cssi/SciSciGPT-SciSciNet huggingface dataset:
Light and dark bars; contrast discrimination.

Abstract Contrast increment thresholds were measured for light and dark bars as a function of the base contrast of the bars. The bars were superimposed on a uniform field of 340 cd/m 2 . They had either rectangular or Gaussian luminance profiles, varied in width from 0.1° to 10°, and in duration from 10 to 200 msec. For the 200-msec presentations, the resulting contrast discrimination functions all had approximately the same shape when contrast was defined as (L max −L min )/(L max + L min ) , and closely resembled corresponding results for sine-wave gratings. The similarity in shape of contrast discrimination functions for light and dark bars is attributed to a retinal nonlinear intensity transformation. The 10 msec contrast discrimination functions differed from the 200-msec functions in ways that can be explained by differences in temporal integration.
Biosystematic research in Aegilops and Triticum

As Kihara had only I to 3 accessions of each diploid analyzer species in his germplasm collection, WE conclude the genome formulae for Aegilops and Triticum published by him between 1920 and 1960 were largely based on the typological concept applied to cytogenetic research. The same restriction applies to his concept of “modified genomes” in the tetraploid Aegilops species, which therefore may not actually be modified. Genome analysis by itself is not a very fine-tuned experimental technique. A biological specier concept based on several different biosystematic studies in Aegilops and Trificurn is preferable to a species concept based only on genome analysis in meiocytes of F, hybrids. Biosystematic studies recognize Aegilopa sharonensis, Ae. peregrinu, and Triticum urarfu as valid species distinct from other species. Our attempts tc resynthesize tetraploid wheats using Ae. spelfoides and Ae. searsii as female parents and T. monococcum and T. urarfu as male parents met with little success. There may be an embryo lethality mechanism operating in these F, hybrid combinations. Sterile hybrid plants were obtained with Ae. longissima, Ae. shuronensis. and Ae. bicornis as female parents in crosses with the two Trificum species as males. Amphidiploid seed was obtained with the use of colchicine.
Novel low-voltage low-power Gb/s transimpedance amplifier architecture

A novel current-mode transimpedance amplifier (TIA) architecture is proposed for optical receivers. This new architecture, based around the use of a uniquely biased common-base current buffer stage, allows stable, DC coupled TIAs to be designed in bipolar or CMOS processes operating from extremely low supply voltages and using very low levels of power. Noise performance is comparable to that of higher power designs that operate from higher supply rails. Simulation results have been obtained for a 47GHz fT SiGe BiCMOS process and also 0.25μm CMOS.
Wave propagation in nonlinear media

The behavior of nonlinear dispersive or dissipative waves is analyzed using the decomposition method.
Discrete colonic ulcers associated with oral contraceptives.

A case of focal colonic ulcerations is presented which probably was secondary to ischemic colitis induced by oral contraceptive use. In addition, the ulcerations were misinterpreted as mural rather than mucosal lesions because of the prominent local mucosal and submucosal edema. Benign ulcer should be considered in the differential diagnosis of focal colonic lesions, especially if the patient is a young female taking oral contraceptives.
Dynamics of population communities with prey migrations and Allee effects: a bifurcation approach

The population dynamics of predator-prey systems in the presence of patch-specific predators are explored in a setting where the prey population has access to both habitats. The emphasis is in situations where patch-prey abundance drives prey dispersal between patches, with the fragile prey populations, i.e. populations subject to the Allee effect. The resulting 3D and 4D non-linear systems depending on some parameters, which reflect 'measures' of factors under consideration, support rich dynamics and in particular a diverse number of predator-prey life history outcomes. The model's mathematical analysis is carried out via submodels that focus in lower-dimensional settings. The outcomes depend on and, in fact, are quite sensitive to the structure of the system, the range of parameter values and initial conditions. We show that the system can support multistability and a diverse set of predator-prey life-history dynamics that include rather complex dynamical system outcomes. It is argued that, in general, evolution should favour heterogeneous settings including Allee effects, prey refuges and patch-specific predators.
Evidence for differences in alpha-adrenergic receptor affinity in stress susceptible swine

pA2-Values were determined using phentolamine-methoxamine. The mean pA2-value on aortic strips from stress susceptible swine was 7.81 and 7.39 for control. The α-adrenergic receptor from stress susceptible swine has a higher affinity than that of control.
Evaluation of an alternative program for MMTP drop-outs: impact on treatment re-entry

Abstract Introduction: Retention in a Methadone Maintenance Treatment Program (MMTP) is predictive of abstaining from heroin and has other benefits. Many individuals leave treatment before they experience these positive outcomes. Objective: This research project targeted MMTP drop-outs with an intervention designed to assist them in returning to drug treatment. Methods: Subjects who had left MMTP within the prior 12 months were randomly assigned to intervention or comparison groups. The 3-month long intervention consisted of street outreach, cognitive behavioral groups, and individual counseling. Data were analyzed for 175 subjects who were out of treatment at baseline and who returned for a 6-month follow-up interview (Intervention group, N =111; Comparison group, N =64). Results: A total of 87% of subjects assigned to the intervention condition participated in at least one component. Intervention subjects who attended two or more cognitive behavioral group sessions were more likely than those who attended 0–1 sessions or those in the comparison group to have returned to treatment during the 6 month follow up time period (72 vs. 53 vs. 50%, respectively, P Conclusion: MMTP drop-outs need not be lost to the drug treatment system if special efforts are made to engage them in interventions developed to encourage treatment re-entry.
Determination of PM2.5 Sulfate and Nitrate with a PC-BOSS Designed for Routine Sampling for Semi-Volatile Particulate Matter.

