cssi/SciSciGPT-SciSciNet huggingface dataset:
1/f noise characteristics of InP/InGaAs heterojunction bipolar transistors

The short-circuit noise characteristics of InGaAs/InP HBTs (heterojunction bipolar transistors) have been characterized in terms of frequency, bias, geometry, and temperature. Frequency dependence characteristics showed essentially 1/f noise behavior for both the collector noise spectra, S/sub IC/(f), and the base noise spectra, S/sub 1B/(f). A decrease was observed at high frequencies which was determined to be due to shallow traps with activation energy=0.07-0.1 eV. Extrapolated results estimate that the transition frequency could be as high as 100 MHz. S/sub IB/ is probably due to recombination noise. The origin of S/sub IC/ is not clear, but at low bias it seems to be due to recombination. Geometry studies revealed that the perimeter to area ratio does not have a significant effect on InP-based HBT noise. Preliminary emitter area studies have shown that the S/sub IC/ is a function of emitter area at low J/sub C/. >
A paradigm for distributed deadlock avoidance in multicomputer networks

A paradigm for avoiding buffer deadlock in point-to-point multicomputer networks is presented which is ideal for today's high connectivity, load sharing networks. Unlike the traditional resource ordering principle, this paradigm not only allows unrestricted routing but uses the existence of multiple paths to its direct advantage. Deadlock is avoided entirely using exchange buffers which are not used for message queues, thus eliminating queueing overhead. The paradigm is topology-independent, imposes no routing restrictions, and uses states of neighboring links only, so that it can be built into link level protocol, providing unrestricted deadlock-free routing, while operating transparent to any fault-tolerant topology-specific routing algorithm. >
“Chromoseratops meiosus”A Simple, Two-Phase Exercise to Represent the Connection between Meiosis & Increased Genetic Diversity

I present an activity to help students make the connection between meiosis and genetic variation. The students model meiosis in the first phase of the activity, and by that process they produce gametes of a fictitious reptilobird species, “Chromoseratops meiosus.” Later on, they will “mate” their gametes and produce a zygote and a resulting reptilobird. They will determine the phenotype of the resulting reptilobird and draw it. As they compare their reptilobirds, they will be able to see all the resulting variations and to discuss the sources of this variation. This activity can be easily used as a basis for sequel activities that will emphasize the implications of genetic variation on natural and sexual selection.
Genetically Engineered Models Have Advantages over Xenografts for Preclinical Studies

Mouse models of human cancer are valuable tools for cancer research. Although xenografts and genetically engineered models (GEMs) possess limitations as well as advantages, each system plays a significant role in preclinical testing. Tumor xenografts are easy to use, relatively inexpensive, and reproducible. The main drawback of xenografts is that the genetics and histology of the tumors are frequently not representative of the respective human tumor and, thus far, these models have not been as predictive of therapeutic success as one would like. By contrast, GEMs are histologically and genetically accurate models of human cancer but have disadvantages of heterogeneity with regard to frequency, latency, and growth. These disadvantages are reminiscent of the variable behavior of actual human tumors. Recently, these shortcomings have been partly overcome with the development of anatomic and molecular in vivo imaging techniques such as magnetic resonance imaging and bioluminescence imaging. These new technologies will hopefully support the use of GEMs in preclinical trials and help determine if trials in GEMs are more predicative than xenografts of human responses.
Pippin's Hegel on Action

Abstract This essay is a commentary on and critique of the conception of human activity that Robert Pippin attributes to Hegel in his recent book, Hegel's Practical Philosophy. Two principal features of this conception are that it treats human activity as indeterminate and that it construes what someone does and why on a given occasion as depending on social contexts. Pippin suggests that these two features will sound strange to contemporary philosophers. The essay claims, by contrast, that these features will not sound strange to philosophers who advocate one of a small family of other accounts that espouse these two ideas. The essay argues, further, that certain such accounts, namely, ones inspired by Heidegger and Wittgenstein, are more promising accounts of human activity than is Hegel's. The bulk of the essay explores the indeterminacy of activity and the dependency of activity on social context as these are analyzed in Pippin's book and in Heidegger and Wittgenstein.
Enzymatic oxidation of alpha-1-proteinase inhibitor in abnormal tissue turnover.

The development of pulmonary emphysema and rheumatoid arthritis is currently believed to be due to uncontrolled proteolysis by elastolytic enzymes, as a result of a deficiency in controlling proteinase inhibitors. This deficiency may arise from a number of factors, including genetically controlled improper synthesis, turnover by proteolytic enzymes not inactivated by these inhibitors, and oxidative inactivation in the case of the major plasma inhibitor, a-l-proteinase inhibitor (α-1-PI).
Identification of annexin VI as a Ca2+-sensitive CRHSP-28-binding protein in pancreatic acinar cells.

