1,960 research outputs found
The Lick AGN Monitoring Project 2011: Reverberation Mapping of Markarian 50
The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our data set covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of ~4 in the U-band continuum and a factor of ~2 in the Hβ line. Using standard cross-correlation techniques, we find that Hβ and Hγ lag the V-band continuum by τ_(cen) = 10.64^(+0.82)_(–0.93) and 8.43^(+1.30)_(–1.28) days, respectively, while the lag of He II λ4686 is unresolved. The Hβ line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region (BLR) dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f = 5.25, the virial estimate of the black hole mass is (3.2 ± 0.5) × 10^7 M_☉. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of BLR structure and dynamics
Case report: Successful treatment of recurrent chordoma and bilateral pulmonary metastases following an 11-year disease-free period
AbstractINTRODUCTIONChordomas are rare but aggressive tumors due to local recurrence and distant metastases. They originate commonly in the sphenooccipital and sacrococcygeal regions, and metastasize to the lungs, bone, skin, liver, and lymph nodes. They occur more frequently in men and people over the age of 40.PRESENTATION OF CASEA 28 year-old female presented with sacrococcygeal chordoma for which she received wide local excision and adjuvant radiation therapy. She enjoyed an unusual disease-free survival for 11 years until a routine surveillance scan of the pelvis identified local recurrence. Further work up revealed bilateral pulmonary metastases. She underwent local excision of the recurrent tumor and video-assisted thoracoscopic (VATS) wedge resection of pulmonary metastases. She also received adjuvant radiation therapy to the recurrent resection bed. Two years later, she remains free of disease and symptoms.DISCUSSIONChordomas are commonly insensitive to chemotherapy and radiation, making surgery the most successful therapeutic modality. However, there are few guidelines on the surveillance and treatment of recurrent chordoma. We report success with aggressive surgical resection of recurrence and metastasis as well as adjuvant radiation therapy.CONCLUSIONThe prolonged survival of our patient underscores the importance of (1) aggressive surgical resection of chordoma, whether primary, recurrent, or metastatic, with adjuvant radiation therapy, (2) minimization of surgical seeding of tumor, and (3) diligent cancer surveillance
Do Black-Owned Banks Substitute for Payday Lenders? An Exploratory Study
The annualized interest rate charged on payday loans can reach 1,950 percent, whereas similar rates charged by banks are typically less than 25 percent. Also, persons borrowing from payday lenders and paying the higher interest rates are disproportionately lower-income Blacks. This provides an incentive for Blacks seeking loans to turn to banks rather than payday lenders. This may be more likely to happen when there are Black-owned banks in communities with greater percentages of Blacks. Indeed, offices of such banks may substitute for payday loan stores, providing a greater opportunity for Blacks to avoid the higher interest rates associated with payday lenders. We hypothesize that to the extent Black-owned banks substitute for payday there is a greater opportunity for lower-income Blacks to substitute/switch firms and thereby seek lower-cost loans. We do find that there are significantly fewer payday loan stores in counties where there are more Black bank offices
Policy Recommendations for Meeting the Grand Challenge to Stop Family Violence
This brief was created forSocial Innovation for America’s Renewal, a policy conference organized by the Center for Social Development in collaboration with the American Academy of Social Work & Social Welfare, which is leading theGrand Challenges for Social Work initiative to champion social progress. The conference site includes links to speeches, presentations, and a full list of the policy briefs
New Empirical Evidence on Factors Influencing the Yield on High-Grade Municipal Bonds
We investigate the impact of federal budget deficits and other factors on the ex-post and ex-ante real yields on high-grade municipal bonds. The estimation results reveal that both yields increase with the real yield on 30-year Moody’s Aaa-rated bonds and provisions in the Community Reinvestment Act but decrease with net capital inflows, the real GDP growth rate, and the average effective federal income tax rate. Most importantly, both yields are increasing functions of the federal budget deficit. These results support limiting the size of federal budget deficits to avoid the excessive crowding out of private investment spending
Loneliness is adversely associated with physical and mental health and lifestyle factors: Results from a Swiss national survey.
Loneliness is a common, emotionally distressing experience and is associated with adverse physical and mental health and an unhealthy lifestyle. Nevertheless, little is known about the prevalence of loneliness in different age groups in Switzerland. Furthermore, the existing evidence about age and gender as potential effect modifiers of the associations between loneliness, physical and mental health and lifestyle characteristics warrants further investigation. Thus, the aim of the study was to examine the prevalence of loneliness among adults in Switzerland and to assess the associations of loneliness with several physical and mental health and behavioral factors, as well as to assess the modifying effect of sex and age.
Data from 20,007 participants of the cross-sectional population-based Swiss Health Survey 2012 (SHS) were analyzed. Logistic regression analyses were used to assess associations of loneliness with physical and mental health or lifestyle characteristics (e.g. diabetes, depression, physical activity). Wald tests were used to test for interactions.
