397 research outputs found
UV, Optical, and Infrared Imaging of the Interacting Galaxy Arp 107 and its Star Forming Regions.
In this study we present GALEX UV, Sloan Digital Sky Survey, and Spitzer infrared imaging, along with an optical Hα map of the interacting galaxy pair Arp 107. IRAF photometry was used to analyze 29 star forming regions identified in previous work done with Spitzer colors. In this paper further analysis of the clumps of newly formed stars was done by creating Spectral Energy Distribution plots to sort the clumps as quiescent or starbursts. Color - color plots were used to estimate the ages and extinctions of the clumps by comparing magnitudes to stellar population synthesis models. Results seem to agree with previous models, and indicate a sequence of increasing age around the galaxy arm
A Century of Instability in Housing Finance in the United States
The U.S. housing sector, including housing starts, house purchasing, and the institutions involved in financing house purchases, has been unstable for most of the past century. We divide the years since 1920 into periods and study the instability for each period. We found that there was no Golden Age of stability in the sector. Instead, the time intervals that we studied were each characterized by metrics of instability that were equal within a reasonable margin of error. These results imply that the U.S. has built a stock of housing and has succeeded in making home ownership an attainable dream, but that accomplishment is overshadowed by the frequent booms and busts. In a second paper we intend to examine the effects on economic growth and recessions that have been associated with the instability in the housing sector. The social costs of instability have been large, and our estimate will be intended to provoke debate and further research
UV/Optical/IR Color Sequences Along the Tidal Ring/Arm of Arp 107
We construct UV/optical/IR spectral energy distributions for 29 star forming
regions in the interacting galaxy Arp 107, using GALEX UV, Sloan Digitized Sky
Survey optical, and Spitzer infrared images. In an earlier study utilizing only
the Spitzer data, we found a sequence in the mid-infrared colors of
star-forming knots along the strong tidal arm in this system. In the current
study, we find sequences in the UV/optical colors along the tidal arm that
mirror those in the mid-infrared, with blue UV/optical colors found for regions
that are red in the mid-infrared, and vice versa. With single-burst stellar
population synthesis models, we find a sequence in the average stellar age
along this arm, with younger stars preferentially located further out in the
arm. Models that allow two populations of different ages and dust attenuations
suggest that there may be both a young component and an older population
present in these regions. Thus the observed color sequences may be better
interpreted as a sequence in the relative proportion of young and old stars
along the arm, with a larger fraction of young stars near the end. Comparison
with star forming regions in other interacting galaxies shows that the Arp 107
regions are relatively quiescent, with less intense star formation than in many
other systems.Comment: Astronomical Journal, in pres
Contracting Agile Developments for Mission Critical Systems in the Public Sector
Although Agile is a well established software development paradigm, major concerns arise when it comes to contracting issues between a software consumer and a software producer. How to contractualize the Agile production of software, especially for security & mission critical organizations, which typically outsource software projects, has been a major concern since the beginning of the \u201cAgile Era.\u201d In literature, little has been done, from a foundational point of view regarding the formalization of such contracts. Indeed, when the development is outsourced, the management of the contractual life is non\u2013trivial. This happens because the interests of the two parties are typically not aligned. In these situations, software houses strive for the minimization of the effort, while the customer commonly expects high quality artifacts. This structural asymmetry can hardly be overcome with traditional \u201cWaterfall\u201d contracts. In this work, we propose a foundational approach to the Law & Economics of Agile contracts. Moreover, we explore the key elements of the Italian procurement law and outline a suitable solution to merge some basic legal constraints with Agile requirements. Finally, a case study is presented, describing how Agile contracting has been concretely implemented in the Italian Defense Acquisition Process. This work is intended to be a framework for Agile contracts for the Italian public sector of critical systems, according to the new contractual law (Codice degli Appalti)
La reducciĂłn de la fecundidad en un programa de salud materno infantil
Incluye BibliografĂaPublicado en Estudios de PlanificaciĂłn Familiar, vol. 6, 197
New discoveries at Woolsey Mound, MC118, northern Gulf of Mexico
Woolsey Mound, a 1km-diameter carbonate-gas hydrate complex in the northern Gulf of Mexico, is the site of the Gulf’s only seafloor monitoring station-observatory in its only research reserve, Mississippi Canyon 118. Active venting, outcropping hydrate, and a thriving chemosynthetic community recommend the site for study. Since 2005, the Gulf of Mexico Hydrates Research Consortium has been conducting multidisciplinary studies to 1. Characterize the site, 2. Establish a facility for real-time monitoring-observing of gas hydrates in a natural setting, 3. Study the effects of gas hydrates on seafloor stability, 4. Establish fluid migration routes and estimates of fluid-flux at the site, 5. Establish the interrelationships between the
organisms at the vent site and the association-dissociation of hydrates. A variety of novel geological, geophysical, geochemical and biological studies has been designed and
conducted, some in survey mode, others in monitoring mode. Geophysical studies involving merging multiple seismic data acquisition systems accompanied by the application of custom processing techniques verify communication of surface features with deep structures. Supporting geological data derive from innovative recovery techniques. Geochemical sensors, used experimentally in survey mode, including aboard an AUV, double as monitoring devices. A suite of pore-fluid sampling devices has returned data that capture change at the site in daily increments; using only noise as an energy source, hydrophones have
returned daily fluctuations in physical properties. Ever-expanding capabilities of a custom-ROV have been determined by research needs. Processing of new as well as conventional data via unconventional means
has resulted in the discovery of new features…..vents, faults, benthic fauna…..and modification of others including pockmarks, hydrate outcrops, vent activity, and water-column chemical plumes.
