cssi/SciSciGPT-SciSciNet huggingface dataset:
Aerosols at a mountaintop observatory in Arizona

[1] This paper discusses physics of aerosols measured at the summit of Mt. Lemmon, Arizona (2790 m), from February to May 2002, where “clean” air representative of the free troposphere sometimes occurs. We confirmed Marti's findings of a persistent daily variation in the number concentration of condensation nuclei (diameter > 10 nm), with a strong maximum occurring in the afternoon and minimum in the early morning. These particles show evidence of growth at rates of 10–23 nm per hour. The diurnal variation was present even on days when the planetary boundary layer remained below the mountain. From the rate of growth and Maxwellian diffusion theory, we deduce that precursor condensable species are present in daytime concentrations of 107–108 cm−3, and that these are produced at a rate of 105–106 cm−3 s−1. Increased convection caused by solar heating of the mountain often carries contaminated air to the summit. Yet only a small (factor of 1.5) diurnal pattern was found for accumulation mode (diameter ∼ 130 nm) particles on days where the convective boundary layer passed well above the station. We hypothesize that these long-lived (e.g., several days) aerosols are pumped into the free troposphere and remain behind at night in a residual layer. The free tropospheric aerosol size distribution measured at Mt. Lemmon was similar in shape but higher in magnitude (by around 50%) than at Jungfraujoch in the Swiss Alps (3580 m). There is much greater diurnal variation in Aitken-sized particles (daily factor of from 7 to 10) at Mt. Lemmon than observed at Jungfraujoch (factor of from 1.0 to 1.6), evidently arising from stronger photochemical rate of productions of precursor gases.
An investigation into the exchange of iron and zinc between soluble, colloidal, and particulate size-fractions in shelf waters using low-abundance isotopes as tracers in shipboard incubation experiments

Avertical mixing event was simulated in shipboard incubation experiments on the mid-continental shelf of the eastern Bering Sea to investigate Fe and Zn cycling between the soluble(b0.03 μm or 200 kDa), colloidal (0.03–0.2 μm), and particulate (0.2–10 μm,N10 μm) size-fractions.TheparticulateFeandZnwerefurtherseparatedintochemicallylabile(25%aceticacid-leachable)andrefractorypools.The experimentemployed 57 Fe(+0.90nM)and 68 Zn(+0.99nM)asstable,low-abundanceisotopeamendmentstothesolublefraction,andthe
Mitochondrial gene expression is impaired by ethanol exposure in cultured chick cardiac myocytes

Objective: A depression in cytochrome c oxidase (COX) activity occurs following chronic embryonic ethanol exposure in vivo. The aim of this study was to examine the effect of chronic ethanol exposure on COX activity in isolated cardiac cells maintained in vitro. Additionally, the mechanism by which ethanol produces an impairment in COX activity was evaluated by examining mitochondrial gene expression. Methods: Spontaneously beating cardiac myocyte cultures were established from 10-day embryonic chick hearts. Various concentrations of ethanol (0–250 mM) were introduced at the time of plating and cells were harvested over 7 days. COX activity was determined in myocyte homogenates. The levels of nuclear-encoded (COXIV) and mitochondrial-encoded (COXII) subunit proteins were measured by Western blotting. Relative levels of mitochondrial DNA and the mitochondrially-encoded COXIII mRNA were determined by Southern and Northern blotting. Results: A consistent decrease in COX activity in ethanol-exposed cardiac myocytes of approximately 30% was observed with an ethanol concentration of 25 mM. Increasing the ethanol concentration to 250 mM produced only a minor enhancement of this effect, while severely decreasing cellular viability. The content of the mitochondrially-encoded COXII subunit was reduced by ethanol exposure, while that of the nuclear-encoded COXIV subunit was unchanged. The content of the mitochondrially-encoded COXIII mRNA was unchanged by ethanol exposure. However, prolonged ethanol exposure produced an increase in mitochondrial DNA levels in cardiac myocytes. Conclusions: Ethanol exposure of cardiac myocytes produces deficits in COX activity in the absence of systemic variables, indicating that ethanol has a direct effect on cardiac mitochondria. The ethanol-induced decrease in COX activity is correlated with a specific decrease in at least one mitochondrially-encoded gene product, COXII. No changes were observed in the level of the nuclear-encoded COXIV subunit, indicating that expression of this nuclear-encoded gene is not impaired by ethanol exposure.
The range of a perturbed Lévy process

A necessary and sufficient Fourier analytic condition is given for a real-valued Levy process X to be such that all perturbations, X+f, of X by measurable functions f have range with positive Lebesgue measure. The condition is compared to one due to Kesten for the range of X alone to have positive Lebesgue measure, and in some cases it is found to coincide, whereas in others it is stronger.
Purification and characterization of a soybean leaf storage glycoprotein.

