cssi/SciSciGPT-SciSciNet huggingface dataset:
Switching and conduction loss analysis of buck converters operating in DCM-only scenarios

Formulas for estimating the most critical switching and conduction losses in low-power buck converters operating in DCM-only schemes with light loads are derived. The derivation takes into account the actual behavior of the converter in DCM instead of relying on commonly-used approximations that are based on CCM operation. This leads to more accurate estimation of losses. The formulas can be used by designers to correctly optimize the sizes of the power FETs and develop realistic budgets for parasitics so as to achieve the best possible efficiency.
Optical character scanning: A discussion of efficiency and politics

Optical Character Recognition is shown to be significantly more expensive than keyboarding, using off-shore contractors, for entry of large amounts of text where high accuracy is required. Using large test samples in French and English, the paper indicates that OCR applications which require significant post-scan editing are labor intensive projects that can be accomplished more efficiently by keyboarding. Most OCR systems are still not capable of entering large amounts of text accurately enough to avoid an expensive editing step.
Distinguishing venues by writing styles

A principal goal for most research scientists is to publish. There are different kinds of publications covering different topics and requiring different writing formats. While authors tend to have unique personal writing styles, no work has been carried out to find out whether publication venues are distinguishable by their writing styles. Our work takes the first step into exploring this problem. Using the traditional classification approach and carrying out experiments on real data from the CiteSeer digital library, we demonstrate that venues are also distinguished by their writing styles.
Evaluation Of Optical Instruments Using Target Detection

When performing psychovisual experiments, the averaged results from a multiplicity of trials are a more reliable measure of image quality than the results from a single trial, e.g., such as those obtained from conventional three-bar measurements. This paper describes the use of multiple targets as a technique for image evaluation of an optical instrument such as a microscope. On the basis of experiments conducted at Perkin-Elmer, related to specialized photographic test targets, the Landolt Ring target array was chosen as a basic image evaluation probe signal. The targets, organized in groups having different sizes, modulations, and magnifications, are in circular arrays with the opening in the Landolt Rings randomly placed in four orientations. An observer is asked to identify the orientation of the opening. After the identification, his responses are scored against the known orientations, and the curves of probability of correct orientation are plotted as a function of target size. This function forms a quantitative measure for evaluating the performance of optical instruments. The theoretical analysis portion of this paper is con-cerned with the development of a mathematical model by which optical instrument performance may be ranked. By means of a series of psychovisual experiments, Human Factors Research, Incorporated, has independently determined curves for probability of correct orientation for a number of observers. There is generally good agreement between empirical data and model predictions, approximately 90% for both unaided eye viewing and microscope viewing of test target arrays.
Paleomagnetism of the Ocotillo Badlands, southern California, and implications for slip transfer through an antidilational fault jog

Abstract The right-lateral Coyote Creek fault is the southernmost segment of the San Jacinto fault zone in California. At the Ocotillo Badlands, an anticlinorium of locally updomed material is exposed at a step-over between echelon segments of the fault. Here, uplift and deformation most probably result from multiple slip increments transferred across the antidilational fault jog, under the assumption that material away from the jog region deforms by rigid body translation. Within the 2 km wide fault jog, contraction has occurred by folding of the Quaternary sedimentary strata about east-west trending hinge lines. Structural analysis of this deformation shows that folding has accommodated ∼ 800 m of fault slip transferred through the antidilational jog. By comparison, total right slip on the Coyote Creek fault is 2.5 km, measured 25 km to the northwest at Coyote Ridge. A magnetostratigraphic study of the deformed strata was undertaken to determine the longevity of this fault discontinuity at the Ocotillo Badlands. The eroded core of the updomed material at the Ocotillo Badlands exposes a 325 m thick sequence of sedimentary rock, made up by the lacustrine Borrego Formation (∼ 200 m) and the overlying conglomeratic Ocotillo Formation (∼ 125 m). Stepwise thermal demagnetization of samples from the exposed strata suggests that the formation boundary also marks a magnetic polarity reversal, of reversed field to normal field as one travels upwards through the composite section. The inferred primary magnetization is probably produced by a detrital remanent magnetization (DRM) and is often overprinted with a weak, viscous present field component. Comparison with magnetostratigraphy of the Borrego Badlands 10 km to the northwest indicates that the reversal sampled is the onset of the Jaramillo event (0.97 Ma). The presence of a 20° angular unconformity within the upper portion of the exposed stratigraphy shows that deformation within the Ocotillo Badlands began during deposition of the Ocotillo Formation, shortly after the time of the field reversal. If total slip on the Coyote Creek fault at the Ocotillo Badlands is greater than 800 m, it appears that the fault jog has been a transitory feature within the fault zone, with slip alternately bypassing it or being transferred across it. Such switchyard behavior of slip transfer through the fault jog has important implications for understanding structural controls on earthquake rupture.
Preparation and characterization of planar Ni-Au bimetallic model catalysts

