cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultraviolet generation with passively Q-switched microchip lasers: errata.

First, second, third, fourth, and fifth harmonics of the output of a fiber-pumped passively Q-switched Nd:YAG microchip laser have been obtained at pulse energies of 8.0, 3.5, 0.3, 0.7, and 0.01 μJ, respectively, in an optical head occupying a volume of less than 3 cm3. This compact, economical all-solid-state source provides coherent subnanosecond multikilowatt infrared, visible, and ultraviolet pulses at repetition rates in excess of 10 kHz.
Precipitation of Au nanoclusters in SrTiO3 by ion implantation

Gold nanoclusters dispersed in single-crystal SrTiO3 (STO) (001) have been prepared by ion implantation at both 300 and 975 K followed by annealing at 1275 K for 10 h. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field imaging in an aberration-corrected dedicated scanning TEM, and image simulations were used to study the morphology, size, and crystallographic orientation of the Au nanoclusters with respect to the STO matrix, as well as the interface structure between the Au nanoclusters and STO. Gold ion implantation at 300 K leads to amorphization of the STO surface layer, which is corrugated to form bumps and valleys on the surface. Annealing at 1275 K for 10 h leads to epitaxial recrystallization of the amorphized layer within which Au clusters of several nanometers and a narrow size distribution were formed. Implantation at 975 K and subsequent annealing produces much larger Au clusters ∼50 nm in diameter and a very wide size distribution. The precipitated Au cluster...
Designing reliable polymer coatings

A method to predict the ultimate adhesion performance of coatings subjected to biaxial, tensile stress is presented. A set of equations is developed to predict the onset of failure when the locus of failure is cohesive in the coating. The equations also have been extended to predict fatigue lifetime when a coating is cycled from a low temperature to room temperature. To test these equations, the Edge Liftoff Test (ELT) was developed. It consists of fabricating coatings of various heights on a rigid substrate and dicing the latter, so that the edges are 90° to the interface. The parts are cooled and the temperature of debonding is recorded. For thermal fatigue validation, cycles at which the first debond is observed are recorded. ELT results have been collected for a typical epoxy for both monotonic and cyclic cooling. The predictions are in agreement with results.
Degenerative spondylolisthesis in ancient and historic skeletons from New Mexico Pueblo sites.

The objective of this study was to identify the presence of degenerative spondylolisthesis in adult Native American skeletons recovered from prehistoric and historic Pueblo sites in New Mexico. The vertebral columns of 491 individuals that were complete enough to allow the necessary observations produced 64 cases, with a total of 74 affected levels. The L5-S1 level was affected most frequently (78%), in contrast to clinical and anatomical studies where the L4-L5 level was usually affected (80%). Age and sex were found to be important factors, with the condition limited to middle and old adults, and occurring in females over males at a ratio of approximately 5:1. Olisthesis was shown to occur only in association with severe osteoarthritis of the zygapophysial joints, but severe osteoarthritis did not always result in olisthesis, particularly in males. Parallel or convergent inferior articular processes were found to increase in frequency in the presence of olisthesis, apparently resulting from degenerative remodeling that produced the olisthesis. The data also suggest that individuals with cranial border shifting in the column may be especially prone to olisthesis. Degenerative olisthesis was also observed in the cervical region.
Distribution of the mRNAs encoding torsinA and torsinB in the normal adult human brain.

To gain insight into the neural pathways involved in the pathogenesis of DYT1 dystonia, we have mapped the cellular expression of the mRNA encoding torsinA and the closely related family member, torsinB, in normal adult human brain. Here, we report an intense expression of torsinA mRNA in the substantia nigra pars compacta dopamine neurons, the locus ceruleus, the cerebellar dentate nucleus, Purkinje cells, the basis pontis, numerous thalamic nuclei, the pedunculopontine nucleus, the oculomotor nucleus, the hippocampal formation, and the frontal cortex. Within the caudate-putamen, the cellular expression of torsinA mRNA was heterogeneous; a moderate signal was found overlying large cholinergic neurons, and most striatal neurons exhibited only a very weak signal. A moderate signal was detected in numerous midbrain and hindbrain nuclei. A weak cellular signal was detected in neurons of the globus pallidus and subthalamic nucleus. In marked contrast to torsinA, no specific mRNA signal was detected for torsinB. That torsinA mRNA is enriched in several basal ganglia nuclei, including the dopamine neurons in the substantia nigra, is intriguing since it suggests that DYT1 dystonia may be associated with a dysfunction in dopamine transmission.
The Royal Society Nuffield Lecture: Economic Behaviour under Uncertainty