Removing the pods from soybean (Glycine max [L.] Merr. cv Wye) plants induces a change in leaf function which is characterized by a change in the leaf soluble protein pattern. The synthesis of at least four polypeptides (∼27, 29, 54, and 80 kilodaltons) is enhanced, and these polypeptides accumulate to levels comprising over 50% of the soluble protein. Heat girdling the petiole also causes the accumulation of these polypeptides, suggesting that the signal for changing leaf function may be associated with inhibition of phloem transport. The 27 and 29 kilodalton polypeptides are glycosylated and have been purified to greater than 90% by (NH4)2SO4 fractionation, concanavilin A affinity, and gel filtration chromatography. These peptides appear to comprise a single protein. Mouse antiserum has been prepared against this glycoprotein and has been used to check for cross-reactivity with seed proteins and to quantitate changes with leaf development. No cross-reactivity was observed with seed soluble proteins from several stages of development. Quantitation showed the highest content in podded plants at, and shortly following, flowering, with levels subsequently declining in conjunction with seed growth. In depodded plants, the level of glycoprotein continued to increase following flowering and accounted for 45% of the soluble leaf protein by 4 weeks after depodding.
Current research on the disposal of hazardous wastes

Abstract The Solid and Hazardous Waste Research Laboratory is one of six laboratories in the Environmental Protection Agency (EPA), National Environmental Research Center at Cincinnati, Ohio. The laboratory is responsible for research into new and improved systems of solid and hazardous waste management, development of technology, determination of environmental effects, and collection of data necessary for the establishment of processing and disposal guidelines. In the past, the laboratory concentrated on problems associated with municipal solid waste; but recently the emphasis has shifted, and present efforts are directed primarily toward the problem of industrial hazardous waste disposal on land. Under the solid waste program, investigations were initiated on the migration of municipal landfill leachate and leachate containment with synthetic liners. These studies have been underway for more than a year, but they will not be discussed here because of the present emphasis on industrial hazardous waste problems. Although none of our research projects is concerned specifically with the disposal of residues and sorbants generated during cleanup of hazardous material spills, much of the forthcoming information will be applicable to spill-cleanup problems. The extramural projects and program areas described here involve many activities that could be useful in spill problems.
Experimental validation of a fluorescence tomography algorithm based on the equation of radiative transfer

We have developed an optical fluorescence image reconstruction algorithm that is based on the equation of radiative transfer. First image reconstruction results of a three-dimensional fluorescent source distribution in a tissue-like medium are presented.
The Productivity Slowdown and the Fall in the U.S. Rate of Profit, 1947-76:

I find that the general rate of profit in the United States economy remained fairly stable from 1947 to 1967 and then declined sharply between 1967 and 1976. I argue that the movement of the rate o...
Finite element analysis of lithiation-induced decohesion of a silicon thin film adhesively bonded to a rigid substrate under potentiostatic operation

Abstract Insertion-induced stress and interfacial decohesion are studied for a silicon thin film adhesively bonded to a rigid substrate under potentiostatic operation. An axisymmetric finite element model with traction–separation law governing the interfacial degradation is used to study the highly nonlinear diffusion-induced volumetric expansion. Plastic yielding of the film, coupling effects between diffusion and stress, diffusion from both the edge and the top surfaces, and concentration dependence of material properties are considered. It is found interface fails in shear mode, and interfacial decohesion initiates at the interface corner and propagates toward the center. A smaller yield stress of the film is beneficial to structural integrity. The side surface and the top surface near the corner are the critical regions for fracture.
The Behavior of Single-Input Super-Articulated Mechanisms

Super-articulated mechanical systems tems have more degree of freedom than actuators. For these systems, the relationship between actuator inputs and configuration space trajectories in nonholonomic in the sense that when the input variables return to their initial values it will not generally be the case that configuration variables also return to the initial values. Ih this paper, the long-term effects produced by periodic forcing of super-articulated mechanical systems are studied. For a certain class of Lagrangian control systems with symmetry, it is shown that the stability of equilibrium motions may be assessed in terms of a quantity which we call the averaged potential. For systems in which there is great complexity in the periodically forced dynamics (for instance in the rotating kinematic chains studied in [2] and [4]), appears to afford an attractively simple approach. The method is illustrated in solving the classical problem of stabilising an inverted pendulum by forced vertical oscillation of the point of suspension.
Tobacco prevention with Mississippi elementary teachers and students

Purpose – To examine a tobacco prevention elementary school project completed in 2000 in one rural state in the southeastern USA.Design/methodology/approach – Initially, 721 public school fourth through sixth grade teachers across Mississippi attended (for reimbursement) a tobacco prevention workshop that included curriculum‐integrated material; 658 completed a follow‐up questionnaire (91.3 percent return rate). In addition, 1,762 of their students completed an anti‐tobacco pre‐test and 1,723 (868 girls, 853 boys) completed an anti‐tobacco post‐test (97.8 percent return rate).Findings – Students improved from pre‐ to post‐test; girls scored better than boys. African American students and teachers completed more lessons than White students and teachers. Sixth graders completed fewer lessons and scored lower than fourth and fifth graders.Research limitations/implications – The test had a yes‐no format and a low ceiling, so many students answered correctly at pretest. Also, teachers were mostly white women, ...
Disease mutations in desmoplakin inhibit Cx43 membrane targeting mediated by desmoplakin–EB1 interactions