Abstract Ni–Au bimetallic model catalysts were prepared as thin films on Re(0 0 0 1) or Ru(0 0 0 1) single crystal substrates. Surface compositions and electronic structures of the Ni–Au thin films were characterized by low energy ion scattering spectroscopy and X-ray photoelectron spectroscopy, respectively. Surface alloys were prepared by annealing Ni–Au thin films from 500 to 800 K, resulting in substantial surface enrichment of Au. Annealing a Ni–Au thin film with a 1:1 bulk composition ratio at 700 K for 10 min resulted in a surface alloy with 84% (atomic concentration) of Au in the outermost surface layer. The surface atomic structure was investigated using CO as probe molecules, which exclusively adsorbs on the Ni atoms rather than on the Au atoms at room temperature. Polarization modulation infrared reflection absorption spectroscopy of CO adsorption on Ni–Au surface alloys showed that CO adsorption on two-fold bridge sites decreased and finally disappeared with an increase of Au surface concentration. The absence of Ni bridge site CO adsorption indicated that Ni atoms were isolated by Au atoms on Ni–Au alloyed surface.
Symmetric designs with bruck subdesigns

IfP is a finite projective plane of ordern with a proper subplaneQ of orderm which is not a Baer subplane, then a theorem of Bruck [Trans. AMS 78(1955), 464–481] asserts thatn≧m2+m. If the equalityn=m2+m were to occur thenP would be of composite order andQ should be called a Bruck subplane. It can be shown that if a projective planeP contains a Bruck subplaneQ, then in factP contains a designQ′ which has the parameters of the lines in a three dimensional projective geometry of orderm. A well known scheme of Bruck suggests using such aQ′ to constructP. Bruck’s theorem readily extends to symmetric designs [Kantor, Trans. AMS 146 (1969), 1–28], hence the concept of a Bruck subdesign. This paper develops the analoque ofQ′ and shows (by example) that the analogous construction scheme can be used to find symmetric designs.
Prevalence of hepatitis B and C in patients with meningiomas and glioblastoma multiforme

The prevalence of hepatitis B and C in patients with glioblastoma multiforme or meningiomas has not been described. These infections are known to modulate the activity of the immune system, which potentially influences the development and course of cancer. We hypothesized that chronic hepatitis infection, which activates the immune system, decreases the risk of brain tumors, particularly those that are highly malignant. We performed a retrospective study to examine the prevalence of hepatitis B and C in patients with meningiomas and glioblastomas. The combined prevalence of hepatitis B and C in the USA from 1999–2008 was 5.7%. The prevalence of hepatitis B and C in patients with meningiomas was 2.4%; while among glioblastoma patients, the prevalence of hepatitis B and C was 1.38%. The odds ratio of having hepatitis B or C with glioblastoma versus meningiomas was 0.56, with a confidence interval of 0.19–1.6 and a P-value of 0.29. Compared with historical controls, the prevalence of hepatitis B and C in meningioma and glioblastoma patients was decreased. However, this difference may be attributed to the retrospective nature of our data and the natural history of hepatitis B and C infections. The prevalence of these viral infections was not statistically different in patients with meningiomas and glioblastomas. This suggests that hepatitis B and C primarily influence slow-growing, benign tumors and more aggressive cancers equally, if at all. To definitively test our hypothesis, future studies in which data are prospectively gathered are likely to be required.
Aqueous shunt exposure: a retrospective review of repair outcome.

Purpose To describe the patient outcomes and factors affecting those outcomes after aqueous shunt exposure repair. Patients and methods Forty-three eyes from Robert Cizik Eye Clinic and Bascom Palmer Eye Institute from 1995 to 2007 suffered from aqueous shunt exposure and were repaired by participating surgeons. Thirty-three were tube exposures and 7 were plate exposures. The remaining 3 exposure classified complications included a patch graft exposure, an elbow exposure, and 1 unknown complication. Forty eyes were followed for evidence of additional aqueous shunt exposures or additional surgical interventions for 46.6 weeks (40.2 wk) (range: 3 to 168 wk). Results Seventeen of 40 eyes required additional surgical intervention: 15 (45%) from the tube exposure group and 2 (29%) from the plate exposure group. Five (13%) eyes needed eventual removal of the shunt. Black race, diabetes mellitus, a high number of glaucoma medications before shunt implantation, a history of multiple glaucoma laser procedures, and combination of an initial aqueous shunt implantation with another surgery were found to be associated with a worse outcome after exposure repair. Conclusions Intraocular pressure, number of medications, and visual acuity remained stable during follow-up after revision. Diabetes mellitus was associated with a shorter average time between initial repair and reintervention, and 4 other variables were associated with a higher likelihood of reintervention.
Stochastic programming models for air quality management

Abstract Five stochastic programming models are developed for identifying cost-effective acid rain control strategies. Four of the models are based upon chance constrained formulations—the last is a two-stage programming model with simple recourse. The chance constrained models include both traditional forms in which individual constraint reliability levels are user-prescribed constants, we well as a joint chance constrained model in which reliability levels are cast as decision variables.
The World as a Company Town: A Case Study from Indonesia