Though real-time monitoring awaits communications and power link to land, periodic data-collection reveals a carbonate-hydrate mound, part of an immensely complex hydrocarbon system
Binge drinking and perceived ethnic discrimination among Hispanics/Latinos: Results from the Hispanic community health study/study of Latinos sociocultural ancillary study
The study assessed whether overall perceived ethnic discrimination and four unique discrimination types were associated with binge drinking in participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) who also completed the HCHS/SOL Sociocultural Ancillary Study (n = 5,313). In unadjusted analyses that were weighted for sampling strategy and design, each unit increase in discrimination type was associated with a 12 - 63% increase in odds of binge drinking; however, after adjusting for important demographic variables including age, sex, heritage group, language, and duration of US residence, there was no longer an association between discrimination and binge drinking. Further research still needs to identify the salient factors that contribute to increased risk for binge drinking among Hispanics/Latinos
A Combined First Principles and Kinetic Monte Carlo study of Polyoxometalate based Molecular Memory Devices
In this paper, we combine Density Functional Theory with Kinetic Monte Carlo methodology to study the fundamental transport properties of a type of polyoxometalate (POM) and its behaviour in a potential flash memory device. DFT simulations on POM molecular junctions helps us demonstrate the link between underlying electronic structure of the molecule and its transport properties. Furthermore, we show how various electrode-molecule contact configurations determine the electron transport through the POM. Also, our work reveals that the orientation of the molecule to the electrodes plays a key role in the transport properties of the junction. With Kinetic Monte Carlo we extend this investigation by simulating the retention time of a POM-based flash memory device. Our results show that a POM based flash memory could potentially show multi-bit storage and retain charge for up to 10 years
The lytic granules of natural killer cells are dual-function organelles combining secretory and pre-lysosomal compartments.
Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set
BACKGROUND: A multi-cancer early detection (MCED) test used to complement existing screening could increase the number of cancers detected through population screening, potentially improving clinical outcomes. The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was a prospective, case-controlled, observational study and demonstrated that a blood-based MCED test utilizing cell-free DNA (cfDNA) sequencing in combination with machine learning could detect cancer signals across multiple cancer types and predict cancer signal origin (CSO) with high accuracy. The objective of this third and final CCGA substudy was to validate an MCED test version further refined for use as a screening tool. PATIENTS AND METHODS: This pre-specified substudy included 4077 participants in an independent validation set (cancer: n = 2823; non-cancer: n = 1254, non-cancer status confirmed at year-one follow-up). Specificity, sensitivity, and CSO prediction accuracy were measured. RESULTS: Specificity for cancer signal detection was 99.5% [95% confidence interval (CI): 99.0% to 99.8%]. Overall sensitivity for cancer signal detection was 51.5% (49.6% to 53.3%); sensitivity increased with stage [stage I: 16.8% (14.5% to 19.5%), stage II: 40.4% (36.8% to 44.1%), stage III: 77.0% (73.4% to 80.3%), stage IV: 90.1% (87.5% to 92.2%)]. Stage I-III sensitivity was 67.6% (64.4% to 70.6%) in 12 pre-specified cancers that account for approximately two-thirds of annual USA cancer deaths and was 40.7% (38.7% to 42.9%) in all cancers. Cancer signals were detected across >50 cancer types. Overall accuracy of CSO prediction in true positives was 88.7% (87.0% to 90.2%). CONCLUSION: In this pre-specified, large-scale, clinical validation substudy, the MCED test demonstrated high specificity and accuracy of CSO prediction and detected cancer signals across a wide diversity of cancers. These results support the feasibility of this blood-based MCED test as a complement to existing single-cancer screening tests. CLINICAL TRIAL NUMBER: NCT02889978
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