Mechanisms by which microtubule plus ends interact with regions of cell–cell contact during tissue development and morphogenesis are not fully understood. We characterize a previously unreported interaction between the microtubule binding protein end-binding 1 (EB1) and the desmosomal protein desmoplakin (DP), and demonstrate that DP–EB1 interactions enable DP to modify microtubule organization and dynamics near sites of cell–cell contact. EB1 interacts with a region of the DP N terminus containing a hotspot for pathogenic mutations associated with arrhythmogenic cardiomyopathy (AC). We show that a subset of AC mutations, in addition to a mutation associated with skin fragility/woolly hair syndrome, impair gap junction localization and function by misregulating DP–EB1 interactions and altering microtubule dynamics. This work identifies a novel function for a desmosomal protein in regulating microtubules that affect membrane targeting of gap junction components, and elucidates a mechanism by which DP mutations may contribute to the development of cardiac and cutaneous diseases.
Reversed hemispheric lateralization of cerebral function: a case study.

Abstract A case is presented of a right-handed man with a large left fronto-temporo-parietal infarct which did not result in aphasia. He did, however, show a pattern of deficits in visuospatial/constructional, attentional, and affective functioning which is typically seen in patients with right hemisphere lesions. These findings are most parsimoniously explained by reversed hemispheric lateralization.
Aeration in tower‐type fermentors: Effect of tower diameter and number of aeration disks

The rate of oxygen absorption by aqueous sodium sulphite solutions in tower-type fermentors up to 6 in. in diameter was related both to tower diameter and to the number of sintered Pyrex disks used for dispersing air entering the towers. Maximal rates of absorption were obtained in towers 2.5 in. in diameter. Under comparable conditions, rates of oxygen transfer in towers containing one aeration disk were approximately 30% higher than those in similar towers containing two or more disks. In towers greater than 6 in. in diameter, the absorption rate was independent of vessel diameter and number of aeration disks when more than one disk was used. Bubble coalescence was the main cause of the difference in the rate of oxygen absorption.
Swenson receives 2011 Geodesy Section Award: Response

Sean Claude Swenson received the 2011 Geodesy Section Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is given in recognition of major advances in geodesy
Electron Sheaths in Low-Pressure Weakly Collisional Plasma

Summary form only given. Electron sheaths are normally only present near small probes when they are biased more positive than the plasma potential or at electron emitting surfaces in weakly collisional low pressure plasma. Here, electron sheaths created along the axis of a large positively biased plate (diameter = 10 cm) located in a multi-dipole argon plasma are described. Experimental data show that the electron sheath can collect all electrons produced by ionization if sufficient loss area is provided for ions at the chamber walls. Measurements of the plasma potential with emissive probes and Langmuir probes show potential dips form at the sheath edges to limit electron loss and increase ion energy. The use of electron sheaths for extracting electron beams from plasmas will also be discussed
Spatial and Functional Organization of Bacterial Subcellular Structures in Superresolution

Current advances in fluorescence-based superresolution imaging have illustrated great details of cellular structures that are invisible to conventional fluorescence light microscopy. The significantly improved spatial resolution is especially advantageous for bacterial cells because of their small sizes. In the past few years the spatial organization and dynamics of a variety of bacterial cellular structures and protein macromachineries have been revealed with unprecedented details. As the field matures, it is now time to focus on the functional aspect of the observed spatial organizations and dynamics. Are they essential in carrying out a specific cellular function? Do they play a regulatory role in controlling the on and off of a certain cellular process? In this work I will present a few examples from our laboratory that examine the spatial and functional organization of macromolecules involved in bacterial cell division and transcription. We combine superresolution imaging with biochemical activity detection to illustrate the spatial organization-function relationship for E. coli RNA polymerase and the cytokinesis FtsZ-ring.
Polybacterial challenge effects on cytokine/chemokine production by macrophages and dendritic cells.

Objective To investigate the polymicrobial infection of periodontal disease, which elicits inflammatory mediators/cytokines/chemokines in the local gingival tissues, and a polybacterial challenge of antigen-presenting cells, e.g. macrophages and dendritic cells (DCs), at the mucosal surface.
Solute Focusing Techniques for Bioseparations

The growth of industrial biotechnology has had a major impact on the research and development of both analytical and preparative focusing techniques. Pioneering methods such as isoelectric focusing are being modified to overcome the limitations of batch mode Operation, scale up difficulties, high power requirement, and excessive heat generation. Present advances in focusing techniques have been made by either overcoming the limitations of standard techniques or by investigating new focusing systems. Here we review the background and history of isoelectric focusing and discuss several new focusing techniques including recycle isoelectric focusing (RIEF), counteracting chromatographic electrophoresis (CACE), and countercurrent gradient chromatography (CGC).
Integration of body temperature into the analysis of energy expenditure in the mouse