CRHSP-28 is a member of the tumor protein D52 protein family that was recently shown to regulate Ca2+-stimulated secretory activity in streptolysin-O-permeabilized acinar cells (Thomas, D. H., Taft, W. B., Kaspar, K. M., and Groblewski, G. E. (2001)J. Biol. Chem. 276, 28866–28872). In the present study, the Ca2+-sensitive phospholipid-binding protein annexin VI was purified from rat pancreas as a CRHSP-28-binding protein. The interaction between CRHSP-28 and annexin VI was demonstrated by coimmunoprecipitation and gel-overlay assays and was shown to require low micromolar levels of free Ca2+, indicating these molecules likely interact under physiological conditions. Immunofluorescence microscopy confirmed a dual localization of CRHSP-28 and annexin VI, which appeared in a punctate pattern in the supranuclear and apical cytoplasm of acini. Stimulation of cells for 5 min with the secretagogue cholecystokinin enhanced the colocalization of CRHSP-28 and annexin VI within regions of acini immediately below the apical plasma membrane. Tissue fractionation revealed that CRHSP-28 is a peripheral membrane protein that is highly enriched in smooth microsomal fractions of pancreas. Further, the content of CRHSP-28 in microsomes was significantly reduced in pancreatic tissue obtained from rats that had been infused with a secretory dose of cholecystokinin for 40 min, demonstrating that secretagogue stimulation transiently alters the association of CRHSP-28 with membranes in cells. Collectively, the Ca2+-dependent binding of CRHSP-28 and annexin VI, together with their colocalization in the apical cytoplasm, is consistent with a role for these molecules in acinar cell membrane trafficking events that are essential for digestive enzyme secretion.
Stellar activity on the lower main sequence in Praesepe

An αΩ dynamo is considered responsible for magnetic activity in late K/early M main sequence stars, which is expected to be enhanced in later types as the surface convection zone deepens. At about spectral type M3, where the star presumably becomes fully convective, the magnetic field is theorized to change in character, switching to a more uniform, turbulence-generated surface field. As a consequence, the nature of activity is expected to change at later spectral types. In field stars, age, mass, rotation and perhaps metallicity play a role in determining the activity level, but the effects are difficult to disentangle. Therefore, open clusters with a more homogeneous sample can provide valuable information on the dynamo operation and magnetic activity of lower main sequence stars. We present preliminary results of our spectroscopic study for activity indicators among the lower main sequence stars of the intermediate age (700 My) open cluster Praesepe. Chromospheric activity as manifested by the presence/absence of Hα in late K/M stars is presented, and other activity indicators are discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
The Discovery of Chemical Neurotransmitters

Neurotransmitters have become such an intrinsic part of our theories about brain function that many today are unaware of how difficult it was to prove their existence or the protracted dispute over the nature of synaptic transmission. The story is important not only because it is fascinating science history, but also because it exemplifies much of what is best in science and deserving to be emulated. The friendships formed among such major figures in this history as Henry Dale, Otto Loewi, Wilhelm Feldberg, Walter Cannon, and others extended over two world wars, enriching their lives and facilitating their research. Even the dispute-the "war of the sparks and the soups"--between neurophysiologists and pharmacologists over whether synaptic transmission is electrical or chemical played a positive role in stimulating the research needed to provide convincing proof.
Disorders of hyperpigmentation.

Hyperpigmentation of the skin is a common complaint among patients consulting with dermatologists. The majority of the world's population is brown-skinned, and an enormous amount of interest worldwide is focused on restoring hyperpigmented skin to its natural color by skin care specialists. Treatment of hyperpigmentation disorders, however, is often difficult and prolonged, requiring a great deal of patience and knowledge of a variety of therapeutic modalities to achieve success. Over the past decade, a variety of new treatments have been developed for disorders of hyperpigmentation.
Safety and efficacy of aspirin, clopidogrel, and warfarin after coronary stent placement in patients with an indication for anticoagulation.

Abstract Background Dual antiplatelet therapy with aspirin and clopidogrel has replaced aspirin and systemic anticoagulation with warfarin as the preferred antithrombotic therapy after percutaneous coronary intervention (PCI) with stent placement. However, a number of patients have indications for all 3 drugs. We sought to determine the frequency and type of hemorrhagic complications in patients who undergo systemic anticoagulation with warfarin while receiving aspirin and clopidogrel after a PCI with stent placement. Methods We performed a retrospective analysis of the Mayo Clinic PCI database and identified 66 consecutive patients who were discharged from hospital after PCI between January 2000 and August 2002 (inclusive) receiving a combination of dual antiplatelet therapy (aspirin and clopidogrel) and systemic anticoagulation (warfarin) to determine the incidence of bleeding and other clinical events during the treatment period. Results Six patients (9.2%; 95% CI, 3.5–19.0) reported a bleeding event; 2 patients required a blood transfusion. No patient died or sustained a myocardial infarction or stent thrombosis. Conclusions The risk of bleeding may be increased in patients treated with aspirin, a thienopyridine, and warfarin early after PCI with stent placement.
The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1

