cssi/SciSciGPT-SciSciNet huggingface dataset:
Preliminary Results of the Induced Environment Contamination Monitor (IECM) Measurements of Space Transport System (STS-2)

Preliminary analyses of the Induced Environment Contamination Monitor (IECM) measurements obtained from the STS-2 mission are given by the Instrument Scientists and their colleagues. These first comprehensive measurements of the Space Shuttle induced contamination environment are encouraging, and future flights of the IECM are planned to further define this environment.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Ferrimagnetic Nonlinear Transmission Lines as High-Power Microwave Sources

Ferrimagnetic nonlinear transmission lines (NLTLs) have the potential to fill a high-power microwave niche where compact cost-effective sources are lacking. NLTLs utilize nonlinear ferrimagnetic properties and magnetization dynamics to provide ultrafast pulse rise times (100 ps or less) and microwave signals with peak power ranging from kilowatts to hundreds of megawatts. The frequency of operation has been shown to range from 900 MHz up to 5 GHz depending on geometry and external magnetic fields. NLTLs, theoretically, can be pulsed to tens of kilohertz with little to no variance in microwave signal between shots. This paper covers recent advances in ferrimagnetic-based NLTLs, specifically effects of applied and bias magnetic fields on peak power and frequency, as well as temperature dependence.
Three-dimensional crystal-melt wulff-shape and interfacial stiffness in the Al-Sn binary system

The quantitative determination of the three-dimensional Wulff shape for a metallic crystal-melt system is reported here. The anisotropy of crystal-melt interfacial free energy is experimentally measured for the $\mathrm{Al}--\mathrm{Sn}$ binary system at temperatures of 300 and $500\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$. Equilibrium shapes of liquid droplets entrained within the crystalline phase are measured experimentally on sequential two-dimensional sections, and the three-dimensional Wulff plot is reconstructed. For this system, it is found that a single-parameter description of anisotropy is not sufficient, and the anisotropy is reported using the leading terms of the relevant cubic harmonics. Accordingly, the anisotropy coefficients are determined to be ${\ensuremath{\epsilon}}_{1}=(1.81\ifmmode\pm\else\textpm\fi{}0.36)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$ and ${\ensuremath{\epsilon}}_{2}=(\ensuremath{-}1.12\ifmmode\pm\else\textpm\fi{}0.13)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$. In addition, the corresponding normal stiffness components as well as a generalized stiffness are quantified and compared with available predictions from atomistic simulations.
Early Embryonic Exposure to Polychlorinated Biphenyls Disrupts Heat-Shock Protein 70 Cognate Expression in Zebrafish

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that have documented neurological effects in children exposed in utero. To better define neuronally linked molecular targets during early development, zebrafish embryos were exposed to Aroclor 1254, a mixture of PCB congeners that are common environmental contaminants. Microarray analysis of the zebrafish genome revealed consistent significant changes in 38 genes. Of these genes, 55% (21) are neuronally related. One gene that showed a consistent 50% reduction in expression in PCB-treated embryos was heat-shock protein 70 cognate (Hsc70). The reduction in Hsc70 expression was confirmed by real-time polymerase chain reaction (PCR), revealing a consistent 30% reduction in expression in PCB-treated embryos. Early embryonic exposure to PCBs also induced structural changes in the ventro-rostral cluster as detected by immunocytochemistry. In addition, there was a significant reduction in dorso-rostral neurite outgrowth emanating from the RoL1 cell cluster following PCB exposure. The serotonergic neurons in the developing diencephalon showed a 34% reduction in fluorescence when labeled with a serotonin antibody following PCB exposure, corresponding to a reduction in serotonin concentration in the neurons. The total size of the labeled neurons was not significantly different between treated and control embryos, indicating that the development of the neurons was not affected, only the production of serotonin within the neurons. The structural and biochemical changes in the developing central nervous system following early embryonic exposure to Aroclor 1254 may lead to alterations in the function of the affected regions.
An Evaluation of Gentamicin, Tobramycin, and Amikacin Pharmacokinetic/Pharmacodynamic Parameters in HIV-Infected Children.

