cssi/SciSciGPT-SciSciNet huggingface dataset:
Reduce afterpulsing of single photon avalanche diodes using passive quenching with active recharge

We report a new quenching circuit for single photon avalanche diodes that passively quenches avalanche current and actively recharges the device. Afterpulsing can be reduced by minimizing the stray capacitance of the package to reduce the total charge flow during avalanche.
Unimolecular rectifiers and beyond

We discuss three unimolecular rectifiers: γ-hexadecylquinolinium tricyanoquinodimethanide, 2,6-di[dibutylamino-phenylvinyl]-1-butylpyridinium iodide and dimethylanilino-aza[C60]fullerene, and discuss the progress towards useful one-molecule electronic devices for the ultimate reduction in integrated circuit sizes.
Infantile autism and the schizophrenias

The Stanley R. Dean Research Award, given annually to an outstanding scientist for major contributions to basic research on schizophrenia, was awarded May 4 this year to Dr. Leo Kanner at the American Psychiatric Association meetings in New York. Honored for his pioneering work on infantile autism, Dr. Kanner presented the following lecture as the Dean Award recipient.
Orientation discrimination in foveal and extra-foveal vision: effects of stimulus bandwidth and contrast.

The parameter E2 is used in many spatial scaling studies to characterize the rate at which stimulus size must increase with eccentricity to achieve foveal levels of performance in detection and discrimination tasks. We examined whether the E2 for an orientation discrimination task was dependent on the spatial frequency bandwidth of the stimulus used. Two methods were employed. In Experiments 1 and 2 stimuli were presented at a fixed high level of contrast across viewing conditions. In both experiments the E2s recovered for narrowband stimuli were larger than those recovered for broadband stimuli. In Experiment 3 we controlled for the potentially confounding effects of perceptual contrast by measuring orientation thresholds over a range of stimulus contrast levels. Only thresholds which had reached an asymptotic level, such that increases in stimulus contrast led to no further changes to thresholds, were included in the calculation of E2. We observed that E2s recovered in the latter condition were in the range of 1.29°–1.83° and similar for narrowband and broadband stimuli. We conclude that a failure to consider the role of perceptual contrast may result in inflated estimates of E2.
Correction and addenda to: On the surjectivity of the exponential map for certain lie groups

The main result, Theorem (2.1), of my article [10], states that any non-compact, centerless, rank 1 simple group, or product thereof, is exponential. The proof of this statement in [10] was incomplete and valid only for groups, SOo(n, 1), of hyperbolic motions (even in this case a little more needs to be said). But, as we shall see below, leaving aside the exceptional rank 1 group, Ad F(4,-2o), which, according to the very recent article [6], by D. DJOKOVIC and N. TnANG, is not exponential, the result is correct in general. In addition, there were certain other statements, of less importance, which were invalid. It is the purpose of this note to clear up the entire situation and point out some additional results which have only recently come to my attention. Theorem (3.3) of the article is incorrect. A counterexample is the following: Let G be the semidirect product of SL(2, C) acting in the natural way on C 2 . Then G is a Euclidean and therefore Zariski connected algebraic group with trivial center. However it is not exponential, since if it were, its quotient G/C 2 = SL(2, C) would also be exponential. This is false. The element (_ix) g = 0 1
Marine speciation on a small planet

The scale of population structure in many marine species is on the order of thousands to tens of thousands of kilometers. How does speciation take place in oceans that are only about this same size? Recent results suggest an important role for transient isolation, gamete ecology and molecular evolution at gamete recognition loci. These factors have long been appreciated by plant biologists, and are likely to be a fruitful area of research for marine biologists as well.
Short-term metabolic and cardiovascular effects of metformin in markedly obese adolescents with normal glucose tolerance

Objective: Although metformin (MET) is an insulin sensitizer currently used as an adjunct to the treatment of some of the complications of childhood obesity besides type 2 diabetes mellitus, few studies have comprehensively examined its metabolic and clinical effects in obese children with normal glucose tolerance (NGT). Methods: We therefore conducted a 4-month double-blind clinical trial in 28 obese [mean body mass index (BMI): 40.3 ± 5.7 kg/m2], insulin-resistant [homeostasis model assessment – insulin resistance: 7.6 ± 2.8 and whole body insulin sensitivity index (WBISI): 1.5 ± 0.7] adolescents (age 15.0 ± 1.3 yr) randomized to MET (n = 15, dose 1500 mg daily) or placebo (n = 13). Results: The treatment with MET was well tolerated. MET treatment was associated with a decreased BMI (p = 0.02) as well as with a reduction in subcutaneous fat (p = 0.03), particularly the deep subcutaneous fat (p = 0.04) as assessed by magnetic resonance imaging. Postintervention, the MET group had a 35% improvement in insulin sensitivity (WBISI) compared with the placebo group (p = 0.008). However, significance was lost with adjustments for differences in baseline insulin sensitivity (p = 0.09). While there was no change in inflammatory cytokines or lipid parameters, cardiovascular function as assessed by heart rate recovery after exercise improved with MET and worsened in placebo (p = 0.03). Conclusion: Short-term use of MET is well tolerated by obese children with NGT and has a beneficial effect on BMI and autonomic control of the heart as well as a trend toward improved insulin sensitivity. Thus, long-term treatment with MET may provide a means to ameliorate the cardio-metabolic consequences of adolescent obesity.
Growth dynamics of oak seedlings (Quercus macrocarpa Michx. and Quercus muhlenbergii Engelm.) from gallery forests: implications for forest expansion into grasslands