Bacteria expand their genetic diversity, spread antibiotic resistance genes, and obtain virulence factors through the highly coordinated process of conjugative plasmid transfer (CPT). A plasmid-encoded relaxase enzyme initiates and terminates CPT by nicking and religating the transferred plasmid in a sequence-specific manner. We solved the 2.3 A crystal structure of the relaxase responsible for the spread of the resistance plasmid pCU1 and determined its DNA binding and nicking capabilities. The overall fold of the pCU1 relaxase is similar to that of the F plasmid and plasmid R388 relaxases. However, in the pCU1 structure, the conserved tyrosine residues (Y18,19,26,27) that are required for DNA nicking and religation were displaced up to 14 A out of the relaxase active site, revealing a high degree of mobility in this region of the enzyme. In spite of this flexibility, the tyrosines still cleaved the nic site of the plasmid's origin of transfer, and did so in a sequence-specific, metal-dependent manner. Unexpectedly, the pCU1 relaxase lacked the sequence-specific DNA binding previously reported for the homologous F and R388 relaxase enzymes, despite its high sequence and structural similarity with both proteins. In summary, our work outlines novel structural and functional aspects of the relaxase-mediated conjugative transfer of plasmid pCU1.
Surface chemistry of a microcoated energetic material, pentaerythritoltetranitrate (PETN)

A microcoating technique was used to apply a polymer to an energetic explosive material. The explosive was pentaerythritoltetranitrate (PETN), and the coating was a copolymer consisting of vinylchloride/trifluorochloroethylene in a 1.5/1.0 molecular ratio. X-ray photoelectron spectroscopy (XPS) and ion scattering spectroscopy (ISS) were used to study the surface and interfacial chemistry of PETN powders and pellets made from compressed powders having either 0.5 or 20 wt% coating. Two simple models were used to discuss the nature of the copolymer film on the PETN. Model I shows the copolymer completely coating PETN; Model II depicts the copolymer as only partially covering PETN. Model II was applicable in explaining the 0.5 and 20 wt% microcoating of powders, as well as the 0.5 wt% coated pellets. However, the pellets with 20 wt% coating showed the copolymer to completely coat PETN (Model I), suggesting copolymer redistribution during pelletization. XPS and ISS results showed the copolymer film to be thin. An XPS expression modified to accommodate ISS data was developed for the calculation of the average copolymer thickness of PETN. The thicknesses were determined to be 10 A and 6 A for 0.5 wt% coated PETN powders and pellets, respectively. Bonding between the copolymer and PETN was concluded to be mechanical.
Consent, coercion, and limit: The medieval origins of parliamentary democracy

(1990). Consent, coercion, and limit: The medieval origins of parliamentary democracy. History of European Ideas: Vol. 12, No. 2, pp. 291-292.
Integral cross section for electron-impact excitation of the 3p53d states of argon

Theoretical close-coupling R-matrix and two different first-order distorted-wave Born approximation (DWBA) calculations are presented for excitation of argon from its ground state to the twelve states in the (3p53d) manifold. The results are found to be very sensitive to the choice of atomic wavefunctions. The low-energy R-matrix results in general and, in several cases, the unitarized DWBA as well as the high-energy DWBA results are in fair agreement with the experimental data of Chilton and Lin (1999 Phys. Rev. A 60 3712).
Reflectance anisotropy of Upper Carboniferous coals in the Appalachian foreland basin, Pennsylvania, U.S.A.

Abstract Patterns of vitrinite reflectance anisotropy in coal are represented by a three-dimensional graphical form resembling an ellipsoid, termed the vitrinite reflectance indicating surface (VRI). Naturally occurring VRIs from the Northern Appalachian basin, Pennsylvania, range in shape from biaxial negative to biaxial positive depending on their coalification history and tectonic setting. VRI shapes are measured by estimating the magnitudes of the three principal reflectances, Rmax, Rint, and Rmin, either on oriented blocks or non-oriented grain mounts. Spatial orientations of the principal axes are determined by reflectance measurements on oriented polished cores. The various VRI shapes are portrayed on axial ratio diagrams, i.e. plots of R max R int on the vertical axis and R int R min on the horizontal axis. Axial ratio diagrams are also used to depict the progressive change in VRI shape with coalification. Standard deviations of the principal reflectance axes, as measured on oriented cores, average around 0.09% in magnitude and 5° in orientation. Measurements are highly reproducible between pairs of oriented cores. Estimates of the principal reflectance magnitudes, as measured on oriented vs. non-oriented samples, agree on average to within 0.04% for Rmax, 0.08% for Rint, and 0.20% for Rint. Coal-bearing strata in the North-Central coal fields (medium-volatile bituminous coal to semianthracite), in northern Pennsylvania were diagenetically altered in a predominantly burial-strain environment and exhibit structural evidence of only mild tectonic deformation. VRIs from this suite of coals are biaxial negative with Rmin axes roughly perpendicular to bedding. With increasing rank toward the southeast, these VRIs plot along a straight line pathway on the axial ratio diagram, emanating from near the origin and extending through the biaxial negative deformation field. VRIs of coals from the Western Middle anthracite field exhibit a wide range of shapes and orientations, which is indicative of a more complex tectonic history. In their present-day orientation, Rmin axes are scattered about a great circle distribution, the pole to which is precisely coincident with regional fold axes. When beds are unfolded to a flat-lying orientation they become significantly less scattered, indicating that most coalification here preceded the final phase of Alleghanian folding. Rmax axes of sporinite grains are alwayas aligned parallel to bedding, which suggests that the strata were still flat-lying, and not subject to tectonic forces, when the coals passed through the 1st and 2nd “coalification jumps”.
Regulating Inclusion: Spatial Form, Social Process, and the Normalization of Cycling Practice in the USA

