cssi/SciSciGPT-SciSciNet huggingface dataset:
Experimenting with cigarettes and physical activity among Mexican origin youth: a cross sectional analysis of the interdependent associations among sensation seeking, acculturation, and gender.

Sensation seeking tendencies tend to manifest during adolescence and are associated with both health-compromising behaviors and health-enhancing behaviors. The purpose of this study is to evaluate the relationship between sensation seeking and physical activity, a health-enhancing behavior, and between sensation seeking and experimenting with cigarettes, a health compromising-behavior, among a cohort of Mexican origin adolescents residing in the United States with different levels of acculturation. In 2009, 1,154 Mexican origin youth (50.5% girls, mean age 14.3 years (SD = 1.04)) provided data on smoking behavior, physical activity, linguistic acculturation, and sensation seeking. We conducted Pearson’s χ2 tests to examine the associations between categorical demographic characteristics (i.e. gender, age, country of birth and parental educational attainment) and both cigarette experimentation and physical activity and Student’s t-tests to examine mean differences on the continuous variables (i.e. sensation seeking subscale) by the behaviors. We examined mean differences in the demographic characteristics, acculturation, and both behaviors for each of the sensation seeking subscales using analysis of variance (ANOVA). To examine relationships between the sensation seeking subscales, gender, and both behaviors, at different levels of acculturation we completed unconditional logistic regression analyses stratified by level of acculturation. Overall, 23.3% had experimented with cigarettes and 29.0% reported being physically active for at least 60 minutes/day on at least 5 days/week. Experimenting with cigarettes and being physically active were more prevalent among boys than girls. Among girls, higher levels of sensation seeking tendencies were associated with higher levels of acculturation and experimentation with cigarettes, but not with physical activity. Among boys, higher levels of sensation seeking tendencies were associated with higher levels of acculturation, experimenting with cigarettes and being physically active. Our results suggest that interventions designed to prevent smoking among Mexican origin youth may need to address social aspects associated with acculturation, paying close attention to gendered manifestations of sensation seeking.
An open multicenter efficacy and safety evaluation of amlodipine in the treatment of symptomatic myocardial ischemia.

Abstract The efficacy and safety of amlodipine (5-10 mg) once daily were studied in an open study in patients with symptomatic myocardial ischemia. The study is ongoing and this report is based on an interim analysis of data from 78 patients. A 2-week baseline period in which patients maintained their current antianginal therapy was followed by a 10-week treatment period with 5-10 mg of amlodipine/day. Both the median number of angina attacks per week and the median number of nitroglycerin (NTG) tablets consumed/week were significantly reduced after amlodipine (mean daily dose of 8.6 mg) when compared with baseline (p < 0.05). A total of 98.4% of patients (63/64) experienced a reduction in the frequency of angina attacks/week and 91% of patients (58/64) had angina attacks reduced to < or = 2/week. In self-assessments, 95% of patients (55/58) reported improved angina control and 91% (53/58) felt their ability to perform usual activities had improved. Twenty-seven patients experienced adverse events reported as drug related. The most common adverse event noted was edema. Amlodipine once daily significantly reduced the incidence of angina attacks and the concomitant need of nitroglycerin for relief of symptoms and thus improved the patients' ability to perform daily activities. Most adverse events reported were mild or moderate and the incidence is as would be expected in this patient population.
An execution profiler for modular programs

In modular programs, groups of routines constitute conceptual abstractions. A method for providing execution profiles for such programs is presented. The central idea is that the execution time for a routine is charged to the routines that call it. The implementation of this method by a profiler called gprof is described. The techniques used to gather the necessary information about the timing and structure of the program are given, as is the processing used to propagate routine execution times along arcs of the call graph of the program. The method for displaying the profile to the user is discussed. Experience using the profiles for hand-tuning large programs is summarized. Additional uses for the profiles are suggested.
Partial matching of planar polylines under similarity transformations

Given two planar polylines T and P with n and m edges, respectively, we present an O(m{sup 2}n{sup 2}) time, O(mn) space algorithm to find portions of the {open_quotes}text{close_quotes} T which are similar in shape to the {open_quotes}pattern{close_quotes} P. In the common case of a simple pattern, such as a line segment or comer, m = O(l) and our algorithm requires O(n{sup 2}) time and O(n) space. We use the well-known arclength versus cumulative turning angle graph to judge how well a scaled, rotated, and translated version of the pattern matches a piece of the text. Our match scoring function balances the length of a match against the mean squared error in the match; given two matches with the same mean squared error (length), the longer (lower mean squared error) match will have a higher score. The match score is a function of the pattern scale, orientation, and position within the text, and our algorithm seeks to find local maxima of the scoring function. An analytic formula for the highest scoring pattern orientation in terms of scale and position leaves us with a search problem in scale-position space. This space is divided by a set of lines into combinatorially distinctmore » regions in each of which we have an analytic formula for the scoring function. Our algorithm discovers local maxima of the scoring function by performing a topological line sweep over this scale-position space line arrangement.« less
A Quality of Health Outcomes Model for Guiding Obstetrical Practice

