibody considered protective remain debatable. Evidence suggests that clinical disease does not occur at antibody levels lower than those currently accepted as protective. Furthermore, hepatitis A vaccine has been proved effective in controlling outbreaks worldwide. Research data show that a single dose of vaccine can halt outbreaks if an adequate number of susceptible individuals are vaccinated. Information from rapid-outbreak control studies and those assessing postexposure administration of hepatitis A vaccine suggest that late vaccination provides a significant degree of protection. For these reasons, hepatitis A vaccine may be administered at any time before departure because it will still provide travelers with protection.
Fractal geometry: a tool for describing spatial patterns of plant communities

Vegetation is a fractal because it exhibits variation over a continuum of scales. The spatial structure of sandrim, bryophyte, pocosin, suburban lawn, forest tree, and forest understory communities was analyzed with a combination of ordination and geostatistical methods. The results either suggest appropriate quadrat sizes and spacings for vegetation research, or they reveal that a sampling design compatible with classical statistics is impossible. The fractal dimensions obtained from these analyses are generally close to 2, implying weak spatial dependence. The fractal dimension is not a constant function of scale, implying that patterns of spatial variation at one scale cannot be extrapolated to other scales.
Vascular Endothelial Growth Factor Up-regulates ICAM-1 Expression via the Phosphatidylinositol 3 OH-kinase/AKT/Nitric Oxide Pathway and Modulates Migration of Brain Microvascular Endothelial Cells

Abstract Endothelium of the cerebral blood microvessels, which constitutes the major component of the blood-brain barrier, controls leukocyte and metastatic cancer cell adhesion and trafficking into the brain parenchyma. In this study, using rat primary brain microvascular endothelial cells (BMEC), we demonstrate that the vascular endothelial growth factor (VEGF), a potent promoter of angiogenesis, up-regulates the expression of the intracellular adhesion molecule-1 (ICAM-1) through a novel pathway that includes phosphatidylinositol 3 OH-kinase (PI3K), AKT, and nitric oxide (NO), resulting in the migration of BMEC. Upon VEGF treatment, AKT is phosphorylated in a PI3K-dependent manner. AKT activation leads to NO production and release and activation-deficient AKT attenuates NO production stimulated by VEGF. Transfection of the constitutive myr-AKT construct significantly increased basal NO release in BMEC. In these cells, VEGF and the endothelium-derived NO synergistically up-regulated the expression of ICAM-1, which was mediated by the PI3K pathway. This activity was blocked by the PI3K-specific inhibitor, wortmannin. Furthermore, VEGF and NO significantly increased BMEC migration, which was mediated by the up-regulation of ICAM-1 expression and was dependent on the integrity of the PI3K/AKT/NO pathway. This effect was abolished by wortmannin, by the specific ICAM-1 antibody, by the specific inhibitor of NO synthase,N G-l-monomethyl-arginine (l-NMMA) or by a combination of wortmannin, ICAM-1 antibody, and l-NMMA. These findings demonstrate that the angiogenic factor VEGF up-regulates ICAM-1 expression and signals to ICAM-1 as an effector molecule through the PI3K/AKT/NO pathway, which leads to brain microvessel endothelial cell migration. These observations may contribute to a better understanding of BMEC angiogenesis and the physiological as well as pathophysiological function of the blood-brain barrier, whose integrity is crucial for normal brain function.
Toward professional development for teachers grounded in a theory of decision making

There is now robust evidence that teachers’ and others’ in-the-moment decision making can be modeled and explained as a function of the following: their knowledge and other intellectual, social, and material resources; their goals; and their orientations (their beliefs, values, and preferences). The role of beliefs as they affect teachers’ behavior can thus be described at a level of mechanism—but of necessity in interaction with resources and goals. This paper outlines and exemplifies how resources, goals, and orientations shape teachers’ behavior. It indicates how they are interconnected, and why their evolution is necessarily slow. It then suggests how these understandings can be used as a foundation for mathematics teachers’ professional development, and describes how they are being used to shape a course of participatory professional development for middle school mathematics teachers.
Estimation of distances on the body.

in body image, were not significantly related to size-estimations of body or nonbody stimuli. Head (1920, 1926) proposed that body experiences are organized into schemata, neurological models of the personal body that serve as reference standards and supply meaning to current stimulation from body soiuces. Koffka ( 1935 ) incorporated Head's ideas into Gestalt theory, but research psychologists have tended to ignore the problem of personal-body perception. Not until recent years have a significant number of studies required Ss to estimate the size, shape, or configuration of their own bodies. The present study served four purposes. The first was to replicate a previously reported pattern of estimation errors, consistently associated with judgments of distances between points on the personal body. Shontz (1963a, 1963b, 1965) found that the absolute magnitudes of such judgments varied with changes in measurement conditions. Under all conditions, however, relatively higher or more positive error scores, indicating overestimation, were obtained for estimates of head width and forearm length. Lower or more negative error scores, indicating underestimation, were obtained for estimates of hand length and foot length. Intermediate scores were obtained for estimates of waist width. Shontz presented evidence that the patterning of error scores cannot be accounted for by sizes of body parts alone. In the present snidy, the emor patter% hypothesis was tested by requiring S to estimate distances on his own body in two ways: by adjusting the separation between markers on a horizontal rod (linear response mode) and by drawing a 1:4 scale picmre of himself (pictorial response mode). The study's second purpose was to examine judgment error scores for possible differences between the linear and pictorial response modes. No specific hypotheses were advanced, bur Shonrz's earlier findings ( 1965) suggested that response-mode differences should be investigated further.
Nine-step enantioselective total synthesis of (+)-minfiensine.