AbstractIn recent years, bicycle infrastructure has been emerged as a valued part of urban development policy in many American cities, and a process that depends on the normalization of cycling practice in three respects. First, the various ‘less confrontational’ mutations of Critical Mass have redefined the politics of cycling in cultural and consumerist terms. Second, this ‘bike culture’ is mediated through Internet networks that generate concepts of proper cycling practice. Third, both spatial models and standards of ‘correct’ ridership circulate through these networks, linking ‘bike culture’ to institutional networks of implementation. While positive from the standpoint of increased ridership, this may reinscribe the exclusions that are constitutive of the contemporary American city and may limit cycling’s egalitarian potential.
A Longitudinal Assessment of Hormonal and Physical Alterations during Normal Puberty in Boys. V. Rising Leptin Levels May Signal the Onset of Puberty

Leptin, the product of the ob gene, is an adipocyte-derived hormone that signals the amount of adipose tissue energy stores to the brain and exerts major effects on energy homeostasis and neuroendocrine function. Leptin has recently been shown to affect reproductive function in leptin-deficient and normal rodents. As puberty, the process of sexual maturation and acquisition of reproductive competence, has been proposed to be triggered by the attainment of a critical amount and/or distribution of fat, we examined whether changes in circulating leptin levels could represent the hormonal signal responsible for triggering the onset of puberty in humans. Eight prepubertal boys (Tanner genital stage 1 or early stage 2 at the initiation of the study) were evaluated longitudinally for 2.5-5.1 yr depending on when Tanner stage 5 of genital development was achieved. Sera for the determination of leptin, testosterone, and dehydroepiandrosterone sulfate were obtained every 4 months during the period of the study. Compared to baseline prepubertal levels (8 months before the onset of puberty, as defined by the initial rise in testosterone above the detection limit of the assay), leptin levels rose by approximately 50% just before the onset of puberty and decreased to approximately baseline values after the initiation of puberty (P < 0.01, by ANOVA), remaining stable for more than 2 yr. These changes occurred despite constantly increasing body mass index (P < 0.05, by ANOVA). No significant association between leptin and dehydroepiandrosterone sulfate concentrations was detected. In conclusion, the levels of circulating leptin are consistent with the hypothesis that this molecule is an important signal responsible for triggering the onset of puberty. The stimulus for a surge in leptin levels just before the onset of puberty is currently unknown.
Practice patterns for surveillance of Barrett's esophagus in the united states.

Abstract Background: Endoscopic surveillance of Barrett's esophagus is recommended to detect dysplasia or cancer at an early and potentially treatable stage. However, little is known about the clinical practice patterns for endoscopic surveillance in the United States. Methods: A questionnaire regarding surveillance intervals, techniques and management approaches for patients with Barrett's esophagus was mailed to 1000 randomly selected members of the Clinical Practice Section of the American Gastroenterological Association. Results: The response rate was 455 of 1000 (45%). Not all respondents answered all questions. Seventy-nine percent of respondents were in community practices, and 21% were in academic practices. Nearly all (96%) performed endoscopic surveillance, but it was practiced more commonly in the community (334 of 341 [98%]) than in the academic setting (83 of 93 [89%], p Conclusions: Surveillance for Barrett's esophagus is widely practiced in the United States but there is considerable variation in interval and technique. A clearer consensus on endoscopic surveillance is warranted to optimize care of patients with Barrett's esophagus. (Gastrointest Endosc 2000;52:197-203.)
Differences in Allelic Protein Expression in the Milk of Heterozygous κ-Casein Cows

Abstract The objective of this study was to determine whether heterozygous κ-casein AB cows express the A and B proteins in equal quantities in their milk. Milk samples were collected from 148 heterozygous κ-casein cows. Chymosin was added to casein isolated from the milk samples to liberate the κ-casein A and B macropeptides. Alkaline urea PAGE was used to separate and resolve the A and B macropeptide bands. These bands were quantified using densitometric tracings of the gel. Densitometric values were verified by quantification of the bands using amino acid analyses. There was a greater proportion of the total κ-casein macropeptide located in the protein band derived from the κ-casein B allele, suggesting that this allele does have an elevated level of protein expression in the bovine mammary gland. This supports previous findings that the proportion of κ-casein in milk is related to the κ-casein genotype BB > AB > AA. It would be of interest to know the cause of this increased expression because of the importance of the κ-casein protein on the manufacturing properties of milk.
Wavelet Analysis of Cirrus Multiscale Structures from Lidar Backscattering : A Cirrus Uncinus Complex Case Study