Purpose: To describe the application of the Quality of Health Outcomes Model introduced by the American Academy of Nursing Expert Panel on Quality of Health Care to obstetrical care particularly second-stage labor. Organizing framework: The model is different from the more linear structure-process-outcome frameworks used in the past to a dynamic conceptualization of reciprocal relationships among the system intervention client and outcome components. Analysis of these components can provide a comprehensive picture of the complexity of patient care decision making in hospital labor and delivery units. Conclusions: Research findings indicate that interventions such as cesarean delivery and epidural analgesia may result in several significant quality of health outcomes for women that should receive increased attention. Uses of this model for shaping best practices among physicians and nurses and for setting directions for priorities in future interdisciplinary research and health policy are discussed. (authors)
Molecular detection and characterization of circulating tumor cells and micrometastases in prostatic, urothelial, and renal cell carcinomas.

The detection and molecular characterization of circulating tumor cells (CTCs) and micrometastases in urinary tract and prostatic tumors may have important prognostic and therapeutic implications. In the last decade, numerous groups have attempted the detection of occult tumor cells in renal, prostatic, and urothelial carcinomas using the highly sensitive reverse-transcriptase polymerase chain reaction (RT-PCR). In prostatic carcinoma (PC), tissue-specific transcripts were detected with high specificity in the blood of patients with localized and advanced disease. PCR assays for PC detection were shown to be strong predictors of poorer outcome in some reports, while a lack of prognostic significance was found in other studies. There was a vast difference in the PCR positivity rates between various groups studying PC. This discrepancy could be due to variations in PCR methodology. In urothelial and renal cell carcinoma, the amount of research on the subject is still too limited. Currently, these assays for occult tumor cells are promising but are not yet ready to use in PC and urinary tract tumors. Because of the many limitations of PCR (e.g., false positives), many groups are developing new approaches for the detection of occult tumor cells. The most attractive technique involves immunomagnetic isolation of intact CTC and micrometastases prior to downstream analysis. The tumor-rich magnetic fraction can be subjected to RT-PCR, immunocytochemistry, and in situ hybridization. This will lead to better quantification and molecular characterization of these tumor cells.
High pressure synthesis of solids

Abstract The field of high pressure synthesis of solid state compounds is reviewed, for the period between late 1997 through late 1998. The review does not cover syntheses of organic compounds, nor high pressure mineralogy. Emphasis is placed on new solid state compounds discovered during the reviewing period, and on recent findings in on-going areas of high pressure research. The main classes of materials receiving on-going attention are (i) ‘super-hard’ materials, including compounds based on the diamond structure, advances in the search for C3N4, interesting new materials derived from fullerite (C60 and C70), and icosahedral borides, and (ii) high T c oxide superconductors, as well as (iii) other new compounds and classes of compound synthesized for the first time by high pressure techniques. Current research on synthesis of new organometallic compounds prepared at high pressure is also mentioned briefly.
HRM practices of JIT firms in Canada

Abstract Many firms have adopted the just-in-time (JIT) philosophy to compete successfully in the global environment. The literature suggests that die success of JIT implementation depends on sound human resource management (HRM) practices that will attract, maintain, and retain employees with the required workforce characteristics. However, only a few field studies investigate the effectiveness of such practices. This empirical study examines HRM practices of 69 JIT manufacturing firms in Ontario, Canada. Specifically, it identifies important workforce characteristics, recruitment sources and selection instruments used by JIT firms. It also evaluates die degree of change in training, compensation, employee retention, and labour relations practices in the firms since JIT implementation. The level of attainment of various expected outcomes of JIT implementation and die competitiveness of the JIT firms are investigated. Problems faced by HRM managers are also discussed.
Dimensional Mappings In Discrete Fourier Transforms And Circular Convolution

Abstract. We briefly review the dimensional mappings used in fast discrete Fourier transform and convolution algorithms and point out the equivalence between these discrete mappings and some of the mappings used in optical signal processing.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Local regional effectiveness of surgery and radiation therapy in the treatment of breast cancer

Although gross tumor can be controlled with high doses of radiation therapy, control is achieved at the expense of severe radiation sequelae. In order to improve tumor control with minimum complications, the field of treatment should contain only subclinical disease. This article reviews the successful combination of surgery for the removal of gross cancer and radiation of moderate dose for the treatment of subclinical disease in patients with breast cancer. In patients with clinically favorable and operable disease, the combination of a radical or modified radical mastectomy and postoperative radiation therapy of 5000 rad to the peripheral lymphatics and chest wall can secure 90% of the treated areas. For patients with locally and regionally advanced breast cancer, the combination of a simple mastectomy and dissection of the lateral axilla followed by postoperative irradiation of 5000 rad in 5 weeks to the chest wall, axilla, and peripheral lymphatic areas will control more than 85% of the patients treated as compared with approximately 70% control when surgery or radiotherapy alone is used, even with chemotherapy. Yet another clinical application of the subclinical disease concept is the successful combination of conservation surgery (whether segmental mastectomy, quadrantectomy, or wide excision) for gross tumor in the breast and axilla and irradiation for residual microscopic and multiple foci of tumor, yielding more than 90% control of locoregional disease with survival rates equal to those patients treated with radical or modified radical mastectomy. Results of multiple clinical trials and reported series are reviewed.
Modernizing peasant agriculture: Lessons from El Palmar, Colombia

