cssi/SciSciGPT-SciSciNet huggingface dataset:
Improved Stein-type shrinkage estimators for the high-dimensional multivariate normal covariance matrix

Many applications require an estimate for the covariance matrix that is non-singular and well-conditioned. As the dimensionality increases, the sample covariance matrix becomes ill-conditioned or even singular. A common approach to estimating the covariance matrix when the dimensionality is large is that of Stein-type shrinkage estimation. A convex combination of the sample covariance matrix and a well-conditioned target matrix is used to estimate the covariance matrix. Recent work in the literature has shown that an optimal combination exists under mean-squared loss, however it must be estimated from the data. In this paper, we introduce a new set of estimators for the optimal convex combination for three commonly used target matrices. A simulation study shows an improvement over those in the literature in cases of extreme high-dimensionality of the data. A data analysis shows the estimators are effective in a discriminant and classification analysis.
Open problems in real-time scheduling

We state some of the most important open algorithmic problems in real-time scheduling, and survey progress made on these problems since the 2009 Dagstuhl scheduling seminar.
Analysis of a Two-PMT System for Simultaneous Back- and Forward-Fluorescence Detection in Multiphoton Microscopy

A two-PMT system is analyzed as an opportunity to improve the S/N ratio in a multiphoton microscope. Conditions under which this arrangement is optimal and sub-optimal are presented and discussed with representative data.
Using Censored Data to Estimate Implicit Values of Swine Breeding Stock Attributes

Production of more desirable products and production efficiency are primary concerns in the swine industry. Genetic improvement provides an avenue for producers to address these concerns. This article examines the value of genetic improvements in breeding animals (boars) via a hedonic pricing model. The approach uses data from a test station auction to estimate the implicit prices for back fat, loineye area, average daily gain, and feed efficiency. All of these variables significantly impact the auction prices of boars. Separate models were estimated on data collected before and after 1990. Results suggest that large adjustments occurred in all of the implicit prices between the two time periods.
Application of Ab Initio Methods to Secondary Lithium Batteries

Ab initio methods have started to be widely used in materials science for the prediction of properties of metals, alloys and compounds. These methods basically require only the atomic numbers of the constituent species. Such methods not only provide one with predictions of some of the properties of the material (even before synthesizing it) but also help one in understanding the phenomena that control those properties. The use of ab initio methods in the field of electrochemistry is, however, quite recent and rare. In this study, the authors demonstrate how ab initio methods can be used to investigate the properties of secondary lithium batteries. Particular examples will be given in predicting average insertion voltages in spinel Li-Mn and Li-Co oxides and in layered LiMO{sub 2} (M = Ti, V, Mn, Fe, Co and Al) compounds. Additionally, the stability of these compounds to metal reduction and structural stability of LiCoO{sub 2} upon lithium removal is investigated. They find that the oxygen anion plays an active role in the electrochemical intercalation of lithium. The amount of electron transfer to oxygen occurring upon lithium intercalation correlates strongly with the cell voltages. The more electron transfer to oxygen occurs, the higher lithium intercalation potentialmore » is obtained.« less
Identification of key volatiles responsible for odour quality differences in popped popcorn of selected hybrids

Abstract Volatile compounds from six hot-air-popped popcorn hybrids, being also classified into three types, were evaluated by a gas chromatograph equipped with a mass spectrometer (GC/MS). In addition, 68 panelists determined odour quality differences of the popped kernels by an aroma ranking test. Total number of volatiles detected by GC/MS were 195, of which 51 peaks were positively identified, 92 peaks were tentatively identified, and 52 peaks were unidentified. The relationships between quality/quantity of volatiles and sensory results revealed that 2-acetylpyridine was considered to contribute to the overall popped popcorn aroma quality favorably or not adversely. However, 2,5-dimethylpyrazine, (E,E)-2,4-decadienal, 2-methylpyrazine, ethylpyrazine, 2-ethyl-5-methylpyrazine and 3-ethyl-2, 5-dimethylpyrazine were found to be important popcorn volatiles, but to contribute negatively to characteristic popped popcorn odour. Numerous other volatiles such as 2-furfurylthiol (2-furanmethanthiol), pyrrole, 3-(methylthio)propanal (methional), 3-furaldehyde, 4-vinyl-2-methoxyphenol (4-vinylguaiacol), 2-pentylfuran, 2-furanmethanol (furfuryl alcohol), hexanal, 1-pentanol, 2-methyl-5-vinylpyrazine, 2-methoxyphenol (guaiacol), 2-acetylpyrrole and others may be responsible in part of typical popcorn aroma characteristics.
Pore Size Distributions by Analysis of Back-Scattered Electron and Fluorescence Images: ABSTRACT