Abstract Although cirrus cloud structures play an important role in dynamics issues, cloud radiative calculations, and cloud parameter retrievals from satellite measurements, fully understanding cirrus cloud structures still remains a challenge. A case study of a cirrus containing mesoscale uncinus complexes (MUC) with a two-layer structure observed by a high-resolution lidar is presented using the method based on wavelet transform. The results indicate that dynamical processes play a leading role in determining cloud multiscale structures. The uncinus cells with a length scale on the order of ∼1 km, embedded in both the top and lower layers, have similar spectral features and are probably produced by a similar mechanism—thermal perturbation generated by heating and cooling effects associated with phase changes of water (i.e., adiabatic heating) and radiative processes. However, the mesoscale cloud patches are probably involved in different dynamics processes, suggesting that understanding of the interact...
Oxidation Performance of High Temperature Mo-Si-B Alloys and Coatings

Mo-Si-B alloys are attractive due to their high temperature mechanical properties and high melting temperature. The oxidation of multiphase alloys develops in two distinct stages. First, there is a transient stage that corresponds to the evaporation of the volatile MoO3 and to an initial high recession rate. The steady state stage of the oxidation begins when the slower forming borosilicate layer becomes continuous and inhibits further rapid oxidation. Then, the oxidation rate is limited by oxygen diffusion through the borosilicate layer. In order to inhibit the transient stage, a coating strategy has been developed to capitalize on the interdiffusion reactions and to employ a kinetic bias to modify interface reaction products in order to maximize the high temperature stability and performance. In order to achieve a compatible interface coating together with enhanced oxidation resistance, a pack cementation process has been adopted to synthesize metal-rich silicide and borosilicide surface layers. The analysis of the enhanced oxidation performance indicates that a strategy based upon the operating principles of interface reactions in multicomponent systems is effective for developing stable and robust coating systems.
Level Crossings of an Oscillating Marked Random Walk

This paper deals with a class of real-valued random-walk processes, observed over random epochs of time, that forms a delayed renewal process. The present model does not restrict this class to a merely monotone random walk, which is easier to analyze and find explicit form functional. The objective is to find the first passage of the process exiting a rectangular set and registering the value of the process at this time, thus generalizing past models where either the observed process was monotone or the first passage time reduced to the moment of the first drop. The joint transformation of the named random characteristics of the process are derived in a closed form. The paper concludes with examples, including numerical examples, demonstrating the use of the results as well as practical applications to finance.
Adsorption of a polyfunctional surface-active amine accelerator on hydroxyapatite☆

Abstract Adsorption of a polyfunctional surface-active amine polymerization accelerator (“PolySAM-1”) from chloroform solutions on synthetic hydroxyapatite is exhaustive and completely irreversible from very dilute solutions. The adsorption is irreversible until the formation of a “monomolecular layer,” at which point the additional adsorption is reversible. At relatively low equilibrium concentrations the adsorption is not exhaustive and the isotherm is linear. Adsorption isotherms of the adsorbate which is reversibly bound and of the adsorbate on a hydroxyapatite sample containing a preadsorbed monolayer of the same are identical and follow the Langmuir plot. Evidence shows that the irreversibly adsorbed material is probably chemisorbed. The tensile strength of a polymer, filled with synthetic hydroxyapatite having an adsorbed monolayer of PolySAM-1, did not exceed that of the polymer filled with untreated apatite for any of the polymerization-initiating systems that were studied. This implies that tertiary aromatic amine accelerators of this type do not form free radical sites capable of initiating or terminating significant graft polymerization under these conditions after their reaction with benzoyl peroxide.
Analytic model of a passive vapor transport heating system

Abstract After reviewing passive systems for downward transprot of heat, this article presents an approximate mathematical model for one particular system in which refrigerant that is evaporated in a solar collector transports heat to a condenser located at some arbitrary elevation below the collector. The vapor pressure lifts the liquid from the condenser to an accumulator above the collector, from which it periodically flows into the collector. It is shown that the maximum energy delivery to the condenser can occur when the accumulator loses a specified amount of energy to the environment. Use of one of the ordinary refrigerants as the working fluid should be appropriate for passive space- or water-heating systems in which the collector can be several meters above the condenser.
Exploiting phase inter-dependencies for faster iterative compiler optimization phase order searches

The problem of finding the most effective set and ordering of optimization phases to generate the best quality code is a fundamental issue in compiler optimization research. Unfortunately, the exorbitantly large phase order search spaces in current compilers make both exhaustive as well as heuristic approaches to search for the ideal optimization phase combination impractical in most cases. In this paper we show that one important reason existing search techniques are so expensive is because they make no attempt to exploit well-known independence relationships between optimization phases to reduce the search space, and correspondingly improve the search time. We explore the impact of two complementary techniques to prune typical phase order search spaces. Our first technique studies the effect of implicit application of cleanup phases, while the other partitions the set of phases into mutually independent groups and develops new multi-stage search algorithms that substantially reduce the search time with no effect on best delivered code performance. Together, our techniques prune the exhaustive phase order search space size by 89%, on average, (96.75% total search space reduction) and show immense potential at making iterative phase order searches more feasible and practical. The pruned search space enables us to find a small set of distinct phase sequences that reach near-optimal phase ordering performance for all our benchmark functions as well as to improve the behavior of our genetic algorithm based heuristic search.
On Boundary Conditions for Acoustic Computations in Non-Uniform Mean Flows