Ambient particles contain substantial quantities of material that can be lost from the particles during sample collection on a filter. These include ammonium nitrate and semi-volatile organic compounds. As a result, the concentrations of these species are often significantly in error for results obtained with a filter pack sampler. The accurate measurement of these semi-volatile fine particulate species is essential for a complete understanding of the possible causes of health effects associated with exposure to fine particles. Past organic compound diffusion denuder samplers developed by the authors (e.g., the Brigham Young University Organic Sampling System (BOSS)) are not amenable to routine field use because of the need to independently determine the gas-phase semi-volatile organic material efficiency of the denuder for each sample. This problem has been eliminated using a combined virtual impactor, particle-concentrator inlet to provide a concentrated stream of 0.1-2.5-μm particles. This is followed by a BOSS diffusion denuder and filter packs to collect particles, including any semi-volatile species lost from the particles during sampling. The sampler (Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS)) contains a post-denuder multifilter pack unit to allow for the routine collection of several sequential samples. The PC-BOSS can be used for the determination of both fine particulate nitrate and semi-volatile organic material without significant positive or negative sampling artifacts. Validation of the sampler for the determination of PM 2.5 sulfate and nitrate based on comparison of results obtained at Riverside, CA with collocated PC-BOSS, annular denuder, and ChemSpec samplers indicates the PC-BOSS gives accurate results for these species with a precision of ±5-8%. An average of 33% of the PM 2.5 nitrate was lost from the particles during sampling for both denuder and single filter samplers.
A novel photovoltaic maximum power point tracker for battery charging applications

This paper proposes a novel MPPT algorithm mainly for battery charging applications which are considered constant voltage type loads. This is achieved mainly with output current maximization. This technique benefits from advantages such as very simple current controller and also circuit topology independency. This provides high efficiency for energy conversion with low cost for low power, low cost applications. A new hybrid PV model is introduced for simulation purposes. Finally, simulation results will be provided confirming the validity of the algorithm.
The preparation, performance and factors affecting band spreading of high efficiency extraction chromatographic columns for actinide separations

Abstract High efficiency extraction chromatographic columns containing di(2-ethylhexyl)orthophosphoric acid (HDEHP) as the stationary phase and Celite as the inert support were prepared by a slurry packing method. Column performance was studied as a function of particle size of the support, liquid loading of HDEHP, temperature, column cross-sectional area and bed length by measuring the plate height, H, as a function of mobile phase velocity, ν, for the elutions of Cf(III) and Cm(III). In order to determine the major causes of band spreading for the elution of Cf(III), self-diffusion coefficients of Eu(III) were measured in dilute HNO3 and undiluted HDEHP as a function of temperature. H vs ν data were analyzed in terms of the reduced plate height and velocity. Comparison of calculated and experimental H vs ν and H vs capacity factor, k′, curves showed that the slow rate of extraction of Cf(III) from the stationary to the mobile phase was the major cause of band spreading at 25°C, whereas, flow phenomena were the major causes of band spreading at 75°C.
Targeted Share Repurchases, Free Cash Flows, and Shareholder Wealth: Additional Evidence

This paper presents evidence that the valuation consequences of targeted share repurchase announcements are positively related to the size of the firms' pre‐repur‐chase free cash flows and to the firms' pre‐repurchase build‐up of liquid assets. The paper further reports that the level of liquid assets declines permanently following the share repurchases. The results suggest that a share repurchase is a viable means to cut down surplus cash and that such decision can increase shareholder wealth by reducing agency costs of free cash flows.
Anisotropic Magnetic Susceptibility Measurements on a Phonolite and on a Folded Metamorphic Rock

i A description of a method of measuring anisotropic magnetic susceptibility in rocks, based on an original method by Ising, is followed by the results of a series of measurements made on an intrusion, and on a metamorphosed sedimentary rock. These results show a good correlation between the textures of the rock, and the axes of anisotropic susceptibility.
Evaluating a New Technology Alternative: Case Study

ABSTRACT This case study examines the real situation where a considerable inventory savings exists by introducing an advanced manufacturing equipment that provides much needed manufacturing flexibility for a manufacturer of disks for airplane turbine engines. The case also documents the actual economic analysis procedures conducted by the firm by presenting the sensitivity analysis of the key input variables, probabilistic analysis and simulation analysis. Due to the nature of proprietary information, the actual company name has been disguised.
Macrophage responses in inflammatory demyelinating neuropathies.