Stepchildren of Progress: the Political Economy of Development in an Indonesian Village, Kathryn M. Robinson. (SUNY Press: Albany, NX 1986. xvi. 315 pp. Hardcover $44.50, paper $16.95.). Volume in the SUNY Anthropology of Work Series, Edited by June Nash).
First-principles calculations of the dielectric properties of perovskite-type materials

We compare first-principles (FP) calculations of the ionic effective charges, phonon frequencies, and static dielectric permittivities K, of several perovskite-type materials. Transition metal ions have anomalously large effective charges, though in the double perovskite CaAl 1/2 Nb 1/2 O 3 (CAN), the effective charge of Nb is significantly lower than in the simple perovskite KNbO 3 , showing different Nb-O bonding chemistry. Tolerance factors, cation chemistry, and structural phase transitions all affect the nature of the softest phonons in perovskites. For the solid solution (CaAl 1/2 Nb 1/2 O 3 ) 1-x (CaTiO 3 ) x (CAN-CT), κ s is modeled via a cluster expansion, with the parameters determined from FP. In pure CAN, K, is found to increase when cation disorder increases, in agreement with experimental results on analogous systems. The dielectric constant of CAN-CT increases nonlinearly with x, in agreement with experiment.
Professional Development for Early Childhood Education: A National Perspective

The article introduces the reader to a special issue of NHSA Dialog that focuses on the professional development (PD) of early childhood educators. The article opens with a perspective from a historical lens, namely that of PD in K--12 education and the evolution of Learning Forward, formerly the National Staff Development Council. The recently (2011) revised Standards for Professional Learning are included, leading into more recent developments in early childhood education professional learning. Finally, the article introduces the reader to each research article included in the issue.
Statistical treatment of fluctuations in the gravitational focusing of light due to stellar masses within a gravitational lens.

When light from small, distant sources in the universe is gravitationally focused by an intervening galaxy, the gravitational lens can be influenced by the granularity of the matter distribution which is caused by the stellar (or other compact) masses in the galaxy. A largely analytic, statistical calculation for a gravitational lens due to a collection of compact masses - valid for sources of finite size and for large (as well as small) 'optical depths' for the lens - is developed to treat fluctuations in the light caused by such 'microfocusing' effects. Previous treatments have been either numerical simulations of the Monte Carlo type or limited to single-star (i.e., low-optical-depth) effects.
Sequential Equivalence Checking for Clock-Gated Circuits

Sequential logic synthesis often leads to substantially easier equivalence checking problems, compared to general-case sequential equivalence checking (SEC). This paper theoretically investigates when SEC can be reduced to a combinational equivalence checking (CEC) problem. It shows how the theory can be applied when sequential transforms are used, such as sequential clock gating, retiming, and redundancy removal. The legitimacy of such transforms is typically justified intuitively, by the designer or software developer believing that the two circuits reach the same state after a finite number of cycles, and no difference is observed at the outputs due to fanin non-controllability and fanout non-observability effects.
A case for molecular recognition in nuclear separations: sulfate separation from nuclear wastes.

In this paper, we present the case for molecular-recognition approaches for sulfate removal from radioactive wastes via the use of anion-sequestering systems selective for sulfate, using either liquid–liquid extraction or crystallization. Potential benefits of removing sulfate from the waste include improved vitrification of the waste, reduced waste-form volume, and higher waste-form performance, all of which lead to potential cleanup schedule acceleration and cost savings. The need for sulfate removal from radioactive waste, especially legacy tank wastes stored at the Hanford site, is reviewed in detail and primarily relates to the low solubility of sulfate in borosilicate glass. Traditional methods applicable to the separation of sulfate from radioactive wastes are also reviewed, with the finding that currently no technology has been identified and successfully demonstrated to meet this need. Fundamental research in the authors’ laboratories targeting sulfate as an important representative of the class ...
Body composition changes during androgen deprivation therapy for prostate cancer: A 2-year prospective study

Background Little is known about the long-term impact of androgen deprivation therapy (ADT) on body composition in men with prostate cancer. We compared body composition parameters in men with non-metastatic prostate cancer on or not on therapy with healthy, age-matched controls at baseline and monitored changes over a 2-year period.
Comparison of T1rho imaging between spoiled gradient echo (SPGR) and balanced steady state free precession (b-FFE) sequence of knee cartilage at 3T MRI

Poster: "ECR 2015 / C-0291 / Comparison of T1rho imaging between spoiled gradient echo (SPGR) and balanced steady state free precession (b-FFE) sequence of knee cartilage at 3 tesla" by: "T. Nozaki, Y. Kaneko, H. Yu, K. Kaneshiro, R. Schwarzkopf, H. Yoshioka; Orange, CA/US"
Corporate Cultures: The Rites and Rituals of Corporate Life