Seedling growth dynamics of Quercus macrocarpa Michx. and Quercus muhlenbergii Engelm. were compared over a 3-month period under optimal growth conditions. These two species are the dominant trees at the western limit of the eastern deciduous forest, and are typically confined to gallery forests along stream beds in tallgrass prairie. Since tallgrass prairie is characterized by a highly variable climate and is prone to periodic drought, we hypothesized that these oaks would have rapid root growth and produce deep taproots as seedlings, enabling them to avoid drought stress and persist in this region. These traits may also facilitate forest expansion into the more xeric tallgrass prairie if fires are suppressed. Taproots of Q. macrocarpa and Q. muhlenbergii grew to approximately 140 cm and 100 cm in length, respectively, after 104 days. In both species, 65% or more of seedling biomass was allocated below ground, and root/total biomass was significantly greater in Q. muhlenbergii at 0–20 and 21–40 days after germination. The seedling taproot elongation rates reported here are much greater than rates reported in other eastern deciduous forest trees. Long-term precipitation data and soil moisture patterns from tallgrass prairie, when combined with rapid taproot elongation rates, suggest that soil moisture may not limit oak establishment or growth in tallgrass prairie in most years, although water uptake by roots was not measured in this study. Other factors, such as fire, herbivory, and seed predation and dispersal may be equally important in constraining the distribution of these species to gallery forests.
Evolution of the interface and metal film morphology in the vapor deposition of Ti on hexadecanethiolate hydrocarbon monolayers on Au.

The combination of in situ X-ray photoelectron spectroscopy, infrared reflection spectroscopy, atomic force microscopy, and time-of-flight secondary ion mass spectrometry are used to probe the nature of the evolving interface chemistry and metal morphology arising from Ti vapor deposition onto the surface of a CH3(CH2)15S/Au{111} self-assembled monolayer (SAM) at ambient temperature. The results show that for a deposition rate of ∼0.15 Ti atom·nm-2·s-1 a highly nonuniform Ti overlayer is produced via a process in which a large fraction of impinging Ti atoms do not stick to the bare SAM surface. The adsorbed atoms form isolated Ti clusters and react with CH3 groups to form carbide products at the cluster−SAM interfaces. Further growth of Ti clusters appears to be concentrated at these scattered reaction centers. The SAM molecules in the local vicinity are subsequently degraded to inorganic products, progressing deeper into the monolayer as the deposition proceeds to give an inorganic/organic nanocomposite....
The rate and mechanism of the gas-phase oxidation of hydroxyacetone

Abstract The rate and mechanism for gas-phase destruction of hydroxyacetone, CH 3 C(O)CH 2 OH, by reaction with OH, Cl-atoms, and by photolysis have been determined. The first quantitative UV absorption spectrum of hydroxyacetone is reported over the wavelength range 235 to 340 nm; the spectrum is blue-shifted by about 15 nm relative to that of acetone and peaks at 266 nm, with a maximum absorption cross section of (6.7±0.6) ×10 -20 cm 2 molecule -1 . Measurable absorption extends out to about 330 nm. The quantum yield for photolysis of hydroxyacetone in the region relevant to the troposphere ( λ> 290 nm) was found to be significantly less than unity. Rate coefficients for the reaction of hydroxyacetone with OH radicals and Cl-atoms were determined at 298 K using the relative rate technique. The rate coefficient for reaction with OH was found to be (3.0±0.7)×10 -12 cm 3 molecule -1 s -1 , while the rate coefficient for reaction with Cl-atoms was found to be (5.6±0.7)×10 -11 cm 3 molecule -1 s -1 . Both values agree well with previous studies. The data were used to determine the lifetime of hydroxyacetone in the troposphere. Reaction with OH is the major gas-phase destruction mechanism for this compound, limiting its lifetime to about 4 days, while photolysis is found to be only of minor importance.
Subglottic stenosis following repeated double-lumen tube intubation for wholelung lavage in a teenager with pulmonary alveolar proteinosis

Abstract Pulmonary alveolar proteinosis is a rare disorder with decreased clearance of surfactant from the pulmonary alveoli resulting in progressive respiratory distress. Whole-lung lavage remains an important procedure for symptomatic
Interpretation of Tests of Time-Reversal Invariance

Some of the most sensitive tests of time-reversal invariance in particle and nuclear physics involve the measurement of certain polarization quantities in elastic scattering which are thought to be exactly zero when time-reversal invariance holds. It is shown that a nonzero result for such quantities need not indicate a violation of time-reversal invariance, but can be the consequence of a dynamics which is time-reversal invariant but which violates rotation or Lorentz invariance. These two alternatives can be told apart by subsidiary measurements.
Phase Separation of Grafted Copolymers