Computerized image analysis provides direct, rapid, and highly accurate measurement of pore size in thin or plane sections. The method can be applied to a wide range of rock types and requires only conventional sample-preparation techniques. Back-scattered electron or fluorescence microscopy images of impregnated samples are scanned, converted to digital form, and stored and processed on a microcomputer. Individual picture points from a matrix of up to 600,000 elements per scan are classified as rock or pore based on gray level. Pore size is obtained by area measurements of individuals pores and by Feret's diameter, the maximum spacing between parallel tangents to a pore in up to 56 directions. The measurements are readily summarized as pore size distributions. Cumulative porosity vs. pore diameter crossplots indicate how porosity is distributed and can be used to aid reservoir evaluation and production assessment. The crossplots can also be used to determine the amount of porosity contributed by different pore types. Individual pores, or groups of pores classified by size or shape, can be interactively identified on the image analyzer monitor, enabling the user to make a visual association of pore type with size. Rocks having a wide range of pore size can be analyzed at more than one level of magnification, and the data can be merged to form a composite pore size distribution for the sample. Pore size distributions of carbonate rocks containing complex pore systems show changes in slope that are indicative of pore type. Other carbonates, including fine crystalline dolomites and microcrystalline limestones, show relatively uniform pore size distributions, which reflect a single pore type. End_of_Article - Last_Page 304------------
Preoperative cardiac risk stratification 2007: evolving evidence, evolving strategies.

Various guidelines and risk indices have optimized cardiac risk stratification, and the emphasis has shifted to reducing perioperative risk. This review is an update on invasive (CABG/PCI) and noninvasive (medical therapy with beta-blockers, alpha-agonists, and statins) strategies to reduce cardiac risk for noncardiac surgery and the controversies surrounding their use. Journal of Hospital Medicine 2007;2:174–180. © 2007 Society of Hospital Medicine.
Swelling and rheology of saponified starch-g-polyacrylonitrile copolymers. Effect of starch granule pretreatment and grafted chain length

A series of well-characterized starch–g–polyacrylonitrile (PAN) graft copolymers was prepared from corn starch which had been heated in water at temperatures up to 94°C to vary the extent of starch granule swelling and disruption. Graft polymerization onto gelatinized starch gave less frequent grafting of higher molecular weight PAN than comparable graft polymerizations onto ungelatinized starch. A graft copolymer was also prepared from gelatinized starch under high dilution conditions to give lower molecular weight grafted PAN and more frequent grafting. Graft copolymers were then saponified with sodium hydroxide to convert nitrile substituents to a mixture of carboxamide and sodium carboxylate. Saponified graft copolymers were only partially water soluble and consisted largely of highly swollen, insoluble gel, which was separated from solubles for the study of physical properties. Saponification mixtures were also dried to yield highly absorbent polymer films. With the exception of the graft copolymer prepared under high dilution conditions, the physical properties of saponified graft copolymers depended on whether or not the granules of starch were gelatinized before graft polymerization. Compared with saponified graft copolymers derived from ungelatinized starch, those prepared from gelatinized starch gave films that absorbed larger amounts of aqueous fluids. Also, the gel fractions from these saponified gelatinized polymers exhibited higher water swelling, lower shear modulus, and a lower reduced viscosity function (η/cQ). The saponified graft copolymer prepared from gelatinized starch under high dilution conditions more closely resembled those prepared from ungelatinized starch, suggesting that molecular weight of grafted PAN and the grafting frequency rather than starch granule pretreatment might be the most important factor which influences properties.
The Influence of Temperature and Food Quality on the Growth of Hydropsyche betteni (Trichoptera) and Simulium vittatum (Diptera)

Growth responses of Simulium vittatum and Hydropsyche betteni were observed at 5 C, 14 C and 20 C while on diets restricted to sterile or conditioned fine particulate leaf detritus (FPOM), cultured...
Transcendental illusion and transcendental realism in Kant's second antinomy

Etude de la double antinomie mathematique et dynamique de la raison pure developpee par Kant dans la premiere «Critique» (A406/B433). Proposant une interpretation de l'argument kantien qui rend compte a la fois de l'illusion transcendantale de la metaphysique et de la critique du realisme trascendantal, l'A. montre que la resolution de la seconde antinomie, fondee sur la notion de substance composee en reponse a la these de la substance simple et a l'antithese de la divisibilite a l'infini de la substance materielle, s'inscrit dans la critique kantienne de la cosmologie rationnelle
Cross-Cultural Study of the Use of Elections for Selection of the Village Headman:

Because political democracy in nonindustrial societies has received rela tively little attention in past research, this paper was undertaken to study the differences between societies using electio...
Mortality analysis of Pleistocene bears and its paleoanthropological relevance.