Macrophages are prominent participants in inflammatory demyelinating neuropathies. To provide a different means of evaluating macrophage behavior, we used immunostaining of teased nerve fibers and endoneurial blood vessels. We assessed the frequency with which macrophages were seen in inflammatory demyelinating neuropathies, their relationship to normal and demyelinating fibers, and their expression of major histocompatibility Class II markers (Ia antigen). In 6 patients with chronic inflammatory neuropathy and 1 with Guillain-Barre syndrome, we found regularly that macrophages were adherent to teased blood vessels. Cells presumed to be entering the nerve were elongated, often with a polarized appearance suggesting motility, and were Ia-positive. After entry into nerve, the Ia-positive macrophages were adherent to both normal and demyelinating fibers. They often retained their Ia positivity after penetrating into the nerve fiber and removing myelin. Foamy macrophages, judged to be postphagocytic, were Ia-negative. The foamy macrophages found adhering to blood vessels were presumed to be leaving the nerve. This pattern of entry as Ia-positive prephagocytic cells and evolution to Ia-negative foamy macrophages was compared with other experimental and human neuropathies.
3.3.1 Divergent Thinking in Systems Engineering Practice: Is There a Shortfall?

Divergent thinking produces an expanded definition of both problem and solution space. Convergent thinking leads to the selected solution. A balance of the two is an essential element of effective systems engineering practice. A significant predominance of convergent thinkers and shortage of divergent thinkers has been noticed in a group of systems engineering students. A negative impact on exercise results was also noticed. If this is a valid observation of the general systems engineering field, there are serious implications that must be addressed in training and at work. This paper outlines the initial observation, impact, and potential for future research.
Nyx: a display energy optimizer for mobile web apps

Energy is a critical resource for current mobile devices. In a smartphone, display is one of the most energy consuming components. Modern smartphones often use OLED screens, which consume much more energy when displaying light colors than displaying dark colors. In our previous study, we proposed a technique to reduce display energy of mo- bile web apps by changing the color scheme automatically. With this approach, we achieved a 40% reduction in display power consumption and 97% user acceptance of the new color scheme. In this tool paper, we describe Nyx, which implements our approach. Nyx is implemented as a self- contained executable file with which users can optimize en- ergy consumption of their web apps with a simple command.
Outcome of Treatment of Epilepsy in Adult Patients with Cerebral Palsy (P01.068)

Objective: To study the treatment outcome, defined as degree of seizure control, in adult patients with Cerebral Palsy who have Epilepsy. Background Cerebral Palsy is the most common cause of motor disability in early childhood. Cerebral palsy is associated with a high incidence of epilepsy. The incidence of epilepsy in patients with cerebral palsy ranges from 15-90%. There is a paucity of data on outcomes of epilepsy in adult patients with cerebral palsy. Design/Methods: This is a retrospective study reviewing the database of Cerebral Palsy patients with Epilepsy seen at Creighton Epilepsy Center. 49 Cerebral Palsy patients with were identified who had epilepsy and were treated with antiepileptic medications. The seizure outcome was classified as follows:Class 1- Seizure free for the last 1 yearClass 2- One seizure per year to 1 seizure per monthClass 3- One seizure per month to one seizure per weekClass 4- One seizure per week to daily seizures. Results: 29(59.1%) out of 49 patients were free of epileptic seizures for at least the last one year. 12 patients(24.5%) had a Class 2 outcome. 3 patients(6.1%) had a class 3 outcome. 5 patients(10.2%) had a Class 4 outcome. 83.6% of patients with cerebral palsy and epilepsy had less than 1 seizure a month. 5 patients had a VNS implanted. 2 patients were seizure free and were off all anti-epileptics. 26.5% were on one antiepileptic medication(AED), 24.4% on two AED9s,18.3% on three AED9s and 26.5% patients were on 4 anti-epileptic medications. Conclusions: This study shows that around 59.1% of Cerebral Palsy patients with Epilepsy were seizure free when treated with antiepileptic medications. And the majority of the rest had less than one seizure per month. This study shows that majority of patients with cerebral palsy who have epilepsy can achieve adequate seizure control with appropriate treatment. Disclosure: Dr. Alareddy has nothing to disclose. Dr. Sankaraneni has nothing to disclose. Dr. Singh has nothing to disclose.
A prospective multicenter study of written action plans among emergency department patients with acute asthma.