We consider the demixing of diblock copolymers grafted densely to a surface in the melt state using mean-field methods. The layer contains equal numbers of A-B and complementary B-A chains. The incipient demixing leads to a density have of composition, produced by splaying of the chains. In an equal mixture of A-C and B-C copolymers where only the free ends are immiscible, phase separation takes place in a thin zone near the free surface of the layer. Because the free end density is singular at the free surface, the A-B interaction strength required for demixing scales linearly with the length of the terminal A and B block, rather than quadratically, which would be the case for demixing of a blend of the same copolymers
Direct evidence for β-hydride elimination on Si (100)

Abstract The adsorption and decomposition of ethylbromide on Si(100)−(2×1) is investigated as a way of generating surface ethyl groups. The interactions of ethylbromide with Si are explored by a variety of methods including ultraviolet photoelectron spectroscopy, temperature-programmed desorption and high-resolution electron energy loss spectroscopy. Enthylbromide adsorbs molecularly on Si(100) at a surface temperature of 110 K. The CBr bond cleaves by warming the surface to temperatures greater than 200 K. The resulting ethyl groups decompose at surface temperatures greater than 500 K to yield ethylene and molecular hydrogen. Deuterium labelling of the ethyl groups is used to verify that the predominant pathway to ethylene production is through a β-hydride elimination step.
Choline Administration Elevates Brain Phosphorylcholine Concentrations

The phosphorylcholine concentration of rat brain rises and falls in response to parallel changes in the concentration of circulating choline. A single oral dose of choline chloride (20 mmol/kg) elevated whole-brain concentrations of both choline and phosphorylcholine 5 h after administration; a greater proportion of exogenously administered choline was retained by the brain in its phosphorylated form than as the free amine. Striatal phosphorylcholine concentrations were elevated within 2 h of choline administration and continued to be significantly greater than control values for up to 34 h after treatment. The response of striatal choline levels to exogenous choline was of shorter duration than that of phosphorylcholine and was correlated with a significant increase in striatal acetylcholine concentrations. The consumption of a choline-free diet for 7 days lowered both serum choline and striatal phosphorylcholine concentrations, but had no effect on striatal choline or acetylcholine. These results suggest that choline kinase is unsaturated by its substrate in vivo and may thus serve to modulate the response of brain choline concentrations to alterations in the supply of circulating choline.
The Effect of Screening on Beta-Ray Spectra and Internal Conversion

The Dirac equation for an electron in the field of a Thomas-Fermi-Dirac atom is solved numerically on the ENIAC for a large number of cases. The resulting wave functions are used to calculate the effect of screening (by the atomic electrons) on allowed beta-spectra and on the internal conversion coefficients of gamma-rays. It is seen that the negatron spectra are essentially unaffected by screening; positron spectra are affected appreciably in a direction such as to increase the number of low energy positrons. Where a comparison can be made between the present calculations and previous ones in which the screening has been neglected, it is seen that the effect of screening is to increase the conversion coefficients slightly. Most of the present calculations, however, are for the soft gamma-ray region, for which only approximate formulas for the conversion coefficients exist. Thus the results of this paper are used to test the accuracy of these formulas. An attempt is also made to classify a number of experimentally observed gamma-rays.
Aflatoxin Effects in Poultry

SummaryA systematic study was made of the effect of graded levels of dietary aflatoxin on the performance of broilers under simulated practical conditions. No adverse effects were detected when a ration containing 400 ppb aflatoxin was fed to Arbor-Acres broiler chicks from 1 day to 8 weeks of age. At higher levels (800 and 1600 ppb) adverse liver effects were detected, based on biochemical and histological studies. By chemical analysis, no evidence of aflatoxin was found in the meat, liver or blood of broilers fed 1600 ppb for 60 days prior to slaughter, nor in the eggs, meat, liver, or blood of White Leghorn hens fed a ration containing 2700 ppb aflatoxin for a period of 48 days.
ECONOMIC EVALUATION OF MANAGEMENT INFORMATION SYSTEMS: AN ANALYTICAL FRAMEWORK

This paper provides a framework for analyzing the ingredients involved in the economic evaluation of computer based management information systems (MIS). The approach presented revolves around viewing the development of MIS configurations as a series of economic decisions. These decisions are categorized into analysis decisions – what information should the MIS provide to management – and design decisions – what technology should the MIS employ to provide this information. Using this decision dichotomy, the types and sources of benefits and costs can be more accurately identified and evaluated.
Bounds on the driving point impedence of equivalent LC networks whose elements lie within known tolerances