Abstract Bear bones and Paleolithic stone artefacts often co-occur in Pleistocene cave deposits of Eurasia, raising the question of how these associations come about and the need for effective methods with which to obtain a clear answer. Building upon knowledge of modern bears, I present a method for testing two competing hypotheses about the causes of bear mortality in hibernation contexts. The first hypothesis proposes that age-dependent deaths resulted from non-violent causes (principally starvation), implying that bears' presence in a cave was not linked in time to human activities there. The second hypothesis proposes that random bear deaths in caves resulted from hunting by humans or other large predators, implying a temporal link between them; the expectation of a nonselective age pattern in this circumstance arises from the fact that the individual characters of hibernating bears are hidden from predators. Three elements of the method and its development are presented: (1) a brief review of the biological bases of hibernation-related mortality in modernUrsus, its paleontological consequences, and test expectations drawn therefrom; (2) a detailed, illustrated technique for age-scoring isolated bear cheek teeth based on tooth eruption-wear sequences, developed primarily for cave and brown bears; and, (3) a simple, accurate way to evaluate real cases in terms of contrasting mortality models. The final step is demonstrated by application to a Middle Pleistocene cave bear assemblage (Ursus deningeri) from Yarimburgaz Cave in Turkey, a large collection found in general stratigraphic association with Paleolithic artefacts. The advantages of the method include its ability to (a) handle small samples, (b) use isolated tooth specimens, and (c) evaluate cases simultaneously in terms of idealized age structure models and the variation that normally is associated with each under natural conditions. While the more obvious benefit of bear mortality analysis may be to research on ancient bear demography, the prin-ciples and procedures offered here are equally pertinent to archaeological studies of carnivore-mediated formation processes in cave sites. As is generally true in taphonomic research, however, bear mortality patterns are most effective when used in combination with independent lines of evidence to address questions about assemblage formation.
The Best Child I Ever Had Teacher Influence on the Decision Making of Three Urban High School Principals

Case studies of three principals who "'saved" their schools by unorthodox and nonparticipatory means.
A 90nm CMOS 60GHz Radio

CMOS-based circuits operating at mm-wave frequencies have emerged in the past few years. This paper discusses the integration of a 60GHz CMOS single-chip transmitter and a single- chip receiver using a standard 90nm CMOS technology demonstrating a reliable solution for 60GHz single-chip radio. Proper transistor layout, complete and accurate modeling and optimized parasitic extraction method enabled the robust design of the wideband super-heterodyne architecture to support the entire 57- to-66GHz band. The analog radio front-end is controlled by a serial digital interface and has been co-designed and integrated together with a high-speed digital signal processor including analog-to-digital conversion, high speed PHY signal processing such as frequency-offset compensation, phase tracking, FIR and DFE, to support both advanced OFDM and SCBT modulation scheme. The resulting single-chip solution enables data throughputs exceeding 7Gb/s (QPSK) and 15Gb/s (16QAM) for a total DC power budget of below 200mW in TDD operation. In combination with a low-cost FR4-based packaging technology, it provides a high-performance cost-effective solution for a wide range of high volume consumer electronic applications.
The effects of species manipulation on growth and survival of an assemblage of juvenile estuarine fish

Growth and survival of Cyprinodon variegatus, Fundulus heteroclitus, Menidia beryllina, and Lucania parva, held in combination with an omnivorous grass shrimp–Palaemonetes pugio, and a predatory diving beetle Tropisternus lateralis, were measured at 12–60% in outdoor static microcosms that simulate salt marsh ponds. We predicted that the low species richness of this abiotically harsh but highly productive habitat would lead to a high degree of interaction among species. The presence of the beetle had no effect on the fish or the shrimp. Removal of the shrimp similarly had no detectable effect on the fish. There was a trend in proportions of survival among three fish: C. variegatus>F. heteroclitus>M. beryllina. Survival of M. beryllina was greater when it was alone at low densities of its own species (333 v. 667 fish m −3), and less when it was paired with F. heteroclitus. Interactions with other species diminished the growth of M. beryllina. Survival of F. heteroclitus was greater when it was alone at low density (333 m −3), than when the same number were placed together with Menidia and Cyprinodon at a total fish density of 999 m −3. There were no effects of removal of other species on survival or growth of C. variegatus at either 12′5 or 24%. This study showed that a complex array of interactions occurred among six common members of a salt marsh food web, but the degree of interaction Was less than We predicted.
Mortality from stroke among U.S. veterans in Georgia and 5 western states. IV. Clinical observations.

Abstract Clinical records relating to the last year of life of 2072 U.S. Veterans, who died in Georgia or in five western states during 1 yr, were reviewed to determine the occurrence of cerebrovascular disease as a cause of death. The proportion of intracranial hemorrhage among the white veterans in Georgia was greater than in the western states. Blood pressure levels during the terminal illness also tended to be much higher among white veterans dying in Georgia than in those in the West. The nonwhite population also had higher blood pressure levels and more cerebral hemorrhage. A diagnosis of some type of cerebrovascular disease was found in 86 per cent of the medical records from Georgia and 77 per cent of those from the West when stroke had been certified as the underlying cause of death. The higher mortality from cerebrovascular disease reported in Georgia and in the Southeastern U.S. appears to be real and due chiefly to a greater frequency of cerebral hemorrhage.
Set Adrift in the Prenatal Diagnostic Marketplace: Analyzing the Role of Users and Mediators in the History of a Medical Technology

The medical marketplace is populated by a diverse array of users, producers, mediators, and commentators. While historians of technology have previously highlighted the role that "mediators" play in the broader consumer marketplace, little attention has been paid to how such intermediaries, like medical professionals and government regulators, impact the diffusion and uptake of new medical instruments and procedures. In the medical marketplace, mediators make decisions about what technologies should be available when and to whom. They may also choose to provide or promote certain techniques over others for a variety of personal, professional, and experiential reasons. This paper uses a historical case study of two competing prenatal diagnostic techniques, amniocentesis and chorionic villus sampling, to examine the dual role of mediators, potential users, and media commentators within the medical marketplace in promoting as well as impeding, the availability and uptake of new medical technologies.
MONETARY POLICY AND THE PUBLIC DEBT