BACKGROUND: The purpose of the study was to calculate gentamicin, tobramycin, and amikacin pharmacokinetic parameters in HIV-infected children and compare conventional multiple daily aminoglycoside dosing to once-daily aminoglycoside (ODA) dosing in attaining peak serum aminoglycoside concentrations (SACs) to minimum inhibitory concentration for 90% of isolates (MIC(90)) ratios ≥8 against selected pathogens. METHODS: Patients (<13yrs) receiving an aminoglycoside (15 patients/drug) in the treatment of gram-negative infection were studied. Intravenous gentamicin/ tobramycin were administered at a dose of 6-7.5 mg/kg/day and amikacin at 20-30 mg/kg/d divided every 8 hrs. Peak and trough serum concentrations were obtained and pharmacokinetic parameters were calculated utilizing a one-compartment steady-state model. SACs for gentamicin/tobramycin dosed at 7.5 mg/kg and amikacin at 22.5 mg/kg once daily were simulated using the calculated pharmacokinetic parameters. Peak SAC:MIC(90) ratios were calculated for each dosing method. RESULTS: Mean pharmacokinetic parameters were within 1 standard deviation of reported literature values. Mean peak:MIC(90) ratio of ≥8 was attained only for Klebsiella species (MIC90 1 μg/mL) using conventional gentamicin/tobramycin dosing whereas mean amikacin peak:MIC(90) ratios ≥8 were reached for Klebsiella, Enterobacter, and Citrobacter species (MIC(90) 4 μg/mL). ODA simulations predicted gentamicin/tobramycin peak:MIC(90) ratios ≥8 in 100% of patients with an organism-MIC(90) of 1 μcg/mL and in 80% of patients with an organism-MIC(90) of 2 μg/mL. Amikacin peak:MIC(90) ratio ≥8 was predicted for 93% of patients with an organism-MIC(90) of 4 μg/mL but in only 27% if the MIC(90) was 8 μg / mL. CONCLUSION: Optimal peak SAC:MIC90 ratios using conventional aminoglycoside dosing were predicted only for organisms with low MIC(90) values. ODA dosing represents an option for improving pharmacodynamic outcomes.
Blalock-Taussig shunt to a pulmonary vein: an unusual surgical complication.

Thickening of the wall of pulmonary veins in cyanotic congenital heart disease and the presence of hilar vessel anatomic variants may mislead a surgeon into incorrectly anastomosing the subclavian artery to the pulmonary vein when performing a Blalock-Tassig shunt. Emergency selective angiography is the study of choice for the identification of this operative complication.
Effect of 3-Methylcholanthrene Pretreatment on Aflatoxin B1 Metabolism in Hamster Liver

AbstractThe effects of 3-methylcholanthrene (MC) pretreatment of hamsters on the hepatic metabolism of aflatoxin B1 (AFB1) have been investigated in studies with subcellular, isolated hepatocytes and in vivo. Pretreatment of hamsters with MC (2.5 mg/100 g body wt.) 24 hr. before sacrifice not only increased microsomal cytochrome P-450 content by 70% but also increased the specific activity of cytochrome P-450 dependent metabolic activation of AFB1 as judged by AFB1-DNA binding by 65%. Even in isolated hepatocytes, AFB1-DNA binding was elevated by 65% in MC-treated hepatocytes. The ratios of AFB1-glutathione (AFB1-SG) to AFB1-DNA were about the same in both hepatocyte system. Hepatic AFB1-DNA binding was also increased by 85% in intact animals after MC treatment. It appears that the increased hepatic AFB1-DNA binding after MC treatment of hamsters is a result of higher specific activity and higher levels of cytochrome P-450 species involved in the activation of AFB1.
Thermal management of cylindrical batteries investigated using wind tunnel testing and computational fluid dynamics simulation

Abstract This work studied the thermal management of lithium ion batteries both numerically and experimentally. Numerically, a two dimensional CFD (computational fluid dynamics) model has been developed to perform detailed simulations of the thermal management issues within a battery pack cooled by air. Experimentally, systematic tests were performed to provide datasets to validate the CFD model. The main components in the experimental facility included a multi-cell battery pack and a wind tunnel. The wind tunnel facility generated well-controlled cooling air flow with velocity up to 30 m s−1 (∼67 miles per hour). So that the study can be performed under flow conditions directly relevant to practice. The major contributions from this combined numerical-experimental study are threefold. First, the CFD model has been shown to capture the dynamics of the cooling of battery modules consisting of multiple battery cells, including temperature non-uniformity among cells. Second, the CFD simulations have been compared directly against experimental data to quantify the accuracy and validity of the CFD models. Third, based on the validated CFD models, a reduced-order model is developed to predict the maximum cell temperature in the battery module. The accuracy and simplicity of the reduced-order model makes it promising for in situ monitoring and control purposes.
Development of the Inverted Sputter Source

A sputter source is described in which the beam is extracted through the ionizer. This gives a very compact source with easily changed cones. The beam transmissions through an electrostatic accelerator are good and life times of in excess of a month between services are normal.
Intravenous immunoglobulins in gram-negative bacteremia

To the Editors: I wish to point out a significant omission in the otherwise excellent article by Berkman and colleagues (1) on clinical uses of intravenous immunoglobulins. The possible utility of ...
CHROMOSOME COMPLEMENTS OF FIVE SPECIES OF POA WITH AN ANALYSIS OF VARIATION IN POA PRATENSIS