Abstract If elements of equivalent LC networks vary within certain specified tolerances, the bounds on their driving point reactances will be identical at all frequencies at which bounds exist for each network. This is a consequence of the fact that the slope of the driving point reactance with respect to any single element (e.g. d X/ d L or d X/ d C) is non-negative. Corresponding results hold for RL and RC networks on the negative σ axis.
Some Questions Raised in the Middle East

nately, the author completed her visit before the greater clash came as a result of the U.N. decision on partition in Palestine. Nevertheless, political and social tensions and unrest were giving a sinister warning to all who would heed them in Egypt, Palestine, Transjordan, Lebanon, Syria, Turkey and Greece. The Middle East provides the religious educator data on so many levels of religious history that it is difficult to chart one's course for study during a few months there. Because of the increasing attempts to improve the curricula for religious education and to make more adequate use of the rich resources for teaching biblical, church and other religious history now available from the efforts of numerous scholars, it seemed important to examine the social, political and religious resources of the Middle East in each particular period of time. Too much of the historical material given to the laymen in our churches has been a confusing hodge-podge of events, ideas, and literature mixed together as "biblical" without much consideration of the changing cultural and religious backgrounds out of which these have come. Beginning with Egypt and continuing across Palestine, Lebanon, Syria, Turkey and Greece it was possible to recapture from ancient monuments, museums, and the works of scholars vivid approaches to the different s rata f our religious history. It was fascinating to examine the network of influences created by the numerous invaders and conquerors. On entering Egypt the magnificent homes an the hospital of the wealthy Greeks in Alexandria were a vivid reminder of the long history of the Greeks in this city so definitely connected with the conqueror, Al xander the Great, and with later Christian movements.
Characterization of Alum Floc by Image Analysis

In-situ monitoring of particle characteristics is of general interest for both natural and engineered aquatic systems and of particular interest in studying the fragile floc that typically is formed by the addition of chemical coagulants. A nonintrusive photographic technique coupled with digital image processing for in-situ analysis of aggregates formed by the addition of alum [Al2(SO4)3·18H2O] to lake water and a montmorillonite clay suspension is described. The technique is unique in that there is no need for sample collection and handling. The analysis method is used to test the hypothesis that charge-neutralization and sweep-floc mechanisms produce fundamentally different particle characteristics, including differences in fractal dimension. For comparative purposes, particle characteristics prior to coagulant addition also are reported. It is found that fractal dimension is lower for sweep-floc coagulation where larger and more irregular aggregates are produced. The results presented here provide ins...
Integrated 222-GHz corner-reflector antennas

A high-gain monolithic millimeter-wave antenna has been designed, fabricated, and tested at 222 GHz. The structure consists of a traveling-wave antenna integrated on a 1.2-micron dielectric membrane and suspended in a longitudinal cavity etched in a silicon wafer. A new traveling-wave antenna design yields a wideband input impedance and a low cross-polarization component in the E- and quasi-H-plane patterns. A directivity of 17.7 dB and a main-beam efficiency of 88.5 percent are calculated from the 222-GHz pattern measurements. The integrated corner-reflector antenna is well suited for millimeter- and submillimeter-wave imaging applications in large f-number systems.
Method of computing magnet coil current settings for the NRL isochronous cyclotron

Abstract In order for the modern isochronous cyclotron to accelerate ions of different mass and charge state to a variable final energy, the magnetic field in the accelerating region must be precisely tailored. A deviation of 15 G in 18 kG may lead to a loss of beam. The approximate magnetic field of the NRL cyclotron for isochronous accelaration is achieved by iron pole pieces arranged in a 3-sector, hill-valley configuration. This basic field may deviate from that necessary for isochronous acceleration by two or more kG at some radii. Compensation for this field error is achieved by various current-carrying coils wound in the magnet gap. This paper discusses the extent of the magnetic field measurements and the computer program developed at NRL for computing operational parameters (knob-settings) for all current- carrying coils. Innovations introduced in the calculations include minimizing the first harmonic introduced by the extraction elements and imperfections of the iron. In addition, allowance is made for the lack of linear independence of the trim coils as well as for the perturbation of the flutter field due to the trim coils. The influence of the extraction elements on the accelerating region and the function of each element for beam extraction is also discussed. Measurements on the internal and external beam verify the calculations.
Video-based analysis of multimodal social interaction

Qualitative research using video data requires a systematic approach to elicitation, collection and analysis of recordings. An analytic procedure was designed for a recent study focused on the creation of visual information as communicative practice. Video recordings of face-to-face conversations during which images were made provided rich evidence of both verbal and non-verbal modes of communication. This poster will present the video-based methodology used in this research to study multimodal social interactions associated with the creation of visual artifacts.
An epigenetic map of age-associated autosomal loci in northern European families at high risk for the metabolic syndrome