BROADLY PUT, THIS thesis is a study of monetary and debt-management policies during the years 1940-55. The main point of focus is the controversy between the Treasury and the Federal Reserve. The thesis is divided into three parts. Part I covers the development of monetary and debt-management policies up until the time of the "accord." First of all, an attempt is made to show how events in the financial sector of the economy which took place in the late 1930's influenced wartime monetary and debt policies. This is followed by a discussion of the over-all financial policy of the war years, the primary aim of which is to demonstrate how wartime policy contributed to the postwar monetary dilemma (i.e., whether or not, in the face of a vastly altered public debt structure, to proceed to a flexible monetary policy). Against this background, the major policy positions adopted and actions taken by the Treasury and the Federal Reserve between the end of the war and the "accord" are analyzed in quite some detail. The main conclusion of this section is that the Treasury erred in opposing for so long the System's desire to raise short-term interest rates but that its position on long-term rates was essentially sound. Perhaps the most interesting aspect of the discussions of the postwar monetary problem was the development of the so-called "new theory" of credit control (sometimes referred to as the "Roosa" or "availability doctrine"), the aim of which was to demonstrate the compatibility of flexible monetary policy and the existence of a large public debt. Part II of the thesis is devoted to an examination of this doctrine. First, the new theory is outlined; then it is interpreted in terms of the categories of supply and demand; and, finally, its formal properties are considered. The most important conclusion of Part II is as follows: (1) That so long as market imperfection (i.e.,
Testing a random phase approximation for bounded turbulent flow

Tractable implementation of a spectral closure requires that the modal representation of the energy satisfy a restricted random phase approximation (RRPA). This condition is exactly satisfied when the statistical system is homogeneous and the basis functions are Fourier modes. In this case, the ensemble average of the spectral covariance diagonalizes, i.e., =delta(k(1)+k(2)) , where c(k,t) is a Fourier coefficient in a Galerkin representation of the velocity field. However, for inhomogeneous statistical systems in which the Fourier system is inappropriate, the RRPA requires validation. We use direct numerical simulations (DNSs) of the Navier-Stokes and truncated Euler equations to test the degree to which the RRPA is satisfied when applied to a recent representation due to Turner (LANL Unclassified Report No. LA-UR-96-3257) of a bounded turbulent rectangular channel flow with free slip, stress free walls. It is shown that a complete test of the RRPA for a fully inhomogeneous DNS with N3 grid points actually requires N3+1 members in the ensemble. The "randomness" of the phase can be characterized by a probability density function (PDF) of the modulus of the normalized spectral covariance. Results reveal that for both the Navier-Stokes and Euler systems the PDF does not change in time as the turbulence decays, and that the PDF for the Euler system is virtually identical to the one produced from an ensemble of random fields. This result is consistent with the equipartition of energy for the Euler system, in which the RRPA becomes an exact result rather than an approximation as the number of realizations approaches N3+1. The slight differences observed between the PDF produced from the random fields and the one from the Navier-Stokes system are thus shown to be entirely a result of the presence of a finite viscosity. It is also shown that there is great variation between statistics computed over the ensemble and those for a single realization.
Two-Allergen Model Reveals Complex Relationship between IgE Crosslinking and Degranulation

Allergy is an immune response to complex mixtures of multiple allergens, yet current models use a single synthetic allergen. Multiple allergens were modeled using two well-defined tetravalent allergens, each specific for a distinct IgE, thus enabling a systematic approach to evaluate the effect of each allergen and percentage of allergen-specific IgE on mast cell degranulation. We found the overall degranulation response caused by two allergens is additive for low allergen concentrations or low percent specific IgE, does not change for moderate allergen concentrations with moderate to high percent specific IgE, and is reduced for high allergen concentrations with moderate to high percent specific IgE. These results provide further evidence that supraoptimal IgE crosslinking decreases the degranulation response and establishes the two-allergen model as a relevant experimental system to elucidate mast cell degranulation mechanisms.
Substructure-Magnetic Property Correlation in Co/ag Composite Thin Films

Three series of nanostructured, 2μm thick, Co/Ag composite thin films (13, 39 and 61 volume % Co) were produced by dc magnetron sputtering at various substrate temperatures (100-sh600°C) to determine their magnetic properties and characterize the microstructure. The films were found to be composed of finely dispersed Ag and Co particles. The film surfaces become rougher as the substrate temperature was increased. The crystal lattice structure of the Co was found to be fcc except at the lower substrate temperatures (<300°C) in the 61 volume % films where it was found to be a mixture of fcc and some hcp. The average diffracting particle size of both the Co and Ag rich phases increase with substrate temperature. The magnetic coercivity of the films reached a maximum value when the Co particle size was between 100–150A.
The Influence of Axial-Torsional Coupling on the Natural Frequencies of an Aerial Cable