Many acoustic problems involve acoustic wave radiation to the exterior field. A common approach in numerical simulations is to restrict the computational domain to a finite region with artificial boundaries. The so-called radiation or non-reflecting boundary conditions must be imposed at those artificial boundaries. Most existing non-reflecting boundary conditions are derived for computing disturbances propagating in a known uniform mean flow near the boundaries. In many applications such as the computation of jet noise or turbofan noise, the mean flow at an artificial boundary is non-uniform and unknown. The mean flow also needs to be computed in these cases. Incorrect computation of this mean flow at the boundary could directly affect the near field physics as well as the far field acoustics. In the present paper, a set of boundary conditions is proposed which focuses on computing the correct mean solution at an artificial boundary, while still maintaining the non-reflecting feature for the outgoing transient and acoustic waves.
Can Online Videos Increase Turnout? A Field Experiment Testing the Effect of Peer-Created Online Videos on Youth Turnout

Previous field experimental studies of the effects of e-mails on turnout show that e-mails are not effective at boosting turnout, even among populations that frequently use e-mail. However, these studies have primarily relied on text-only e-mails. The authors attempt to increase registration and turnout among university undergraduates by sending them videos created by fellow students encouraging students to register and vote. These videos are created by peers, are more engaging than text, and may appeal to individuals who are not likely to vote anyway. Field experimental results show that sending a video by e-mail did not increase registration or turnout. The authors conclude with a discussion of other methods that may be effective in increasing turnout in an online campaign.
Dry matter content of apical and basal portions of Russet Burbank potatoes

Studies were made over a 4-year period of some factors affecting the dry matter content of the apical and basal portions of growing Russet Burbank potatoes. The greatest difference between portions was obtained from tubers of the normally irrigated plots of 1969. The amounts in the two portions in 1970 were nearly equal throughout the growing season. The major differences between the 2 years was a slightly cooler June and warmer maximum temperatures in July of the 1970 growing season. Moisture stress, particularly, early in the stage of tuber development (1972 season) caused a switch in amount of dry matter in the apical and; basal portions. Stress later in the development stage (1969 season) did not cause a switch. Fertility level was not as influential as moisture stress in affecting the ratio of dry matter in the two ends, whether under stress or normal moisture conditions.
Predicting the risk of abrupt vessel closure after angioplasty in an individual patient.

Abstract Objectives. We proposed to examine the relation between angiographic morphologic characteristics and abrupt closure after coronary angioplasty and to develop an empirically based risk stratification system. Background. Certain lesion morphologic characteristics are associated with higher rates of abrupt closure after coronary angioplasty. Previous approaches have been limited by relatively small sample sizes and an inability to combine multiple characteristics to predict risk in an individual patient. Methods. Lesion morphology was determined for 779 lesions in 658 patients undergoing an elective first angioplasty. Abrupt closure occurred in 63 lesions (8.1%). Variables associated with abrupt closure were identified by univariate and stepwise multiple logistic regression analysis, and internal validity was assessed by use of bootstrapping. An empirically based scoring system was developed by assigning diferent weights to each predictive characteristic and was then validated. Results. Almost all lesion characteristics previously labeled “adverse” were associated with an increased risk of abrupt closure, but only total occlusion, location at a branch point, increasing lesion length, evidence for thrombus and right coronary artery location were statistically significant independent predictors. Despite the large sample size, the study was underpowered to detect even a 50% increase in risk with many characteristics. Using a scoring system, we assigned each lesion a specific risk of abrupt closure. The distribution of risk was broad, with 20% of patients having ≤2.5% risk and 25% having >10% risk. Internal validation techniques revealed that when 10% of patients were randomly eliminated from the sample in multiple iterations, the risk estimates varied, again pointing to the need for a larger sample. Conclusions. Empirically based weighting of lesion characteristics could quantify the risk of abrupt closure for individual patients, but a very large sample will be required to understand the interplay of complex lesion characteristics in altering expected outcomes.
Computer modeling for smoke control design

The concept of using pressurization to control smoke movement in building fire situations has developed considerably over the past decade and a half. This paper discusses a steady state, network, airflow computer model which can be used for smoke control system design. Assumptions, equations and numerical solution technique are presented. An example problem also is included.
Genome-wide DNA methylation analysis of Haloferax volcanii H26 and identification of DNA methyltransferase related PD-(D/E)XK nuclease family protein HVO_A0006