Background. The prevalence of written “action plans” (APs) among emergency department (ED) patients with acute asthma is unknown. Objective. To determine the prevalence of APs among ED patients, to describe the demographic and clinical profile of patients with and without APs, and to examine the appropriateness of response to an asthma exacerbation scenario. Methods. Using a standard protocol, 49 North American EDs performed a prospective cohort study involving interviews of 1,756 patients, ages 2–54, with acute asthma. Among children only, a random sample was contacted two years after the index ED visit to assess current AP status and parents' self-management knowledge. Results. The overall prevalence of APs was 32% (95% confidence interval [CI], 30%–34%), and was higher among children than adults (34% vs. 26%, respectively; p = 0.001). Patients with APs had worse measures of chronic asthma severity (p < 0.05) and were more likely to be hospitalized (multivariate odds ratio, 1.5; 95%CI, 1.1–2.1). After 2...
Accuracy of death certificate ages for the extreme aged

This study attempts to verify age reporting on the death certificate for the “extreme aged” population and to evaluate the accuracy of recent death rates for this group in light of the findings. In addition, methods used and problems encountered in carrying out a record linkage study, particularly a low match rate, are identified. A sample of more than three thousand death records was selected from those filed for decedents age 85 and over in Pennsylvania and New Jersey in the 1968 to 1972 period. Death certificates of 53 percent of whites and 30 percent of nonwhites were linked to the 1900 U.S. Census. A comparison of age on the death certificate with the age reported for the same individual in the census record showed a high level of agreement for whites, except at ages 100 and over; for nonwhites, however, age agreement levels were substantially lower. Within racial groups, there was little difference by sex in agreement on age. These results, corroborating those of earlier studies, make it clear that nonwhite mortality at the oldest ages has been consistently understated in official statistics.
Effect of vitamin E deficiency and supercritical fluid aerosolized vitamin E supplementation on interleukin-1-induced oxidative lung injury in rats

Abstract We hypothesized that alterations in lung vitamin E levels would impact the development of acute oxidative lung injury. We found that dietary induced deficiency of vitamin E diminished lung tissue levels of vitamin E and increased lung leak following intratracheal administration of interleukin-1 (IL-1) to rats. Conversely, rats administered vitamin E directly to the lungs as an inhaled aerosol (0.3–3 μm particles) formed by supercritical fluid aerosolization (SFA) had increased lung tissue vitamin E levels and decreased IL-1 induced lung leak compared to control rats. Lung myeloperoxidase (MPO) activities, reflecting neutrophil concentrations, were increased in rats given IL-1 intratracheally compared to rats given saline intratracheally but were not different for control or vitamin E depleted rats. Lung MPO activities in rats given IL-1 intratracheally were slightly higher in SFA vitamin E treated rats than in control rats. Our results suggest that vitamin E levels affect susceptibility to IL-1 induced, neutrophil-dependent lung injury. We speculate that supercritical fluid aerosol (SFA) delivery of vitamin E can rapidly increase lung vitamin E levels and decrease acute oxidative lung injury.
Blending chaotic attractors using the synchronization of chaos

Building a source of low-dimensional chaotic signals with specified properties poses new challenges in the study of nonlinear systems. We address this problem using two synchronized asymmetrically coupled chaotic systems. As an uncoupled oscillator, each produces chaotic signals with distinctively different properties. The chaotic signal produced by the synchronized oscillators possesses properties intermediate with respect to the two original signals. The properties of this synthesized signal can be controlled by the ratio of the coupling parameters.
Functional interactions between phage T4 and E. coli DNA-binding proteins during the presynapsis phase of homologous recombination

Abstract The “protein machine” for phage T4 homologous recombination has begun to be assembled in vitro. A particularly heavily studied reaction has been the uvsX protein (a RecA-like strand transferase)-mediated homologous pairing reaction between single and double-stranded DNAs, a key step in the recombination cycle in vivo. A necessary prerequisite for uvsX protein-mediated pairing is the polymerization of this factor along the invading single strand, a process known as presynapsis. Recent work has indicated that at least two other T4 recombination factors are involved in this process as well, the uvsY and gene 32 products. These proteins are also ssDNA-binding factors and exhibit an affinity for UvsX and each other. In order to begin to sort out the potential functional roles played by these protein-protein interactions in presynapsis, I have examined the ability of the uvsX protein to form stable filaments along ssDNA in the presence of these proteins. It is shown that the uvsY protein relieves the inhibition to filament formation due to the presence of the gene 32 protein, but experiments with the E. coli SSB protein (the bacterial analogue of gp32) suggest that this effect does not involve a direct interaction between UvsY and gp32.
Synthetic properties of starburst galaxies

We present the results of an extensive grid of evolutionary synthesis models for populations of massive stars. The parameter space has been chosen to correspond to conditions typically found in objects like giant H II regions, H II galaxies, blue compact dwarf galaxies, nuclear starbursts, and infrared luminous starburst galaxies. The models are based on the most up-to-date input physics for the theory of stellar atmospheres, stellar winds, and stellar evolution. A population of massive stars is not only important in terms of its output of radiation but also via its deposition of mechanical energy. The output of radiative and mechanical luminosity is compared at various starburst epochs. In a supernova dominated instantaneous starburst, the mechanical luminosity can be as large as almost 10% of the total radiative luminosity. This occurs when most massive O stars have disappeared, and the synthetic spectrum in the optical and near-ultraviolet is dominated by B and A stars. During this epoch, the output of ionizing radiation below 912 A becomes very small, as indicated by a very large Lyman discontinuity and a very small ratio of ionizing over mechanical luminosity. We discuss the relevance of these results for the interpretation of starburst galaxies, active galactic nuclei, and the energetics of the interstellar medium.
Differences in an ensemble of streamside salamanders (Plethodontidae) above and below a barrier to brook trout