The equations of motion for the small oscillations of a stranded, overhead transmission line are derived and linearized about the static equilibrium position. The influence of axial-torsional coupling on the natural frequencies is studied analytically and an expression is presented for the coupled natural frequency in torsion. In order to verify the analytical results, a finite element analysis of the linearized coupled differential equations is carried out. The results of each analysis are compared and show close agreement. The results of the zero coupling case also closely agree with previous work.
Complex formation of collagen with copper and its application to the quantitative determination of collagen

Abstract 1. 1. A copper-collagen complex was prepared at pH 13.5 by a method which renders this complex free of inorganic copper. 2. 2. The stoichiometry of the formation of this complex as well as its spectroscopic properties over the wave length range from 800-230 nm were determined. 3. 3. The application of this copper-collagen complex to the quantitative determination of collagen in aqueous solution is described for a concentration range from 0.01–0.30 mg/ml.
Synthesis and analysis of inductor-isolated switched-mode converter

A procedure is developed for the synthesis and analysis of complete classes of inductor-isolated PWM (pulse width-modulated) converters. The procedure is useful in the identification of converters in which the isolation inductors can be integrated with the rest of the inductors on the same magnetic structures. The information obtained from the procedure is useful in the selection of the converter most suitable for a given application and in the design of this converter with minimum component stresses, high power density, and low cost.
Ophthalmic Artery Chemosurgery for Less Advanced Intraocular Retinoblastoma: Five Year Review

Background Ophthalmic artery chemosurgery (OAC) for retinoblastoma was introduced by us 5 years ago for advanced intraocular retinoblastoma. Because the success was higher than with existing alternatives and systemic side effects limited we have now treated less advanced intraocular retinoblastoma (Reese-Ellsworth (RE) I-III and International Classification Retinoblastoma (ICRB) B and C). Methodology/Principal Findings Retrospective review of 5 year experience in eyes with Reese Ellsworth (Table 1) I (7 eyes), II (6 eyes) or III (6 eyes) and/or International Classification (Table 2) B (19 eyes) and C (11 eyes) treated with OAC (melphalan with or without topotecan) introduced directly into the ophthalmic artery. Patient survival was 100%. Ocular event-free survival was 100% for Reese-Ellsworth Groups I, II and III (and 96% for ICRB B and C) at a median of 16 months follow-up. One ICRB Group C (Reese-Ellsworth Vb) eye could not be treated on the second attempt for technical reasons and was therefore enucleated. No patient required a port and only one patient required transfusion of blood products. The electroretinogram (ERG) was unchanged or improved in 14/19 eyes. Conclusions/Significance Ophthalmic artery chemosurgery for retinoblastoma that was Reese-Ellsworth I, II and III (or International Classification B or C) was associated with high success (100% of treatable eyes were retained) and limited toxicity with results that equal or exceed conventional therapy with less toxicity.
Terminal digit bias in a specialty hypertension faculty practice.

Traditional blood pressure (BP) methodology is subject to observer error such as terminal digit preference and single number preference leading to inaccuracies in measurement. A high percentage (60–90%) of terminal BP readings digit being zero has been reported from general medical- and hospital-based clinics. This study examined terminal digit preference in a hypertension specialty practice and assessed clinical factors that may be associated with zero preference in this setting. A retrospective chart review of patients presenting to the hypertension clinic at the University of Connecticut Health Center during the month of September 2001 was performed. Data were extracted on age, gender, height, weight, treatment status, and systolic and diastolic BP measurements taken by nursing staff and attending physicians. Terminal digit preference was apparent in BP readings taken by both nursing staff and physicians. Zero was the terminal systolic BP digit in 40% of readings taken by the nursing staff and 31% of readings taken by physicians. For diastolic BP readings, the percentages were 23 and 36%, respectively. Nurses also recorded 43% of diastolic BP readings with terminal digit 2. Age was significantly higher in those persons in whom the physician diastolic BP terminal digit was zero than in those with nonzero terminal digits (67±14 vs 59±18 years, P=0.008). Body mass index was lower in the patient group with diastolic terminal digit zero bias compared to those with nonzero terminal digits (28±5 vs 32±6 kg/m2, P=0.02). In conclusion, although the frequency of zero digit preference did not reach the 60–80% levels found in previous studies, there was evidence of terminal digit preference in the systolic and diastolic measurements taken by nursing staff and attending physicians in a specialist hypertension clinic. We believe that the lower levels of terminal digit preference observed are an effect of increased training in proper BP measurement and technique. However, the observed bias in measurement even in a hypertension unit argues for regular monitoring and feedback to minimize such errors.
Financial Flexibility and the Choice between Dividends and Stock Repurchases