When the President of the Royal Society did me the honour of inviting me to give this first Nuffield Lecture, he wrote that the Royal Society wished to ‘form some wider contacts with what can broadly be called the behavioural sciences’. I imagine that State Department officials in Washington sometimes speak similarly of the Communist government of China. It is too bad that the State Department has never been bold enough to grasp the forthright solution of inviting one of them to give a lecture. It may be thought that, as a Professor of Economics at the Massachusetts Institute of Technology, I am a particularly suitable person to lecture on economics to scientists. I am afraid that may not be so. I have sat through interminable committee meetings with my scientific colleagues, occasionally have taught economics to their children, and sometimes, having been told of an exciting and exotic new way to move people by rail from Boston to New York in one hour, I have said that it will almost certainly cost too much. But I cannot honestly say that I have ever up to this moment tried to function as a member of a one-and-a-half culture. Perhaps I should also warn you that the phrase ‘behavioural science’ may very well have been invented by other social scientists specifically to exclude economists, with respect to whom they feel a not uncommon mixture of inferiority and distaste.
Coevolution of information ecosystems: a study of the statistical relations among the growth rates of hardware, system software, and application software

With the increasing use of information technology, information ecosystems have emerged. Information ecosystems not only include software products, but also include hardware products. For example, application software depends on system software, and both application software and system software depend on hardware devices. Together, they play important roles in an information ecosystem. This paper analyzes the coevolution of information ecosystem, where three representatives of computer hardware, system software, and application software products are studied. Specifically, we analyze (1) the growth rate of Intel processors, Linux operating systems, and Apache web servers; and (2) the statistical relations among the evolution of Intel processors, Linux operating systems, and Apache web servers. Our study finds that a system software product grows slower than its supporting hardware products and a application software product grows slower than its supporting system software and hardware products.
Enhanced carrier multiplication in engineered quasi-type-II quantum dots

One process limiting the performance of solar cells is rapid cooling (thermalization) of hot carriers generated by higher-energy solar photons. In principle, the thermalization losses can be reduced by converting the kinetic energy of energetic carriers into additional electron-hole pairs via carrier multiplication (CM). While being inefficient in bulk semiconductors this process is enhanced in quantum dots, although not sufficiently high to considerably boost the power output of practical devices. Here we demonstrate that thick-shell PbSe/CdSe nanostructures can show almost a fourfold increase in the CM yield over conventional PbSe quantum dots, accompanied by a considerable reduction of the CM threshold. These structures enhance a valence-band CM channel due to effective capture of energetic holes into long-lived shell-localized states. The attainment of the regime of slowed cooling responsible for CM enhancement is indicated by the development of shell-related emission in the visible observed simultaneously with infrared emission from the core.
Crystal size distribution (CSD) in rocks and the kinetics and dynamics of crystallization

Crystal-size in crystalline rocks is a fundamental measure of growth rate and age. And if nucleation spawns crystals over a span of time, a broad range of crystal sizes is possible during crystallization. A population balance based on the number density of crystals of each size generally predicts a log-linear distribution with increasing size. The negative slope of such a distribution is a measure of the product of overall population growth rate and mean age and the zero size intercept is nucleation density. Crystal size distributions (CSDs) observed for many lavas are smooth and regular, if not actually linear, when so plotted and can be interpreted using the theory of CSDs developed in chemical engineering by Randolph and Larson (1971). Nucleation density, nucleation and growth rates, and orders of kinetic reactions can be estimated from such data, and physical processes affecting the CSD (e.g. crystal fractionation and accumulation, mixing of populations, annealing in metamorphic and plutonic rocks, and nuclei destruction) can be gauged through analytical modeling. CSD theory provides a formalism for the macroscopic study of kinetic and physical processes affecting crystallization, within which the explicit affect of chemical and physical processes on the CSD can be analytically tested. It is a means by which petrographic information can be quantitatively linked to the kinetics of crystallization, and on these grounds CSDs furnish essential information supplemental to laboratory kinetic studies. In this three part series of papers, Part I provides the general CSD theory in a geological context, while applications to igneous and metamorphic rocks are given, respectively, in Parts II and III.
SU-FF-P-01: Conducting a SWOT Analysis - A Useful Framework for Medical Physics Strategic Planning

Purpose: To describe the use of SWOT (Strengths, Weaknesses, Opportunities, Threats) Analysis for medical physics strategic planning. Method and Materials: An organizational profile review of a department's medical physics staff serves as an essential preamble to the SWOT Analysis methodology. The intent of the profile study is to define important components of the work environment including: purpose, mission, vision, values, reporting relationships, workforce relationships, vendor relationships, regulatory environment and productivity tracking. A four‐quadrant SWOT matrix that is consistent with the results of the profile study is created to identify Strengths, Weaknesses, Opportunities and Threats to be used by the medical physics team as an aid in the design of appropriate action items that will lead to successful strategic outcomes. Strengths are organizational characteristics that contribute positively to achieving the defined objectives. Weaknesses are organizational characteristics that are detrimental to achieving the defined objectives. Opportunities are external factors that will assist with achieving the defined objectives. Threats are external factors that could hinder achieving the defined objectives. Results: This methodology facilitates the implementation of specific medical physics operational objectives by utilizing team‐based “brainstorming” techniques that focus on carefully targeted initiatives. Conclusion: SWOT Analysis is a well‐ established management planning tool that has been employed advantageously by diverse industries, including health care, for many years. It is a useful system also for providing medical physicists with a structured, systematic approach in the pursuit of performance excellence.
Cross-sectional Study of Upper Trapezius Muscle Activity and Self-Reported Neck/Shoulder Pain