The prevalence of chronic diseases such as cancer, type 2 diabetes, metabolic syndrome (MetS), and cardiovascular disease increases with age in all populations. Epigenetic features are hypothesized to play important roles in the pathophysiology of age-associated diseases, but a map of these markers is lacking. We searched for genome-wide age-associated methylation signatures in peripheral blood of individuals at high risks for MetS by profiling 485,000 CpG sites in 192 individuals of Northern European ancestry using the Illumina HM450 array. Subjects (ages 6–85 years) were part of seven extended families, and 73% of adults and 32% of children were overweight or obese. We found 22,122 genome-wide significant age-associated CpG sites (P α=0.05 = 3.65 × 10−7 after correction for multiple testing) of which 14,155 are positively associated with age while 7,967 are negatively associated. By applying a positional density-based clustering algorithm, we generated a map of epigenetic ‘hot-spots’ of age-associated genomic segments, which include 290 age-associated differentially methylated CpG clusters (aDMCs), of which 207 are positively associated with age. Gene/pathway enrichment analyses were performed on these clusters using FatiGO. Genes localized to both the positively (n = 241) and negatively (n = 16) age-associated clusters are significantly enriched in specific KEGG pathways and GO terms. The most significantly enriched pathways are the hedgehog signaling pathway (adjusted P = 3.96 × 10−3) and maturity-onset diabetes of the young (MODY) (adjusted P = 6.26 × 10−3) in the positive aDMCs and type I diabetes mellitus (adjusted P = 3.69 × 10−7) in the negative aDMCs. We also identified several epigenetic loci whose age-associated change rates differ between subjects diagnosed with MetS and those without. We conclude that in a family cohort at high risk for MetS, age-associated epigenetic features enrich in biological pathways important for determining the fate of fat cells and for insulin production. We also observe that several genes known to be related to MetS show differential epigenetic response to age in individuals with and without MetS.
Insertion of the Designed Helical Linker Led to Increased Expression of Tf-Based Fusion Proteins

To demonstrate a high-level expression of transferrin (Tf)-based fusion proteins by inserting a helical linker between two protein domains. Tf-based fusion proteins were designed to contain oligonucleotides encoding a helical linker inserted between the protein domains. Plasmid constructs were transfected into HEK293 cells and the secreted fusion proteins were purified from conditioned serum free media. Expression was assessed using both SDS-PAGE and Western Blot using anti-hGH, G-CSF, or Tf antibodies; protein bands were analyzed using Quantity One software. The function of fusion proteins consisting of human growth hormone (hGH) and Tf was evaluated in Nb2 cell proliferation assays. The fusion proteins containing a helical linker, hGH-(H4)2-Tf and Tf-(H4)2-hGH, were expressed 1.7-and 2.4-fold higher, respectively, with a twofold lower ED50 than the hGH-Tf fusion protein without a helical linker. The Tf-(H4)2-G-CSF fusion protein exhibited a greater expression with an 11.2-fold increase compared with Tf-G-CSF fusion protein. The helical linker introduced in Tf-fusion proteins resulted in a high-level of expression with improved in vitro bioactivity. This approach provides a simple method to increase poor expression of other fusion proteins.
The data aggregation project: Free software that transforms the student laboratory experience

THE DATA AGGREGATION PROJECT (DAP) allows an instructor to quickly create a set of simple Web interfaces that make it easy for students to enter and check data, along with a link for the data to be downloaded as a spreadsheet. This means that an instructor can easily challenge students with large sets of data, which provides several practical pedagogic benefits including increasing ability to observe phenomena with small effects, reducing effects of observational errors, and providing a rationale for using technology to perform data analysis. In the introductory biology course at the University of Massachusetts Amherst, a large lecture course with 30 laboratory sections, adoption of the DAP resulted in an increase in the number of data points students analyzed per semester from N=80 (estimated) to N=2237 (observed), an increase by a factor of almost 30.
Gender and language: Dialect, silence and the disruption of discourse

(1987). Gender and language: Dialect, silence and the disruption of discourse. Women's Studies: Vol. 14, No. 1, pp. 65-78.
A microfluidic approach to assembling ordered microsphere arrays

Hydrodynamic flow through an array of channels has been utilized to assemble microspheres on a flat surface. The channels, about 6 µm in lateral size, were etched through a 60 µm thick silicon wafer using deep reactive ion etching (DRIE). Droplets containing 6–8 µm fluorescent polystyrene microspheres were placed on the top side of the horizontally-oriented silicon wafer, while the bottom side was connected to a syringe that draws the fluid through the channels. In this way the microspheres are guided and secured at the inlets of the channels, and remain in place when the suction ceases. This technique, which combines favorable features such as high throughput, high resolution rate and reusability, can be a powerful platform for a new generation of protein microarrays. Antigens can be bound to the microspheres as 'targets', which can then be exposed to different fluorescence-tagged antibodies so that their binding can be confirmed. This system can also be used to study the functional roles of gene fragments and their relations to human diseases. The high throughput feature will make it possible to screen a large number of DNA fragments and identify the genetic basis of various diseases effectively.
Manometric diagnosis of diffuse esophageal spasm.