The paper measures the growth in open-market stock repurchases and the manner in which stock repurchases and dividends are used in U.S. corporations. We find that aggregate repurchases have increased dramatically over this period: the number and value of repurchase program announcements has grown from 115 and $15.4 billion in 1985 to 755 and $115 billion in 1996. Actual share repurchases have grown from approximately $8.8 billion in 1985 to over $63 billion in 1996. These repurchases represent an economically important source of payouts, and are responsible for much of the variation in aggregate payouts. Nonetheless they are still small relative to the $142 billion in dividends paid by industrial firms listed on Compustat in 1996. Stock repurchases and dividends are used at different times from one another, by different kinds of firms. Stock repurchases are very pro-cyclical, while dividends increase steadily over time. Dividends are paid by firms with higher "permanent" operating cash flows, while repurchases are used by firms with higher "temporary", non-operating cash flows. Repurchasing firms also have much more volatile cash flows and distributions. These results are consistent with the view that the flexibility inherent in repurchase programs is one reason why they are sometimes used instead of dividends.
Effects of Selected Food Additives on Growth of Pseudomonas fragi

Abstract Tests were made of inhibition of Pseudomonas fragi in lactose-yeast extract broth by the food additives chlortctraeycline, nisin, bacitracin, chloramphenicol, lysozyme, ethylenediaminetetraacetic acid (EDTA), nitrofurazone, propyl-p-hydroxybenzoate, sodium benzoate, and potassium sorbate. The additives that proved effective in broth were tested in skimmilk and half-and-half. Nisin, bacitracin, lysozyme, and nitrofurazone were ineffective in broth; chloramphenicol increased the lag period prior to development of turbidity but resulted in chloramphenicol-resistant populations; and EDTA inhibited the organism slightly in broth but not in skimmilk or half-and-half. Propyl-p-hydroxybenzoate, chlortetracycline, and a mixture of lysozyme and EDTA were effective in broth but not in skimmilk or half-and-half, a difference attributed to metal ions in dairy products that react with chlortetracycline and EDTA. Sodium benzoate retarded P. fragi in broth, but only at low pH. Potassium sorbate was ineffective at pH 6.5 in broth, but at pH 5.5 and 5.2 inhibited growth of P. fragi in broth, skimmilk, and half-and-half.
Paint-on metamaterial: Low cost fabrication of absorbers at X band frequencies

This paper presents a new “paint-on” method for low-cost, large-scale fabrication of metamaterials. Specifically, latex paint, silver conducting ink, and regular copy paper are used to create a perfect absorber working at X-band frequencies. The fabricated metamaterial is symmetrical and arranged in a cross-dipole like structure, making it polarization insensitive. Simulation results show absorbency depths of over 90% and near perfect reflection at all other frequencies. These results are obtained using a sandwiched layer of paint (insulator) between two paint conductor metallic planes made from silver ink, one of which contains the cross-dipoles. The approach demonstrates the viability of this new manufacturing method as a new way to create low-cost, large-scale high-performance meta-materials for a wide-range of real world applications. Material measurement and construction techniques are documented in addition to suggestions for improvement
“Fire and Society in Modern China: Fire Disasters and Natural Landscapes in East Asian Environmental History” (1820-1965)

Land clearance and agriculture have long been associated with fire. Open fire, whether from natural or human ignition, has changed the face of many natural landscapes, especially in frontier regions. Much of modern China’s landscape has been shaped by fire, yet fire has been treated as a “disaster” ( huozai ) in official literature. However, fire in Chinese agriculture also played a positive role in the development of regional economies. This essay will review different meanings of “fire disasters” in recent Chinese environmental history by analyzing a few illustrative examples of late Imperial to Mao-era agricultural development, warfare, and legal institutions. By examining these elements of fire-culture landscapes, this paper will consider problems and management practices of Chinese environmental history, especially distinct ethnic, regional, and temporal trends in legal and administrative forms of fire control. These examples enable us to examine aspects of China military, agricultural, and social and ethnic history that lend themselves to cross cultural and environment comparison.
Design of Waste Disposal Wellsa

In this paper, basic design principles for disposal wells are set out and then exemplified by discussion of two recently constructed wells for disposal of very corrosive refinery waste. One well is designed for 700 gpm of waste containing 4200 ppm hydrogen sulfide. The other is designed for 50 gpm of waste containing 32 percent hydrochloric acid. Both wells are in the Gulf Coastal Plain and are completed in a deep, unconsolidated fine sand containing salt water. Screens fabricated from exotic metals were incorporated in the design. Unique combinations of materials were used for the casing. It is pointed out that oil field type completions are often used in disposal well construction, which usually results in low specific injection capacity, high operation and maintenance costs, and short useful life of the hydraulic structure.
The experimental effects of "autonomy" on performance and self-reports of satisfaction.