I examined the species composition, relative abundances, and size distributions of an ensemble of streamside salamanders in two contiguous sections of an Appalachian headwater stream: one containing brook trout and one that was trout free. The two stream sections were separated by a natural waterfall that formed a permanent barrier to the upstream movement of fish. The two stream sections differed in the overall abundance of salamanders, the relative abundance of the six species present, and the size-distribution of the salamander ensemble. These results suggest that brook trout have an effect on the structure of co-occurring ensembles of salamanders, and that the continued coexistence of stream salamanders with brook trout does not indicate lack of strong ecological interactions.
High-resolution Measurement of Odor-Driven Behavior in Drosophila Larvae

Olfactory responses in Drosophila larvae have been traditionally studied in Petri dishes comprising a single peripheral odor source. In this behavioral paradigm, the experimenter usually assumes that the rapid diffusion of odorant molecules from the source leads to the creation of a stable gradient in the dish. To establish a quantitative correlation between sensory inputs and behavioral responses, it is necessary to achieve a more thorough characterization of the odorant stimulus conditions. In this video article, we describe a new method allowing the construction of odorant gradients with stable and controllable geometries. We briefly illustrate how these gradients can be used to screen for olfactory defects (full and partial anosmia) and to study more subtle features of chemotaxis behavior.
The prevalence of obesity and obesity-related health conditions in a large, multiethnic cohort of young adults in California

Purpose To identify population groups that are most susceptible to obesity-related health conditions at young age.
Natural Medicines Comprehensive Database (NMCD): A Review

The Information Rx column reviews resources of interest to medical libraries. Natural Medicines Comprehensive Database (NMCD) is an evidence-based database for medical, nursing, pharmacy, and pharmacy technician programs and health care providers. It provides descriptions and efficacy information on complementary, alternative, and integrative medicines and techniques. There are four versions of NMCD: book version, PDA version, professional version, and consumer version. This article reviews the professional version of NMCD.
Are solar flares a result of a sudden conversion of magnetic energy stored prior to their onset

It has long been believed that solar flares result from a sudden conversion of magnetic energy stored prior to their onset. However, it is difficult to prove such an idea without knowing both the rate of energy input and the rate of energy output in the flare region. In spite of the fact that a similar mechanism has long been contemplated, magnetospheric substorms are found to be directly driven by an enhanced dynamo process. The results suggest also that the presence of magnetic energy in the magnetotail does not mean that it can be consumed for substorms. Implications of this finding for solar flares are discussed.
The use of colloidal quantum dots on focal plane arrays for optical communications

A well-known use of focal plane arrays is to obtain an image of a scene in various photonic bands- most commonly in the visible and infrared domains. Recent developments in colloidal quantum dot technology allow utilization of thin nano-crystals films in conjunction with detector arrays to sensitize detection outside the conventional bands. For example, downshifting PbS quantum dots have been recently demonstrated to produce an image in the UV and VIS bands using SWIR focal planes. In this paper we discuss our results as well as approaches to extend these sensitized focal planes into another mission, UV wireless communications, to achieve a dual-use capability for a conventional imager.
Photodynamic treatment of Herpes simplex virus infection in vitro.

— The effects of photodynamic action on in vitro herpes simplex virus infections of CV-1 monkey kidney fibroblasts or human skin fibroblasts were determined using proflavine sulfate and white fluorescent lamps. Photodynamic treatment of confluent cell monolayers prior to virus infection inactivated cell capacity, i.e. the capacity of the treated cells to support subsequent virus growth as measured by plaque formation. The capacity of human cells was more sensitive to inactivation than the capacity of monkey cells when 6 μM proflavine was used. Treated cell monolayers recovered the capacity to support virus plaque formation when virus infection was delayed four days after the treatment. Experiments in which the photodynamically treated monolayers were infected with UV-irradiated virus demonstrated that this treatment induced Weigle reactivation in both types of cells. This reactivation occurred for virus infection just after treatment or 4 days later. A Luria-Latarjet-type experiment was also performed in which cultures infected with unirradiated virus were photodynamically treated at different times after the start of infection. The results showed that for the first several hours of the virus infection the infected cultures were more sensitive to inactivation by photodynamic treatment than cell capacity. By the end of the eclipse period the infected cultures were less sensitive to inactivation than cell capacity. Results from extracellular inactivation of virus grown in monkey cells at 6 μM proflavine indicated that at physiological pH the virus has a sensitivity to photodynamic inactivation similar to that for inactivation of cell capacity. The combined data indicated that photodynamic treatment of the cell before or after virus infection could prevent virus growth. Thus, photodynamic inactivation of infected and uninfected cells may be as important as inactivation of virus particles when considering possible mechanisms in clinical photodynamic therapy for herpes simplex.
Simulations of limiting currents for transport of intense relativistic electron beams in conducting wave guides