GRASS INVESTIGATIONS in the past lhave dealt primarily with the taxonomic aspect. Recently, however, turf culture and soil conservation have created a need for a more thorough knowledge of the genetic constitution and interrelationships of the plants employed. This study, primarily concerned with variation in Poa pratensis, attempts to extend investigations beyond the realm of comparative morphology and to correlate with morphology evidence gleaned from cytological studies. Such a procedure seems necessary in order to arrive at a clearer understanding of the entities involved. The genus Poa, considered usually as one of the more important groups of economic grasses, presents many difficulties from the standpoint of taxonomy and phylogeny. These are due to a number of factors, particularly the large number of species, wide distribution, and extensive cultivation. The taxonomic difficulty is evidenced by the disagreement regarding the position of several species within the genus, which is itself rather loosely held together by more or less arbitrary characters. Sections are in some cases delimited on vegetative characters, which, to say the least, are extremely variable. The author wishes to express his appreciation to Dr. Edgar Anderson, under whose direction this work has been done, for suggestions and helpful criticisms offered throughout the course of the investigation. To Mr. R. L. Hensel, the author is grateful for the supply of living plants of Poa arachnifera from Texas. MATERIALS AND METHODS.-Living material for cytological study, for the most part, came from the Missouri Botanical Garden Arboretum, Gray Summit, Missouri, and the Missouri Botanical Garden, St. Louis, Missouri. Plants were selected from well established sod, root tips taken from them, and the plants removed either to the garden nursery or greenhouse, depending upon the time of year at which they were taken from the field. In all cases they were brought into flowering, and herbarium specimens have or will be made from them for permanent records. In addition to the Missouri Botanical Garden plants, material from Green Bank, West Virginia, Schooleraft, Mlichigan, Washington, D. C., Vanceburg, Kentucky, and College Station, Texas, has been examined. Plants grown from commercial seed from Mangelsdorf Seed Co. and Palmer Seed Co., St. Louis, Missouri, and Scott Seed Co., Marysville, Ohio, have also been examined. This seed, for the most part, came from the region around Kansas City, Missouri. Root tips were fixed in La Cour's 2 BD or Navashin's fixative, the first always giving superior reults. Following fixation, the tips were run into paraffin according to the method described by La Cour 1 Received for publication June 29, 1939. (1931), then sectioned at 12-15 ,u, and the sections stained witlh crystal violet. Metaphase plates were drawn with the aid of a camera lucida, after which the chromosomes were counted from the drawing. When there is any doubt as to the exact number of chromosomes present, this has been indicated by + 1.
An infinite module-decomposition

(1992). An infinite module-decomposition. Communications in Algebra: Vol. 20, No. 10, pp. 2793-2814.
2D:4D digit ratio predicts depression severity for females but not for males

Abstract Depression affects at least twice the number of women than men. This difference appears to be relatively consistent across a wide range of cultures, with an average female to male ratio of 2:1 (Immerman & Mackey, 2003). Explanations of this sex difference have focused on hormones, the role that early traumas such as sexual abuse play in predisposing females to depression, and socialization influences (Nolen-Hoeksema, 1998). Digit ratio (2D:4D index to ring finger) is a well-established sexually dimorphic trait in humans, with females having a higher ratio than males (Martin, Manning, & Dowrick, 1999). This trait, stable across the lifetime, has been correlated with many other sexually dimorphic traits (Austin, Manning, McInroy, & Matthews, 2001). Previous research has shown contradictory results regarding whether depression is associated with a more masculine digit ratio or a more feminine digit ratio. The purpose of this study was to further investigate whether digit ratio is predictive of severity of depression. Results indicated that higher digit ratio is correlated with higher depression scores in females, but not males. Study limitations and further directions are considered.
Growth Inhibitory, Insecticidal, and Feeding Deterrent Effects of (12Z, 15Z)-1-Acetoxy-2-Hydroxy-4-Oxo-Heneicosa-12,15-Diene, a Compound from Avocado Fruit, to Spodoptera exigua

We isolated and identified (12Z,15Z)-1-acetoxy-2-hydroxy-4-oxoheneicosa-12,15-diene (persin) from avocado as a compound toxic to Spodoptera exigua larvae. Persin was obtained from oil extracted from the specialized idioblast cells of avocado fruit. When tested for activity using neonates in no-choice artificial diet bioassays, persin at concentrations of 200 μg/g inhibited growth; larvae gained only ∼50% of the weight attained by control insects after seven days. At concentrations of 400 μg/g or above, larval growth was reduced by >70% as measured by weight gain, and significant mortality occurred. In choice tests, persin at concentrations of 400 μg/g or higher deterred feeding, with significantly more larvae being found on control diet than on persin-treated diet. Possible applications of persin as a natural insecticide are discussed.
Stimulation by immune complexes of mucus release from goblet cells of the rat small intestine

Immune complexes (bovine serum albumin with rat antibodies to bovine serum albumin) formed in twofold antibody excess were injected into the duodenum of normal rats. In comparison to controls injected with antigen only, there was a marked increase in the percentage of disrupted goblet cells (an index of mucus release) in segments from the intestine of rats exposed for 3 hours to immune complexes in vivo. Similarly, there was a significant increase in 35S-labeled mucus recovered by filtration of intestinal wash, rinse, and mucosal homogenate fluids from rats exposed to immune complexes compared to those from rats exposed to bovine serum albumin or purified rat antiserum to bovine serum albumin alone. These findings suggest that certain immune complexes can stimulate mucus release from intact rat small intestine; enhanced mucus release may have a role in clearing the surface of complexes.
Influence of high-energy ion loss on DT reaction rate in laser fusion pellets

Because of the longer mean free path of highenergy ions, they will be preferentially lost from small pellets containing thermonuclear reactants. This effect has been calculated and, in the most extreme case calculated, a factor-of about-four reduction of the reaction rate in DT from the Maxwell average rate at the same mean ion kinetic energy is found.
Survey and examination of an electromagnetic vacuum accelerating effect and its astrophysical consequences

A rigorous detailed review of the concepts and calculations behind the acceleration of particles by the electromagnetic zero-point field is presented. The acceleration is enhanced in regions of great size and low particle density. Astrophysical scenarios are suggested and discussed and cosmological possibilities are briefly outlined. It is shown that the acceleration follows both from a semiclassical approach in the manner of Stochastic Electrodynamics and from quantum theory with a zero-point field that most naturally (but not necessarily) may be interpreted as time-symmetric in the manner of the Wheeler-Feynman form of Quantum Electrodynamics. It is shown that both approaches yield essentially identical results.
A comparison of office and adult day care center older volunteers: social-psychological and demographic differences.