The article presents a review of the book “Corporate Cultures: The Rites and Rituals of Corporate Life,” by Terrence E. Deal and Allan A. Kennedy.
Model Based Power-Split and Control for Electric Energy System in a Hybrid Electric Vehicle

In this paper, a configuration of electric energy storage system for Hybrid Electric Vehicles has been proposed that consists of a small battery and ultracapacitor pack coupled to the vehicle bus through dc-dc converters. The entire system, together with necessary power electronics pack, has been modeled and a Model Predictive Controller (MPC) has been designed for the purpose of power management of the linearized system. This controller has been simulated with the nonlinear plant for charging and discharging current profiles and is shown to be working well around the equilibrium point of the plant. Results show the effectiveness of this approach in keeping the battery current small and steady during fast transients and peak load conditions.Copyright © 2006 by ASME
The Evolution of Balanced, Low-Mode Vortices on the β-Plane

Abstract Numerical solutions are examined for nearly axisymmetric geopotential monopole vortices whose vertical structure is essentially confined to the lowest few vertical modes. The vortex environment is a rotating, stratified fluid with spatially variable Coriolis frequency (the β-plane). Solutions are examined with Rossby numbers in an order one range about zero, and therefore the balance equations are and appropriate model. Solutions From the quasi-geostrophic and primitive equations are also examined, and we find that the balance equations are much more accurate than the former and more efficient, both conceptually and computationally, than the latter. The central parameter regime is one of stable vortex propagation, accompanied by week Rossby wave radiation and slow changes in vortex shape, with the latter due more to the radiation than the weak dissipation. Various types of instability—baroclinic, barotropic, and inertial—act to delimit the stable regime for vortices.
Simulation-Based Estimate of QoS for Voice Traffic over WCDMA Radio Links

WCDMA radio links are subjected to multipath fading which introduce burst errors in the transmitted vocoder frames. This paper presents a methodology for assessing the impact of bursty frame errors on voice quality as measured by MOS (Mean Opinion Score) using waveform level simulations. The approach presented consists of simulating the frame error sequence and mapping the frame error sequence to a sequence of instantaneous MOS values using the ITU E-Model and a recency model. The proposed methodology is applied to estimate the QoS for voice traffic over a wide variety of WCDMA radio channels. Both average MOS scores and link availability (defined as the fraction of time the MOS is greater than an acceptance threshold) are estimated. It is shown that there exits a simple relationship between the average frame error rate (which is a parameter for the physical layer design) and the average MOS and link availability for voice traffic over a broad range of radio channels with multipath fading.
Some structural, biochemical and biophysical characteristics of L-929 cells growing in the presence of hyperosmotic sorbitol concentrations

Mouse L-929 cells (a fibroblast-like line) were transferred from normal growth medium to one supplemented with 0.3 M sorbitol, doubling the normal external osmotic pressure. After a short lag phase and minimal cell death, the cells began to grow, and the growth rate reached that of controls after about one week. These chronically grown cells (S) have been compared to those of control cultures (C) with regard to general morphology, ability to reverse when returned to normal condition, water content, volume and selected metabolic parameters. S-cell cultures exhibited considerable heterogeneity but most contained vesicle-like cytoplasmic structures, sometimes in abundance. These structures do not appear to be completely bounded by membranes, but that is uncertain. S cells become larger and contain more water than C cells; however, the ratio of total water to total dry mass is indistinguishable from controls suggesting regulation at that level. S and C cells were found to be remarkably similar, on a per cell basis, with regard to their rate of respiration and the incorporation of glucose into metabolites and macromolecules. These results are interpreted in terms of current views on the composition and organization of the aqueous compartments of animal cells.
Diffusion and solution of gases into thermally softened or molten polymers: Part II. Relation of diffusivities and solubilities with temperature pressure and structural characteristics

Solubilities and diffusivities of various gases (helium, nitrogen, carbon dioxide, argon, neon, krypton, and monochlorodifluoromethane) in molten or thermally softened polymers (polyethylene, polypropylene, polyisobutylene, polystyrene, and polymethylmethacrylate) have been correlated with structural characteristics, temperature, and pressure. Temperature dependence of both Henry's Law constants and diffusivities were of the Arrhenius equation form. No appreciable effect of pressure was found for either Henry's Law constants or diffusivities up to 300 atm. Earlier correlations for Henry's Law constants in solid polymer systems were found to be inapplicable for molten and thermally softened polymers. New correlations were developed individually for the latter systems. The correlating factor used was the gas Lennard-Jones force constant. Existing correlations for diffusivities were also found not to apply to molten and thermally softened systems. New correlations were again developed on an individual polymer basis. These related diffusivity to gas Lennard-Jones collision diameter or molecular diameter. Generalized correlations were also developed that held for a number of polymers. These were for both Henry's Law constants and diffusivities.
Encoding frequency Modulation to improve cochlear implant performance in noise