Summary form only given, as follows. The limiting current for all intense magnetized relativistic electron beam injected into a grounded metal pipe is investigated with 2-D particle-in-cell code MAGIC. Results are presented for a solid, uniform current density electron beam with injected currents below and above published theoretical limiting current estimates. Transmitted currents 15% above the well known Bogdankevich-Rukhadze limiting current value are observed, consistent with other particle-in-cell simulations [3,4]. A summary of published theoretical limiting current estimates is presented. In addition, the transition between vacuum and ion-focused-regime transport, with and without an applied axial magnetic field is examined.
Compressibility of polycrystal and monocrystal copper: Acoustic-resonance spectroscopy

Using a method used mainly by geophysicists for small specimens-acousticresonance spectroscopy (ARS)-we measured the elastic-stiffness constants of centimeter-size copper specimens with rectangular-parallelepiped shapes. The polycrystal consisted of heavily twinned 75-μm crystallites. From the specimens' macroscopic resonance-vibration frequencies (midkilohertz to low-megahertz), we calculated the least-squares elastic-stiffness coefficients, two and three for the two cases. Using the same specimens, we augmented the ARS measurements with conventional pulse-echo-method measurements. Using rod specimens, we measured the Young modulus E and torsional modulus G, and we calculated the bulk modulus B. The less direct and less familiar ARS method gives the same results as a usual pulse-echo method and a rod-resonance method. The small difference between polycrystal and monocrystal values may arise from mobile twin boundaries that contribute a small reversible plastic strain to the intrinsic elastic strain. We list 16 advantages of the ARS method to measure elastic constants.
The production of chlorine atoms from the reaction of OH with chlorinated hydrocarbons

Measurements from previous studies have shown that when hydroxyl radicals react with various chlorinated hydrocarbons under atmospheric conditions, free chlorine atoms can be produced. In one such study (Edney et al., [3]) from an analysis of the rate equations under a strict set of assumptions, Cl-atom yields could be inferred. Since the approach was indirect, a more direct method for obtaining these yields has been developed. The technique described in this study involves scavenging Cl atoms produced by the reaction (using ethylene or propylene as the scavenger) and then measuring the yield of the stable chlorinated product generated. Cl-atom yields were determined for allyl chloride, vinyl chloride, vinylidene chloride, trichloroethylene, and benzyl chloride. The experiments were performed by irradiating mixtures of CH3ONO/NO/chlorinated hydrocarbon/alkene in air in 150-L Teflon chambers. The yields for the reaction of Cl atoms with the alkenes generating the stable products were determined in seperate experiments. Yields for the formation of Cl atoms upon reaction with hydroxyl radicals are as follows (with 1 σ deviation): allyl chloride: 0.37 ± 0.10, vinyl chloride: 0.04 ± 0.01, vinylidene chloride: 0.23 ± 0.09, trichloroethylene: 0.63 ± 0.34, and benzyl chloride: 0.08 ± 0.03.
Cardiac sarcolemmal KATP channels: Latest twists in a questing tale!

Reconstitution of K(ATP) channel activity from coexpression of members of the pore-forming inward rectifier gene family (Kir6.1, KCNJ8, and Kir6.2 KCNJ11) with sulfonylurea receptors (SUR1, ABCC8, and SUR2, ABCC9) of the ABCC protein sub-family, has led to the elucidation of many details of channel gating and pore properties, as well as the essential roles of Kir6.2 and SUR2 subunits in generating cardiac ventricular K(ATP). However, despite this extensive body of knowledge, there remain significant holes in our understanding of the physiological role of the cardiac K(ATP) channel, and surprising new findings keep emerging. Recent findings from genetically modified animals include the apparent insensitivity of cardiac sarcolemmal channels to nucleotide levels, and unenvisioned complexities of the subunit make-up of the cardiac channels. This topical review focuses on these new findings and considers their implications.
Solar system: When the dust unsettles

Two attempts to measure the isotopic composition of oxygen in the Sun from particles trapped in lunar soils give very different results. A rethink of why the Solar System is as it is might be required.
Towards an Understanding of the Evolution of the Chorioallantoic Placenta: Steroid Biosynthesis and Steroid Hormone Signaling in the Chorioallantoic Membrane of an Oviparous Reptile