The purpose of this cross-sectional study was to compare the observed associations between upper trapezius muscle activity, as estimated with several summary measures obtained from surface electromyography (EMG), and self-reported neck/shoulder pain among a sample of 231 manufacturing workers. EMG methods used in this study included mean root-mean-square amplitude, the amplitude probability distribution function (APDF), EMG gaps analysis, and clustered exposure variation analysis. The observed seven-day prevalence of neck/shoulder pain was 13.9%. Of the EMG summary measures, only the 90 th percentile of the APDF was significantly associated with symptoms, with crude and adjusted odds ratios of 2.57 (1.02–6.49) and 2.78 (1.07–7.21) per natural log unit, respectively. This study was largely inconclusive due to the similarity in the distributions of the summary measures between symptomatic and non-symptomatic participants, and explicit measures of posture and repetition may produce stronger associations with...
The RATE Study: The Faculty:

For 3 years, teacher education faculty from 80 institutions have been surveyed by the Association of Colleges for Teacher Education. Results indicate that faculty responding to the questionnaire were predominantly White males, around 50 years old, who were likely to remain in their current positions. Nearly all teacher education faculty had prior experience in the lower schools, and the majority reported ongoing work in schools. Publication rates were comparable to faculty in higher education generally.
Spectral electroencephalographic correlates of iron status: Tired blood revisited

Abstract For some time, clinical reports have described impairment of affective and cognitive functions in iron deficient persons. Recent studies suggest that both brain biochemistry and cognitive performance capacity may be disrupted by inadequate intake of dietary iron, but the relationship of the possible neurophysiological effects to psychological ones is unclear. To examine the relationship of iron status to simultaneous measures of cortical activation and cognitive performance, 8 channels of electroencephalographic (EEG) data were recorded during a resting period and during the performance of several cognitive tasks in two groups of men. The EEG data were spectrally analyzed, and measures of total power and frequency of peak power in each of several bands of the power spectrum for each channel were used as predictors in multiple regression analyses with serum iron and serum ferritin as alternative criteria. Measures of power in the delta frequency in the resting period appeared relevant to iron status in both groups, perhaps indicating alertness or arousal level. Consistently in these regressions, the asymmetry of the EEG appeared relevant to iron and ferritin. These findings suggest that the combination of EEG and performance measures may help characterize the neuropsychological effects of trace element nutrition.
Edge electrostatics of a mesa-etched sample and edge-state-to-bulk scattering rate in the fractional quantum Hall regime

To study the effects of Coulomb interactions on the properties of fractional quantum Hall edge states, we introduce a realistic model of a two-dimensional electron gas at a mesa-etched sample edge and solve it within electrostatic and Hartree-Fock approximations. We discuss the physics of the fractional quantum Hall strips separating the conducting edge channels and ways of estimating the widths of these strips. We relate our results to the measurements of nonlocal resistance by estimating the quasiparticle scattering rate and the corresponding equilibration length between the edge states and the conducting bulk.
An extremal criterion for epimorphic regeneration

Many developing systems obey the principle of continuity: a morphogenetic field, when perturbed, tends to restore the normal local pattern of structures in its organ district. We have investigated physical field theories for a morphogenetic field, seeking constraints which would make a field theory produce the principle of continuity. We assume that during embryonic (ontogenetic) development a leg develops a pattern of positional values and a length which extremize a time-independent functional—the integral, over the length of the leg, of a function of positional values and position. For a single state variable which represents positional value, if a unique extremizing solution for the ontogenetically generated pattern and the length exists, and if no position-dependent functions other than the state variable appear in the integrand, then the principle of continuity is valid: in any regenerated leg the state variable is continuous and each region is locally identical to a region of the ontogenetically generated leg. This proposition is applied to three simple examples. For an exponential gradient and a Jacobi elliptic function there is a set of parameter values and boundary values for which a functional is minimized and the ontogenetically generated leg has an optimal length. Thus a leg which meets these constraints will obey the principle of continuity. However, a functional which when extremized gives a sinusoidal pattern does not in general provide a unique extremal length. Mathematical conditions are discussed under which an ontogenetically generated limb or a regenerated limb represents an asymptotically stable steady state. For a specific model of the transient dynamics in the exponential gradient case, the steady state gradient is asymptotically stable.
Development of subtype-selective ligands as antagonists at nicotinic receptors mediating nicotine-evoked dopamine release.