Numerous researchers have compared older adults who volunteer with those who do not volunteer on several demographic variables. In contrast, in the present study we compared older adults (minimum age = 55 years old) who volunteered to work for a community organization at an office or in a day care center on social-psychological and demographic predictors. It was hypothesized that day care center volunteers would have higher scores than office volunteers on sympathy, role taking, and self-based salience of volunteer role (i.e., personal identity). In addition, office volunteers were expected to have higher scores than day care center volunteers on other-based salience of volunteer role (i.e., social identity). Discriminant function analysis indicated that day care center volunteers were higher than office volunteers on sympathy whereas office volunteers were higher than day care center volunteers on educational attainment, involvement in clubs and organizations, and role taking.
From Cyber Space to Cybernetic Space: Rethinking the Relationship between Real and Virtual Spaces

The interaction between real and virtual spaces can be reconceptualized by mobilizing the notion of cybernetic space to signify the relationship between spaces, culture and identity in the synthetic space we tend to live in. The new metaphor can allow for a holistic examination of the Internet in popular culture.
Study of Fracture Behavior of Molybdenum Alloys Using Moire´ Interferometry

Molybdenum-based intermetallics are currently being developed for high temperature application (>1000°C) in advanced fossil energy combustion systems. The goal is to maintain the desired high-temperature mechanical properties while also achieving the required high-temperature oxidation/ hot corrosion resistance. In this research, molybdenum alloys were investigated using high temperature moire interferometry. Three-point-bending tests were conducted, and detailed fracture behavior around crack tip was investigated at both room temperature and elevated temperature. Grain boundary sliding was observed through high resolution in-plane deformation fields. For each test, a follow-up fractography and microstructural analyses were carried out. Test results showed that molybdenum alloy with silicide has higher toughness and enhanced grain boundary strength at elevated temperature. The effect of oxygen on grain boundary cohesive strength of Mo alloy was also studied using atomistic modeling and simulations.Copyright © 2005 by ASME
SU-E-I-54: Using Quantitative Measurement of Image Quality to Standardize Clinical Performance Across a Diverse Population of CT Scanners

Purpose: To develop an Image Quality metric, in order to establish consistent Image Quality among a population of CT scanners, of different make/model and locations in a health system. Methods: Through discussion with radiologists, it was decided to use image noise as a metric. Image noise was defined as the standard deviation of an ROI placed in the image. Radiologists selected target values for the desired level of image noise. For head examinations, the ROI was placed in the solid tissue at the level of the fornix. For abdomen images, the ROI was placed at mid‐liver. For the actual metric, the average of two ROI's was used. For each scanner in t he system, two data sets (brain and abdomen) of 100 images each were evaluated. Population statistics were acquired and the range of variation was measured. Data analysis was done on the entire population of images, as well as subsets, specifically location and scanner make/model.Based on the results of the analysis, protocols were revised, where necessary, to address excessive variation, and to correlate with the desired image noise target, 4.0 for the brain and 11.5 for the abdomen. Results: Use of the application resulted in a decrease in the range of image noise for brain images from 3.6 ‐ 5.5 to 4.1 ‐ 4.9. The range for abdomen images decreased from 7.0 ‐ 17.4 to 9.6 ‐ 14.1. Average noise values for abdomen images decreased from 12.3 to 11.8. Average Image Noise for the brain decreased from 4.6 to 4.3.The initial difference in average image noise between the two main scanner populations was 2.9 for abdomen scans. After the project the interscanner abdomen image noise difference decreased to 1.3. Conclusion: Image noise is a viable metric for comparing scanner performance and standardizing protocols.
The union image: Concept, programs and analysis

Several key labor leaders have expressed the need to improve the public image of unions. This paper defines the core elements of the current negative image and describes factors contributing to it. The basic direct and indirect approaches employed by unions to improve their image are systematically presented. It is concluded that prospects for image change are minimal due to limited image building efforts overall, lack of strategic thrust and union coordination, limited understanding of the nature of the image, and virtually no evaluation of image building efforts.
Issues Facing the Field of Learning Disabilities.