Different from traditional Fourier analysis, a signal can be decomposed into amplitude and frequency modulation components. The speech processing strategy in most modern cochlear implants only extracts and encodes amplitude modulation in a limited number of frequency bands. While amplitude modulation encoding has allowed cochlear implant users to achieve good speech recognition in quiet, their performance in noise is severely compromised. Here, we propose a novel speech processing strategy that encodes both amplitude and frequency modulations in order to improve cochlear implant performance in noise. By removing the center frequency from the subband signals and additionally limiting the frequency modulation's range and rate, the present strategy transforms the fast-varying temporal fine structure into a slowly varying frequency modulation signal. As a first step, we evaluated the potential contribution of additional frequency modulation to speech recognition in noise via acoustic simulations of the cochlear implant. We found that while amplitude modulation from a limited number of spectral bands is sufficient to support speech recognition in quiet, frequency modulation is needed to support speech recognition in noise. In particular, improvement by as much as 71 percentage points was observed for sentence recognition in the presence of a competing voice. The present result strongly suggests that frequency modulation be extracted and encoded to improve cochlear implant performance in realistic listening situations. We have proposed several implementation methods to stimulate further investigation.
Tropospheric methane retrieved from ground-based near-IR solar absorption spectra

High-resolution near-infrared solar absorption spectra recorded between 1977 and 1995 at the Kitt Peak National Solar Observatory are analyzed to retrieve column abundances of methane (CH_4), hydrogen fluoride (HF), and oxygen (O_2). Employing a stratospheric “slope equilibrium” relationship between CH_4 and HF, the varying contribution of stratospheric CH_4 to the total column is inferred. Variations in the CH_4 column due to changes in surface pressure are determined from the O_2 column abundances. By this technique, CH_4 tropospheric volume mixing ratios are determined with a precision of ∼0.5%. These display behavior similar to Mauna Loa in situ surface measurements, with a seasonal peak-to-peak amplitude of approximately 30 ppbv and a nearly linear increase between 1977 and 1983 of 18.0 ± 0.8 ppbv yr^(−1), slowing significantly after 1990.
The relationship between parental alcohol use, early and late adolescent alcohol use, and young adult psychological symptoms: A longitudinal study

We tested the hypothesis that there is a mediational pathway from parental alcohol use during the participants' adolescence to the participants' psychological symptoms in young adulthood. This pathway includes the participants' alcohol use and their psychological symptoms, both during adolescence. The participants are inner city African American and Puerto Rican early adolescents followed until young adulthood. They reported their own and their parents' behavior. Structural equation modeling showed that parental alcohol use was related to early adolescent alcohol use, which was associated with late adolescent alcohol use. Late adolescent alcohol use was related to psychological symptoms in late adolescence, which predicted young adult psychological symptoms. Males reported more alcohol use and more psychological symptoms than females in late adolescence and more psychological symptoms in young adulthood. Findings suggest that parents' and adolescents' alcohol use should be a focus in interventions designed to prevent or treat psychological symptoms in late adolescence and young adulthood.
Microstrip transmission line excitation of dielectric resonator antennas

A systematic investigation of the excitation of a cylindrical dielectric resonator antenna was undertaken to illustrate the possibility of such a feed structure and to characterise the coupling behaviour and radiation patterns of the system.
A Galërkin approach to electronic near-degeneracies in molecular systems

We consider superposition states of various numbers of eigenstates in order to study vibrating quantum billiards semiquantally. We discuss the relationship between Galerkin methods, inertial manifolds, and partial differential equations such as nonlinear Schrodinger equations and Schrodinger equations with time-dependent boundary conditions. We then use a Galerkin approach to study vibrating quantum billiards. We consider one-term, two-term, three-term, d-term, and infinite-term superposition states. The number of terms under consideration corresponds to the level of electronic near-degeneracy in the system of interest. We derive a generalized Bloch transformation that is valid for any finite-term superposition and numerically simulate three-state superpositions of the radially vibrating spherical quantum billiard with null angular-momentum eigenstates. We discuss the physical interpretation of our Galerkin approach and thereby justify its use for vibrating quantum billiards. For example, d-term superposition states of one degree-of-vibration quantum billiards may be used to study nonadiabatic behavior in polyatomic molecules with one excited nuclear mode and a d-fold electronic near-degeneracy. Finally, we apply geometric methods to analyze the symmetries of vibrating quantum billiards.
Critical isotherms from virial series using asymptotically consistent approximants

The low-density equation of state of a fluid along its critical isotherm is considered. An asymptotically consistent approximant is formed having the correct leading-order scaling behavior near the vapor-liquid critical point, while retaining the correct low-density behavior as expressed by the virial equation of state. The formulation is demonstrated for the Lennard–Jones fluid, and models for helium, water, and n-alkanes. The ability of the approximant to augment virial series predictions of critical properties is explored, both in conjunction with and in the absence of critical-property data obtained by other means. Given estimates of the critical point from molecular simulation or experiment, the approximant can refine the critical pressure or density by ensuring that the critical isotherm remains well-behaved from low density to the critical region. Alternatively, when applied in the absence of other data, the approximant remedies a consistent underestimation of the critical density when computed from the virial series alone. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3336–3349, 2014
Three-dimensional tracking of fluorescent particles