Abstract N-n-Alkylation of nicotine converts it from an agonist into an antagonist at neuronal nicotinic acetylcholine receptor subtypes mediating nicotine-evoked dopamine release. Conformationally restricted analogues exhibit both high affinity and selectivity at this site, and are able to access the brain due to their ability to act as substrates for the blood–brain barrier choline transporter.
Relationship Between Approach and Avoidance Inclinations to Use Alcohol and Treatment Outcomes

Abstract Background Despite growing recognition of the importance of multidimensional assessments of craving, little is known about how both approach and avoidance of alcohol inclinations change during the course of treatment, or relate to treatment outcomes. The current study examined the relationship between approach inclinations, avoidance inclinations, and treatment outcomes in individuals seeking treatment for alcohol dependence, and investigated whether changes in approach and avoidance ratings were associated with changes in drinking. Methods Individuals (n = 81) seeking treatment for alcohol dependence were randomized to receive either 12-sessions of cognitive–behavioral therapy plus healthy living skills or 12-sessions of cognitive–behavioral therapy plus affect regulation training. Participants provided pre- and post- treatment scores on various measures including drinking behaviors and approach and avoidance inclinations to use alcohol. Results Results indicated that both approach and avoidance inclinations were uniquely and significantly associated with problem recognition, and that avoidance inclinations were uniquely related to taking steps to make a change in alcohol use at baseline. In addition, avoidance inclinations were positively associated with number of sessions attended with no association found for approach ratings. Finally, results suggested that changes observed in drinking outcomes (drinks/day and% days abstinent) were significantly associated with changes in approach, but not avoidance inclinations. Conclusions These findings highlight the importance of measuring both desire to consume and desire to avoid consuming alcohol simultaneously and suggest that avoidance inclinations are associated with treatment initiation and retention, and approach inclinations with positive treatment outcomes.
Can dermal thickness measured by ultrasound biomicroscopy assist in determining osteoporosis risk

Background and purpose: A study was undertaken to evaluate the relationship between dermal thickness and bone density. Ninety-eight female subjects were recruited from a population of patients attending a university hospital osteoporosis clinic. The subject population ranged in age from 30 to 88 years with a mean age of 60. The weight range was from 91 to 274 pounds, mean 142 pounds. Methods: Dermal thickness measurements were taken at the right forearm using a Longport high resolution 20 MHz ultrasound scanner. Bone density measurements were taken using a GE Lunar Prodigy DXA scanner at both hips. Results: Statistical analysis using the intraclass correlation coefficient (ICC) of the skin measurements showed that the dermal measurement technique was highly reliable (CI=0.87, 0.92). Linear regression was used to examine the value of dermal thickness as a predictor of bone density. The correlation coefficient between dermal thickness and hip T score was statistically significant in the positive direction (corr.=0.304, P=0.001). We further investigated the relationship between dermal thickness and T scores using penalized splines. Conclusion: This analysis indicated that the strongest association with bone density occurred between 1.0 and 1.5 mm of dermal thickness. In those subjects identified as having osteoporosis dermal thickness measure of ≥1.04 corresponds to 4% of the subjects having osteoporosis. If dermal thickness is <1.04 then 23% have osteoporosis.
Fluorine mobility during early diagenesis of carbonate sediment: An indicator of mineral transformations

Abstract The abundant occurrence of calcium carbonate minerals in marine sediment, their well-documented dissolution or precipitation during diagenesis, and their high F content suggest that carbonate mineral diagenesis may be an important influence on F behavior in marine sediment. To test this hypothesis, we have examined the geochemistry of F in shallow carbonate mud bank sediment of Florida Bay, USA. The F content of biogenic calcium carbonate in Florida Bay varies with mineralogy, positively correlates with the Mg content of calcite, and occurs in similar abundance to Sr (high-Mg calcite: F Sr = 2.4 mol/mol ; aragonite: 0.53–0.79 mol/mol; low-Mg calcite: 0.22 mol/mol). Models of porewater distributions, direct solute flux measurements, and reaction rate estimates over the upper 0–16 cm of sediment from Bob Allen Key Bank predict net fluxes out of the sediment of 170 μmol F/m2/d, 230 μmol Sr/m2/d, and 5.6 mmol Ca/m2/d. The net solute flux ratio of F Sr (0.71 mol/mol) is consistent with dissolution of aragonite or high-Mg calcite, but F Ca and Sr Ca ratios (28 mmol/mol and 40 mmol/mol, respectively) are 3–10 × that of biogenic carbonate sources. Selective dissolution of a high F and Sr content phase or, more likely (based on dissolution experiments), concurrent dissolution and reprecipitation of phases with different F and Sr contents account for this discrepancy. The loss of F, Sr, and Ca to fluorapatite precipitation, as predicted from a stoichiometric model of phosphate release, can be added to the transport-reaction model predicted net fluxes. A resulting, more complete mass balance model incorporating both carbonate mineral reactions and fluorapatite formation yields total release estimates of F, Sr, and Ca of 770 μmol, 332 μmol, and 53 mmol/m2/d, respectively. Calcium carbonate minerals apparently undergo transformation whereby 34 mmol high-Mg calcite/m2/d and 19 mmol aragonite/m2/d dissolve, and 46 mmol low-Mg calcite/m2/d precipitates (ignoring other cations besides Ca). If no fluorapatite formation occurs, the required fluxes are that 23 mmol aragonite/m2/d dissolves and 3.4 mmol high-Mg calcite/ m2/d and 14 mmol low-Mg calcite/m2/d precipitate. Net loss of CaCO3 from the deposit by dissolution is ~6–7 mmol/m2/d (3% of the accumulation flux). The magnitude of these fluxes could cause significant mineralogical and chemical changes on rapid time scales in nearshore carbonate sediment. Fluorine is probably mobile in other carbonate deposits undergoing diagenetic alteration on short and longer time scales and is a powerful additional constraint on the rates and nature of carbonate mineral diagenesis.
DIRECT APPROACH TO THERMOELASTICITY