Abstract This paper examines the short-run and anticipated long-run output and income results of the modernization of production in a Colombian peasant community, El Palmar. The study finds that in the short run there were increases in output and in producer income, as well as increases in local employment and trade opportunities which benefited land-poor households. However, the incidence of extreme poverty in the community was still high after 10 years of modernization. The gains from modernization had been limited by the failure of the projects to achieve stable, low-risk increases in the productivity of peasant resources, and many producers had pulled back from adoption of full technological packages in favor of selective and limited adoption. The lessons from the community of El Palmar are applied to an assessment of the peasant modernization program of the Colombian government, where it is shown that the problems encountered in El Palmar are reflective of problems with the Colombian modernization strategy in general. The conclusion drawn is that the income gains that can be achieved from the modernization of peasant production, in the context of peasant land scarcity and the poor market conditions for traditional peasant products, are limited.
Reduction of spurious scattering in Ilford G-5 and K-5 emulsions

In an attempt to reduce the amount of spurious scattering in the emulsions, two batches of Ilford G-5 and two batches of Ilford K-5 stripped emulsions, 600 Μm thick, have been exposed to the 6.2 GeV internal proton beam from the Berkeley Bevatron, and developed in several different ways. The methods of development used included isothermal development at 5 ‡C, 10 ‡C and 15 ‡C, and temperature cycle development with the warm stages at 10 ‡C, 15 ‡C and 20 ‡C with the plates immersed in a boric acid-potassium bromide solution. For comparison some emulsions were also developed with the ‡ dry ‡, warm development at 25 ‡C which was usually employed in previous work. As a further precaution against distortions in the emulsions potassium alum hardener has been added to the fixing bath, and the emulsions were dried slowly at a temperature below 10 ‡C. Scattering measurements performed on the 6.2 GeV proton tracks in the emulsions have shown that the spurious scattering has been reduced to about half of the value which has usually been obtained previously and by other workers. This applies to all the plates, except for a G-5 emulsion from one batch and developed at 25 ‡C. It has been observed that the amount of spurious scattering depends on the development temperature: (i) It does not change between temperatures of 5 ‡C and 10 ‡C. (ii) Above 10 ‡C there is a gradual increase with temperature, (iii) In some batches of emulsions a marked increase of spurious scattering occurs at a temperature of about 25 ‡C. Some variation in the amount of spurious scattering present in the different batches of emulsions used has been observed, but there appears to be no difference in that respect between the G-5 and the K-5 emulsions. Good grain densities on minimum tracks and improved uniformity of development with depth in both the G-5 and the K-5 emulsions have been obtained using the temperature cycle methods of development with warm stages at 10 ‡C 15 ‡C and 20 ‡C.
Analysis of multihypothesis motion-compensated prediction for error resilient video transmission

Multi-hypothesis motion compensated prediction (MHMCP) predicts a block from a weighted sum of multiple reference blocks in the frame buffer. By efficiently combining these reference blocks, MHMCP can provide less prediction errors so as to reduce the coding bit rates. Although MHMCP was originally proposed to achieve high coding efficiency, it has been observed recently that MHMCP can also enhance the error resilient property of compressed video. In this work, we investigate the error propagation effect in the MHMCP coder. More specifically, we study how the multi-hypothesis number as well as hypothesis coefficients influence the strength of propagating errors. Simulation results are given to confirm our analysis. Finally, several design principles for the MHMCP coder are derived based on our analysis and simulation results.
On the existence of upper bounds on the performance index of nonlinear systems

Abstract Several interesting results are presented in determining the value of an integral performance index for certain types of finite changes in the characteristics of the system. In particular, we consider the assumed model of the system to be linear, while an accurate representation is given to a system containing a single nonlinearity. These assumptions, in many physical situations are quite reasonable. The performance index is specified as the integral of a quadratic function of the state of the system. Two theorems concerning the existence of upper-bounds for the values of the performance index are proved. Consideration of these theorems may lead to a meaningful insight into the relationship between changes in the system characteristics and the corresponding changes in the performance index.
Channel-length effects in quarter-micrometer gate-length GaAs MESFET's

The electrical performance of 0.25-µm gate-length GaAs MESFET's with channel lengths (i.e., source-drain spacings) of 2.1 and 0.5µm is compared. An extremely short channel length has been found experimentally to lead to significant increases in the electron average drift velocity, transconductance, and forward transducer gain. Increases in both the electron average drift velocity and intrinsic dc transconductance of ∼70 percent were observed in these 0.25-µm gate-length devices when the source-drain spacing was reduced from 2.1 to 0.5µm. Deleterious effects such as increased output conductance and interelectrode capacitances were also noted.
Are Selling, General, and Administrative Costs "Sticky"?