An enantioselective total synthesis of the Strychnos alkaloid (+)-minfiensine has been accomplished. Prominent features of this synthesis include (i) a new enantioselective organocatalytic Diels−Alder/amine cyclization sequence to build the central tetracyclic pyrroloindoline framework in four steps from commercial materials and (ii) a 6-exo-dig radical cyclization to forge the final piperidinyl ring system. This total synthesis of (+)-minfiensine was completed in nine chemical steps and 21% overall yield.
Transcriptional analysis of the virion-sense genes of the geminivirus beet curly top virus.

Abstract The genome of the geminivirus beet curly top virus (BCTV) consists of a single circular DNA containing overlapping open reading frames (ORFs) located on both the virion-sense and complementary-sense DNA strands. To investigate the expression of these ORFs, RNA extracted from infected Nicotiana benthamiana and Beta vulgaris has been examined for the presence of viral transcripts. An abundant 1.1-kb virion-sense polyadenylated RNA and four complementary-sense polyadenylated RNAs of 1.7, 1.5, 1.3, and 0.7 kb have been identified by northern blot hybridization, confirming the bidirectional transcription strategy implied by the arrangement of ORFs. We previously demonstrated that two overlapping virion-sense ORFs are involved in coat protein synthesis (ORF V1) and viral single-stranded DNA accumulation (ORF V2). Mutants of a third virion-sense ORF (ORF V3), located upstream and overlapping ORFs V1 and V2, retain the ability to replicate efficiently in N. benthamiana leaf discs but produce an asymptomatic infection in N. benthamiana and B. vulgaris at low frequency, associated with reduced levels of viral DNA compared to wild-type infection. Our data support the recent suggestion that ORF V3 participates in virus movement. The 1.1 kb virion-sense RNA comprises a population of overlapping transcripts with 5′ termini suitably positioned for the expression of ORFs V1, V2, and V3. The overlapping arrangement of the transcripts and juxtaposition of putative regulatory elements could provide a means for the temporal control of virion-sense gene expression.
Seeing Ghosts: Photometry of Saturn's G Ring

Saturn's faint and narrow G Ring is only visible to the eye in two Voyager images, each taken at a rather high solar phase angle of about 160 deg. In this paper we introduce a new photometric technique for averaging across multiple Voyager images, and use it to detect the G Ring at several additional viewing geometries. The resultant phase curve suggests that the G Ring is composed of dust particles obeying a very steep power-law size distribution. The dust is generally smaller than that seen in other rings, ranging down to 0.03 micron. The G Ring occupies the region between orbital radii 166,000 and 173,000 km, and has a peak somewhat closer to the inner edge. Based on these limits, we demonstrate that Voyager 2 passed through and directly sampled this ring during its 1981 encounter with Saturn. Combined analysis of additional data sets suggests that a population of larger bodies is also present in the G Ring; these bodies occupy a narrower band near the observed peak and are likely the source for the visible dust. Based on some preliminary dynamical models, we propose that these larger bodies represent leftover debris from the collisional breakup of a small moon in Saturn's distant past.
Ichthyoplankton transport in relation to floodplain width and inundation and tributary creek discharge in the lower Savannah River of Georgia and South Carolina

We report the results of a 3-year study of ichthyoplankton in the lower Savannah River and its coastal plain tributaries. Sampling was weekly from February through July in 1983, 1984 and 1985. Ichthyoplankton transport was used as an estimate of ichthyoplankton production. Ichthyoplankton transport in the river, for both total and most common taxa, was highest in 1983 and lowest in 1985. Ichthyoplankton transport into the river from tributary streams was also highest in 1983 and lowest in 1985. Ichthyoplankton transported from these tributaries sometimes comprised a significant percent of the larval transport at the next river station downstream from the tributary mouth. The highest larval transport occurred when the spring flood pulse was most elevated for the longest time, and larval transport at particular river stations or creeks was correlated with floodplain width in 1983 and 1984, years when flood pulses were high enough so that the adjacent floodplain was inundated during or following spawning. In 1985 the flood pulse was brief, inundation levels were low, and inundation occurred in February before most fish had spawned. Except for American shad and sunfishes, larval transport for all common taxa was greatly reduced in 1985 compared to 1983.
Smeared Crack Model Based on Point Interpolation Meshless Method

Based on the tensile feature and rupture mechanism, the point interpolation meshless algorithm of smeared crack model is proposed. When the displacement of crack opening and the fracture energy are smeared into the node influence area, the calculation results vary with the size of the node influence area which is called size effect. According to the conversation law of fracture energy, the solution of size effect of simulation of tensile crack process using the blunt crack band model is proposed and verified through a numerical test of concrete three-point bend beam.
Enhancing RNA repair efficiency by combining trans-splicing ribozymes that recognize different accessible sites on a target RNA.