The Laplace transforms with respect to time of the governing equations of one-dimensional thermoelasticity are obtained, with the displacement and temperature fields coupled. Elimination of the Laplace transform of either field variable between the resulting linear, simultaneous, and coupled ordinary differential equations results in ordinary differential equations in the other field variable. The characteristic equations are identical for both variables. Depending on the sequence in which the elimination is carried out, the solutions are obtained in two different forms. The equivalence of these forms is established by using the properties of the characteristic roots. (This process provides an alternative to the state approach recently developed by the authors.) Applications to problems pertaining to a half-space and a layer of finite thickness are presented.
Reaction of hydroxyl radical with p-hydroxymercuribenzoic acid

Abstract Radiolysis of a 0.1 mmol l −1 aqueous solution of p -hydroxymercuribenzoic acid ( p -HMBA) results in the formation of p -hydroxybenzoic acid ( p -HBA) and 3, 4-dihydroxybenzoic acid (3, 4-DHBA). Spectrophotometric and liquid chromatographic analysis of irradiated nitrous oxide saturated solutions indicate a disappearance yield G(-HMBA) of 3.1×10 −7 mol J −1 , a formation yield of 1.5×10 −7 mol J −1 for p -HBA and 0.44×10 −7 mol J −1 for 3, 4-DHBA. Pulse radiolysis of N 2 O saturated solutions of p -HMBA at pH 9.2 provides a rate constant of (6.3±0.8)×10 9 M −1 s −1 for the formation of a hydroxycyclohexadienyl radical. Similar experiments provided rate constants at pH 7.0 and 12.0 of (6.6±1.0)×10 9 and (1.6±0.3)×10 9 M −1 s −1 , respectively. The UV/Vis absorption spectrum of the hydroxycyclohexadienyl radical has a λ max =340 nm with a molar absorption coefficient of 4.1×10 3 l mol −1 cm −1 .
Hereditary callosities with blisters

A family with calluses of the soles associated with blistering is described. Electron microscopic study of a bulla showed an intraepidermal blister with cytolysis of keratinocytes and clumping of tonofilaments. Review of the literature and our own experience with keratoderma palmaris et plantaris revealed no similar patients with this combination of findings. The appearance of the soles is similar to pachyonychia congenita, but the lack of nail and mucous membrane changes is not consistent with that disorder. Treatment with isotretinoin caused reduction in the size of the calluses but exacerbated the blistering.
Development of the second generation Wide-Field Planetary Camera for Hubble Space Telescope service mission

The Wide Field and Planetary Camera (WFPC) is the principal instrument of the Hubble Space Telescope (HST), occupying the central portion of the telescope's focal plane. The Wide Field Camera meets the originally conceived requirement for an imaging device that covers a square field of view 2.67 arc minutes on a side with a pixel size of 0.1 arc second. The so-called Planetary Camera of WFPC offers a longer effective focal length over a smaller field (yielding 0.043 arc second per pixel) to better sample the point spread function of the telescope for critical definition imaging. The first generation WFPC (WFPC-1) was initiated in late 1977 and launched with the HST in April, 1990. A second generation backup instrument (WFPC-2) currently scheduled for launch in late 1993 will carry corrective optics to restore the flawed vision of the HST. The present paper traces the history of these developments.
Do neural factors underlie age differences in rapid ankle torque development

OBJECTIVES: Rapid torque development is substantially slower in healthy old adults compared with young adults, but the underlying cause of this age-related loss remains unclear. Measurements of myoelectric signals in ankle dorsi- and plantarflexor muscles during rapid exertions were used to explore the extent to which the loss might be attributed to neural factors. METHODS: Myoelectric signals were measured in a laboratory setting in 24 healthy young and 24 healthy old adult volunteers during rapid isometric and isokinetic torque development. Premotor times, muscle activation rates, and myoelectric activity levels of agonistic and antagonistic muscles were quantified. RESULTS: There were few marked age differences in the premotor times or in the onset rates or magnitudes of agonistic muscles activities during maximum isometric and during isokinetic exertions. Premotor times were statistically associated with age but, in the mean, were only approximately 10 to 25 ms longer in the old. Age effects on agonist muscle activity magnitudes were significant only in the lateral gastrocnemius. Small decreases in antagonistic muscle activity levels with age were found. CONCLUSIONS: Given the outcomes of this study, the differences observed previously in rapid torque development abilities in healthy older adults, compared with healthy younger adults, seem attributable largely to differences in muscle contraction mechanisms rather than to differences in speeds of stimulus sensing or central processing of motor commands, or to differences in muscle recruitment strategies.
Fractals and interpolating dimensions