A fundamental assumption in cost accounting is that the relation between costs and volume is symmetric for volume increases and decreases. In this study, we investigate whether costs are “sticky”—that is, whether costs increase more when activity rises than they decrease when activity falls by an equivalent amount. We find, for 7,629 firms over 20 years, that selling, general, and administrative (SG&A) costs increase on average 0.55% per 1% increase in sales but decrease only 0.35% per 1% decrease in sales. Our analysis compares the traditional model of cost behavior in which costs move proportionately with changes in activity with an alternative model in which sticky costs occur because managers deliberately adjust the resources committed to activities. We test hypotheses about the properties of sticky costs and how the degree of stickiness of SG&A costs varies with firm circumstances.
Hopanoid enrichment in a detergent resistant membrane fraction of Crocosphaera watsonii: Implications for bacterial lipid raft formation

Abstract Hopanoids are bacterial membrane lipids with close structural and evolutionary ties to sterols. Extraction of hopanoid containing membranes of Crocosphaera watsonii in a non-ionic detergent demonstrates that a hopanoid identified as bacteriohopanetetrol cyclitol ether (BHT-CE) is enriched in a detergent resistant membrane (DRM) fraction. Detergent resistance indicates that hopanoids, like sterols in eukaryotes, are likely associated with putative lipid rafts in bacterial membranes. These results are consistent with previous work suggesting analogous roles of hopanoids and sterols and may imply that hopanoids are essential to the physiology of putative lipid rafts in hopanoid producing bacteria.
Description Of Optical Turbulence Effects On Propagation In The Atmospheric Surface Boundary Layer

A methodology is presented to characterize propagation through clear air turbulence in the surface boundary layer of the atmosphere, based on readily obtained environmental observables. Obukhov similarity theory is employed to define a consistent set of flux profile relationships, and the Kolmogorov principle of universal equilibrium to estimate a profile for the refractive index structure parameter. This profile serves as input to a propagation model based on weak perturbation theory, allowing estimates of log-amplitude variance, receiver coherence diameter, isoplanatic effective path length, and scintillation averaging length, as well as a variety of subsidiary imaging statistics.
Enzyme activity responses to nutrient loading in subtropical wetlands

Eutrophication caused by anthropogenic nutrient inputs is one of the greatest threats to the integrity of freshwater wetlands. The resultant changes in organic carbon cycling and nutrient mineralization may be expressed through increased decomposition rates, which are ultimately dependent on the metabolism of the resident microbial community. Specifically, microbial nutrient acquisition is controlled through the activity of enzymes, which are in turn influenced by local biogeochemical conditions. This study examines enzyme activities along distinct North-South P gradients within four distinct hydrologic units of the Florida Everglades. The results indicate that nutrient enriched sites exhibit lower N and P limitations on microbially constrained C mineralization, in addition to enhanced cellulose decomposition rates. Nutrient loading resulted in decreased microbial mobilization of resources for P mineralization, resulting in greater energetic allocation for C mineralization. Additionally, N appears to become less limiting to C mineralization in the enriched sites within Everglades National Park, the least P enriched area within the Everglades. A simple two component model, incorporating total P and the relationship between the enzymes involved in C and P mineralization accounted for between 46 and 92% of the variability in measured cellulose decomposition rates and thus demonstrates the significant influence that P loading plays in these systems. These results also suggest there is an environmental threshold TP concentration below which changes in enzyme-based resource allocation will not occur.
Oncogene mutations as intermediate markers

Tumors arise through a series of genetic changes which include activation of protooncogenes and inactivation of tumor suppressor genes. It is now possible to identify rare cells containing genetic mutations in an excess background of normal cells. Theoretically, the identification of a clonal population of cells sharing an early genetic marker for malignant transformation would lead to valuable intermediate endpoints and could diagnose premalignant lesions amenable to chemoprevention. Ideally, these genetic changes would be specific point mutations that occur early in the tumor cascade, prior to the development of a clinically significant tumor. To identify these markers, precise histopathologic and genetic tumor models must be described. Early candidate markers include p53 point mutations in squamous cell carcinoma of the aerodigestive tract.
Physical activity promotion: a responsibility for both K-12 physical education and kinesiology.