Four issues facing the field of learning disabilities are discussed: (a) defining learning disabilities in terms of discrepancy scores, (b) delineating the boundaries of how specific a learning dis...
MOLECULAR ENGINEERING OF POLYMER FILMS FOR AMPLITUDE AND PHASE MEASUREMENTS OF TI:SAPPHIRE FEMTOSECOND PULSES

Using second-harmonic frequency-resolved optical gating and a tricyanovinylaniline polymer thin film, we have measured the amplitude and the phase of mode-locked Ti:sapphire laser pulses as short as 13 fs. These thin films are ideally suited for ultrashort-pulse diagnostics because they eliminate the angle tuning associated with birefringent phase-matched crystals, minimize pulse distortions introduced by group-velocity dispersion, and exhibit excellent photochemical stability.
The far infrared spectrum of magnesium hydride

The rotational spectrum of MgH in its ground 2∑ state has been observed for the first time using a new tunable far infrared spectrometer. The molecular constants derived are of sufficient accuracy to permit astrophysical identification of this species.
dmBridge: Building a collaborative solution for streamlined digital library design and development

Purpose – Development of library digital initiatives increasingly requires integration of new technologies and collaboration between staff to accomplish specialized responsibilities. Yet, as responsibilities have evolved, the software tools used to fulfill them have largely failed to keep pace. This paper aims to show how UNLV Libraries overcame these challenges by developing a collaborative workflow model in a team with mixed technical skills. Design/methodology/approach – The paper offers a case study of one library's effort to transform inefficient web development processes in the digital library unit into an agile, collaborative team workflow through the development of a tool (dmBridge) that helps to reduce redundancies and encourage cooperation in the digital library design process. Findings – dmBridge came about in response to the growing necessity to create a sustainable digital library workflow within a framework capable of accommodating advanced customizability and relatively simple web development for CONTENTdm digital collections. Practical implications – As libraries seek to extend technology and digitization partnerships and cultivate successful grant funding, the authors demonstrate how development of tools like dmBridge can deliver an improved user experience, boost project efficiency, and support the strategic goals of the institution. Originality/value – dmBridge fills a need for a more modern, feature‐rich, customizable digital collections framework. In doing so, it has brought about a considerable transformation in digitization projects workflow and resource provisioning.
Chemical Physics: Molecular Clouds, Clusters, and Corrals

In its modern incarnation, chemical physics as a field is generally regarded as having been born in 1933, along with the The Journal of Chemical Physics. Its first editor, H. C. Urey, declared that “the boundary... has been completely bridged... chemists and physicists have become equally serious students of atoms and molecules” (Urey, 1933). Among other evangelical founders were P. Debye, H. Eyring, G. B. Kistiakowsky, I. Langmuir, G. N. Lewis, L. Pauling, K. S. Pitzer, J. C. Slater, J. H. Van Vleck, and E. B. Wilson, Jr. Actually, Urey’s bridge was still rickety and had to stretch over a wide cultural gulf (Nye, 1993). A major impetus for the new journal was the fact that The Journal of Physical Chemistry refused to accept any purely theoretical paper (and continued to do so for another two decades). By 1939, however, Slater had published his Introduction to Chemical Physics, and by 1942 Wilson and Van Vleck had established at Harvard the first Ph.D. program in chemical physics. Over the next 50 years, means of elucidating molecular structure and dynamics developed enormously, by virtue of pervasive applications of quantum theory and experimental tools provided by physics, especially myriad spectroscopic methods.
Impact of hormones on the regulation of cerebral vascular tone

Abstract A number of circulating hormones affect cerebral vascular function. Using isolated blood vessels from rodent models, we have found that the gonadal hormones estrogen and testosterone and the pineal hormone melatonin modify cerebral vascular tone. Melatonin directly constricted vascular smooth muscle, whereas prior in vivo treatment with gonadal steroids altered endothelial function. Endothelium-dependent dilation in pressurized cerebral arteries was decreased by testosterone but enhanced by estrogen. In vivo estrogen treatment also increased nitric oxide synthase (NOS) activity, as well as protein levels of endothelial NOS (eNOS), cyclooxygenase-1 (COX-1) and prostacyclin synthase in cerebral blood vessels. In vitro overnight incubation of isolated brain vessels with estrogen alone and with estrogen receptor blockers confirmed that estrogen is acting directly on vascular estrogen receptors to increase levels of eNOS. Western blot analysis also indicated the presence of estrogen receptors in cerebral vessels. When using mice deficient in the alpha estrogen receptor (ERKO mice), effects of estrogen on cerebral vascular tone and protein levels of eNOS and COX-1 were not observed. Together, these studies indicate that vascular function in the brain may vary with time of day (melatonin) or gender (estrogen/testosterone) and underscore the important impact that circulating hormones have on the cerebral circulation.
A micro method for the identification and estimation of ethylene in ripening fruits

The above article is a practical example of the application of microchemical methods to a problem in botany (plant physiology). A micro method was devised for the qualitative and semi-quantitative determination of traces of ethylene present in the atmosphere of ripening fruits. An efficient absorption unit, particularly suited for this type of work, and other apparatus were devised for both the absorption and the chemical conversion of the reaction gases involved. Conclusive experimental evidence of the evolution of ethylene by bananas during ripening was obtained by converting the ethylene to ethylene bromide and this to acetylene and to copperand silver acetylide respectively. The latter was then identified by the quantitative determination of its silber content. The amount of ethylene given off by bananas during the ripening period is approximately 0.1 to 0.2 ml. (N. T. P.) per 100 pounds of fruit. This amount of ethylene was isolated from 6000 liters of air which corresponds to the isolation of 1 part out of 10 million.
Resonance Raman spectra of native and mesoheme-reconstituted horseradish peroxidase and their catalytic intermediates.