Abstract We describe a computer study of Ising models on a generalization of Sierpinsky carpets of Hausdorf dimension between one and four. We measure the critical coupling and the exponent γ as a function of dimension. We also show how finite size scaling analyses can be done using fractals. Our results strongly suggest that fractals of the Sierpinsky carpet type can be used to interpolate between integer dimensions to study the critical behavior of statistical systems.
Variation of monitor luminance on radiologist productivity in the interpretation of skeletal radiographs using a picture archiving and communication system

T HE cathode ray tube (CRT) display used in picture archiving and communication system (PACS) workstations have been shown to have lower spatial resolution and luminance compared with conventional film-screen radiographs displayed on an illuminator. Laboratory observer studies indicate display brightness to be an important parameter in the interpretation of radiological images. This study was undertaken to evaluate the effects of varying monitor luminance on radiologist productivity and accuracy in the interpretation of skeletal radiographs with the hope of identifying the ideal monitor luminance for everyday practice. One hundred randomly selected skeletal radiographs were evatuated prospectively by three board certified radiologists with extensive PACS experience. Each examination was reviewed independently on a four-monitor, high-resolution (2048 • 1536 pixels) workstation at three different levels of monitor brightness (40, 65, and 90 footlamberts). Ambient room light was maintained at a constant level throughout the study. Interpretation
Exact confidence regions for scale and location parameters based on sample quartiles

In this paper we present relatively simple (ruler, paper, and pencil) nonparametric procedures for constructing joint confidence regions for (i) the median and the inner quartile range for the symmetric one-sample problem and (ii) the shift and ratio of scale parameters for the two-sample case. Both procedures are functions of the sample quartiles and have exact confidence levels when the populations are continuous. The one-sample case requires symmetry of first and third quartiles about the median. The confidence regions we propose are always convex, nested for decreasing confidence levels and are compact for reasonably large sample sizes. Both exact small sample and approximate large sample distributions are given.
Development of fiber optic sensor systems

A number of the recent developments in the field of fiber optic interferometric sensing will be discussed. The major areas in which these developments occurred will be briefly reviewed.
Long range untriggered two particle correlations

Relativistic Heavy Ion Collider experiments exhibit correlations peaked in relative azimuthal angle and extended in rapidity. Called the ridge, this peak occurs both with and without a jet trigger. We argue that the untriggered ridge arises when particles formed by flux tubes in an early glasma stage later manifest transverse flow. Combining a blast wave model of flow fixed by single-particle spectra with a simple description of the glasma, we find excellent agreement with current data.
Mechanism of action of cytochalasin B on actin

Substoichiometric cytochalasin B (CB) inhibits both the rate of actin polymerization and the interaction of actin filaments in solution. The polymerization rate is reduced by inhibition of actin monomer addition to the "barbed" end of the filaments where monomers normally add more rapidly. 2 microM CB reduces the polymerization rate by up to 90%, but has little effect on the rate of monomer addition at the slow ("pointed") end of the filaments and no effect on the rate of filament annealing. Under most ionic conditions tested, 2 microM CB reduces the steady state high shear viscosity by 10-20% and increases the steady state monomer concentration by a factor of 2.5 or less. In addition to the effects on the polymerization process, 2 microM CB strongly reduces the low shear viscosity of actin filaments alone and actin filaments cross-linked by a variety of macromolecules. This may be due to inhibition of actin filament-filament interactions which normally contribute to network formation. Since the inhibition of monomer addition and of actin filament network formation have approximately the same CB concentration dependence, a common CB binding site, probably the barbed end of the filament, may be responsible for both effects.
The adult patient in the pediatric emergency department

Study objective: To establish the frequency of use of pediatric emergency departments by adult patients and the spectrum of disease with which they present. Design: Prospective, descriptive study and unblinded survey. Setting: Children's Hospital pediatric ED. Type of participants: Seventy-two adult patients presenting to a pediatric ED during a two-year period and 31 pediatric emergency medicine fellowship directors. Interventions: For each patient, we recorded demographic information, chief complaint, interventions by physicians, diagnosis, condition, and disposition after initial care. Pediatric emergency medicine fellowship training program directors were surveyed by telephone regarding their experiences with adult patients and the extent of adult emergency medicine training within their programs. Main results: Of the 72 adult patients evaluated, one third (22) were treated for trauma and the remaining 50 for medical illness. More than 40 different diagnoses were encountered, including stroke and myocardial infarction. Twenty patients (27.8%) required hospitalization, four (5.6%) in intensive care settings. Of the 31 fellowship directors surveyed, 27 (87.1%) indicated that adult patients had been managed in their EDs during the previous year. All but one reported that their fellowship programs incorporated between one and four months of adult emergency medicine in their curricula. Conclusion: Adults frequently present to pediatric EDs for both minor and serious illnesses. Training in adult emergency medicine should be a part of all pediatric emergency medicine fellowship programs.
Analysis of base station morphine orders: Assessment of supervising physician consistency