(2008). Physical Activity Promotion. Journal of Physical Education, Recreation & Dance: Vol. 79, No. 6, pp. 47-56.
Surface Profile of the Internal Elastic Lamina May Modulate Thrombosis Following Intracoronary Radiation in Balloon‐Injured Porcine Arteries

Background: Intracoronary radiation (IR) can prevent neointima formation (NF) by reducing smooth muscle cell (SMC) proliferation after balloon angioplasty, but is complicated by subacute and late thrombosis. Rupture or abnormalities of the internal elastic lamina (IEL) structure and subsequent exposure of blood to the injured arterial wall can induce thrombosis and inflammation. The purpose of this study was to evaluate the effect of IR on the media and IEL after balloon overstretch injury in porcine coronary arteries. Methods: Seventeen juvenile swine (25 coronary arteries) were injured by overstretch balloon and subsequently given IR at doses of 0 or 18 Gy 90Y prescribed to 1.2 mm from vessel wall inner surface. Two weeks following treatment, tissue sections were perfusion fixed and stained by hematoxylin-eosin or by Verhoeff-von Giesson. Smooth muscle cell α-actin was detected immunocytochemically and quantified by digital image analysis using arbitrary density units. Histomorphometry was carried out to assess intimal area (IA) and IA corrected for medial fracture length (IA/FL). The roughness index (RI) of the IEL was calculated from the surface profile length and the straight-line length. Results: NF was markedly smaller after IR as compared to control treatment. Mural thrombi were increased significantly in irradiated versus control arteries (11/14 [78%] vs 1/11 [9%]; P < 0.001). A significant decrease in SMC density was observed in the irradiated group (128 ± 13 vs 74 ± 10; P < 0.001) despite a lack of difference in medial area. The surface of the IEL was more irregular in irradiated arteries, particularly at the medial breaks (RI =20.1 ± 3.1 vs 8.7 ± 1.2; P < 0.001). When mural thrombi were present, thrombus area correlated with RI (α= 0.76; P < 0.01). Furthermore, in the irradiated group RI correlated positively with SMC density (α=0.64; P < 0.01). Conclusion: Medial structure and RI may be useful parameters by which to assess arterial healing following IR. These findings may influence the design of future IR studies aimed at reducing thrombosis and enhancing arterial healing.
Computational Study of the Impact of Unsteadiness on the Aerodynamic Performance of a Variable-Speed Power Turbine

The design-point and off-design performance of an embedded 1.5-stage portion of a variable-speed power turbine (VSPT) was assessed using Reynolds-Averaged Navier-Stokes (RANS) analyses with mixing-planes and sector-periodic, unsteady RANS analyses. The VSPT provides one means by which to effect the nearly 50 percent main-rotor speed change required for the NASA Large Civil Tilt-Rotor (LCTR) application. The change in VSPT shaft-speed during the LCTR mission results in blade-row incidence angle changes of as high as 55 . Negative incidence levels of this magnitude at takeoff operation give rise to a vortical flow structure in the pressure-side cove of a high-turn rotor that transports low-momentum flow toward the casing endwall. The intent of the effort was to assess the impact of unsteadiness of blade-row interaction on the time-mean flow and, specifically, to identify potential departure from the predicted trend of efficiency with shaft-speed change of meanline and 3-D RANS/mixing-plane analyses used for design.
Measuring Patient Opinion of Pain Management

Pain management has been increasingly recognized as an important indicator of quality patient care. In this article, we describe the development of a measure of patients' perception of pain management. Based upon the American Pain Society's guidelines, the six-item Patient Opinion of Pain Management (POPM) scale demonstrated promising internal consistency, reliability, and validity in a sample of 241 patients from 11 hospitals. The POPM is discussed in the context of previous research on the assessment of pain management.
Radioligand binding studies reveal agmatine is a more selective antagonist for a polyamine-site on the NMDA receptor than arcaine or ifenprodil

Ifenprodil, arcaine and agmatine have all been reported to inhibit the NMDA receptor by actions at polyamine-sites, however the specific sites with which these compounds interact is unknown. Here we used radioligand binding of [3H]MK-801 to a membrane preparation from rat cerebral cortex to investigate the interactions of these compounds with the NMDA receptor complex. In the absence of exogenous polyamines, agmatine reduced [3H]MK-801 binding only at concentrations over 500 micro M, as opposed to the putative polyamine-site antagonists arcaine and ifenprodil which directly reduce ligand binding at much lower concentrations (5 micro M) in the absence of polyamines. In our studies, all three compounds significantly reduced spermidine-potentiated [3H]MK-801 binding, however agmatine was the only compound effective at concentrations below those that produced direct inhibition of [3H]MK-801 binding. Under these conditions, agmatine had a K(i)=14.8 micro M for spermidine-potentiated [3H]MK-801 binding and displayed characteristics of a competitive antagonist. Agmatine, as well as ifenprodil and arcaine, also displaced [3H]spermidine from rat cortical membranes at concentrations similar to those that were effective at reducing spermidine-potentiated [3H]MK-801 binding. In conclusion, these data suggest that agmatine reduces the potentiating effects of polyamines by competitive antagonism at a specific site on the NMDA receptor complex, and that these actions of agmatine differ from those of ifenprodil and arcaine.
Design, analysis, and testing of an aerobrake test model