Objectives: We quantified the effect of environmental temperature on mouse energy homeostasis and body temperature.Methods: The effect of environmental temperature (4e33 C) on body temperature, ene ...
Synthesis, characterization, and Diels–Alder extension of cyclopentadiene telechelic polyisobutylene. III. Silylcyclopentadiene‐telechelic polyisobutylene

Telechelic polyisobutylenes with silylcyclopentadiene termini (CpSi-PIB-SiCp) were prepared, starting with α,ω-di(t-chloro)polyisobutylene and followed by dehydrochlorination, hydrosilylation, and cyclopentadienylation. The prepolymer was characterized and found to have a terminal functionality close to 2.0. Thermal chain extension by Diels–Alder addition of the end groups did not occur, most likely because of fluxional isomerization of the silylcyclopentadiene end groups, confirmed by model studies. Chain coupling of CpSi-PIB-SiCp prepolymers with stoichiometric amounts of bismaleimide gave rise to degrees of extension of more than 11.
Hot pressing of hafnium diboride aided by different sinter additives

Experiments were conducted by hot-pressing to densify HfB2 commercial powders using HfSi2 (5 vol%) or B4C (7 vol%) as sinter additives. The former was very effective as sintering enhancer: 15 min at 1,600 °C was a sufficient condition to achieve near full density. The occurrence of a liquid phase sintering, which substantially enhanced densification during hot-pressing, was found out. The HfB2–B4C powder mixture, hot-pressed at 1,900 °C for 40 min, achieved a relative density of 94%. Aside the key role of sintering enhancer, B4C also allowed the development of a uniform microstructure, preventing an excessive growth of the diboride matrix (2 μm mean size). On the contrary, thanks to the liquid phase that sustained substantial transfer of mass during heating, the HfSi2-doped composition had an uneven and more obvious grain growth (4 μm mean size), with faceted diboride grains up to 10 μm.
Factors associated with mothers' obesity stigma and young children's weight stereotypes

Abstract Parents and children hold negative attitudes about obesity, but little is known about individual differences in obesity stigma. The current study examined authoritarian parenting style, beliefs about the controllability of weight and fear of fat in relation to mothers' dislike of overweight individuals. Factors related to children's weight stereotypes were also investigated. Forty-nine mothers and children (43% girls) participated. Mothers showed more dislike and blame toward adults who are overweight than children who are overweight; parents were most often blamed for children's weight status. Authoritarian parenting and beliefs about controllability were related to mothers' anti-fat attitudes, but fear of fat was not. However, mothers' fear of fat was the best predictor of children's negative stereotypes toward overweight peers. The current study provides some preliminary insight into the role of mothers in children's attitudes about weight. Examining individual difference factors is also useful in planning targeted interventions to lessen obesity stigma.
Isoperoxidase Activity and Induction in Cultured Tissues of Wild Carrot: a Comparison of Proembryos and Embryos

Several anodic isoperoxidases were found in embryonic tissues of cultured wild carrot, Daucus carota L., which were not present in the proembryo masses from which they originate. This difference is further reflected in the higher specific activity of peroxidase in embryo extracts as compared to proembryonic tissues. The absence of anodic isoperoxidases and depressed peroxidase activity in carrot tissue cultures in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D) suggests a regulatory role for this plant growth regulator in controlling peroxidase activity.
Intercorrelations Among Musical Aptitude Profile and Seashore Measures of Musical Talents Subtests.

IN 1919 THE FIRST standardized group musical aptitude test, the Seashore Measures of Musical Talent} was published. This battery, in its latest revised form (Seashore, 1960), is comprised of six subtests which measure basic auditory sensory discrimination. According to the test author (Seashore, 1938), "everything that is rendered as music or heard as music may be expressed in terms of the concepts of the sound wave." Pitch, Loudness, Rhythm, Time, Timbre} and Tonal Memory are tested by requiring subjects to compare a pair or short series of tones which are produced on a beat-frequency oscillator (except on the Tonal Memory subtest). Because these subtests are supposedly void of the interaction of melody, rhythm, and musical expression, music psychologists (Mursell, 1937) have described and condemned the battery as being "atomistic" and unmusically-oriented. Specifically, the "omnibus" group, antagonists of the Seashore approach, believe that musicality consists of more than just the ability to discriminate audio-acoustical differences in the sound wave. Further, these music psychologists, many of whom are European (Lowery, 1940; and Mainwaring, 1947), argue that musical aptitude is not compnsed of separate abilities, but rather, that it is one general ability. They contend that a musical instrument should be used as the medium for stating music test items and that the content of each item should, in and of itself, have "musical meaning." The comparatively new Musical Aptitude Profile (Gordon, 1965) has been described as an eclectic test because both preference and nonpreference subtests constitute the test battery and also because, while the content of the test items is musical and is performed by professional musicians, the battery does, nevertheless, provide for the evaluation of seven postulated dimensions of musical aptitude. The musical dimensions measured by this standardized group test are classiSed into three main divisions: Tonal Imagery, Rhythm Imagery, and Musical Sensitivity. Two separate subtests are provided for each of the nonpreference tests: Melody and Harmony for Tonal Imagery, and Tempo and Meter for
Invariant solutions for steady diffusion and reaction inpermeable catalysts

