The Remarkably Featureless High Resolution X-ray Spectrum of Mrk 478

An observation of Mrk 478 using the Chandra Low Energy Transmission Grating Spectrometer is presented. The source exhibited 30-40% flux variations on timescales of order 10000 s together with a slow decline in the spectral softness over the full 80 ks observation. The 0.15--3.0 keV spectrum is well fitted by a single power law with photon index of Gamma = 2.91 +/- 0.03. Combined with high energy data from BeppoSAX, the spectrum from 0.15 to 10 keV is well fit as the sum of two power laws with Gamma = 3.03 +/- 0.04, which dominates below 2 keV and 1.4 +/- 0.2, which dominates above 2 keV (quoting 90% confidence uncertainties). No significant emission or absorption features are detected in the high resolution spectrum, supporting our previous findings using the Extreme Ultraviolet Explorer but contradicting the claims of emission lines by Hwang & Bowyer (1997). There is no evidence of a warm absorber, as found in the high resolution spectra of many Sy 1 galaxies including others classified as narrow line Sy 1 galaxies such as Mrk 478. We suggest that the X-ray continuum may result from Comptonization of disk thermal emission in a hot corona through a range of optical depths.Comment: 21 pages, 7 figures; accepted for publication in the Astronomical Journa

X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180

The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days and 12 days with ASCA and RXTE (and EUVE for Ton S180). The short time scale (hours-days) variability patterns were very similar across energy bands, with no evidence of lags between any of the energy bands studied. The fractional variability amplitude was almost independent of energy band. It is difficult to simultaneously explain soft Seyferts stronger variability, softer spectra, and weaker energy-dependence of the variability relative to hard Seyferts. The soft and hard band light curves diverged on the longest time scales probed, consistent with the fluctuation power density spectra that showed relatively greater power on long time scales in the softest bands. The simplest explanation is that a relatively hard, rapidly-variable component dominates the total X-ray spectrum and a slowly-variable soft excess is present in the lowest energy channels of ASCA. Although it would be natural to identify the latter with an accretion disk and the former with a corona surrounding it, a standard thin disk could not get hot enough to radiate significantly in the ASCA band, and the observed variability time scales are much too short. The hard component may have a more complex shape than a pure power-law. The most rapid factor of 2 flares and dips occurred within ~1000 sec in Ark 564 and a bit more slowly in Ton S180. The speed of the luminosity changes rules out viscous or thermal processes and limits the size of the individual emission regions to <~15 Schwarzschild radii (and probably much less), that is, to either the inner disk or small regions in a corona

Inactivation of the Saccharomyces cerevisiae SKY1 gene induces a specific modification of the yeast anticancer drug sensitivity profile accompanied by a mutator phenotype

The therapeutic potential of the highly active anticancer agent cisplatin is severely limited by the occurrence of cellular resistance. A better understanding of the molecular pathways involved in cisplatin-induced cell death could potentially indicate ways to overcome cellular unresponsiveness to the drug and thus lead to better treatment results. We used the budding yeast Saccharomyces cerevisiae as a model organism to identify and characterize novel genes involved in cisplatin-induced cell kill, and found that SKY1 (SR-protein-specific kinase from budding yeast) is a cisplatin sensitivity gene whose disruption conferred cisplatin resistance. In cross-resistance studies, we observed resistance of yeast sky1 Delta cells (i.e., cells from which the SKY1 gene had been disrupted) to cisplatin, carboplatin (but not oxaliplatin), doxorubicin and daunorubicin, and hypersensitivity to cadmium chloride and 5-fluorouracil. Furthermore, these cells did not display reduced platinum accumulation, DNA platination or doxorubicin accumulation, indicating that the resistance is unrelated to decreased drug import or increased drug export. Based on the modification of the anticancer drug sensitivity profile and our finding that sky1 Delta cells display a mutator phenotype, we propose that Sky1p might play a significant role in specific repair and/or tolerance pathways. Disruption of the S. cerevisiae SKY1 gene would thus result in deregulation of such mechanisms and, consequently, lead to altered drug sensitivity

Orthorhombic Phase of Crystalline Polyethylene: A Constant Pressure Path Integral Monte Carlo Study

In this paper we present a Path Integral Monte Carlo (PIMC) simulation of the orthorhombic phase of crystalline polyethylene, using an explicit atom force field with unconstrained bond lengths and angles. This work represents a quantum extension of our recent classical simulation (J. Chem. Phys. 106, 8918 (1997)). It is aimed both at exploring the applicability of the PIMC method on such polymer crystal systems, as well as on a detailed assessment of the importance of quantum effects on different quantities. We used the $NpT$ ensemble and simulated the system at zero pressure in the temperature range 25 - 300 K, using Trotter numbers between 12 and 144. In order to investigate finite-size effects, we used chains of two different lengths, C_12 and C_24, corresponding to the total number of atoms in the super-cell being 432 and 864, respectively. We show here the results for structural parameters, like the orthorhombic lattice constants a,b,c, and also fluctuations of internal parameters of the chains, such as bond lengths and bond and torsional angles. We have also determined the internal energy and diagonal elastic constants c_11, c_22 and c_33. We discuss the temperature dependence of the measured quantities and compare to that obtained from the classical simulation. For some quantities, we discuss the way they are related to the torsional angle fluctuation. In case of the lattice parameters we compare our results to those obtained from other theoretical approaches as well as to some available experimental data. In order to study isotope effects, we simulated also a deuterated polyethylene crystal at a low temperature. We also suggest possible ways of extending this study and present some general considerations concerning modeling of polymer crystals.Comment: 18 pages, RevTex, 18 figures, 3 tables, submitted to Phys. Rev.