Paramedic contact with a base station should gemerate consistent recommendations reflecting a consensus of base station physician care. In our urban EMS system, paramedics must contact a single base station to provide morphine sulfate (MS) for a patient with chest pain. We performed a retrospective cohort analysis of all prehospital MS requests for chest pain to determine the consistency of the circumstances for which the paramedic team was refused MS. These MS requests represented 123 of the 1,715 (7%) on-line physician consultations during the 6-month study. Only 15 of the 123 (12%) MS requests were refused. Neither the mean patient age, sex distribution, or presenting vital signs correlated with MS refusal. A maximum estimate of transport time to the hospital of ≤5 minutes was noted for 7 of 15 (47%) medication refusals compared to only 11 of 96 (11%) approvals with documented estimated transport times (P ≤ 0.005). A simultaneous request for nitroglycerin (NTG) was noted for 6 of the 15 (40%) medication refusals and 15 of the 108 (14%) approvals (P < 0.05). We found refusal of MS administration to be uncommon. Supervising physicians tended to refuse MS when the transport time was short and when NTG was requested for concomitant administration. We also noted physician inconsistencies in refusal scenarios. These findings can guide physician consensus development to avoid sending mixed messages to paramedics.
Thermomechanical interactions in repository design

Abstract The design goal for radioactive waste repository design is a configuration that will last a very long time and restrict radionuclide migration. Because experiments and prototype observations cannot be relied upon to ascertain fully the long-term behavior of the repository, numerical modeling has been employed in attempts to predict the future repository conditions. Unfortunately, the variability of geologic media defies accurate modeling. Models may be verified for numerical accuracy but may not be validated by actual observations of the phenomena to the degree desired. Hence, there is a need to establish a strategy for design and performance assessment that does not fully rely on the validation of models. A strategy proposed here relies on an identification of plausible and possible failure modes rather than on a reliable prediction of aspects of repository behavior. Once failure modes have been identified, efforts can be concentrated on dealing with them, either by assessing their (low) probability of occurrence, or by preventing these failure modes by appropriate repository design.
Nonthermal plasma synthesis of semiconductor nanocrystals

Semiconductor nanocrystals have attracted considerable interest for a wide range of applications including light-emitting devices and displays, photovoltaic cells, nanoelectronic circuit elements, thermoelectric energy generation and luminescent markers in biomedicine. A particular advantage of semiconductor nanocrystals compared with bulk materials rests in their size-tunable optical, mechanical and thermal properties. While nanocrystals of ionically bonded semiconductors can conveniently be synthesized with liquid phase chemistry, covalently bonded semiconductors require higher synthesis temperatures. Over the past decade, nonthermal plasmas have emerged as capable synthetic approaches for the covalently bonded semiconductor nanocrystals. Among the main advantages of nanocrystal synthesis in plasmas is the unipolar electrical charging of nanocrystals that helps avoid or reduce particle agglomeration and the selective heating of nanoparticles immersed in low-pressure plasmas. This paper discusses the important fundamental mechanisms of nanocrystal formation in plasmas, reviews the range of synthesis approaches reported in the literature and discusses some of the potential applications of plasma-synthesized semiconductor nanocrystals.
Direct Observation of the Luminescence from the 3δδ* Excited State of Re2Cl2(p-OCH3form)4

There are only a few reports on the measurement of the energy of the low-lying 3δδ* state of quadruply bonded bimetallic complexes, and the direct observation of the 1δ*δ* excited electronic state was only recently reported. In the quadruply bonded bimetallic complexes reported to date, luminescence arises from their 1δδ* excited state, and the 3δδ* state is nonemissive. Here we report the luminescence of Re2Cl2(p-OCH3form)4 [p-OCH3form = (p-CH3OC6H4)NCHN(p-CH3OC6H4)-] observed upon 400−460 nm excitation with maxima at 820 nm (CH2Cl2, τ = 1.4 μs) and 825 nm (CH3CN, τ = 1.3 μs) at 298 K. From the large Stokes shift, the vibronic progression at 77 K, the quenching by O2, the long lifetime, and the calculated energy of the 3δδ* state, the luminescence of Re2Cl2(p-OCH3form)4 and the corresponding transient absorption signal are assigned as arising from the 3δδ* (3A2u) excited state of the complex.
o-Fluoranil: stereochemistry and mechanism of its Diels-Alder reactions.