Amniotes, mammals, reptiles, and birds form common extraembryonic membranes during development to perform essential functions, such as protection, nutrient transfer, gas exchange, and waste removal. Together with the maternal uterus, extraembryonic membranes of viviparous (live-bearing) amniotes develop as an endocrine placenta that synthesizes and responds to steroid hormones critical for development. The ability of these membranes to synthesize and respond to steroid hormone signaling has traditionally been considered an innovation of placental amniotes. However, our laboratory recently demonstrated that this ability extends to the chorioallantoic membrane (CAM) of an oviparous (egg-laying) amniote, the domestic chicken, and we hypothesized that steroidogenic extraembryonic membranes could be an evolutionarily conserved characteristic of all amniotes because of similarities in basic structure, function, and shared evolutionary ancestry. In this study, we examined steroid hormone synthesis and signaling in the CAM of another oviparous amniote, the American alligator (Alligator mississippiensis). We quantified mRNA expression of a steroidogenic factor involved in the regulation of steroidogenesis (NR5A1), the key steroidogenic enzymes involved in the synthesis of progestins (HSD3B1), androgens (CYP17A1), and estrogens (CYP19A1), and the receptors involved in the signaling of progestins (PR), androgens (AR), estrogens (ESR1 and ESR2), and glucocorticoids (GR). Furthermore, we performed protein immunolocalization for PR and ESR1. Collectively, our findings indicate that the alligator CAM has the capability to regulate, synthesize, and respond to steroid hormone signaling, thus, supporting our hypothesis that the extraembryonic membranes of Amniota share a unifying characteristic, that is, the ability to synthesize and respond to steroid hormones.
Effects of particle size and pressure on combustion of nano-aluminum particles and liquid water

Abstract The combustion wave propagation of nanoaluminum–water mixtures is studied theoretically and experimentally for particles in the size range of 38–130 nm and over a pressure range of 1–10 MPa. A multi-zone framework is established to predict the burning properties and flame structure by solving the conservation equations in each zone and enforcing the mass and energy continuities at the interfacial boundaries. The flame properties are measured by burning nanoaluminum–water strands in a constant-volume vessel. The present study deals with the downward propagating flame. Emphasis is placed on the effects of particle size and pressure. An analytical expression for the burning rate is derived, and physicochemical parameters that dictate the flame behavior are identified. For conditions present in the study, the burning rate shows pressure and particle size dependencies of the form r b [ cm / s ] = 98.8 × ( p [ MPa ] ) 0.32 ( d p [ nm ] ) - 1.0 . The flame thickness increases with increasing particle size and decreasing pressure. Results support the hypothesis that the combustion of aluminum–water mixtures is controlled by mass diffusion across the oxide layers of the particles.
Ritual, Stories, and the Poetics of a Journey Home Among Latino Catholics

This essay centers on a storyteller's performance of ritual in stories to draw associations between the life of the Biblical Mary with her son Jesus and the subjectivities and dispositions of people living in impoverished conditions. The storyteller explores these subjectivities and dispositions, characterizing the exploration as a journey. She also defines an ethical position where the self meets otherness—both sacred and cultural—to engender positive human relations. The essay combines the storyteller's performance with the author's to reproduce the effects, advance the ethics, mitigate the politics of representation, and provide an understanding of the journey's end—a place called home.
Calcitonin stimulates growth and maturation of embryonic chick pelvic cartilage in vitro.

To determine whether calcitonin (CT) affects the growth of avian embryonic skeletal tissue, pelvic cartilages from 9-day-old chick embryos were incubated in a serum-free medium containing CT for 3 days. Porcine CT (PCT), salmon CT (SCT), and human CT (HCT) stimulated increases in cartilage wet weight that were dependent upon the concentration of CT within the medium. Maximal growth was seen with PCT (1.0 U/ml), which increased cartilage wet weight 107% and dry weight 53% above those of cartilage incubated in medium alone. SCT (1.0 U/ml) and HCT (1.0 U/ml) stimulated a 55% increase in cartilage wet weight and a 20% increase in cartilage dry weight over those of cartilage incubated in medium alone. The reason for PCT’s apparent potency was due to trace contamination of thyroid hormone in the PCT preparation, since synthetic PCT caused an increase in cartilage wet weight equivalent to those produced by SCT and HCT. Although each calcitonin increased wet and dry cartilage weights, the DNA content was not chan...
Metamorphic petrology of a high‐pressure, low‐temperature subduction complex in west‐central Baja California, Mexico

The Western Baja terrane (WBt) of west-central Baja California is an uplifted subduction complex that is divided into smaller ‘subterranes’on the basis of bounding faults and petrological differences. Each subterrane contains coherent Early Jurassic to Early Cretaceous sedimentary and mafic volcanic rocks (not melange) that have been metamorphosed under blueschist facies conditions. Key phases in metabasites and metaturbidites include jadeitic to acmitic clinopyroxene, sodic amphibole, lawsonite, aragonite, chlorite, titanite and white mica. Pressure indicators include the jadeite content of clinopyroxene and the presence of aragonite. Temperature indicators include the presence of lawsonite, the absence of greenschist facies minerals and results from vitrinite reflectance studies. Conditions at the peak of metamorphism were >8 kbar, 225–325°C for subterrane 1, 7–8 kbar, 170–220°C for subterrane 2, and 5–6 kbar, 175–200°C for subterrane 3; these correspond to cold geothermal gradients (6–9/km). Vein assemblages that include aegerine–jadeite and aegerine, albite, aragonite, lawsonite and sodic amphibole indicate uplift during continued cold conditions, probably during steady-state subduction.
Optimal capacity expansion for multi-product, multi-machine manufacturing systems with stochastic demand