Abstract Invariant solutions are derived for intraparticle diffusion-reaction problems with generalized heat and mass flux expressions. A uniform state is assum
MAC protocol classification in a cognitive radio network

Most media access control (MAC) protocols can be classified as contention based or controlled based according to their transmission mechanisms. To classify contention based or control based MAC protocols in an unknown primary network, we choose received power mean and variance as two features for support vector machines (SVMs) in a machine learning based algorithm. The data consisting of these two features are collected from two primary network models based on time division multiple access (control based) and slotted Aloha (contention based), respectively. In the training process, data along with their identification class labels (say, 1 denotes time division multiple access, and −1 stands for slotted Aloha) are used to train the SVMs. After training, contention or control based MAC protocols can be effectively determined by the trained SVMs embedded in a cognitive radio terminal of a secondary network.
A comparison of acoustic backscatter between a trawling and a free-running vessel for eastern Bering Sea walleye pollock (Theragra chalcogramma)

Abstract High-quality acoustic backscatter is continuously collected with Simrad ES-60 echosounders during the annual eastern Bering Sea (EBS) bottom trawl survey. Scientists at the Alaska Fisheries Science Center are examining the potential of combining the acoustic backscatter data collected between trawl stations with the trawl catch data to improve the precision of the survey index of walleye pollock ( Theragra chalcogramma ) abundance. A previous study we conducted [von Szalay, P.G., Somerton, D.A., Kotwicki, S., 2007. Correlating trawl and acoustic data in the eastern Bering Sea: a first step toward improving biomass estimates of walleye pollock ( Theragra chalcogramma ) and Pacific cod ( Gadus macrocephalus )? Fish. Res. 86, 77–83.] showed a high correlation between walleye pollock trawl catches and simultaneously collected acoustic backscatter; in this study, we compared walleye pollock acoustic backscatter collected while trawling at 3 knots with that of a free-running vessel traveling at 10 knots. Acoustic data were collected by two vessels during the 2006 and 2007 EBS bottom trawl surveys in a pair-wise fashion at 134 trawl stations. The free-running transects were conducted either immediately before or immediately after the trawl hauls and were parallel to the trawl paths but offset by approximately 250 m. The pollock acoustic backscatter was significantly greater for the trawling vessel in both the layer below the headrope and in the layer above the headrope, and was independent of the order in which the trawling and free-running transects were performed. A comparison of the seabed echo between trawling and free-running did not show a significant difference, suggesting that the discrepancy in the pollock backscatter is due to differences in fish behavior and not to differences in vessel attitude between the two operational modes. The higher backscatter values associated with trawling may be due to reactions of fish within a school that produce a coordinated swimming response, which has the potential to increase the average target strength.
Ultrafast dynamic ellipsometry of laser ablated silicon

Ultrafast dynamic ellipsometry, a technique that probes a sample with chirped laser pulses at two angles and with two orthogonal polarizations, was used to measure the effective refractive index across the ablation region of a Si(111) wafer exposed to a 100 fs ablation pulse. The resulting refractive index data show a significant increase in the extinction coefficient, indicative of the melting of silicon.
T1-selective diffusion weighted fMRI at 1.5 T

Apparent diffusion coefficients (ADC) of protons contributing to the functional signal can be determined from diffusion weighted functional magnetic resonance imaging (MRI) studies. An earlier study indicated that ADCs calculated from the functional signal of an activated primary sensorimotor cortex are large, and consistent with a CSF or intravascular contribution to the functional signal. We have added inversion recovery pulses to isotropic diffusion weighted imaging to null CSF protons selectively within the imaging slice, or to null the outer volume blood flowing into the imaging slice. With the use of gradient recalled diffusion weighted echo-planar imaging at low gradient b factors, and without the use of inversion pulses, the ADCs x 10(3) in mm2/s (+/- SD) from the functional signal were 6.81 +/- 1.19. These ADCs were significantly higher than resting primary sensorimotor cortex ADCs of 2.26 +/- 1.49, measured at the same b factors. When CSF nulling was applied, the functional signal ADCs remained high. Application of inflow nulling decreased the functional signal to such a small value, that ADCs estimated from these functional signals were not assessed. The results are consistent with an intravascular contribution to the functional signal and to its large ADC.
Review of Arons's