Restriction-modification (RM) systems have evolved to protect the cell from invading DNAs and are composed of two enzymes: a DNA methyltransferase and a restriction endonuclease. Although RM systems are present in both archaeal and bacterial genomes, DNA methylation in archaea has not been well defined. In order to characterize the function of RM systems in archaeal species, we have made use of the model haloarchaeon Haloferax volcanii. A genomic DNA methylation analysis of H. volcanii strain H26 was performed using PacBio single molecule real-time (SMRT) sequencing. This analysis was also performed on a strain of H. volcanii in which an annotated DNA methyltransferase gene HVO_A0006 was deleted from the genome. Sequence analysis of H26 revealed two motifs which are modified in the genome: Cm4TAG and GCAm6BN6VTGC. Analysis of the ∆HVO_A0006 strain indicated that it exhibited reduced adenine methylation compared to the parental strain and altered the detected adenine motif. However, protein domain architecture analysis and amino acid alignments revealed that HVO_A0006 is homologous only to the N-terminal endonuclease region of Type IIG RM proteins and contains a PD-(D/E)XK nuclease motif, suggesting that HVO_A0006 is a PD-(D/E)XK nuclease family protein. Further bioinformatic analysis of the HVO_A0006 gene demonstrating that the gene is rare among the Halobacteria. It is surrounded by two transposition genes suggesting that HVO_A0006 is a fragment of a Type IIG RM gene, which has likely been acquired through gene transfer, and affects restriction-modification activity by interacting with another RM system component(s). Here, we present the first genome-wide characterization of DNA methylation in an archaeal species and examine the function of a DNA methyltransferase related gene HVO_A0006.
Phenotypic analysis of a temperature sensitive mutant in the large subunit of the vaccinia virus mRNA capping enzyme

The heterodimeric vaccinia virus mRNA capping enzyme is a multifunctional enzyme, encoded by genes D1R and D12L. Published biochemical experiments demonstrate that, in addition to mRNA capping, the enzyme is involved in early viral gene transcription termination and intermediate viral gene transcription initiation. This paper presents the phenotypic characterization of Dts36, a temperature sensitive mutant in the large subunit of the mRNA capping enzyme (G705D), encoded by gene D1R. At the non-permissive temperature, Dts36 displays decreased steady state levels of some early RNAs, suggesting a defect in mRNA capping. Mutant infections also show decreased steady state levels of some early proteins, while DNA replication and post-replicative gene expression are absent. Under non-permissive conditions, the mutant directs synthesis of longer-than-normal early mRNAs from some genes, demonstrating that early gene transcription termination is defective. If mutant infections are initiated at the permissive temperature and shifted to the non-permissive temperature late during infection, steady state levels of intermediate gene transcripts decrease while the levels of late gene transcripts remain constant, consistent with a defect in intermediate gene transcription initiation. In addition to its previously described role in mRNA capping, the results presented in this study provide the first in vivo evidence that the vaccinia virus mRNA capping enzyme plays a role in early gene transcription termination and intermediate gene transcription.
The American missionary in the Trans-Mississippi West: Sources for future research in Indian history

Abstract This article surveys the primary source material available on Indian missionary activities in the Trans-Mississippi West. It assesses the usefulness of a large number of collections located across the U.S.A. including those found in missionary societies and public archives. The essay should offer short-cuts to either advanced or beginning researchers that have an interest in Indians as well as how the missionary influenced their development.
Hexagonal Multiple Phase-and-Amplitude-Shift-Keyed Signal Sets

Selection of a particular signal set array for a bandwidthConstrained multiple phase-and-amplitude-shift-keyed (MPASK) communication system for a linear additive Gaussian noise channel requires consideration of factors such as average and/or peak power versus symbol error probability, signal amplitude dynamic range, simplicity of generation and detection, and number of bit errors per symbol error (Gray code properties). A simple technique is presented for generating and optimally detecting the honeycomb (hexagonal.) signal set, i.e., the signal set that has the tightest sphere-packing properties. The symbol and bit error probability performance of this set is compared to other two-dimensional signal sets that have been investigated in the literature, and is shown to be slightly superior from an average power standpoint. The paper concludes with a comparison of all of these signal sets from the standpoint of the factors listed above.
Radiosensitivity is predicted by DNA end-binding complex density, but not by nuclear levels of band components.

Abstract Background and purpose We previously determined that the density of a rapidly migrating DNA end-binding complex (termed ‘band-A') predicts radiosensitivity of human normal and tumor cells. The goal of this study was first to identify the protein components of band-A and to determine if the protein levels of band-A components would correlate with band-A density and radiosensitivity. Patients and methods DNA end-binding protein complex (DNA-EBC) protein components were identified by adding antibodies specific for a variety of DNA repair-associated proteins to the DNA-EBC reaction and then noting which antibodies super-shifted various DNA-EBC bands. Band-A levels were correlated with SF2 for a panel of primary human fibroblasts heterozygous for sequence-proven mutations in BRCA1 or BRCA2. The nuclear protein levels of band-A components were determined in each BRCA1 heterozygote by western hybridization. Results DNA-EBC analysis of human nuclear proteins revealed 10 identifiable bands. The density of the most rapidly migrating DNA-EBC band correlated closely with both BRCA-mutation status and radiosensitivity ( r 2 =0.85). This band was absent in cells with homozygous mutations in their ataxia-telangiectasia-mutated protein (ATM) genes. This band was also completely supershifted by the addition of antibodies to ATM, Ku70, DNA ligase III, Rpa32, Rpa14, DNA ligase IV, XRCC4, WRN, BLM, RAD51 and p53. However, the intranuclear concentrations of these proteins did not correlate with either the SF2 or DNA-EBC density. Neither BRCA1 or BRCA2 could be detected in band-A. Conclusions DNA-EBC analysis of human nuclear extracts resulted in 10 bands, at least six of which contained ATM. The density of one of the DNA-EBCs predicted the radiosensitization caused by BRCA haploinsufficiency, and this band contains Ku70, ATM, DNA ligase III, Rpa32, Rpa14, DNA ligase IV, XRCC4, WRN, BLM, RAD51 and p53 but not BRCA 1 or 2. The density of band-A was independent of the nuclear concentration of any of its known component.
Gas chromatographic–mass spectrometric determination of alachlor and its degradation products by direct aqueous injection