Recent reports have demonstrated that trans-splicing ribozymes can be employed to repair mutant RNAs. One key factor that influences RNA repair efficiency is the accessibility of the substrate RNA for ribozyme binding, which is complicated by the fact that RNAs may assume multiple conformations and have proteins bound to them in vivo. Here we describe a strategy to map accessible sites on sickle β-globin (β s -globin) transcripts in vitro and in vivo and to use this information to enhance RNA repair efficiency. Two sites upstream of the sickle mutation were identified as accessible in some fraction of the β-globin RNA by mapping with a ribozyme library and the accessibility of those sites was assessed by in vitro cleavage analyses. Ribozymes targeting either site could only convert a certain fraction of the β s -globin RNA to product but not drive the reaction to completion. However, cleavage and splicing reactions were driven further toward completion when the two ribozymes were both added to the reactions, suggesting that the substrate RNA is present in multiple conformations in vitro. These two ribozymes were each able to repair β s -globin transcripts in erythrocyte precursors derived from peripheral blood from individuals with sickle cell disease. Moreover, the relative accessibility of the targeted sites in vivo is as predicted by mapping and in vitro analyses. These results demonstrate that this novel RNA mapping strategy represents an effective means to determine the accessible regions of target RNAs and that combinations of trans-splicing ribozymes can be employed to enhance RNA repair efficiency of clinically relevant transcripts such as β s -globin RNA.
Determination of the induced ELF electric field distribution in a two layer in vitro system simulating biological cells in nutrient solution

In-vitro studies of biological effects of electromagnetic fields are often conducted with cultured cells either in suspension or grown in a monolayer. In the former case, the exposed medium can be assumed to be homogeneous; however, eventually the cells settle to the bottom of the container forming a two layer system with different dielectric and conductive properties. In the present work the effect of this separation on the electric field distribution is calculated and experimentally measured at selected positions for a commonly used exposure configuration. The settled cell suspension is modeled by a well-defined two layer system placed in a rectangular container with the base of the container parallel to the direction of the magnetic field. Theoretical calculations based on numerical techniques are done for various two layer systems with different conductivities in each layer. The agreement between the theoretical calculations and the experimental measurements is within ± 1.5 mV/m, or 10% of the maximum induced field when the conductivity of the lower layer is ten times that of the upper layer. This result is well within experimental error. When the thickness of one of the layers is small compared to the thickness of the other layer, it is found that the electric field distribution is essentially that of the homogeneous case. The latter situation corresponds to a typical cell exposure condition. © 1993 Wiley-Liss, Inc.
Non-random mating between Boophilus microplus and hybrids of B. microplus females and B. annulatus males, and its possible effect on sterile male hybrid control releases.

WhenBoophilus microplus and Type-II hybrids (B. microplus females×B. annulatus males) were released simultaneously onto bovine hosts, mating between the two forms appeared not to be at random. There were more contypic and fewer intertypic matings than predicted under an assumption of panmixia. An examination of the patterns of matings revealed that more of the matings on the first two days of detachment were between the two sexes ofB. microplus. Engorged females dropping on the last four days of maximum female detachment were predominantly hybrids mated to bothB. microplus and hybrid males. The non-random mating pattern does not appear to be caused by assortative mating betweenB. microplus and Type-II hybrids, but because theB. microplus were competnet to mate two days before the hybrids and theB. microplus males compete for mates of both types better than the Type-II males.
Single Event Upsets in NMOS Microprocessors

Three advanced 16-bit NMOS microprocessors have been observed to suffer single event upset at a rate varying between one upset for every 8 × 1010 to one for every 2 × 1012 n/cm2-upset for cyclotron-produced neutrons with an average energy of 14 MeV. These rates are expected to vary, probably upward, with different types of programs. The errors are inferred to occur in memory-like components of the microprocessors. Many of the errors caused the microcomputer to cease normal operations. This is the first direct experimental verification of logic upsets in microprocessors from neutrons.
The Schwarz-Christoffel Analytical Method Applied to Electric Machine Slot Shape Optimization

The Schwarz-Christoffel method is implemented in a Monte Carlo electric machine slot shape search algorithm attempting to maximize average torque under constrained flux density in a two-dimensional developed machine cross-section. A fixed slot current density is enforced, and the slot shape is varied over a twelve-variable search space. Rotor motion is simulated by changing the position of the machine air gap polygon's rotor vertices while maintaining both a simply-connected polygon and a 90deg shift between stator and rotor q-axis currents. Rotor force is calculated by integrating Maxwell's stress tensor along a closed path enclosing the rotor. A Monte Carlo search with 11,050 points is carried out and a minimum cost horizon curve is deduced from the data. A brief history and context for the Schwarz-Christoffel approach is given with a comparison to the finite element and boundary element methods.
Comparison of the time courses of concomitant and nonconcomitant vertical phoria adaptation