Stephen Arons, author of Compelling Belief: The Culture of American Schooling (Amherst: University of Massachusetts Press, 1986), is one of the most articulate and influential critics of the educational Establishment from the secular Left. In his new book, he takes on the Clinton Administration's efforts to establish national outcome standards--Goals 2000--which he describes as "comprehensive, centralizing, and insensitive to the diversity of goals that students, families, and communities bring to education. Through the use of federal grants and state regulations, it aims to bring every school in every school district in every state into conformity with politically prescribed standards of what should be learned by every child" (page 4). Arons warns that "[o]nce accepted by the public, Goals 2000 will change the balance of power in schoolhouses and courtrooms in a way unlikely ever to be undone. That change in schooling will very likely undermine the freedom of intellect and spirit that has been so essential to the American experience" (page 98).
MRI assessment of cerebral oxygen metabolism in cocaine-addicted individuals: Hypoactivity and dose dependence

Long-term cocaine use is known to negatively impact neural and cerebrovascular systems. However, the use of imaging markers to separately assess these parameters remains challenging. The primary reason is that most functional imaging markers, such as cerebral blood flow, functional connectivity, and task-evoked functional MRI, are known to reflect a complex interplay between neural and vascular components, thus the interpretation of the results is not straightforward. The goal of the present study is to examine neural-activity-specific changes in cocaine addiction, using cerebral metabolic rate of oxygen (CMRO2) as a surrogate marker of aggregated neural activity. We applied a recently developed CMRO2 technique in 13 cocaine-addicted subjects and 13 age- and gender-matched control subjects, and examined the impact of long-term cocaine use on CMRO2. Our results showed that CMRO2 in cocaine-addicted subjects (152 ± 16 µmol/100 g/min) is significantly lower (p = 0.031) than that in controls (169 ± 20 µmol/100 g/min). Furthermore, the severity of this decreased metabolism is associated with lifetime cocaine use (p = 0.05). Additionally, the CMRO2 reduction was accompanied by a trend of decrease in cerebral blood flow (p = 0.058), but venous oxygenation was unaffected (p = 0.96), which suggested that the CMRO2 change may be attributed to a vascular deficiency in chronic cocaine users. To our knowledge, this is the first study to measure CMRO2 in cocaine-addicted individuals. Our findings suggest that CMRO2 may be a promising approach for assessing the long-term effects of cocaine use on the brain.
Time-Varying Jump Tails

We develop new methods for the estimation of time-varying risk-neutral jump tails in asset returns. In contrast to existing procedures based on tightly parameterized models, our approach imposes much fewer structural assumptions, relying on extreme-value theory approximations together with short-maturity options. The new estimation approach explicitly allows the parameters characterizing the shape of the right and the left tails to differ, and importantly for the tail shape parameters to change over time. On implementing the procedures with a panel of S&P 500 options, our estimates clearly suggest the existence of highly statistically significant temporal variation in both of the tails. We further relate this temporal variation in the shape and the magnitude of the jump tails to the underlying return variation through the formulation of simple time series models for the tail parameters.
Test-retest reliability of an icon/calendar-based questionnaire used to assess occupational history.

Background Self-reported work histories can be critical for both epidemiologic and clinical purposes. However, the complexity of some work histories, such as those of migrant farm workers, can hamper recall, resulting in inaccurate reporting. Memory aids may reduce such error. This study assesses the reliability of work histories collected using such aids in the form of an icon/calendar-based questionnaire. Methods Thirty-one males engaged in farmwork and other manual labor for a median 28 years (range: 10–64) were interviewed twice, 8–14 months apart, about their lifetime employment. In each interview, subjects were asked about important life events, which were recorded with icons on a calendar. They were then asked to recount their work history, including for each job the tasks, crops or products handled, starting and ending dates, and location. This information was recorded, job-by-job, on the calendar with icons. Results Interquestionnaire agreement of cumulative reported employment duration (as measured by the correlation coefficient) was moderate to high across all time periods for certain crops (e.g., r = 0.69–0.92 for apple-related work), by location (e.g., r = 0.76–0.95 for Washington State), and for agricultural work in general (r = 0.67–0.94), but was lower for specific tasks. Agreement of job counts was high for total work history for certain crops (e.g., r = 0.93 for apple-related work), by location (e.g., r = 0.90 for Washington State), and for agricultural work in general (r = 0.89), but paradoxically decreased with proximity to the interview date. Agreement of both measures tended to be highest for those tasks and crops in which subjects reported spending the most time. Categorization of subjects into tertiles on the basis of either cumulative duration or counts produced results similar to those observed for job counts. Conclusions The icon-calendar questionnaire is an effective tool for estimating cumulative duration of certain work categorizations among subjects with complex work histories. Am. J. Ind. Med. 40:512–522, 2001. Published 2001 Wiley-Liss, Inc.
Progress in scanning probe microscopy

Abstract In the past decade, the field of microscopy has been revolutionized by the introduction of a range of microscopies—scanning probe microscopes that are capable of measuring physical and chemical properties on the nanoscale. These microscopes—which were stimulated by the scanning tunneling microscope—have had a major impact on the understanding of material surfaces. The development of the key concepts of scanning probe microscopes is reviewed from their early history to current technologies. Some key applications of scanning probe microscopes are presented and the future advances that are likely to come to fruition in the next decade are discussed.
Nutritional and Metabolic Support in Adults With Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable, degenerative, neuromuscular condition. Nutritional and metabolic support is an integral component of care for patients with ALS because those ca...
Improving the educational experience for international clinical nurse specialist students, part III: using culturally sensitive teaching strategies.