Farmers Markets and the Local Food System: The Case of Gettysburg, Pennsylvania

In order to examine and obtain a better understanding of the local food system within Adams County, Pennsylvania, this study explores the characteristics and perspectives of the customers and vendors at the farmers markets in Gettysburg, Pennsylvania. Survey findings from the Gettysburg Farmers Market and the three Adams County Farmers Markets include customer demographic information, perspectives and shopping behavior as well as vendor product information, farm size and location and preference for market management. Introductory background information on the Farm Bill and the influence of agricultural practices on the environment, human health and nutrition and the relationship between farmers markets and the local economy are offered in order to emphasize the value of a well-managed local food system. Conclusions provide evidence that lower income and lower education levels are not sufficiently represented at all the markets and food stamp programs are being underutilized. This study suggests employing additional marketing to target underrepresented demographic groups, public transportation to potentially inaccessible market locations and increased advertisement and encouragement of food stamp programs at all markets in order to expand the customer base and increase access to healthy, local foods for less advantaged citizens. The results from this study are intended to offer evidence that will promote and facilitate market management, strengthen customer/vendor relationships and encourage better ties between the local community and local food systems at the farmers markets within Gettysburg in Adams County, Pennsylvania

SKY1 is involved in cisplatin-induced cell kill in Saccharomyces cerevisiae, and inactivation of its human homologue, SRPK1, induces cisplatin resistance in a human ovarian carcinoma cell line

The therapeutic potential of cisplatin, one of the most active and widely used anticancer drugs, is severely limited by the occurrence of cellular resistance. In this study, using budding yeast Saccharomyces cerevisiae as a model organism to identify novel drug resistance genes, we found that disruption of the yeast gene SKY1 (serine/arginine-rich protein-specific kinase from budding yeast) by either transposon insertion or one-step gene replacement conferred cellular resistance to cisplatin. Heterologous expression of the human SKY1 homologue SRPK1 (serine/arginine-rich protein-specific kinase) in SKY1 deletion mutant yeast cells restored cisplatin sensitivity, suggesting that SRPK1 is a cisplatin sensitivity gene, the inactivation of which could lead to cisplatin resistance. Subsequently, we investigated the role of SRPK1 in cisplatin sensitivity and resistance in human ovarian carcinoma A2780 cells using antisense oligodeoxynucleotides. Treatment of A2780 cells with antisense oligodeoxynucleotides directed against the translation initiation site of SRPK1 led to down-regulation of SRPK1 protein and conferred a 4-fold resistance to cisplatin. The human SRPK1 gene has not been associated with drug resistance before. Our new findings strongly suggest that SRPK1 is involved in cisplatin-induced cell kill and indicate that SRPK1 might potentially be of importance for studying clinical drug resistance

Integration of all FSSIM components within SEAMLESS-IF and a stand alone Graphical User Interface for FSSIM

Agricultural and Food Policy, Environmental Economics and Policy, Farm Management, Land Economics/Use,

A new model for diabetes-focused capacity building – lessons from Sri Lanka

Abstract Sri Lanka is experiencing a rapid increase in the number of people with diabetes mellitus (DM) due to population growth and aging. Physician shortages, outdated technology, and insufficient health education have contributed to the difficulties associated with managing the burden of disease. New models of chronic disease management are needed to address the increasing prevalence of DM. Medical students, business students, and faculty members from the University of Michigan partnered with the Grace Girls’ Home, Trincomalee General Hospital, and Selvanayakapuram Central Hospital to identify and train diabetes-focused medical assistants (MAs) to collect and enter patient data and educate patients about their disease. Return visits to these MAs were encouraged so that patient progress and disease progression could be tracked longitudinally. Data entry was conducted through a cloud-based mechanism, facilitating patient management and descriptive characterization of the population. We implemented this pilot program in June 2016 in coordination with Trincomalee General Hospital and Selvanayakapuram Central Hospital. Over a 12-month period, 93 patients were systematically assessed by the medical assistants. All patients received education and were provided materials after the visit to better inform them about the importance of controlling their disease. Fifteen percent (14/93) of patients returned for follow-up consultation. Trained MAs have the potential to provide support to physicians working in congested health systems in low-resource settings. Public investment in training programs for MAs and greater acceptance by physicians and patients will be essential for handling the growing burden associated with chronic illnesses like DM. Trained MAs may also play a role in improved patient education and awareness regarding diabetes self-management.https://deepblue.lib.umich.edu/bitstream/2027.42/146742/1/40842_2018_Article_74.pd

Continuous-variable optical quantum state tomography

This review covers latest developments in continuous-variable quantum-state tomography of optical fields and photons, placing a special accent on its practical aspects and applications in quantum information technology. Optical homodyne tomography is reviewed as a method of reconstructing the state of light in a given optical mode. A range of relevant practical topics are discussed, such as state-reconstruction algorithms (with emphasis on the maximum-likelihood technique), the technology of time-domain homodyne detection, mode matching issues, and engineering of complex quantum states of light. The paper also surveys quantum-state tomography for the transverse spatial state (spatial mode) of the field in the special case of fields containing precisely one photon.Comment: Finally, a revision! Comments to lvov(at)ucalgary.ca and raymer(at)uoregon.edu are welcom