Abstract A GC–MS method, with direct aqueous injection, has been developed to determine alachlor and its degradation products in water. The method was optimized to give the following conditions: injection with splitless mode, injection port with silanized-glass reverse-cup liner filled with 0.5 cm Carbofrit above the cup; injection temperature of 250°C; and an analytical column with a stationary phase of 5% diphenyl and 95% dimethyl polysiloxane and dimensions of 60 m×0.25 mm×0.25 μm. The minimum detection limit is 0.05 to 1 mg/l in the GC–MS-SIM mode with variation of peak height less than 5% and 5 to 50 mg/l in the GC–MS-Scan mode for alachlor and its degradation products.
An Attentional Goldilocks Effect: An Optimal Amount of Social Interactivity Promotes Word Learning from Video.

Television can be a powerful education tool; however, content makers must understand the factors that engage attention and promote learning from screen media. Prior research has suggested that social engagement is critical for learning and that interactivity may enhance the educational quality of children’s media. The present study examined the effects of increasing the social interactivity of television on children’s visual attention and word learning. Three- to 5-year-old (Mage = 4;5, SD = 9 months) children completed a task in which they viewed videos of an actress teaching them the Swahili label for an on-screen image. Each child viewed these video clips in 4 conditions that parametrically manipulated social engagement and interactivity. We then tested whether each child had successfully learned the Swahili labels. Though 5-year-old children were able to learn words in all conditions, we found that there was an optimal level of social engagement that best supported learning for all participants, defin...
Value and limitations of the electrocardiographic response to exercise in the assessment of patients with coronary artery disease: Controversies in cardiology—II

Abstract The results of exercise testing provide a probability statement rather than a definitive answer regarding the existence of coronary disease. Moreover, in asymptomatic subjects (1) the S-T segment response to exercise testing has a relatively poor predictive accuracy, (2) exercise testing does not appear to be a practical screening method for detecting subjects at high risk of sudden death, and (3) risk factors should be vigorously treated regardless of the results of screening studies for coronary artery disease. Hence, the probability statements derived from the electrocardiographic response to exercise testing do not appear to provide important enough diagnostic or prognostic information to justify routine use in asymptomatic subjects. Although exercise screening studies provide only marginal aid in detecting coronary artery disease in symptomatic patients, important prognostic information may be derived that could influence decisions regarding pharmacologic or surgical therapy. Thus, although electrocardiographic stress testing should not be used as a routine screening procedure, its judicious use in symptomatic patients may provide the physician with important information for patient management.
Concluding remarks: challenges for aerosols and climate

We study aerosols for many reasons, including their effects on human health and climate. For climate, it is important to distinguish between the overall radiative effect of aerosols and the radiative forcing, which has been the anthropogenic change (after rapid atmospheric adjustments) since pre-industrial times. The radiative forcing is in principle much harder to observe than the overall effect because one must understand which particles are natural in today's atmosphere and what aerosols were like in the atmosphere before large-scale human influence. Because we cannot go back and measure the past, the only way to calculate radiative forcing may often require modeling detailed aerosol processes. This is a motivation for many of the processes studied at the Faraday Discussion 165. Other processes may need more attention by the aerosol climate community.
Five ways to avoid storing source wavefield snapshots in 2D elastic prestack reverse time migration

ABSTRACTFive alternative algorithms were evaluated to circumvent the excessive storage requirement imposed by saving source wavefield snapshots used for the crosscorrelation image condition in 2D prestack elastic reverse time migration. We compared the algorithms on the basis of their ability, either to accurately reconstruct (not save) the source wavefield or to use an alternate image condition so that neither saving nor reconstruction of full wavefields was involved. The comparisons were facilitated by using the same (velocity-stress) extrapolator in all the algorithms, and running them all on the same hardware. We assumed that there was enough memory in a node to do an extrapolation, and that all input data were stored on disk rather than residing in random-access memory. This should provide a fair and balanced comparison. Reconstruction of the source wavefield from boundary and/or initial values reduced the required storage to a very small fraction of that needed to store source wavefield snapshots fo...