Abstract Though the job characteristics model proposed by Hackman and his associates has provided the impetus for a large number of correlational studies, few of any studies have involved the systematic manipulation of one or more of the five core dimensions (job properties) while noting the performance outcomes. In this study, the autonomy dimension was experimentally varied (four levels) in a laboratory setting. Four groups of undergraduate students performed a job comprised of three tasks under varying degrees of autonomy while measures of performance, “perceptions” of task properties, and other self-reports were obtained. It was found, contrary to our hypothesis, that variations in autonomy produced a negative effect on quantity of performance and no effect on quality of performance, though subjects in the more autonomous conditions reported a higher level of autonomy. Reservations regarding the strategy of drawing causal inferences from correlational analyses are discussed.
Bacterial sensitivity to UV light as a model for ionizing radiation resistance

Abstract Six bacterial isolates from the U.S. DOE Subsurface Science Program and three references bacteria were tested for resistance to UV light and gamma radiation. The subsurface isolates included three aerobic, pigmented, Gram positive bacteria and three microaerophilic, non-pigmented, Gram negative bacteria. Deinococcus radiodurans was the most resistant bacterium to both types of radiation, with a D 37 value of 4.0 × 10 4 μWs cm −2 to UV light and 300 krads to gamma radiation. The aerobic subsurface bacteria were found to be significantly more resistant ( p
Abstract 4228: Identification of distinct mammary cancer stem cells with differential requirements for the autophagy regulator FIP200

Cancer stem cells (CSCs) contribute to intratumoral heterogeneity and have been implicated in disease relapse and drug resistance. Added to this complexity is the idea that distinct CSC populations can coexist within a tumor and hence, the understanding of this diversity is imperative for effective therapeutic targeting. In this study, we show the co-existence of distinct breast CSC populations which can be identified by ALDH+ and CD29+CD61+ markers respectively using the MMTV-PyMT driven mouse model of breast cancer. While both of these populations exhibit enhanced tumor initiating potential in Nude mice relative to bulk tumor cells, the CD29+CD61+ population have increased invasive abilities and display higher expression of epithelial to mesenchymal (EMT) associated genes. As autophagy has been associated with the acquisition of breast CSC traits, we went on to address the requirement for autophagy in ALDH+ and CD29+CD61+ populations through the deletion of the autophagy regulator, FIP200 in MMTV-PyMT driven tumors. Interestingly, FIP200 deletion only reduces the percentage of CD29+CD61+ cells but does not affect the percentage of ALDH+ cells. However, the tumor initiating properties of both ALDH+ and CD29+CD61+ cells were impaired upon FIP200 deletion. The decrease in the number and CSC potential of CD29+CD61+ cells correlated with diminished TGF-beta signalling upon FIP200 deletion as indicated by decreased TGF-b2, TGF-b3 and phospho-SMAD2 levels. FIP200 deletion also reduced STAT3 activation and it remains to be addressed whether this is responsible for decreased CSC potential in ALDH+ cells. Altogether, our results demonstrate the presence of distinct CSCs in MMTV-PyMT tumors with potentially distinct requirements for divergent signaling pathways. Importantly, we also show that the autophagy regulator FIP200 plays a crucial role in governing the CSC properties of these distinct CSC populations and could represent a potential therapeutic target against breast CSCs. Citation Format: Syn K. Yeo, Jian Wen, Song Chen, Jun-Lin Guan. Identification of distinct mammary cancer stem cells with differential requirements for the autophagy regulator FIP200. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4228. doi:10.1158/1538-7445.AM2015-4228
Flagellar elongation and gene expression in Chlamydomonas reinhardtii.

Lithium (Li+) affects the physiology of cells from a broad range of organisms including plants and both vertebrate and invertebrate animals. Although its effects result presumably from changes in gene expression elicited by its interaction with intracellular signal transduction pathways, the molecular mechanisms of Li+ action are not well understood. The biflagellate green alga Chlamydomonas reinhardtii is an ideal genetic model for the integration of the effects on Li+ on signal transduction, gene expression, and aspects of flagellar biogenesis. Li+ causes C. reinhardtii flagella to elongate to ∼1.4 times their normal length and blocks flagellar motility (S. Nakamura, H. Tabino, and M. K. Kojima, Cell Struct. Funct. 12:369-374, 1987). We report here that Li+ treatment increases the abundance of several flagellar mRNAs, including α- and β-tubulin and pcf3-21. Li+-induced flagellar gene expression occurs in cells pretreated with cycloheximide, suggesting that the abundance change is a response that does not require new protein synthesis. Deletion analysis of the flagellar α1-tubulin gene promoter showed that sequences necessary for Li+-induced expression differed from those for acid shock induction and contain a consensus binding site for CREB/ATF and AP-1 transcription factors. These studies suggest potential promoter elements, candidate factors, and signal transduction pathways that may coordinate the C. reinhardtii cellular response to Li+.
Reasserting the Self: Blocking Self-verifying Behavior Triggers Compensatory Self-verification

Previous research has demonstrated that when people receive self-discrepant feedback from their interaction partners, they respond by engaging in compensatory self-verification. We sought to extend this work by determining if merely preventing people from behaving in a self-verifying manner would trigger compensatory self-verification. Consistent with this possibility, when deprived of the opportunity to demonstrate their assertiveness, participants who perceived themselves as assertive subsequently compensated by displaying increased assertiveness in a subsequent interaction. In addition, self-perceived unassertive participants reported negative affect when forced to act in an assertive manner. Evidence that these effects were predicted by a measure of identity but not a measure of behavioral propensity diminished the plausibility of rival accounts such as ego depletion. We conclude that compensatory self-verification emerges even when people's self-views are indirectly challenged by depriving them of th...
Examining integrative thinking through the transformation of students' written reflections into concept webs