Single molecule measurements are generally made in conditions that depart from physiological conditions, such as with molecules excised from cells or even immobilized on surfaces. Such departures can easily cause measurements on biomolecules to be inexact. A tracking instrument to follow a single molecule's path in three dimensions inside a living cell would be a major step towards enabling single-molecule observations in physiological conditions. We describe an instrument that will extend the state of the art in single-molecule tracking technology, allowing extended observations of single particles as they diffuse and are transported. Computations show that our approach should be capable of tracking a protein-sized object diffusing at intracellular speeds for average times of over two seconds - long enough to track a typical fluorescent molecule from capture to photobleaching.
Dexrazoxane Ameliorates Doxorubicin-Induced Injury in Mouse Ovarian Cells

Doxorubicin (DXR) is a frontline chemotherapy agent implicated in unintended ovarian failure in female cancer survivors. The fertility preservation techniques currently available for cancer patients are often time and cost prohibitive and do not necessarily preserve endocrine function. There are no drug-based ovary protection therapies clinically available. This study provides the first investigation using dexrazoxane (Dexra) to limit DXR insult in ovarian tissue. In KK-15 granulosa cells, a 3-h DXR treatment increased double-strand (ds) DNA breaks 40%-50%, as quantified by the neutral comet assay, and dose-dependent cytotoxicity. Dexra exhibited low toxicity in KK-15 cells, inducing no DNA damage and less than 20% cell loss. Cotreating KK-15 cells with Dexra prevented acute DXR-induced dsDNA damage. Similarly, Dexra attenuated the DXR-induced 40%-65% increase in dsDNA breaks in primary murine granulosa cells and cells from in vitro cultured murine ovaries. DXR can cause DNA damage either through a topoisomerase II-mediated pathway, based on DXR intercalation into DNA, or through oxidative stress. Cotreating KK-15 cells with 2 μM Dexra was sufficient to prevent DXR-induced, but not H(2)O(2)-induced, DNA damage. These data indicated the protective effects are likely due to Dexra's inhibition of topoisomerase II catalytic activity. This putative protective agent attenuated downstream cellular responses to DXR, preventing H2AFX activation in KK-15 cells and increasing viability as demonstrated by increasing the DXR lethal dose in KK-15 cells 5- to 8-fold (LD(20)) and primary murine granulosa cells 1.5- to 2-fold (LD(50)). These data demonstrate Dexra protects ovarian cells from DXR insult and suggest that it is a promising tool to limit DXR ovarian toxicity in vivo.
Learning and Opinion Change, Not Priming: Reconsidering the Priming Hypothesis

According to numerous studies, campaign and news media messages can alter the importance individuals place on an issue when evaluating politicians, an effect called priming. Research on priming revived scholarly interest in campaign and media effects and implied, according to some, that campaigns and the media can manipulate voters. There are, however, alternative explanations for these priming findings, alternatives that previous studies have not fully considered. In this article, I reanalyze four cases of alleged priming, using panel data to test priming effects against these alternatives. Across these four cases, I find little evidence of priming effects. Instead, campaign and media attention to an issue creates the appearance of priming through a two-part process: Exposing individuals to campaign and media messages on an issue (1) informs some of them about the parties’ or candidates’ positions on that issue. Once informed, (2) these individuals often adopt their preferred party's or candidate's position as their own.
Maximum likelihood estimation of 2-D superimposed exponential signals

The problem of maximum likelihood estimation of the parameters (i.e. frequencies, amplitudes, and noise variance) of 2-D superimposed exponential signals is considered. In this paper, a polynomial rooting approach is proposed to obtain the estimates of the 2-D frequencies. Strong consistency and limiting distribution are established for the estimates of the parameters. Furthermore, the covariance matrix of the limiting distribution attains the Cramer-Rao lower bound. >
AMSSM thematic issue: care of the female athlete

Athletic opportunities for females have come a long way since the passage of Title IX in the USA in 1972, and the first Olympic women's marathon in 1984. More than three million girls participate in high-school sports each year in the USA; there have been consecutive increases in participation in the past 24 years. With a steady rise in participation, come the positives and negatives. The positives range from improved academic performance in school age individuals to enhanced well-being in older athletes, in addition to many other benefits that extend across the lifespan. Negative consequences are inevitable, but are largely preventable. In this issue, several articles highlight the impact of sports and exercise on the health of female athletes. Dr De Souza and colleagues1 review the existing literature and present guidelines on clearance …
Diabetic-induced endothelial dysfunction in rat aorta: role of hydroxyl radicals