A one-tenth-scal e test model of a spherical sandwich aerobrake proposed for a lunar transfer vehicle was developed. The objective of this paper is to demonstrate the structural integrity of this aerobrake test model. Membrane stress analysis and the idea of equal stress/strength ratio of the skin material were used in the design. The test model had an outer radius of 4.45 ft (1.36 m), a base diameter of 5 ft (1.5 m), and a total wall thickness of 0.9 in (23 mm). The sandwich shell wall was made out of glass/polyester resin skin and polyvinyl foam core. An air-pressure test was conducted. The measured displacements and strains agreed well with the finite element analysis results. The aerobrake model survived 160% of the design pressure with no structural failure. Nomenclature c = base radius of the aerobrake test model, in. d = total thickness of the shell wall, in. E = elastic modulus, psi p = pressure at any point on the surface of the shell, psi po = stagnation pressure, psi R = mean radius, in. S = material strength, psi t = thickness of the shell, in. v = Poisson's ratio of the material a = stress, psi 0 = spherical angle, deg 01 = spherical angle between the apex and support ring of the shell, deg 02 = spherical angle between the apex and outer edge of the shell, deg Subscripts core m s skin 9 0 = core material = model = structure = skin material = hoop direction = meridional direction
TH-A-217BCD-02: BEST IN PHYSICS (IMAGING) - Spectral Distortion Correction for Breast Tissue Composition Measurement Using Spectral CT

Purpose: To investigate breast tissue compositions using a photon‐counting spectral Computed Tomography(CT) after spectral distortion correction. Methods: A total of 37 postmortem breast samples were scanned with a spectral CT based on a Cadmium‐Zinc‐Telluride (CZT) photon‐counting detector with five energy thresholds. All scans were acquired at beam energy of 100 kVp and a tube current of 1 mA. The energy thresholds of the CZT detector were set at 22, 42, 53, 65 and 90 keV. An image‐based spectral distortion correction method was used to eliminate the pulse pileup and other artifacts. Image‐based dual energy decomposition was performed with a three‐material calibration phantom to quantify postmortem breast tissue into water, lipid and protein contents. Results from dual energy decomposition were compared to chemical analysis. The Root Mean Square (RMS) errors for all samples were compared for images with and without spectral distortion correction. Results: The average RMS percentage errors of water, lipid, and protein over 37 breast samples, compared to data from chemical analysis, were 5.7% and 13.3% for images reconstructed with and without spectral distortion corrections, respectively. Conclusions: The results of this study suggest that the spectral distortion correction reduced the RMS percentage error of breast tissue composition by a factor greater than 2. With the proposed spectral distortion correction method, photon‐ counting detectors can be used for accurate quantitative tissue decomposition studies in spectral CT applications.
Phytoplankton and the Late Paleozoic wave of extinction

Abstract The relationship between phytoplankton productivity and abundance of marine invertebrates postulated by Tappan (1968) is analyzed with respect to the Late Paleozoic wave of extinction of marine invertebrates. It is concluded that the radical decrease in the abundance of phytoplankton beginning in the Late Devonian cannot logically be regarded as the cause for the Late Paleozoic extinction of marine invertebrates, which was largely a Permian event. The marked discordance in the Late Paleozoic and Early Mesozoic between the abundance of fossil phytoplankton and that of marine invertebrates can only be regarded as evidence that the fossil record of phytoplankton abundance is not indicative of true past abundance.
Transient Effects In High Current Gyrotrons

A self consistent and time dependent particle code has been used to simulate the transient effects of a high current gyrotron. At high beam currents, the output wave exhibits the effects of self-modulated oscillation and period doubling. In the regime of high injected signal powers, the locking bandwidth and time constant of high-power gyrotron phase locking simulations are observed to be respectively larger and smaller than the prediction from a lumped circuit theory. The multimode simulation of the risetime wave generation processes also demonstrates some nonlinear processes such as transient mode co-existence and mode suppression which appear to be of general interest and importance for short-pulse gyrotrons.
Marseille's Not for Burning: Comparative Networks of Integration and Exclusion in Two French Cities

Many scholarly studies focus on the historical processes that lead to rioting and war, but few examine the forces that produce peace. This article is a broad, comparative examination of three varia...
HIV-Associated Stroke

To the Editor: We read with particular interest the article by Connor et al1 in view of our approximately concurrent publication on the same topic2 that was not cited. Our study population was very different, the most pertinent aspects being black race, heterosexual HIV infection, and the fact that our series was relatively devoid of opportunistic infection. Our conclusions were similar, however, in …
Investigation of the Physical and Mechanical Properties of Hot-Pressed Boron Nitride/Oxide Ceramic Composites

Billets of hexagonal boron nitride powders (h-BN) were hot-pressed, varying the alignment of the platelike particles and the amount of oxide additives. Increasing either alignment of individual grains or the amount of additives was shown to increase flexural strength, to approximately 120 MPa at ambient temperatures. h-BN was shown to deflect cracks initially propagating normal to its basal planes.
Comparison of the Young's moduli of polymers measured from nanoindentation and bending experiments