Abstract Resonance Raman studies of native and mesoheme-reconstituted horseradish peroxidase and their catalytic intermediates, known as Compounds I and II, have been conducted using both near UV (∼350 nm) and visible (406.7 nm) excitation. Careful power studies indicate that the authentic Compound I spectra are obtainable using near UV excitation, but that use of visible excitation results in contamination of the Compound I spectrum with the spectrum of a Compound II-like photoproduct. Using H218O2, the ν(Fe=O) stretching modes for both systems are unambiguously identified, for the first time, at ∼790 cm−1. The authentic Compound I spectra are indicative of an 2A1u-like ground state for both the native and the mesoheme-reconstituted proteins. Finally, the possible biological implications of such information are briefly discussed.
A high performance monolithic In/sub 0.53/Ga/sub 0.47/As voltage-tunable transimpedance amplifier

The fabrication and performance of the first monolithically integrated In/sub 0.53/Ga/sub 0.47/As JFET voltage-tunable transimpedance amplifier for use in InP-based optoelectronic integrated circuits are reported. A narrow-gate transistor is used as an active feedback resistor. The two-stage voltage amplifier has a voltage gain of 10.7 and a bandwidth of 350 MHz. The closed-loop transimpedance of the amplifier is tunable from 10 to 24 k Omega by controlling the gate bias of the feedback transistor. >
Tangible holography: adding synthetic touch to 3D display

Just as we expect holographic technology to become a more pervasive and affordable instrument of information display, so too will high fidelity force-feedback devices. We describe a testbed system which uses both of these technologies to provide simultaneous, coincident visuo- haptic spatial display of a 3D scene. The system provides the user with a stylus to probe a geometric model that is also presented visually in full parallax. The haptics apparatus is a six degree-of-freedom mechanical device with servomotors providing active force display. This device is controlled by a free-running server that simulates static geometric models with tactile and bulk material properties, all under ongoing specification by a client program. The visual display is a full parallax edge-illuminated holographic stereogram with a wide angle of view. Both simulations, haptic and visual, represent the same scene. The haptic and visual displays are carefully scaled and aligned to provide coincident display, and together they permit the user to explore the model's 3D shape, texture and compliance.
γ-Secretase Substrate Concentration Modulates the Aβ42/Aβ40 Ratio IMPLICATIONS FOR ALZHEIMER DISEASE

Mutation of the amyloid precursor protein (APP), presenilin-1, or presenilin-2 results in the development of early onset autosomal dominant forms of Alzheimer disease (AD). These mutations lead to an increased Aβ42/Aβ40 ratio that correlates with the onset of disease. However, it remains unknown how these mutations affect γ-secretase, a protease that generates the termini of Aβ40 and Aβ42. Here we have determined the reaction mechanism of γ-secretase with wild type and three mutated APP substrates. Our findings indicate that despite the overall outcome of an increased Aβ42/Aβ40 ratio, these mutations each display rather distinct reactivity to γ-secretase. Intriguingly, we found that the ratio of Aβ42/Aβ40 is variable with substrate concentration; increased substrate concentrations result in higher ratios of Aβ42/Aβ40. Moreover, we demonstrated that reduction of γ-secretase substrate concentration by BACE1 inhibition in cells decreased the Aβ42/Aβ40 ratio. This study indicates that biological factors affecting targets such as BACE1 and APP, which ultimately cause an increased concentration of γ-secretase substrate, can augment the Aβ42/Aβ40 ratio and may play a causative role in sporadic AD. Therefore, strategies lowering the Aβ42/Aβ40 ratio through partial reduction of γ-secretase substrate production may introduce a practical therapeutic modality for treatment of AD.
Surface-Enhanced Raman Scattering: Comparison of Three Different Molecules on Single-Crystal Nanocubes and Nanospheres of Silver†

We have investigated the surface-enhanced Raman scattering (SERS) of chemically prepared single-crystal nanocubes and nanospheres of Ag with three different molecules to quantitatively understand the effect of sharp features on the SERS enhancement factor. Both experimental measurements and theoretical calculations confirmed a higher SERS activity for the nanocubes as a result of sharp features on their surfaces. We also found major discrepancies between the measured SERS intensities and those predicted from the electromagnetic mechanism. Through analysis of SERS bands, we concluded that sharp features on the Ag nanocubes could greatly increase the contribution of the chemical enhancement to the SERS intensity.
Changing Patterns of Mycobacterial Disease at a Teaching Community Hospital