This column completes the current series, 1,2 addressing ways to improve the educational experience for international clinical nurse specialist (CNS) students. As noted in the earlier columns, acculturative stress is defined as stress caused by the process of adaptation that accompanies ‘‘a change of cultural environment.’’ Acculturative stressors are multifactorial and common among students living and studying in a foreign country. Understanding the cultural norms and cultural values specific to the students in your institution can help faculty teach in a more culturally sensitive manner to promote an optimal learning environment for students from other nations. Part 1 of this series discussed the challenges that international students need to overcome when applying to and attending nursing programs in the United States. Last month’s column explored cultural differences in communication from a conceptual and theoretical perspective and identified organizational strategies to improve the student experience at the school and campus level. This month’s column will present classroom and clinical strategies that faculty, and hospital educators, can use to decrease acculturative stress and assist international students to adjust to learning in a different cultural environment.
Cerebral 1H MR spectroscopy and neuropsychologic status of patients with hepatic encephalopathy.

Our objective was to assess the metabolite levels (myo-inositol [ml], choline [Cho], creatine [Cr], glutamate or glutamine [Glx], and N-acetyl-L-aspartate [NAA]) visible on 1H MR spectroscopy in patients with subclinical and mild hepatic encephalopathy before and after liver transplantation and to correlate these data with the results of neuropsychiatric tests and related clinical findings.A stimulated-echo sequence was used to localize a single voxel in the parietal region. Seventeen patients and 13 healthy volunteers were investigated. Nine of the 17 patients also were investigated after liver transplantation. A battery of neuropsychologic tests also was administered to patients to assess frontal, memory, and motor functions.Before liver transplantation, significant reductions in mI:Cr (51%) and Cho:Cr (11%) and a significant increase in Glx:Cr (20%) were observed in patients compared with the respective ratios in healthy subjects. Patients also were significantly impaired on neuropsychologic tests meas...
Characterization of marine aerosols and precipitation through shipboard observations on the transect between 31° N–32° S in the West Pacific

Abstract To characterize the chemical composition, size distributions, and fractional Fe solubility of atmospheric particles over Asian marginal seas, South Indian Ocean and Australian coast, selected water–soluble inorganic and organic species in aerosols and precipitation, trace metals and soluble Fe in aerosols were analyzed by multi–instruments. Results showed that sea salt and non–sea–salt sulfate (nss–SO 4 2– ) were the main components in aerosols. Over Asian marginal seas, Cl – and Na + were the dominant ions in precipitation, accounting for ˜;72% of the total ions. Both SO 4 2– and NO 3 – accounted for −26% of the total anions, controlling the acidity of the precipitation. Non–sea–salt Ca 2+ (nss–Ca 2+ ) accounted for 6.9% of the total cations, dominating the neutralizing component in rainwater. Observed methane sulfonate (MSA) concentrations and MSA/nss–SO 4 2– increased southward. The concentrations of sea salt were affected by wind speeds, which was mainly accumulated in particle size >10 μm. Particle size distributions of nss–SO 4 2– and NH 4 + mainly peaked in the fine mode, while NO 3 – was mainly accumulated in the coarse mode. Oxalate presented a bimodal size distribution pattern in both fine and coarse modes. Based on the air mass back trajectories, enrichment factors and Fe/Al, V/Al ratios, aerosol samples collected over Asian marginal seas could be affected by both long–range transported dust and anthropogenic emissions. Good relationship was found between total dissolved iron and nss–SO 4 2– , indicating that acid processing during long–range transport could play an important role in fractional iron solubility in aerosols. The inverse relationship between atmospheric total Fe and fractional Fe solubility fitted in the global–scale trend. This study implicates that dust and acidic air pollutants from continental sources can interact and affect iron solubility in aerosols in the marine atmosphere. However, due to the small size of samples in this study, more investigations need to be conducted in future.
Multiple Restorations: German Political Traditions and the Interpretation of Nazism, 1945–1946

In the longer continuity of German history, the year 1945 will always, in part, represent the “Stunde Null” (zero hour), of catastrophic military defeat and complete moral disgrace and bankruptcy following Nazism and the Holocaust.1 The term “Stunde Null” evokes the need for a new beginning, a moral and political break with disastrous and ultimately criminal national traditions. Yet, because the Third Reich lasted only twelve years, and because there were non- and anti-Nazi traditions and leaders that survived in inner and external emigration, the postwar rejection of Nazism took the form of multiple restorations of these still extant German political traditions. In the first postwar years, the turn away from Nazism in both Germanies, as well as the break with totalitarian dictatorship in general in Western Germany, was taken by political leaders who had been active in Weimar politics and who returned to take center stage in German politics after 1945.2 To be sure, they were all deeply affected in their lives and thinking by the Third Reich. But what changes it did bring about in their political views amounted to rearrangements and different emphases of long-held convictions rather than to wholly new beginnings.
Natural killer cell receptor signaling