Vertical phoria adaptation was measured before, during, and after 1 h of training with either a prism or magnifying lens. With the prism (concomitant adaptation) a single vertical disparity was presented at primary position. With the magnifier (nonconcomitant adaptation) two vertical disparities of opposite sign were presented along the vertical meridian. Following adaptation, binocular vision was prevented with an eye patch, and vertical phorias were measured periodically along the primary vertical meridian over the course of 8 h. Despite individual variation, adaptation followed approximately exponential time courses. The average time constants for the decay of concomitant and nonconcomitant adaptation were 31 and 83 min, respectively. There was no consistent relationship between the rates of acquisition and decay nor was there a strong relationship between the gains of the adaptive responses and the rates of decay although there was a general trend for the gains of the nonconcomitant responses to be higher and the rate of decay slower than the concomitant responses. The results support the notion that concomitant and nonconcomitant phoria adaptation involve different mechanisms but not the contention that adaptation to prisms is easier or more robust than adaptation to lenses.
The Moment Approach to Charged Particle Beam Dynamics

We have derived the hierarchy of moment equations that describes the dynamics of charged particle beams in linear accelerators and can truncate the hierarchy at any level either by discarding higher moments or by a cumulant expansion discarding only correlation functions. We have developed a procedure for relating the density expansion linearly to the moments to any order. The relation of space-charge fields to the density has been derived; and an accurate, systematic, and computationally convenient expansion of the resultant integrals has been developed.
Flash X-Ray Measurements during Shock Wave Interactions with Dense Particle Fields

The explosive dispersal of particles occurs in a variety of engineering problems, including in heterogeneous detonations, where solid particles are initially mixed with explosive material
Cycloheximide activation of the lordotic response in low-dose, estrogen-treated ovariectomized rats: evidence for modulating inhibitory influences of the limbic system on sexual behavior

Abstract This study tested the effect of intracranially injected cycloheximide (CHX), an inhibitor of protein synthesis, on facilitation of sexual receptivity in ovariectomized rats. The rats received 0.5 μg estradiol benzoate (EB), s.c., once daily on days 8 through 12 after ovariectomy (OVX). Either CHX (in 0.5 μl saline) or 0.5 μl saline was injected into the lateral septum (LS), cortical nucleus (ACO) or medial nucleus of the amygdala or medial preoptic area on day 11 after OVX. The dose of EB was insufficient to facilitate lordotic behavior on day 10 or day 12 after OVX unless CHX was injected into the LS or ACO. Injection of saline did not influence lordosis.
Hemin feedback inhibition at reticulocyte δ-aminolevulinic acid synthetase and δ-aminolevulinic acid dehydratase

Abstract Addition of hemin (5–200 μM) to a rabbit reticulocyte iron-free incubation medium, resulted in a progressive inhibition of heme synthesis as measured by incorporation of (14C)-glycine. In contrast when (14C) δ-aminolevulinic acid incorporation into heme was studied, significant inhibition below that of the (14C)-glycine control only occurred with hemin concentrations greater than 100 μM. Hemin progressively inhibited cellular and mitochondrial δ-aminolevulinic acid synthetase activity, as well as cellular δ-aminolevulinic acid dehydratase activity. The results indicated that elevated levels of hemin initially control heme synthesis by feedback inhibition at the rate-limiting enzyme of heme synthesis, δ-aminolevulinic acid synthetase. Hemin inhibition of δ-aminolevulinic acid dehydratase is only significant for the entrire heme synthetic pathway when greater than one-third of this enzyme's activity is inhibited.
Effects of randomized assignment to a smoking cessation intervention and changes in smoking habits on respiratory symptoms in smokers with early chronic obstructive pulmonary disease: the lung health study

Abstract PURPOSE: To evaluate the effects of randomly assigning smokers who have early chronic obstructive pulmonary disease (COPD) to a smoking-cessation intervention on the symptoms of chronic cough, chronic phlegm production, wheezing and shortness of breath, and to determine the effects of quitting smoking on these symptoms. SUBJECTS AND METHODS: A total of 5,887 male and female smokers 35 to 60 years of age with early COPD [defined as a forced expiratory volume in the first second (FEV 1 ) of 55% to 90% of predicted and FEV 1 /forced vital capacity (FVC) RESULTS: Validated 5-year sustained smoking cessation occurred in 22% of participants in the intervention compared with only 5% of participants in the usual-care group. At the end of the study, the prevalence of each of the four symptoms in the two intervention groups was significantly less than in the usual-care group ( P 1 during the study ( P CONCLUSIONS: In this prospective randomized trial using an intention-to-treat analysis, smokers with early COPD who were assigned to a smoking-cessation intervention had fewer respiratory symptoms after 5 years of follow-up.
Establishing and Building Leadership Skills

AbstractLeadership skills are central to the success of any organization. Whether that organization is a project, a program, a company, or even a nation, leadership is essential. In this paper, I will examine two different aspects of leadership. The first originates from the individual perspective, namely, how do each of us become leaders? What are the skills, traits, and characteristics of leaders? And, conversely, what are their obligations? The second aspect of leadership flows from one of the obligations of leadership, specifically, how do you build a culture of leadership in your organization?
Adenocarcinoma in colonic brushing cytology: High-grade dysplasia as a diagnostic pitfall.