A shift is currently taking place in which explicit connections between content are being emphasized. Biology is not an isolated discipline, yet undergraduate courses frequently focus on discrete knowledge. Students often engage in rote learning, struggle with transforming and applying content. Integrative thinking occurs when students recognize connections to content. Written reflections provide students with the opportunity to demonstrate this thinking. We transformed student-written reflections into concept webs to gain insights into how students connect biological concepts. We were interested in determining if characteristics of integrative thinking develop through reflections. The results indicate a significant relationship between concepts and integrated relationships. Integrative thinking varied but declined overall. Concept webs allow for an examination of student integrative thinking through the transformation of reflection and provide insights into the connections and relationships that students draw between biological concepts. Reflections can transform learning by facilitating and allowing for the evaluation of integrative thinking.
Traffic sign recognition in noisy outdoor scenes

This paper presents a noise-tolerant traffic sign recognition method by using both color and shape attributes. First a discriminant analysis is carried out to obtain the color coordinate system giving the best separation between traffic signs and other objects in the scene. Then a recognition algorithm is devised by cascading three modules: an ART2 neural network module to perform color segmentation, a log-polar-exponential grid and Fourier transformation module to extract invariant traffic sign signatures, a backpropagation neural network module to classify such signatures. The performance of this method is evaluated by examining the effect of various noise sources, which may occur in actual outdoor scenes, on the recognition rate. The results obtained indicate the noise-tolerance of the developed methodology.
Mitochondrial ATP-sensitive K+ channels modulate cardiac mitochondrial function

Discovered in the cardiac sarcolemma, ATP-sensitive K+(KATP) channels have more recently also been identified within the inner mitochondrial membrane. Yet the consequences of mitochondrial KATP cha...
An important role for RUNX3 in human L1 transcription and retrotransposition

LINE-1s (long interspersed nuclear elements-1) are abundant non-LTR retrotransposons that comprise 17% of the human genome. The 5' untranslated region (5'UTR) of human L1 (L1Hs) houses a poorly understood internal promoter. Here we report that mutations at a putative runt-domain transcription factor (RUNX) site (+83 to +101) in the 5'UTR decreased L1Hs transcription and retrotransposition in cell culture-based assays. Exogenous expression of RUNX3, but not the other two RUNX family members, RUNX1 and RUNX2, increased L1Hs transcription and retrotransposition, which were otherwise decreased by siRNAs targeting RUNX3 and a dominant negative RUNX. Further more, the specific interaction between RUNX3 and its binding site was demonstrated by an electrophoretic mobility shift assay (EMSA) using an anti-RUNX3 antibody. Interestingly, RUNX3 may also regulate the antisense promoter activity of L1Hs 5'UTR via another putative RUNX site (+526 to +508), as revealed by site-directed mutations and exogenous expression of RUNX factors. Our results indicate an important role for RUNX3 in L1Hs retrotransposition as well as transcription from its 5'UTR in both sense and antisense directions, and they should contribute to our understanding of the mechanism underlying L1Hs retrotransposition and its impact on the expression of adjacent cellular genes.
Fiber-optic nonlinear endomicroscopy with focus scanning by using shape memory alloy actuation.

A miniature fiber optic endomicroscope with built-in dynamic focus scanning capability is developed for the first time for 3-D two-photon fluorescence (TPF) imaging of biological samples. Fast 2-D lateral beam scan- ning is realized by resonantly vibrating a double-clad fiber cantilever with a tubular piezoactuator. Slow axial scan- ning is achieved by moving the distal end of the imaging probe with an extremely compact electrically driven shape memory alloy (SMA). The 10-mm-long SMA allows 150- μm contractions with a driving voltage varying only from 50 to 100 mV. The response of the SMA contraction with the applied voltage is nonlinear, but repeatable and can be ac- curately calibrated. Depth-resolved imaging of acriflavine- stained biological tissues and unstained white paper with the endomicroscope is performed, and the results demon- strate the feasibility of 3-D nonlinear optical imaging with the SMA-based scanning fiber-optic endomicroscope. C 2010
Excystation Signals Do Not Isolate Gregarine Gene Pools: Experimental Excystation of Blabericola migrator Among 11 Species of Cockroaches

Abstract: An experimental excystation assay was used to test the potential species isolating effects of excystation signaling among gregarines. Oocysts of a single gregarine species, Blabericola migrator, were tested for activation, excystation, and sporozoite motility by using intestinal extracts from 11 species of cockroaches representing a cohesive phylogeny of 7 genera, 3 subfamilies, and 2 families of Blattodea. Sporozoite activation, excystation, and motility were observed for all excystation assay replications using intestinal fluid from blaberid hosts, but delayed activation or excystation was observed for all assay replications using intestinal fluid from hosts in the family Blattidae. The results illustrate a trend toward a generalized excystation signal among gregarines that is conserved across the host clade at a subfamily or family level but that is unlikely to play a significant role as a species-isolating mechanism among sibling gregarine species.