Spherical and conical nanoindentation experiments were performed for the same polymer specimens to compare Young’s moduli measured from the elastic loading and unloading curves, and bending experiments. Finite-element simulation was employed to ensure pure elastic deformation during spherical nanoindentation. The moduli measured from the elastic loading curves using Hertz’s contact law are very close to the bending moduli, because both measurements were conducted under the same elastic deformation. However, the moduli measured from the elastic unloading curves are up to 60% higher than the bending moduli owing to plastic deformation close to the sharp conical indenter tip.
Pleistocene glacial history of the southern Ahklun Mountains, southwestern Alaska: Soil-development, morphometric, and radiocarbon constraints

Abstract Four new AMS 14 C ages, glacial mapping, and measurements of soil development, loess thickness, and moraine morphology constrain the age and extent of at least three Quaternary advances by outlet lobes of an ice cap over the Ahklun Mountains of southwestern Alaska. The relative-age data are from 107 sites correlated to 25 ice-marginal positions in the Kanektok, Goodnews, Togiak, and Kulukak River valleys and along the southeastern flank of the range. Radiocarbon ages provide minimum ages for six — and a maximum age for one — of the former ice margins. Soil and morphometric parameters subdivide the ice limits into three relative-age groups. One to three pre-Wisconsin advances, probably middle Pleistocene in age, are represented by drift with relatively thick B horizons (60±5 cm, with Bt horizons), thick loess caps (80±12 cm), and broad moraines (135±134 m) with gentle side slopes (7±5°). An extensive early Wisconsin (sensu lato, s.l.) advance, >39.9 ka, and three associated stillstands or readvances are characterized by intermediate soil and morphometric parameters (Bw and weak Bt horizons with thicknesses of 40±11 cm; loess thicknesses of 69±46 cm; crest widths of 38±13 m; and slope angles of 14±4°). The maximum late Wisconsin advance, >16.9 ka, and two readvances or stillstands are associated with thin (20±5 cm), weakly to moderately developed Bw horizons, thin loess caps (28±8 cm), narrow crest widths (28±9 m), and steep slope angles (18±3°). The data confirm that early-Wisconsin glaciers in southeast Beringia were much more extensive than late Wisconsin glaciers, which were apparently limited by availability of moisture.
Which Advance Directive Matters? An Analysis of End-of-Life Decisions Made in Nursing Homes

This study clarifies the role of advance directives in the process of decision making in nursing homes. Physicians reported on the actual use of advance directives in a medical decision-making process related to status changes in 70 nursing home residents (mean age = 89 years). Charts were also reviewed to assess the specifics of the advance directives. Despite a high prevalence of advance directives, the directives themselves had a very limited role in affecting treatments. The physicians surveyed viewed directives related to hospitalization as the most useful, though these were not the most available directives. The attention and format given to advance directives in the nursing home may need to be reevaluated.
Pesticide photoproducts: Generation and significance

As with the parent pesticide, the significance of a pesticide photoproduct depends on its concentration in a given environmental compartment, its toxicity, and exposure of the organism or ecosystem of interest. This requires an understanding of the production and environmental chemistry of each photoproduct as well as its toxicity. While these data are generally available for the parent pesticide, they are rarely determined in detail for the photoproducts. Although the environmental photochemistry of each pesticide is different, some generalizations can be made. Photochemical oxidations, reductions, hydrolytic reactions, and isomerizations often generate products identical to those of metabolic and nonbiological transformations. The chemistry and environmental stability of each individual photoproduct can be substantially different from those of the original pesticide and other products. With several notable exceptions, however, photoproducts are generally less stable to environmental forces and less toxic than the parent pesticide, at least to the target organism. A most significant exception is the P = S to P = O conversion in the organophosphorus insecticides. This sunlight promoted reaction is important in treated fields and has been implicated as a cause of injury to farmworkers.
Perspectives of the Breast Cancer Survivorship Continuum: Diagnosis through 30 Months Post-Treatment

This study explored breast cancer survivors’ perspectives regarding their experiences of the survivorship continuum from diagnosis through 30 months post-treatment. The sample included women (N = 379) with newly-diagnosed breast cancer undergoing treatment at a Midwestern university-affiliated cancer center. Semi-structured interviews were conducted using the Lymphedema and Breast Cancer Questionnaire at time of diagnosis, post-operatively, quarterly during the first year, and then semi-annually thereafter through 30 months post-treatment. A mixed-methodology was used to analyze participants’ comments. Themes central to long-term survivorship experiences included social support, positive worldviews, breast cancer and lymphedema health literacy, religious/spiritual beliefs, self-empowerment, and recovery expectations. These themes were consistent with a psychoneuroimmunological model of health in which psychosocial variables mediate stress and influence health outcomes. Qualitative data showed that social support and positive worldviews were the two themes with the most significant impact on long-term breast cancer survivorship experiences. Survivors expressed a need to advance their health care literacy in order to share ownership of breast cancer and lymphedema treatment decisions. Since breast cancer is an immune-mediated disease, long-term survivorship planning should address psychosocial factors that influence the long-term psychological distress associated with immune dysfunction.
Correlations between Age at Diagnosis and Time Course for New Intraocular Tumors