Cytologic evaluation of brushing specimens obtained from the colon may be useful in the diagnosis of neoplastic and inflammatory lesions, as previous studies have reported favorable sensitivity and specificity figures for this procedure. In this study, we report our experience with 80 colonic brushings examined over a 5-yr period. Thirty cases received an atypical or malignant cytologic diagnosis. Nineteen of 20 cases diagnosed cytologically as adenocarcinoma revealed adenocarcinoma on biopsy; one case showed only adenomatous epithelium on biopsy and subsequent resection. Cases diagnosed cytologically as “atypical” or “adenomatous” showed adenocarcinoma, adenoma, and inflammatory conditions upon biopsy. Slides from 30 atypical/malignant cases were retrospectively reviewed for a number of cytomorphologic features and were correlated with the histologic diagnosis. Cases from histologically confirmed adenocarcinoma tended to show greater degrees of altered nuclear polarity, nuclear pleomorphism, membrane irregularities, and chromatin pattern alterations than those from histologically proven adenomatous or inflammatory lesions. The most likely cause of a false-positive diagnosis in this setting is sampling of an adenoma with high-grade dysplasia which fails to meet histologic criteria for adenocarcinoma (invasion of the underlying muscularis mucosae). Thus, in the second part of the study, we examined histologic sections from surgically excised adenomas to determine the frequency with which profound nuclear atypia is at least focally present, potentially resulting in a false-positive cytology diagnosis upon brushing. Slides from 51 cases were reviewed; cytologic atypia beyond that typically observed in adenomas was not observed in 43% of cases. However, profound nuclear atypia was present in 6% of cases; cytologic evaluation of a brushing specimen from these lesions may have resulted in a false-positive diagnosis of adenocarcinoma, despite the histologic diagnosis of adenoma with severe dysplasia. The remaining cases demonstrated intermediate degrees of atypia. These findings serve to quantitate the frequency with which cytohistologic discrepancies might be expected for mass lesions of the colon. Diagn. Cytopathol. 24:364–368, 2001. © 2001 Wiley-Liss, Inc.
Efficient techniques for realizing geo-spatial access control

The problem of key management for access control systems has been well-studied, and the literature contains several schemes for hierarchy-based and temporal-based access control. The problem of key management in such systems is how to assign keys to users such that each user is able to compute and have access to the appropriate resources while minimizing computation and storage requirements. In the current paper, we consider key management schemes for geo-spatial access control. That is, the access control policy assigns to a user a specific geographic area, and the user consequently obtains access to her area or information about it.In this work, the geography is modeled as an m × n grid of cells (let m ≥ n). Each cell has its own key associated with it, and a user who wants to access the content of a cell needs to obtain its key. Each user obtains access to a rectangular area (or a finite collection of such rectangles) and is able compute keys corresponding to the cells that comprise her area.Our main result is an efficient scheme with the following properties: (i) each user obtains a small constant number of secret keys that permit access to an arbitrary rectangular sub-grid, (ii) computation to derive the key of a specific cell in that rectangle consists of a constant number of efficient operations, and (iii) the server needs to maintain O(mn(log log m)2 log* m) public information accessible to all users. The public storage requirement is the worst-case bound and can be improved if the grid is partitioned into regions where the cells of a region share the same key.
Supporting the Development of Resilient Message Passing Applications Using Simulation

An emerging aspect of high-performance computing (HPC) hardware/software co-design is investigating performance under failure. The work in this paper extends the Extreme-scale Simulator (xSim), which was designed for evaluating the performance of message passing interface (MPI) applications on future HPC architectures, with fault-tolerant MPI extensions proposed by the MPI Fault Tolerance Working Group. xSim permits running MPI applications with millions of concurrent MPI ranks, while observing application performance in a simulated extreme-scale system using a lightweight parallel discrete event simulation. The newly added features offer user-level failure mitigation (ULFM) extensions at the simulated MPI layer to support algorithm-based fault tolerance (ABFT). The presented solution permits investigating performance under failure and failure handling of ABFT solutions. The newly enhanced xSim is the very first performance tool that supports ULFM and ABFT.
A capacitance-based method for experimental determination of metallurgical channel length of submicron LDD MOSFETs