We consider a discrete-time capacity expansion problem involving multiple product families, multiple machine types, and non-stationary stochastic demand. Capacity expansion decisions are made to strike an optimal balance between investment costs and lost sales costs. Motivated by current practices in the semiconductor and other high-tech industries, we assume that only minimal amounts of finished-goods inventories are held, due to the risk of obsolescence. We assume that when capacity is in short supply, management desires to ensure that a minimal service level for all product families is obtained. Our approach uses a novel assumption that demand can be approximated by a distribution whose support is a collection of rays emanating from a point and contained in real multi-dimensional space. These assumptions allow us to solve the problem as a max-flow, min-cut problem. Computational experiments show that large problems can be solved efficiently.
Heat stability of fungal pectolytic enzymes

Studies on the endopolygalacturonases (endo-PGs) produced by Rhizopus. and Mucor species showed a similar pattern of production of isoenzymes in both apricot and strawberry tissue, although the relative proportion of the isoenzymes varied between fruits. The endo-PGs showed maximum activity between 40 and 60°C and all of the isoenzymes were able to macerate fruit tissue. The major isoenzymes were very heat-stable, retaining activity after heating for 10 min at 100 and 120°C, and many showed a bimodal inactivation, being least stable at 50–60°C. Therefore, the presence of heat-stable and heat-labile isoenzymes did not account for the marked difference in the heat stability of endo-PGs when heated in tissue of apricot and strawberry. This difference is considered to be due to the phenolics present in strawberry tissue, since the endo-PGs showed similar heat stability to those produced in apricot, when strawberry tissue was treated with polyvinylpolypyrrolidone or polyamide (known phenol-absorbing compounds) prior to heating. A similar effect could be obtained by treating strawberry extracts with apricot tissue prior to heating but the mechanism whereby this was achieved is not clear. The bimodal inactivation was maintained after purification of the endo-PGs by ammonium sulphate precipitation, DEAE-cellulose and Sephadex G-100 chromatography which also removed any detectable protease activity. It is suggested, therefore, that inactivation at 50–60°C is not caused by proteolytic activity but is due to conformational changes known to occur in proteins at about 55 °C.
Risk assessment of post-wildfire hydrological response in semiarid basins: the effects of varying rainfall representations in the KINEROS2/AGWA model

Representation of precipitation is one of the most difficult aspects of modelling post-fire runoff and erosion and also one of the most sensitive input parameters to rainfall-runoff models. The impact of post-fire convective rainstorms, especially in semiarid watersheds, depends on the overlap between locations of high-intensity rainfall and areas of high-severity burns. One of the most useful applications of models in post-fire situations is risk assessment to quantify peak flow and identify areas at high risk of flooding and erosion. This study used the KINEROS2/AGWA model to compare several spatial and temporal rainfall representations of post-fire rainfall-runoff events to determine the effect of differing representations on modelled peak flow and determine at-risk locations within a watershed. Post-fire rainfall-runoff events at Zion National Park in Utah and Bandelier National Monument in New Mexico were modelled. Representations considered included both uniform and Soil Conservation Service Type II hyetographs, applying rain over the entire watershed and applying rain only on the burned area, and varying rainfall both temporally and spatially according to radar data. Results showed that rainfall representation greatly affected modelled peak flow, but did not significantly alter the model’s predictions for high-risk locations. This has important implications for post-fire assessments before a flood-inducing rainfall event, or for post-storm assessments in areas with low-gauge density or lack of radar data due to mountain beam blockage.
Nash equilibria of a generic networking game with applications to circuit-switched networks

A generic mechanism for end-user transmission rate control into a differentiated services Internet is formulated and basic results of corresponding Nash equilibria are proved. We consider specific examples of the mechanism including additive increase and multiplicative decrease inspired by present day TCP congestion control. For the example of users sharing access to a bandwidth resource via resizable provisioned label-switched paths (MPLS), we study the equilibria and the performance of the generic mechanism and give analytical results on convergence to equilibria. The fairness of the resulting equilibria when user demands exceed available network resources is also studied.
A new image registration scheme based on curvature scale space curve matching

We propose a new image registration scheme for remote sensing images. This scheme includes three steps in sequence. First, a segmentation process is performed on the input image pair. Then the boundaries of the segmented regions in two images are extracted and matched. These matched regions are called confidence regions. Finally, a non-linear optimization is performed in the matched regions only to obtain a global set of transform parameters. Experiments show that this scheme is more robust and converges faster than registration of the original image pair. We also develop a new curve-matching algorithm based on curvature scale space to facilitate the second step.
Pragmatists and Purists on CPT Invariance in Relativistic Quantum Field Theories

An influential claim in the physics literature states that the violation of CPT invariance in an interacting RQFT entails the violation of Lorentz invariance. This claim is surprising since standard proofs of the CPT theorem require more assumptions than Lorentz invariance, and are restricted to non-interacting, or at best, unrealistic interacting theories. This essay analyzes this claim in the context of the debate between pragmatist approaches to RQFTs, which trade mathematical rigor for the ability to derive predictions from realistic interacting theories, and purist approaches, which trade the ability to formulate realistic interacting theories for mathematical rigor.