Objective: Previous studies suggest a role of superoxide anion radicals (·O2−) in impaired endothelium-dependent relaxation of diabetic blood vessels; however, the role of secondary reactive oxygen species remains unclear. In the present study, we investigated a role of various potential reactive oxygen species in diabetic endothelial dysfunction. Methods: Thoracic aortic rings from 8-week streptozotocin-induced diabetic and age-matched control rats were mounted in isolated tissue baths. Endothelium-dependent relaxation to acetylcholine (ACH) and endothelium-independent relaxation to nitroglycerin (NTG) were assessed in precontracted rings. Results: ACH-induced relaxation was impaired in diabetic compared to control rings and was not improved with either indomethacin or daltroban. ACH-induced relaxation in both control and diabetic rings was completely blocked with the nitric oxide synthase inhibitors, l-nitroarginine methyl ester or l-nitroarginine (l-NA). NTG-induced relaxation was insensitive to l-NA and was unaltered by diabetes. Pretreatment with superoxide dismutase (SOD) at activities which did not alter contractile tone failed to alter responses to ACH in diabetic rings. Similar results were obtained using either catalase or mannitol. In contrast, the combination of SOD plus catalase or DETAPAC, an inhibitor of metal-facilitated hydroxyl radical (·OH) formation, markedly enhanced relaxation to ACH in diabetic but not in control rings. Neither the combination of SOD plus catalase nor DETAPAC altered the sensitivity or relaxation to NTG in control rings with or without endothelium. In diabetic rings with endothelium, both DETAPAC or SOD plus catalase increased sensitivity but not maximum relaxation to NTG. In diabetic rings without endothelium, relaxation and sensitivity to NTG were unaltered by either treatment. In l-NA-treated diabetic rings with endothelium, sensitivity and relaxation to NTG was unaltered by either DETAPAC or SOD plus catalase. Conclusion: Diabetic endothelium produces increases in both ·O2− and H2O2 leading to enhanced intracellular production of ·OH. Thus, ·OH are implicated in diabetes-induced endothelial dysfunction.
Mercer kernels for object recognition with local features

A new class of kernels for object recognition based on local image feature representations are introduced in this paper. These kernels satisfy the Mercer condition and incorporate multiple types of local features and semilocal constraints between them. Experimental results of SVM classifiers coupled with the proposed kernels are reported on recognition tasks with the COIL-100 database and compared with existing methods. The proposed kernels achieved competitive performance and were robust to changes in object configurations and image degradations.
Feminine Hygiene Products—Issues and Answers

With a combination of literature review and report of personal correspondence with 22 companies, an examination of the feminine hygiene products currently on the market is presented. Two Chicago metropolitan area pharmacies were visited, and the names and types of feminine hygiene products offered for sale were noted, along with addresses of companies. The purposelessness of the douche for routine feminine hygiene and the inefficacy of feminine hygiene deodorant sprays were revealed. Sanitary napkins and vaginal tampons were found to be effective ways to absorb menstrual discharge. Tampons also provide an effective way, to absorb postpartum lochia. Nursing implications involved with each product are also discussed.
Changing Communication Environments in MosquitoNet

MosquitoNet is a new project at Stanford University for investigating operating system and application issues in mobile and wireless computing. Our initial goals focus on providing the appearance of continuous network connectivity for mobile hosts. To achieve these goals we must first enable portable computers to move seamlessly from one communications medium to another, for example from an Ethernet connection to a wireless modem, without rebooting or restarting applications. Second, we must determine how to manage the resulting dynamic changes in network characteristics, either transparently or through a simple interface between the network and the applications. Other goals include developing power management policies for network devices and experimenting with file data consistency algorithms for networks in which disconnection may be economically desirable, but seamless network re-connection is almost always possible.
The Process of Innovation Assimilation by Firms in Different Countries: A Technology Diffusion Perspective on E-Business

This paper extends our previous studies on the assimilation of Internet-based e-business innovations by firms in an international setting. Drawing upon theories on the process and contexts of technology diffusion, we develop an integrative model to examine three assimilation stages: initiation → adoption → routinization. The model features technological, organizational, and environmental contexts as prominent antecedents of this three-stage assimilation process. Based on this model, we hypothesize how technology readiness, technology integration, firm size, global scope, managerial obstacles, competition intensity, and regulatory environment influence e-business assimilation at the firm level. A unique data set of 1,857 firms from 10 countries is used to test the conceptual model and hypotheses. To probe deeper into the influence of the environmental context, we compare two subsamples from developed and developing countries. Our empirical analysis leads to several key findings: (1) Competition positively affects initiation and adoption, but negatively impacts routinization, suggesting that too much competition is not necessarily good for technology assimilation because it drives firms to chase the latest technologies without learning how to use existing ones effectively. (2) Large firms tend to enjoy resource advantages at the initiation stage, but have to overcome structural inertia in later stages. (3) We also find that economic environments shape innovation assimilation: Regulatory environment plays a more important role in developing countries than in developed countries. Moreover, while technology readiness is the strongest factor facilitating assimilation in developing countries, technology integration turns out to be the strongest in developed countries, implying that as e-business evolves, the key determinant of its assimilation shifts from accumulation to integration of technologies. Together, these findings offer insights into how innovation assimilation is influenced by contextual factors, and how the effects may vary across different stages and in different environments.
Dynamic Management of Real-Time Location Data on GPS-Enabled Mobile Phones