A capacitance based method for determining L/sub met/ the metallurgical channel length of MOSFET, is proposed in this paper. This method has been extensively evaluated via two-dimensional numerical device simulation of MOSFETs with different source/drain tip and channel impurity concentration profiles as well as different gate oxide thicknesses. For all the impurity profiles tested, results demonstrated that the accuracy in extracting L/sub met/ of MOSFETs with gate oxides thinner than 100 /spl Aring/ is better than 110 /spl Aring/. This method is applicable even when there is significant source/drain reoxidation induced gate oxide thickening, as long as the gate oxide thickening is not extended into the region directly above the metallurgically defined channel region. Unlike the determination of L/sub eff/, the effective electrical channel length, from the drain current, L/sub met/ is extracted from capacitance data and the extraction is free from complications that can be introduced by incomplete removal of the resistive effects associated with contacts and the lightly doped source/drain region. Extensive measurements were performed on MOSFETs of different technologies. It is shown that the measurement is accurately repeatable and no device stressing is experienced over the required bias range. The L/sub met/ and L/sub eff/ extracted from measured capacitance and drain current data are compared. Results showed that L/sub met/ is typically 700 to 1200 /spl Aring/ shorter for submicron MOS technologies, but it tracks with L/sub eff/, i.e. a shorter L/sub met/ corresponds to a shorter L/sub eff/. >
Expression of a Human Lactoferrin cDNA in Tobacco Cells Produces Antibacterial Protein(s)

A suspension tobacco (Nicotiana tabacum L.) cell line was transformed to express human lactoferrin, an iron-binding glycoprotein. The transgenic calli produced a protein that was significantly smaller than the full-length lactoferrin protein. Total protein extracts made from transgenic tobacco callus exhibited much higher antibacterial activity than commercially available purified lacto-ferrin as determined by the decrease of colony-forming units when tested with four phytopathogenic species of bacteria. Introduction of the lactoferrin gene in crop plants may provide resistance against phytopathogenic bacteria.
Analysis of fermentation processes using flow microfluorometry: Amylase and protease activities in Bacillis subtilis batch cultures

Flow microfluorometry, which provides detailed information on the state of a microbial population, has been employed to characterize the Bacillus subtilis population during time intervals in which significant changes in the culture amylase activity occur. Four different batch experiments have been conducted, and the influences of inoculum age, fermentation temperature, and aeration rate on microbial population dynamics and amylase activity have been examined. Relatively high rates of amylase activity increase are observed twice during the batch, first as double cells initiate sporulation and later during germination. Rapid decreases in amylase activity are observed in highly (25–50%) sporulated populations, and in at least one experiment, during a transition from large, rounded protoplast forms to normal rod morphology. Amylase and protease activities do not follow parallel nor proportional trajectories in these 72 hr batch fermentations.
Stokes and anti-Stokes emission in Au nanoparticles and Au-rhodamine 6G complexes

We observed emission of Au nanoparticles. One of its bands corresponded to surface plasmons. This emission could also be excited using anti-Stokes pumping. The efficiency of anti-Stokes excitation strongly increased in the presence of R6G dye.
Heart failure disease management works, but will it succeed?

This editorial refers to "The effectiveness of disease management programmes in reducing hospital re-admission in older patients with heart failure: a systematic review and meta-analysis of published reports" by J. Gonseth et al. on page 1570 and "Heart failure clinics and outpatient management: review of the evidence and call for quality assurance" by F. Gustafsson and J.M.O. Arnold on page 1596 †. Quality of care is defined as "the degree to which health services… increase the likelihood of desired health outcomes and are consistent with current professional knowledge".1 Despite tremendous advances in our understanding of the pathophysiology of heart failure and the development of efficacious therapies, the quality of care for patients with heart failure is suboptimal. For example, although ACE-inhibitors carry a Class I guideline recommendation for patients with left ventricular systolic dysfunction, less than 70% of eligible patients receive such therapy at the time of discharge from a heart failure hospitalisation.2,3 ACE-inhibitor use is even lower among heart failure outpatients, and rates of use of other indicated therapies such as I²-blockers are lower still.4 In other words, the potential of scientific advances to optimise patient outcomes has not been realized because of the failure to implement these discoveries fully in clinical care. The implementation of 'guideline-based' therapies in clinical practice is challenging because of the complexity of the recommendations for care. For example, in symptomatic patients with ischaemic cardiomyopathy, current guidelines support the use of seven or more medications and consideration of interventions such as coronary revascularization, implantable defibrillators, and biventricular pacemakers.5,6 Heart failure care is also intensive, requiring close monitoring on the part of clinicians (e.g., the initiation and up-titration of I²-blockers) and patient self-management (daily weights, diet modification, titration of diuretics, etc.). Finally, heart failure is a disease of the elderly, … *Correspondence to: John S. Rumsfield, Cardiology/CV Outcomes Research (111B), Denver VA Medical Center, 1055 Clermont Street, Denver, CO 80220, USA. Tel.: +1 303 370 7575; fax: +1 303 370 7580 (E-mail: john.rumsfeld{at}med.va.gov).
The Simultaneous Effect of Social Distance and Physical Distance on the Formation of Neighborhood Ties