Natural killer (NK) cell immune responses are regulated by a balance of activating and inhibitory signals transmitted by cell surface receptors. Immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic domains of inhibitory NK receptors recruit tyrosine or lipid phosphatases, which modulate the activation signals transmitted by receptors linked to the Syk and ZAP70 tyrosine kinases and phosphatidylinositol-3 kinases. In addition, recent studies of gene-deficient animals, in particular Syk and ZAP70 double-deficient mice, suggest that NK cells possess a robust and potentially redundant receptor system to ensure their development and function.
Effects of Summer Grazing Strategies on Organic Reserves and Root Characteristics of Big Bluestem

Quantifying root structure response to multiple defoliation events in a grazing situation is critical in developing management plans for warm-season tallgrasses. A pasture experiment was conducted in 1999, 2000, and 2001 near Mead, NE. The objective of the experiment was to determine the effect of timing and frequency of grazing on big bluestem (Andropogon gerardii Vitman) etiolated tiller growth and root and rhizome structure. Paddocks were grazed at a stocking rate of 9.9 Animal Unit Month (AUM) ha -1 in two to four cycles from mid-May to early-September. In April 2002, five 6.6- x 132-cm soil cores were extracted from each paddock. Soil cores were subsampled at 30-cm depth increments for estimates of root mass, root surface area, and root volume. Etiolated tiller tents were used to estimate organic reserves of big bluestem in each paddock in spring 2002. Mean number and weight of etiolated tillers were reduced by up to 40% and 50%, respectively, in paddocks grazed in a sequence of June after internode elongation, early August, and early September. Root structure in the top 30 cm of the soil profile was affected most by multiple defoliation events with 40 d.
Synthesis and bio-functionalization of multifunctional magnetic Fe3O4@Y2O3:Eu nanocomposites

A facile homogenous precipitation method has been developed for the synthesis of multifunctional, magnetic, luminescent nanocomposites with Fe3O4 nanoparticles as the core and europium-doped yttrium oxide (Y2O3:Eu) as the shell. The nanocomposites showed both super-paramagnetic behavior and unique europium fluorescence properties with high emission intensity. Their surface has been modified with a bifunctional ligand, p-aminobenzoic acid (PABA), and further biofunctionalized with biotin; the nanocomposites showed specific targeting for avidin-coupled polystyrene beads.
The weight hierarchies of outer product codes

Abstract The weight hierarchy of the outer product of two self-complementary codes is expressed as a function of the weight hierarchies of the component codes. An alternative method to calculate the rth generalized Hamming weight (and so the weight hierarchy) of the first-order Reed–Muller code is given. The outer product of a self-complementary code and a nonself-complementary code is also discussed.
Physicians' prescriptions of tranquilizers and tranquilizer abuse.

The abuse of tranquilizers is recognized as a major health problem. A substantial number of qualitative studies have suggested that the prescribing practices of physicians are at least partly responsible for the problem. Yet there is still a need to test this contention statistically. This paper tests the strength of the relationship over time between physicians' prescriptions of tranquilizers and tranquilizer abuse. Data on physicians' prescriptions are based on projections calculated by the National Disease and Therapeutic Index (NDTI). Data on tranquilizer abuse are based on emergency room episodes reported to the Drug Abuse Warning Network (DAWN). The correlation between physicians' tranquilizer prescriptions and tranquilizer abuse is found to be. 46 (significant at the. 05 level), after controlling for serial correlations in the data.
Would Accountability Based on Teacher Value Added Be Smart Policy? An Examination of the Statistical Properties and Policy Alternatives

Abstract Annual student testing may make it possible to measure the contributions to student achievement made by individual teachers. But would these “teacher value-added” measures help to improve student achievement? I consider the statistical validity, purposes, and costs of teacher value-added policies. Many of the key assumptions of teacher value added are rejected by empirical evidence. However, the assumption violations may not be severe, and value-added measures still seem to contain useful information. I also compare teacher value-added accountability with three main policy alternatives: teacher credentials, school value-added accountability, and formative uses of test data. I argue that using teacher value-added measures is likely to increase student achievement more efficiently than a teacher credentials-only strategy but may not be the most cost-effective policy overall. Resolving this issue will require a new research and policy agenda that goes beyond analysis of assumptions and statistical p...
Analysis of fast sparse superposition codes

Sparse superposition codes with a fast adaptive successive decoder for the additive white Gaussian noise channel were introduced last year by the authors, along with presentation of reliability at rates approaching capacity. The present work presents ingredients of the distributional analysis of the decoder.