Loneliness was distributed in a slight U-shaped form from 15 to 75+ year olds, with 64.1% of participants who had never felt lonely. Lonely individuals were more often affected by physical and mental health problems, such as self-reported chronic diseases (Odds ratio [OR] 1.41, 95% confidence interval [CI] 1.30-1.54), high cholesterol levels (OR 1.31, 95% CI 1.18-1.45), diabetes (OR 1.40, 95% CI 1.16-1.67), moderate and high psychological distress (OR 3.74, 95% CI 3.37-4.16), depression (OR 2.78, 95% CI 2.22-3.48) and impaired self-perceived health (OR 1.94, 95% CI 1.74-2.16). Loneliness was significantly associated with most lifestyle factors (e.g. smoking; OR 1.13, 95% 1.05-1.23). Age, but not sex, moderated loneliness' association with several variables.
Loneliness is associated with poorer physical and mental health and unhealthy lifestyle, modified by age, but not by sex. Our findings illustrate the importance of considering loneliness for physical and mental health and lifestyle factors, not only in older and younger, but also in middle-aged adults. Longitudinal studies are needed in Switzerland to elucidate the causal relationships of these associations
Dynamic and Transient Performance of Turbofan/Turboshaft Convertible Engine With Variable Inlet Guide Vanes
A convertible engine called the CEST TF34, using the variable inlet guide vane method of power change, was tested on an outdoor stand at the NASA Lewis Research Center with a waterbrake dynamometer for the shaft load. A new digital electronic system, in conjunction with a modified standard TF34 hydromechanical fuel control, kept engine operation stable and safely within limits. All planned testing was completed successfully. Steady-state performance and acoustic characteristics were reported previously and are referenced. This report presents results of transient and dynamic tests. The transient tests measured engine response to several rapid changes in thrust and torque commands at constant fan (shaft) speed. Limited results from dynamic tests using the pseudorandom binary noise technique are also presented. Performance of the waterbrake dynamometer is discussed in an appendix
Review of Methods for Intraoperative Margin Detection for Breast Conserving Surgery
Breast conserving surgery (BCS) is an effective treatment for early-stage cancers as long as the margins of the resected tissue are free of disease according to consensus guidelines for patient management. However, 15% to 35% of patients undergo a second surgery since malignant cells are found close to or at the margins of the original resection specimen. This review highlights imaging approaches being investigated to reduce the rate of positive margins, and they are reviewed with the assumption that a new system would need high sensitivity near 95% and specificity near 85%. The problem appears to be twofold. The first is for complete, fast surface scanning for cellular, structural, and/or molecular features of cancer, in a lumpectomy volume, which is variable in size, but can be large, irregular, and amorphous. A second is for full, volumetric imaging of the specimen at high spatial resolution, to better guide internal radiologic decision-making about the spiculations and duct tracks, which may inform that surfaces are involved. These two demands are not easily solved by a single tool. Optical methods that scan large surfaces quickly are needed with cellular/molecular sensitivity to solve the first problem, but volumetric imaging with high spatial resolution for soft tissues is largely outside of the optical realm and requires x-ray, micro-CT, or magnetic resonance imaging if they can be achieved efficiently. In summary, it appears that a combination of systems into hybrid platforms may be the optimal solution for these two very different problems. This concept must be cost-effective, image specimens within minutes and be coupled to decision-making tools that help a surgeon without adding to the procedure. The potential for optical systems to be involved in this problem is emerging and clinical trials are underway in several of these technologies to see if they could reduce positive margin rates in BCS
P3-[2-(4-hydroxyphenyl)-2-oxo]ethyl ATP for the Rapid Activation of the Na+,K+-ATPase
This is the published version, also available here: http://dx.doi.org/10.1016/S0006-3495(00)76387-9.P3-[2-(4-hydroxyphenyl)-2-oxo]ethyl ATP (pHP-caged ATP) has been investigated for its application as a phototrigger for the rapid activation of electrogenic ion pumps. The yield of ATP after irradiation with a XeCl excimer laser (λ = 308 nm) was determined at pH 6.0–7.5. For comparison, the photolytic yields of P3-[1-(2-nitrophenyl)]ethyl ATP (NPE-caged ATP) and P3-[1,2-diphenyl-2-oxo]ethyl ATP (desyl-caged ATP) were also measured. It was shown that at λ = 308 nm pHP-caged ATP is superior to the other caged ATP derivatives investigated in terms of yield of ATP after irradiation. Using time-resolved single-wavelength IR spectroscopy, we determined a lower limit of 106 s−1 for the rate constant of release of ATP from pHP-caged ATP at pH 7.0. Like NPE-caged ATP, pHP-caged ATP and desyl-caged ATP bind to the Na+,K+-ATPase and act as competitive inhibitors of ATPase function. Using pHP-caged ATP, we investigated the charge translocation kinetics of the Na+,K+-ATPase at pH 6.2–7.4. The kinetic parameters obtained from the electrical measurements are compared to those obtained with a technique that does not require caged ATP, namely parallel stopped-flow experiments using the voltage-sensitive dye RH421. It is shown that the two techniques yield identical results, provided the inhibitory properties of the caged compound are taken into account. Our results demonstrate that under physiological (pH 7.0) and slightly basic (pH 7.5) or acidic (pH 6.0) conditions, pHP-caged ATP is a rapid, effective, and biocompatible phototrigger for ATP-driven biological systems
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