In the absence of significant steric effects, Diels−Alder reactions of the title quinone generally take place with preservation of configuration, and are therefore probably concerted. However, hybrid density functional calculations indicate that often these reactions are highly asynchronous. Steric hindrance can result in reaction at quinone oxygen instead of carbon. Preference for endo over exo cycloaddition is observed, and is reinforced by a repulsive secondary orbital interaction in exo transition states.
Microfabricated polymer devices for automated sample delivery of peptides for analysis by electrospray ionization tandem mass spectrometry.

Delivery of proteins and peptides to electrospray ionization mass spectrometers (ESI-MS) has been demonstrated using glass and quartz microfabricated devices. This paper reports the construction and use of poly(dimethylsiloxane) (PDMS) microfabricated soft polymer devices with mass spectrometry for protein analysis. The PDMS devices were fabricated using replica molding against a patterned photoresist generated by photolithographic techniques. The PDMS devices were connected to the mass spectrometer via a derivatized transfer capillary and samples were transferred by electroosmotic pumping. The formulation of PDMS was optimized for compatibility with ESI, and the devices were tested for performance. The practical application of PDMS devices was demonstrated by the identification of rat serum albumin separated by 2-D gel electrophoresis. Extended contact of the sample with the surface of the PDMS device did not significantly affect the sample analysis, and the limit of detection for samples run on a PDMS d...
Human prehension and dexterous robot hands

The human hand is versatile in its interactions with the envi ronment, demonstrating skills that designers of dexterous robot hands would like to emulate. Various postures and features of the human hand combine to provide a great deal of functional ity. In this article, an analysis of human prehensile capability is presented, comparing a symbolic description of prehension to an opposition-space, parameterized framework. By pointing out features of the human hand in prehensile tasks, we hope to offer insights that designers can use for building more versatile robot and prosthetic hands.
Effects of atmospheric N deposition on coarse organic matter in a headwater stream

Input, storage, export potential, and system-level processing of coarse organic matter were investigated in the intermittent streams that drain the Bear Brook Watershed in Maine (BBWM). BBWM is a paired catchment study investigating ecosystem effects of atmospheric N and S deposition. We predicted that the increased N loading to the treatment catchment would elevate input of organic matter, result in higher levels of coarse organic matter biomass, and increase litter processing rates in the treatment stream relative to the reference stream. We found that the streams draining BBWM did not have statistically different coarse organic matter input, biomass, or processing rates and we found only modest differences in export potential. System-level processing rates for maple (Acer spp.) litter were similar to rates previously quantified using litterbag methods. However, system-level processing rates for American beech (Fagus grandifolia) litter were an order of magnitude faster than rates measured with litterbags. This difference was likely due to movements of these leaves from riffle/runs and pools into debris dams, rather than differences in measurements of leaf tissue processing rates between methods. Organic matter dynamics of the intermittent streams at BBWM were similar to other forested, headwater streams. Our results indicate that the long-term N manipulation experiment at BBWM has not altered input, storage or processing of coarse organic matter in the treatment stream. Physical characteristics of these stream ecosystems appear to regulate organic matter dynamics rather than differences in nutrient chemistry.
Coping with Cancer in the Family

Cancer presents the affected family with major challenges and disruptions. Family therapists offer a valuable but underutilized resource. Multiple marriage and family therapy approaches may be helpful, if appropriately tailored to characteristics of the illness (e.g., phase of treatment) and the family. This article reviews a number of clinical interventions directed toward the following four core strategies: (a) enhancing communication and emotional contact, (b) accommodating structural changes within the family, (c) facilitating a sense of meaning, and (d) addressing mortality issues.
D-alanine interference in microbiological assays of vitamin B6 in human blood.

Abstract Prolonged acid hydrolysis of whole blood prior to microbiological assay increases its apparent vitamin B 6 content for the lactic acid bacteria, L. casei and S. faecium , but not for the yeast, S. carlsbergensis . Since yeast growth reflects all three forms of vitamin B 6 while the lactic acid bacteria respond either to pyridoxal or to pyridoxamine and pyridoxal, the differential assay for vitamin B 6 gives incongruous results when applied to blood. We find the growth of S. faecium and L. casei but not that of S. carlsbergensis reflects the increase in d -alanine and peptide content of the samples with increased hydrolysis time. These substances, known to stimulate growth of the lactic acid bacteria but not yeast, suggest a possible explanation for the curious finding that the total vitamin B 6 content of whole blood estimated microbiologically appears to be many times lower than the sum of its parts.
Some integer formula encodings and related algorithms

We investigate using Sage [5] the special class of formulas made up of arbitrary but finite combinations of addition, multiplication, and exponentiation gates. The inputs to these formulas are restricted to the integral unit 1. In connection with such formulas, we describe two essentially distinct families of canonical formula encodings for integers, respectively deduced from the decimal encoding and the fundamental theorem of arithmetic. Our main contribution is the detailed description of two algorithms which efficiently determine the canonical formula encodings associated with relatively large sets of consecutive integers.