There are no requirements concerning the amplitude of simultaneous contractions among the present criteria for the manometric diagnosis of diffuse esophageal spasm. The purpose of this investigation was to determine whether the current criteria effectively identify an appropriately homogeneous patient population. Sixty consecutive motility tracings that met the criteria for diffuse esophageal spasm were evaluated. A bimodal distribution of the highest simultaneous esophageal contraction for each patient was observed. One group's (N=29) highest simultaneous esophageal contractile amplitude was ≤74 mm Hg, the other's (N=31) highest simultaneous esophageal contractile amplitude was ≥100 mm Hg. Group 1 had significantly decreased lower esophageal sphincter pressure, lower peristaltic amplitude, more aperistalsis, fewer simultaneous contractions, and fewer complaints of chest pain. These comparisons suggest that consideration be given to the amplitude of simultaneous esophageal contractions in the manometric diagnosis of diffuse esophageal spasm.
The effects of an interactive videodisc training program in classroom observation skills used as a teaching tool and as a learning tool

In higher education, instruction is typically teacher-directed through traditional lecture formats and assignments with predetermined criteria. Through hypermedia-based materials, new ways of learning are possible based on learner control and self-directed instruction; such approaches require personal goal-setting, nonlinear exploration of materials, context-based problem solving, and progress monitoring. For students to learn in new ways, instructors have to teach in new ways. Teachers cannot simply take new hypermedia applications and implement them within existing approaches if higher level outcomes are to be realized. The findings in this study are consistent with previous research studies which demonstrate equal or better learning using hypermedia-based instructional materials when students are allowed learner control. If the learning profile for each student determines the effective use of an application, then hypermedia is best implemented as a learning tool.
Structure of a hydrogen-bonded lattice compound between phosphoric acid and 18-Crown-6: H3PO4·0.5(C12H24O6)·3H2O

Abstract Phosphoric acid and 1,4,7,10,13,16-hexaoxa-cyclooctadecane (18-crown-6) have been shown to form a hydrated lattice compound held together by hydrogen bonds. Its crystal structure at 297 K was determined by X-ray diffraction methods. The crystals are monoclinic, space group P 2 1 / c , with a = 8.494(2), b = 10.701(3), c = 15.210(5) A, β = 104.41(2)° and Z = 4. The phosphoric acid molecules form hydrogen-bonded dimers, which are linked by intermediate water molecules to crown ether rings through a series of hydrogen bonds. Each crown ether molecule receives a hydrogen bond to each of its six oxygen atoms, and in this symmetrical arrangement adopts the pseudo- D 3 d conformation often found in crown ether—cation complexes instead of the elongated shape it has in the uncomplexed state.
A psychodynamic approach to brief therapy.

Abstract The University Counseling Center at the State University of New York at Stony Brook has developed a psychodynamic model for brief therapy in order to meet increased demands for service with limited staff resources. Because the center has both a multidisciplinary staff and graduate student training program, the aim of the model was to translate already existing theories of time-limited psychotherapy into practical, usable, teachable techniques. A major issue addressed was the reluctance to accept brief therapy because of its perception of being superficial and amenable only to symptom relief as opposed to “preferred” long-term treatment, seen as providing in-depth change and personality reorganization. The model developed is based on one or two assessment sessions followed by eight sessions of treatment. The major distinguishing characteristic of the model consists of the explicit setting of two goals with the patient. Goal I is based on an assessment of the presenting problem and is directed towa...
New Directions in National Economic Accounting

The national income and product accounts (NIPA) are the most important measures of overall economic activity for a nation. Much as a satellite in space can survey the weather across an entire continent, so can the GDP give an overall picture of the state of the economy. Nevertheless, since their inception, there have been concerns that the accounts are incomplete and misleading because they omit vast continents of nonmarket activity such as unpaid work, the value of leisure time, investment in human capital, and most recently, the environment. The threshold question is: why should we devote scarce intellectual resources to studying nonmarket sectors? The basic insight behind nonmarket accounts is that economic and social welfare does not stop at the market’s border, but extends to many nonmarket activities. Three particular areas are worth emphasizing. One important reason why we need better measures of nonmarket activity is because we spend increasingly fewer of our lifetime hours in market activities. A second and more speculative reason concerns the growing importance (or at least the great importance) of nonmarket assets or mispriced market assets such as the environment and technology. A third point is that current measures of national saving and investment are highly defective. The examples later in this paper address each of these issues. Many of these issues were reviewed in a recent report on augmented accounting by the National Academy of Sciences (see Nordhaus and Edward Kokkelenberg, 1999).
The IOC algorithm: efficient many-class non-parametric classification for high-dimensional data

This paper is about a variant of k nearest neighbor classification on large many-class high dimensional datasets.K nearest neighbor remains a popular classification technique, especially in areas such as computer vision, drug activity prediction and astrophysics. Furthermore, many more modern classifiers, such as kernel-based Bayes classifiers or the prediction phase of SVMs, require computational regimes similar to k-NN. We believe that tractable k-NN algorithms therefore continue to be important.This paper relies on the insight that even with many classes, the task of finding the majority class among the k nearest neighbors of a query need not require us to explicitly find those k nearest neighbors. This insight was previously used in (Liu et al., 2003) in two algorithms called KNS2 and KNS3 which dealt with fast classification in the case of two classes. In this paper we show how a different approach, IOC (standing for the International Olympic Committee) can apply to the case of n classes where n > 2.IOC assumes a slightly different processing of the datapoints in the neighborhood of the query. This allows it to search a set of metric trees, one for each class. During the searches it is possible to quickly prune away classes that cannot possibly be the majority.We give experimental results on datasets of up to 5.8 x 105 records and 1.5 x 103 attributes, frequently showing an order of magnitude acceleration compared with each of (i) conventional linear scan, (ii) a well-known independent SR-tree implementation of conventional k-NN and (iii) a highly optimized conventional k-NN metric tree search.
Measuring Impact of JAMA Dermatology Practice Gaps Section on Training in US Dermatology Residency Programs