A retrospective analysis of 355 eyes from 325 patients with bilateral retinoblastoma followed for at least five years was analyzed for the development of new ocular tumors. Eighty-eight eyes (24.8%) developed new tumors with more than 95% of these seen in patients diagnosed before the age of two years. Excluding one patient, no new tumors were seen in patients who were initially diagnosed after 33 months of age. The relative risk for developing new tumors was greater (45.1%) for patients diagnosed within the first six months of life than for patients diagnosed after the age of six months (14.2%). The highest percentage of patients (58%) to develop new tumors were those diagnosed before the age of three months. In patients initially treated before two years of age, new tumors were noted to develop up to 4.5 years later, whereas among eyes diagnosed after the age of two years, 100% of all new tumors were seen before 1.5 years of follow-up. Regardless of the age at diagnosis, however, the upper age limit for...
Efficacy of Immunity-to-Change Coaching for Leadership Development

This study is the first formal, quantitative investigation of the effectiveness of Immunity-to-Change coaching for leadership development. Forty-five supervisors who engaged in Immunity-to-Change coaching were compared with a comparison group of 25 supervisors from the same company to determine whether coached participants reported more progress on their leadership development goals than did comparisons. Coached participants indicated their likelihood of using Immunity-to-Change tools to pursue further goals and identified the coaching components they found most useful. Extensive analyses revealed that the coached group reported significantly more progress toward their leadership development goals than their comparison group counterparts. Accordingly, a vast majority of coached participants indicated intent to use Immunity-to-Change coaching tools again in the future, especially the four-column map. These findings suggest that Immunity-to-Change coaching may be an effective intervention for corporate empl...
Nonnegative Matrix Factorization for Combinatorial Optimization: Spectral Clustering, Graph Matching, and Clique Finding

Nonnegative matrix factorization (NMF) is a versatile model for data clustering. In this paper, we propose several NMF inspired algorithms to solve different data mining problems. They include (1) multi-way normalized cut spectral clustering, (2) graph matching of both undirected and directed graphs, and (3) maximal clique finding on both graphs and bipartite graphs. Key features of these algorithms are (a) they are extremely simple to implement; and (b) they are provably convergent. We conduct experiments to demonstrate the effectiveness of these new algorithms. We also derive a new spectral bound for the size of maximal edge bicliques as a byproduct of our approach.
Drosophila FANCM Helicase Prevents Spontaneous Mitotic Crossovers Generated by the MUS81 and SLX1 Nucleases

Several helicases function during repair of double-strand breaks and handling of blocked or stalled replication forks to promote pathways that prevent formation of crossovers. Among these are the Bloom syndrome helicase BLM and the Fanconi anemia group M (FANCM) helicase. To better understand functions of these helicases, we compared phenotypes of Drosophila melanogaster Blm and Fancm mutants. As previously reported for BLM, FANCM has roles in responding to several types of DNA damage in preventing mitotic and meiotic crossovers and in promoting the synthesis-dependent strand annealing pathway for repair of a double-strand gap. In most assays, the phenotype of Fancm mutants is less severe than that of Blm mutants, and the phenotype of Blm Fancm double mutants is more severe than either single mutant, indicating both overlapping and unique functions. It is thought that mitotic crossovers arise when structure-selective nucleases cleave DNA intermediates that would normally be unwound or disassembled by these helicases. When BLM is absent, three nucleases believed to function as Holliday junction resolvases—MUS81-MMS4, MUS312-SLX1, and GEN—become essential. In contrast, no single resolvase is essential in mutants lacking FANCM, although simultaneous loss of GEN and either of the others is lethal in Fancm mutants. Since Fancm mutants can tolerate loss of a single resolvase, we were able to show that spontaneous mitotic crossovers that occur when FANCM is missing are dependent on MUS312 and either MUS81 or SLX1.
Protocol independence through disjoint encryption

One protocol (called the primary protocol) is independent of other protocols (jointly called the secondary protocol) if the question whether the primary protocol achieves a security goal never depends on whether the secondary protocol is in use. We use multiprotocol strand spaces to prove that two cryptographic protocols are independent if they use encryption in non-overlapping ways. This theorem applies even if the protocols share public key certificates and secret key "tickets". We use the method of Guttman et al. (2000) to study penetrator paths, namely sequences of penetrator actions connecting regular nodes (message transmissions or receptions) in the two protocols. Of special interest are inbound linking paths, which lead from a message transmission in the secondary protocol to a message reception in the primary protocol. We show that bundles can be modified to remove all inbound linking paths, if encryption does not overlap in the two protocols. The resulting bundle does not depend on any activity of the secondary protocol. We illustrate this method using the Neuman-Stubblebine protocol as an example.