Prior studies have separately suggested the importance of physical distance or social distance effects for the creation of neighborhood ties. This project adopts a case study approach and simultaneously tests for propinquity and homophily effects on neighborhood ties by employing a full-network sample from a recently-developed New Urbanist neighborhood within a mid-sized southern city. The authors find that physical distance reduces the likelihood of weak or strong ties forming, suggesting the importance of accounting for propinquity when estimating social tie formation. The authors simultaneously find that social distance along wealth reduces the likelihood of weak ties forming. Social distance on life course markers—age, marital status, and the presence of children—reduces the formation of weak ties. Consistent with the systemic model, each additional month of shared residence in the neighborhood increases both weak and strong ties. An important innovation is this study’s ability to directly compare the effects of physical distance and social distance, placing them into equivalent units: a ten percent increase in home value difference is equivalent to a 5.6 percent increase in physical distance.
Identification of active contrasts in unreplicated factorial experiments

Abstract A graphical method for the identification of active contrasts in unreplicated factorial experiments is described. It is an extension of Daniel's normal probability plot technique but takes into account the different ways of labeling factor levels. The method is illustrated with examples and compared in a simulation experiment against a recent method of Lenth (Technometrics, 31, 1989).
β-Arrestin-2 Mediates Anti-apoptotic Signaling through Regulation of BAD Phosphorylation

β-Arrestins, originally discovered as terminators of G protein-coupled receptor signaling, have more recently been appreciated to also function as signal transducers in their own right, although the consequences for cellular physiology have not been well understood. Here we demonstrate that β-arrestin-2 mediates anti-apoptotic cytoprotective signaling stimulated by a typical 7-transmembrane receptor the angiotensin ATII 1A receptor, expressed endogenously in rat vascular smooth muscle cells or by transfection in HEK-293 cells. Receptor stimulation leads to concerted activation of two pathways, ERK/p90RSK and PI3K/AKT, which converge to phosphorylate and inactivate the pro-apoptotic protein BAD. Anti-apoptotic effects as well as pathway activities can be stimulated by an angiotensin analog (SII), which has been previously shown to activate β-arrestin but not G protein-dependent signaling, and are abrogated by β-arrestin-2 small interfering RNA. These findings establish a key role for β-arrestin-2 in mediating cellular cytoprotective functions by a 7-transmembrane receptor and define the biochemical pathways involved.
A Case Study to Distill Structural Scaffolding Guidelines for Scaffolded Software Environments

A challenge for HCI researchers and designers involves developing software tools for learners to support them in mindfully doing and learning complex new work practices. Such "learner-centered" tools incorporate scaffolds-software features that address the cognitive obstacles learners face so they can engage in the work in an educationally productive manner. However, designers still lack specific scaffolding design guidelines for developing effective scaffolded tools. The HCI contribution of this paper is a set of scaffolding guidelines distilled from an empirical case study. The study evaluated Symphony, a scaffolded environment for high school students learning science inquiry. The study evaluated the "effects with" the Symphony scaffolds, which described how students worked with the scaffolds to do their science work. The scaffolds were evaluated using several usability and learner-centered criteria, and the resulting information was correlated with structural characteristics of the scaffolds to distill a set of structural scaffolding guidelines
The elastic properties of thin-film silicon nitride

The elastic properties of thin-film silicon nitride (Si/sub 3/N/sub 4/) were investigated using surface-acoustic-wave (SAW) propagation data for plasma-enhanced chemical-vapor-deposition (PECVD) grown Si/sub 3/N/sub 4/ on gallium arsenide. For three films with thicknesses of 102 nm, 250 nm, and 497 nm, elastic constants were calculated from least-squares fits of theoretical dispersion curves to phase velocity data at different film thickness-to-wavelength ratios. The measured film density decreased from 2800 to 2500 kg/m/sup 3/ with increasing film thickness. Within this density range the longitudinal elastic modulus averaged near 1.83*10/sup 11/ N/m/sup 2/ and the shear elastic modulus decreased from 0.918*10/sup 11/ N/m/sup 2/ to 0.561*10/sup 11/ N/m/sup 2/ as the film density decreased. The elastic moduli of thin-film silicon nitride are comparable to those of Si/sub 3/N/sub 4/ ceramics at similar densities. >
Recent advances in the biochemistry of chromium(III)

The biochemistry of chromium(III) [Cr(III)] has been a poorly understood field of endeavor; studies of the biochemistry of none of the other transition metals have been as problematic. Despite four decades of investigation, only recently has a clear picture of the role of Cr potentially been defined. The biologically important form is the trivalent ion. Cr(III) apparently is required for proper carbohydrate and lipid metabolism in mammals, although Cr deficiency is difficult to achieve. Conditions that increase circulating glucose and insulin concentrations increase urinary chromium output. Chromium is excreted after an insulin challenge, probably in the form of the oligopeptide chromodulin. Chromodulin may be the key to understanding the role of chromium at a molecular level as the molecule has been found to bind to activated insulin receptor, stimulating its kinase activity. A mechanism for the action of chromodulin has recently been proposed; this mechanism can serve as a potential framework for further studies to test the role of chromium in metabolism. An examination of the use of chromium picolinate, [Cr(pic)3], illustrates the difficulties associated with biochemical studies dealing with Cr(III). J. Trace Elem. Exp. Med. 16:227–236, 2003. © 2003 Wiley-Liss, Inc.
Pathological consequences from the infusion of unstable lipid emulsion admixtures in guinea pigs