Importance JAMA Dermatology Practice Gaps commentaries are intended to aid in the interpretation of the literature to make it more practical and applicable to daily patient care. Practice Gaps commentaries have had an impact on physician clinical practice and dermatology residency curricula. Objective To assess the impact of JAMA Dermatology Practice Gaps commentaries on dermatology residency training programs in the United States, including journal club discussions and local quality improvement activities. Design, Setting, Participants A web-based questionnaire of 17 questions was sent via e-mail to US dermatology residency program directors (PDs) in February 2012. Main Outcomes and Measures Program director report of incorporating Practice Gaps themes and discussions into resident journal club activities, clinical practice, quality improvement activities, or research projects in the residency programs, as a result of a Practice Gaps commentary. Results Of the 114 surveys distributed to US dermatology residency PDs, 48 were completed (42% response rate). Sixty percent of PDs reported familiarity with the Practice Gaps section of JAMA Dermatology , and 56% discuss these commentaries during resident journal club activities. Quality improvement and research projects have been initiated as a result of Practice Gaps commentaries. Conclusions and Relevance Practice Gaps commentaries are discussed during most dermatology residency journal club activities. Practice Gaps have had an impact on physician practice and dermatology residency curricula and can serve as a tool for enhanced continuing medical education and quality improvement initiatives.
Critical Time in Pineal “Priming”

Three groups of rats were raised in environments of diurnal lighting, constant lighting, and total darkness following 18–21 days of diurnal lighting. Those groups exposed to 20 and 21 days of diurnal lighting before being placed in total darkness (groups 20D and 21D) matured later than any of the other groups, and had the greatest pineal weights and lowest ovarian weights. The light-reared group, and the group reared for 18 days in diurnal lighting prior to exposure to total darkness (group 18D), matured earlier than the diurnal group and had the lowest pineal weights, with ovarian weights second only to the diurnal group. The findings confirm earlier studies and reveal that 20 days of exposure to diurnal lighting is necessary for subsequent total darkness to produce a delay in pubertal onset. (Endocrinology 82: 1249, 1968)
Results and Prospects for SNO

I describe here the results of the Low Energy Threshold Analysis (LETA) of the Sudbury Neutrino Observatory (SNO) Phase I and Phase II data sets, and the prospects for future results from SNO.
Antioxidant activity of lazaroid (U-75412E) and its protective effects against crystalline silica-induced cytotoxicity.

Abstract Lazaroids (21-amino steroids) are believed to be powerful scavengers of reactive oxygen species (ROS) and inhibitors of lipid peroxidation. Crystalline silica, a potent cytotoxic agent, causes pulmonary fibrosis in experimental animals and humans. ROS have been previously shown to be involved in crystalline silica-induced pulmonary injury and inflammation. In the present study, the reaction rate of lazaroid (U-75412E) with hydroxyl radical ( • OH) generated by Fenton reaction (Fe(II) + H 2 O 2 → Fe(III) + OH − + • OH) was investigated using ESR spin-trapping competition reactions. The reaction rate constant was found to be 1.0 × 10 10 M −1 s −1 , which was comparable with those of other efficient • OH radical scavengers. As indicators of crystalline silica-induced cytotoxicity and its protection by this antioxidant lazaroid (U-75412E) we measured lactate dehydrogenase, N -acetyl-β- d -glucosaminidase, superoxide dismutase, glutathione peroxidase, and hydrogen peroxide released from rat alveolar macrophages. Lipid peroxidation, a prominent manifestation of • OH radical-induced cell injury, was also measured to evaluate the protective value of lazaroid. Alveolar macrophages treated with lazaroid (U-75412E) before crystalline silica exposure were protected against cell injury and lipid peroxidation as demonstrated by those indicators. Lazaroid (U-75412E) scavenges • OH radicals generated by crystalline silica-mediated reaction from H 2 O 2 and inhibits lipid peroxidation in macrophages induced by these particles.
A cryogenic data addressed memory

A computer storage system which is addressed by content rather than location is described. The design has been verified by constructing and successfully operating a three-word module consisting of 81 crossed-film cryotrons on a 6-inch by 3-inch substrate.
Biophysical studies of the ultrasonic fragmentation of tobacco mosaic virus.