Objectives: To evaluate trends in the occurrence and diagnosis of mycobacterial disease. Design: Prospective surveillance study using a central tuberculosis registry at a 611-bed teaching community hospital. Results: Data pertaining to 715 patients were entered into the registry between 1976 and 1991 on the basis of positive smears or cultures for acid-fast bacilli (AFB). Over time, the ratio of isolates of Mycobacterium tuberculosis to isolates of nontuberculous mycobacteria reversed (from 3.2 to 1 between 1976 and 1981 to 1 to 1.6 between 1986 and 1991). The sensitivity of the sputum AFB smear for diagnosis of pulmonary tuberculosis increased (from 0.73 to 0.96), but the positive predictive value of the sputum AFB smear declined (from 0.72 to 0.59). The acquired immunodeficiency syndrome epidemic accounted for these changes only to a small extent. Conclusions: The increasing occurrence of non-tuberculous mycobacterial disease and the declining positive predictive value of the sputum AFB smear at this hospital imply that respiratory isolation and antituberculous therapy will be used inappropriately for many patients. The development and use of newer tests for early isolation and specific identification of M tuberculosis should be accelerated.
Seasonal Variations in Circadian Rhythms Persist in Gonadectomized Golden-Mantled Ground Squirrels

Circadian wheel-running activity was monitored in intact and gonadectomized female and male golden-mantled ground squirrels maintained in a 14L:10D photoperiod at 21 degrees C. Marked advances in phase angle of activity onset and increases in the duration of the daily active phase occurred each year in intact animals coincident with the phase of reproductive activity. Surprisingly, long-term gonadectomized squirrels of both sexes manifested similar seasonal changes in the circadian system. Seasonal circadian variations in locomotor activity are generated by a circannual clock independent from and not influenced by concurrent changes in secretion of gonadal hormones.
Shape Optimization and Fluid Dynamic Analysis of a Translating Flexible Body

The translation (swimming) of an oscillating, slender, flexible body through an initially stationary fluid was explored using computational models and optimization routines. The computational model included fully-coupled two-dimensional fluid and solid finite element domains. The body leading edge was subjected to a prescribed vertical sinusoidal displacement, whereas the entire body was free to move horizontally. Large body deformation resulted in thrust production and horizontal body translation. Gradient-based optimization methods were used to find the body shape that yielded the maximum horizontal displacement over one period of vertical oscillation. It is shown that a tapered body with a “rounded” leading edge achieved significantly greater horizontal velocity than a body of uniform thickness. The computational domains, numerical models, optimization routines, and model verification studies are described. The predicted responses of uniform and optimal bodies are compared, and the sensitivity of horizontal displacement to body shape is quantified.
Past and future of wearable augmented reality displays and their applications

A wearable augmented reality (AR) display enables the ability to overlay computer-generated imagery on a person’s real-world view and it has long been portrayed as a transformative technology to redefine the way we perceive and interact with digital information. In this paper, I will provide an overview on my research group’s past development efforts in augmented reality display technologies and applications and discuss key technical challenges and opportunities for future developments.
Temperature dependence of the vibrational population lifetime of OH(ν = 1) in fused silica

Abstract An infrared picosecond transient bleaching technique was used to measure vibrational lifetimes ( T 1 ) of hydroxyl groups in fused silica over the temperature range 100–1450 K. T 1 decreases from 109 to 15 ps in this range. The T 1 temperature dependence is compared to non-radiative relaxation theory for the decay of the OH(ν = 1) quantum by a multiphonon mechanism.
Structural and spectroscopic characterization of 17- and 18-electron piano-stool complexes of chromium. Thermochemical analyses of weak Cr-H bonds.

The 17-electron radical CpCr(CO)2(IMe)• (IMe = 1,3-dimethylimidazol-2-ylidene) was synthesized by the reaction of IMe with [CpCr(CO)3]2, and characterized by single crystal X-ray diffraction and by electron paramagnetic resonance (EPR), IR, and variable temperature 1H NMR spectroscopy. The metal-centered radical is monomeric under all conditions and exhibits Curie paramagnetic behavior in solution. An electrochemically reversible reduction to 18-electron CpCr(CO)2(IMe)− takes place at E1/2 = −1.89(1) V vs Cp2Fe+•/0 in MeCN, and was accomplished chemically with KC8 in tetrahydrofuran (THF). The salts K+(18-crown-6)[CpCr(CO)2(IMe)]−·1/2THF and K+[CpCr(CO)2(IMe)]−·3/4THF were crystallographically characterized. Monomeric ion pairs are found in the former, whereas the latter has a polymeric structure because of a network of K···O(CO) interactions. Protonation of K+(18-crown-6)[CpCr(CO)2(IMe)]−·1/2THF gives the hydride CpCr(CO)2(IMe)H, which could not be isolated, but was characterized in solution; a pKa of 27...
High resolution isotope study of the latest deglaciation based on Bermuda Rise cores

Abstract A stable isotope and 14C investigation of carbonates from three late Quaternary cores with high rates of sedimentation from the northeastern Bermuda Rise has produced the highest resolution record of the glacial maximum to Holocene stable isotope change yet obtained from an open ocean location. The record includes a three-step “termination” and the first direct evidence of an early deglacial meltwater “spike” in the open sea.
Interaction of human plasma high-density lipoprotein HDL2b with discoidal complexes of dimyristoylphosphatidylcholine and apolipoprotein A-I.