Summary The pathophysiologic effects of infusing unstable lipid emulsions are unclear, but these were shown to cause reticuloendothelial system (RES) dysfunction in animals and humans. We investigated the effects of unstable lipid emulsions in RES organs defined by two levels of the percent fat >5μm (percentage of fat, PFAT>5μm) in a guinea pig model. Two identical injectable lipid emulsions with differing (stable versus unstable) PFAT >5μm levels, were infused for over 24h into two groups of animals ( n = 5 \/ group ). The PFAT>5μm concentration was measured before and at the end of the infusion to ascertain the dose range of enlarged fat globules in each group. Animals were euthanized and specimens from the upper, middle and lower lung, and a single liver sample were examined histologically and for micromolar concentrations of malondialdehyde (MDA) per gram (μmol −1 g) of wet tissue. The PFAT>5μm concentrations pre-infusion were 0.004±0.001 and 2.418±0.273 for the stable and unstable injectable lipid emulsions respectively. At 24h, the PFAT>5μm level increased in both the groups (stable: 0.161±0.008; unstable: 7.861±0.291). MDA concentrations were significantly higher in the lungs of animals receiving the unstable (47.2±26.2μmol −1 g) versus stable (32.4±11.2μmol −1 g) injectable lipid emulsions ( P = 0.033 ), but was not different for the liver specimens (stable: 16.9±7.6μmol −1 g versus unstable: 17.7±2.2μmol −1 g, P = 0.944 ). These preliminary data suggest that infusion of unstable injectable lipid emulsions has pathological consequences showing greater evidence of oxidative stress in the lungs.
Iron, nutrient, and phytoplankton distributions in Oregon coastal waters

[1] The relationship between iron and nitrate concentrations was examined off the coast of Oregon during the upwelling season. Surface Fe and N (nitrate + nitrite) concentrations measured underway by flow injection analysis ranged from <0.3 to 20 nmol L−1 and <0.1 to 30 μmol L−1, respectively. Total dissolvable Fe concentrations, measured in unfiltered, acidified samples in surface waters and in vertical profiles, ranged from <0.3 to 300 nmol L−1. Surface water Fe and N concentrations were highly variable and uncoupled. Our observations indicate two dominant sources of Fe to Oregon coastal waters: Slope or shelf sediments and the Columbia River. Sedimentary iron, probably largely in the particulate form, appears to be added to surface waters through wind-induced vertical mixing during strong winds, through thickening of the bottom mixed layer during relaxation or downwelling favorable wind conditions, and through outcropping of shelf bottom waters during upwelling events. The existence of multiple iron sources and the generally high iron concentrations may explain why the distribution of phytoplankton, measured both remotely (by Sea-viewing Wide Field-of-view Sensor) and underway (by in vivo fluorescence), appeared to be driven primarily by physical dynamics and was not strongly linked to the distribution of iron. Nevertheless, at some offshore stations where underway Fe concentrations were <0.3 nmol L−1, underway measurements of the physiological state of phytoplankton by fast repetition rate fluorometry were consistent with mild iron stress, and cross-shelf nutrient distributions were consistent with iron regulation of the magnitude of phytoplankton blooms.
PATTERNS OF INCIDENCE AND TRENDS IN DIAGNOSTIC CLASSIFICATION OF CEREBROVASCULAR DISEASE IN WASHINGTON COUNTY, MARYLAND, 1969–1971 TO 1974–1976

A study was conducted to provide baseline data on patterns of cerebrovascular disease incidence in the community of Washington County, Maryland, over two time intervals--1969-1971 and 1974-1976--and to evaluate any temporal trends with regard to their possible relation to reported declines in stroke death rates. Among the statistically significant changes in incidence between 1969-1971 and 1974-1976 were a decline in the rate of cerebral thrombosis and a concomitant increase in frequency of cerebrovascular disease-unspecified, most likely a reflection of a change in diagnostic terminology. In addition, the findings of a significant decrease in incidence of cerebral hemorrhage (for all ages over 55 years and both sexes) and a non-significant decrease in incidence rates for all types combined among those in the oldest age category between the two study periods support the role of changing incidence rates in the stroke death rate decline. It is clear, however, that monitoring of this community over a longer period of time will be necessary before the validity of these trends can be established and their causes elucidated. The need for more complete recording of historical data and clinical findings on admission, as well as adherence to standardized diagnostic and classification protocols was underscored by this study.