Abstract The physical and biological effects of 7-Mc. sound on tobacco mosaic virus have been investigated. From these studies, the following results have been observed: 1. 1. At comparatively low ultrasonic intensities, insignificant fragmentation of the monomers occurs. Brushheap aggregates of the virus are dissociated, causing a slight increase in infectivity. 2. 2. As the intensity is increased, electron-microscope and infectivity studies show fracture of polymeric forms of the virus into predominantly monomeric lengths. This is accompanied to a lesser extent by partial fragmentation of a small percentage of the monomers. 3. 3. Our studies show some predominance of breaking of the virus monomers at a point 175–205 mμ from one end. This indicates perhaps a fundamental weakness at a particular locus in the monomer. 4. 4. As previously shown by Oster (6), the percentage of fragmented virus is a function of the time of exposure to sound, except when cavitation in the sample occurs. 5. 5. At cavitational levels, extreme fragmentation has been produced, the extent of which appears to be comparatively independent of time of exposure. A loss of 95 % in the infectivity has been noted following treatment at high intensities of ultrasound. 6. 6. Concentrated suspensions of the multiply-fragmented virus did not show any tendency to form molecular arrays, in spite of the spherical appearance of a large number of the fragments.
Generational Patterns in Mexican Americans' Academic Performance in an Unwelcoming Political Context.

Abstract Research has shown that immigrant students often do better academically than their U.S.-born peers from the same ethnic group, but it is unclear whether this pattern holds for Mexican Americans. We examined the academic performance of four generations of Mexican American students from 5th to 10th grade looking for generation differences and explanations for them. Using data from 749 families, we tested a model with 5th-grade variables that differed by generation as potential mediators linking student generation to 10th-grade academic performance. Results showed that immigrants were academically behind at 5th grade but caught up by 7th. Only economic hardship mediated the long term relation between student generation and 10th-grade academic performance; maternal educational expectations and child language hassles, English usage, discrimination, and mainstream values helped explained the early academic deficit of immigrant children. The results identified potential targets for interventions to improve Mexican American students' academic performance.
Rest potentials of oxide-free platinum electrodes

Summary The anomalous rest potentials of phase-oxide free platinum oxygen electrodes in acid electrolyte are discussed in terms of a mixed potential mechanism, where the anodic process is a Temkin-type adsorption of −O and −OH on platinum. It is shown that this mechanism is consistent with the reported polarization behavior, time-dependent O 2 partial pressure behavior, and pH dependence of the platinum-oxygen polyelectrode.
The impact of stocks and flows of organizational knowledge on firm performance: an empirical investigation of the biotechnology industry

The knowledge-based view of the firm is a recent approach to understanding the relationship between firm capabilities and firm performance. Specifically, this approach suggests that knowledge generation, accumulation and application may be the source of superior performance. Other research has conceptualized organizational knowledge in terms of stocks of accumulated knowledge in the firm and flows of knowledge into the firm. This paper tests the relationship between stocks and flows of organizational knowledge and firm performance in the biotechnology industry. We suggest that a firm’s geographic location, alliances with other institutions and organizations and R&D expenditures are representative of knowledge flows, while products in the pipeline, firm citations and patents are indicative of knowledge stocks. Through factor analysis, we develop an aggregated measure of location from several variables. A regression model suggests that location is a significant predictor of firm performance as are products in the pipeline and firm citations. A major contribution of this investigation is the operationalization of geographic location and its statistically significant link to firm performance. Copyright © 1999 John Wiley & Sons, Ltd.
Abciximab reduces mortality in diabetics following percutaneous coronary intervention.

RESULTS In the 1,462 diabetic patients, abciximab decreased the mortality from 4.5% to 2.5%, p 5 0.031, and in the 5,072 nondiabetic patients, from 2.6% to 1.9%, p 5 0.099. In patients with the clinical syndrome of insulin resistance— defined as diabetes, hypertension, and obesity— mortality was reduced by abciximab treatment from 5.1% to 2.3%, p 5 0.044. The beneficial reduction in mortality with abciximab use in diabetics classified as insulin-requiring was from 8.1% to 4.2%, p 5 0.073. Mortality in diabetics who underwent multivessel intervention was reduced from 7.7% to 0.9% with use of abciximab, p 5 0.018. In a Cox proportional hazards survival model, the risk ratio for mortality with abciximab use compared with placebo was 0.642 (95% confidence interval 0.458 ‐ 0.900, p 5 0.010). CONCLUSIONS Abciximab decreases the mortality of diabetic patients to the level of placebo-treated nondiabetic patients. This beneficial effect is noteworthy in those diabetic patients who are also hypertensive and obese and in diabetics undergoing multivessel intervention. Besides its potential role in reducing repeat intervention for stented diabetic patients, abciximab therapy should be strongly considered in diabetic patients undergoing PCI to improve their survival. (J Am Coll Cardiol 2000;35:922‐ 8) © 2000 by the American College of Cardiology
Triangulating an exotic T quark

Limits on an exotic heavy quark $T$ are broadly generalized by considering the full range of $T\ensuremath{\rightarrow}Wb$, $th$ or $tZ$ branching ratios. We combine results of specific $T\ensuremath{\rightarrow}tZ$ and $T\ensuremath{\rightarrow}Wb$ searches with limits on various combinations of decay modes evaluated by reinterpreting other searches. We find strong bounds across the entire space of branching ratios, ranging from ${m}_{T}g415\text{ }\text{ }\mathrm{GeV}$ to ${m}_{T}g557\text{ }\text{ }\mathrm{GeV}$ at 95% confidence level.