Abstract The interaction of HDL 2b , a major subclass ( d = 1.063–1.100 g / ml ) of human plasma high-density lipoproteins, with discoidal complexes composed of dimyristoylphosphatidylcholine (DMPC) and apolipoprotein A-I (weight ratio, DMPC/apolipoprotein A-I (2.1–2.5:1); dimensions, 10.0 × 4.4 nm) was investigated. Incubation at 37° C for 4.5 h of HDL 2b with discoidal complexes resulted in a transfer of DMPC from the discoidal complexes to the HDL 2b , a release of lipid-free apolipoprotein A-I from the discoidal complexes during such transfer, and a dissociation of some apolipoprotein A-I from the HDL 2b surface. The number of discoidal complexes degraded during interaction with HDL 2b depended on the initial molar ratio of HDL 2b to discoidal complexes. Approximately one molecule of HDL 2b was required for the degradation of one discoidal complex particle, and the degradation process appeared limited by the capacity of the HDL 2b for uptake of DMPC. Degradation of discoidal complexes was also observed when human plasma LDL ( d = 1.006–1.063 g / ml ) was substituted for HDL 2b in the interaction mixture.
Learning style preferences of community mental health professionals

Programs of continuing education in mental health are increasing at a rapid pace. This study examines selected personal and occupational characteristics of enrollees in one such program and classifies the nature of enrollee motivation for participating in specialized programs of community mental health training. The learning-style preferences of these highly experienced profes- sionals are also explored and recommendations are made concerning the design of similar educational programs under development elsewhere. Programs of continuing education for mental health profes- sionals are expanding at an accelerated pace. A recent publication of the National Institute of Mental Health, for example, listed more than 117 specialized programs in postgraduate mental health education, and the com- pilers of that report, projecting ahead, anticipate the continued proliferation of even more programs by the end of the current decade (National Institute of Mental Health, 1974). Clearly, mental health professionals want programs of continuing education which, when available, tend to be utilized by large numbers of persons from all areas of the field. The paper that follows reviews the educational experience of a representa- tive sample of 1,400 human service workers who, received specialized post- graduate education at the Center for Training in Community Psychiatry and Mental Health Administration (CTCP) in Berkeley, California (now known as the Health Training Resources Center, Northern Division; for descrip- tions of the predecessor, CTCP, the reader is referred to Hume, 1963; Brown, 1972; Shapiro, 1974) between 1961 and 1973. The paper will focus on the gen- eral characteristics of these trainees and will seek to uncover trainee motiva- tions for pursuing advanced programs of study. In particular, special atten- tion will be given to trainee preferences regarding a variety of learning and pedagogical styles in use at the Berkeley center during this period. An attempt will be made to identify those teaching approaches that mental health pro- fessionals experience as being the most and the least conducive to the achievement of their particular educational objectives. Finally, several rec- ommendations will be offered for consideration by teaching faculties and con-
Using the oocyte donation model to identify early trophoblast pregnenolone production.

Purpose To investigate production of progesterone’s precursor, pregnenolone, in the early oocyte donation pregnancy.
Inhibitors in hemophilia: nature or nurture?

There has long been debate regarding the respective roles of inherited or environmental factors in the development of hemophilic inhibitors. Factor VIII (FVIII) gene mutations, polymorphisms of key biologic response modifiers (interleukin 10, tumor necrosis factor alpha), ethnicity, and family
The Role of Discrimination and Acculturative Stress in the Physical Health of Mexican-Origin Adults

The authors propose that perceived discrimination has an effect on self-reported health statuses, which are known to affect future morbidity and mortality. A sample of 3,012 Mexican-origin adults from the Mexican American Prevalence and Services Study in California is utilized to test this hypothesis. Dependent variables include a self-rating of health and a count of self-reported chronic conditions; the key independent variable is a scale of overall discrimination specific to one’s Mexican origin. Results indicate that discrimination is related to poor physical health—net of controls for acculturation stress, national heritage, sociodemographic variables, and social support. Depression is identified as a major mechanism through which discrimination may affect physical health. Notably, job market stress/discrimination has a very strong association with poorer physical health, net of depression. Individual-level effects of discrimination found in this study, as well as institutional-level conditions and co...
Interactive analysis and design program for phase-controlled rectifiers

The authors describe an interactive computer program that accurately determines rectifier time waveforms in the periodic steady-state condition without the need for many of the previously used simplifying assumptions. The program provides important input data for the design of components associated with the rectifier. The DC, RMS, and peak currents through the output filter inductor and the DC voltage across and the RMS current through the output filter capacitor are sufficient for the selection and design of these components. The rectifier time waveforms are analysed for line-current harmonics, rectifier power factor, and other important rectifier performance data providing the user with a complete and accurate description of rectifier performance as a function of rectifier design. >
Improving the deployment of inspection tools; tutorial on inspection capacity and sample planning

To help fabs improve their use of inspection tools a practical guide to inspection capacity and sample planning is presented. A comprehensive approach involving data collection, parameter estimation, and model based sample planning is covered. The objective is to enable yield engineers to develop basic inspection planning toolboxes in a spreadsheet and/or more effectively manage inspection planning projects. For parameter estimation, the use and performance of a hidden Markov model and the E-M algorithm is introduced
Ecological indicators for system-wide assessment of the greater everglades ecosystem restoration program

Developing scientifically credible tools for measuring the success of ecological restoration projects is a difficult and a non-trivial task. Yet, reliable measures of the general health and