Advanced location based services have the ability to track users with Global Positioning System (GPS)-enabled cell phones in real-time. These applications share a common problem; the continuous calculation and transmission of GPS fixes from the mobile phone to a server consumes a considerable amount of energy and increases data transmission costs. Therefore, an application-level algorithm is necessary to reduce the number of GPS fixes calculated and transmitted, while continuing to track the user in real-time and record an accurate representation of his or her travel path. In this paper, two complementary algorithms are presented: the critical point (CP) algorithm, which filters data points to be transmitted to the server, and the location-aware state machine, which dynamically manages the frequency of the location re-calculation update rate. Both algorithms were implemented in TRAC-IT, a Java Micro Edition (Java ME) application designed to automatically collect user travel behavior; the proposed algorithms allow TRAC-IT to build an accurate representation of the user's path with a considerably reduced number of fixes while significantly extending mobile device battery life.
Hormone predictors of abnormal bone microarchitecture in women with anorexia nervosa.

Osteopenia is a complication of anorexia nervosa (AN) associated with a two- to three-fold increase in fractures. Nutritional deficits and hormonal abnormalities are thought to mediate AN-induced bone loss. Alterations in bone microarchitecture may explain fracture risk independent of bone mineral density (BMD). Advances in CT imaging now allow for noninvasive evaluation of trabecular microstructure at peripheral sites in vivo. Few data are available regarding bone microarchitecture in AN. We therefore performed a cross-sectional study of 23 women (12 with AN and 11 healthy controls) to determine hormonal predictors of trabecular bone microarchitecture. Outcome measures included bone microarchitectural parameters at the ultradistal radius by flat panel Volume CT (fpVCT); BMD at the PA and lateral spine, total hip, femoral neck and ultradistal radius by dual energy X-ray absorptiometry (DXA); and IGF-I, leptin, estradiol, testosterone and free testosterone levels. Bone microarchitectural measures, including apparent (app.) bone volume fraction, app. trabecular thickness, and app. trabecular number, were reduced (p<0.03) and app. trabecular spacing was increased (p=0.02) in AN vs. controls. Decreased structural integrity at the ultradistal radius was associated with decreased BMD at all sites (p=0.05) except for total hip. IGF-I, leptin, testosterone and free testosterone levels predicted bone microarchitecture. All associations between both IGF-I and leptin levels and bone microarchitectural parameters, and most associations between androgen levels and microarchitecture remained significant after controlling for body mass index. We concluded that bone microarchitecture is abnormal in women with AN. Endogenous IGF-I, leptin and androgen levels predict bone microarchitecture independent of BMI.
Maximizing STEM Education Initiatives on a Minimized Library Budget

This article provides practical suggestions for making opportunities for STEM education partnerships and programming, despite the funding struggles of many academic libraries. With the pressure from internal and external funding avenues, academic libraries must create an environment where libraries and librarians reach out in order to drive buy in for library programs, services, and support. Using the book budget cuts and serial subscription reconfiguration at the University Libraries of the University of Memphis as a jumping off point, this article explores creative but necessary strategies for connecting with students, faculty, librarians and others engaged in STEM education. The creation of the Center for Research and Innovation for STEM Teaching and Learning (CRISTAL) at the University of Memphis presented a critical opportunity for engagement with the libraries. Points of discussion include how the University Libraries became involved with CRISTAL, the ways the CRISTAL has driven its engagement with our Libraries, resources implemented to broaden the impact of this relationship, literature supporting the approaches and opportunities related to such collaborations, and our plans moving forward. This article also includes suggestions for how such opportunities might present, and might be embraced, at other institutions, whether you have a CRISTAL or not.
Combinatorial Methods for Polymer Materials Science: Phase Behavior of Nanocomposite Blend Films

Polymer materials are often mixed with inorganic materials in the bulk to enhance properties, including mechanical, electrical, thermal, and physical. Such property enhancements are induced not only by the physical presence of the filler but also significantly by the interaction of the polymer with the filler via altering the local properties of the polymer material. In this regard, recently layered silicate nanocomposites have been shown to be effective in modifying the polymer properties because of their high surface area of contact between the polymer and the high aspect ratio nanoparticle. Potential property enhancements should also occur in polymer nanocomposite thin films owing to nanoparticle orientation from film confinement effects. In this paper we investigate the effect of layered silicate nanoparticles on the phase behavior of a classic polymer blend using small angle neutron scattering and compare those results to phase diagrams obtained by high throughput combinatorial methods.