2,345 research outputs found
Low-Mass Eclipsing Binaries in the Initial Kepler Data Release
We identify 231 objects in the newly released Cycle 0 dataset from the Kepler
Mission as double-eclipse, detached eclipsing binary systems with Teff < 5500 K
and orbital periods shorter than ~32 days. We model each light curve using the
JKTEBOP code with a genetic algorithm to obtain precise values for each system.
We identify 95 new systems with both components below 1.0 M_sun and eclipses of
at least 0.1 magnitudes, suitable for ground-based follow-up. Of these, 14 have
periods less than 1.0 day, 52 have periods between 1.0 and 10.0 days, and 29
have periods greater than 10.0 days. This new sample of main-sequence,
low-mass, double-eclipse, detached eclipsing binary candidates more than
doubles the number of previously known systems, and extends the sample into the
completely heretofore unexplored P > 10.0 day period regime. We find
preliminary evidence from these systems that the radii of low-mass stars in
binary systems decrease with period. This supports the theory that binary
spin-up is the primary cause of inflated radii in low-mass binary systems,
although a full analysis of each system with radial-velocity and multi-color
light curves is needed to fully explore this hypothesis. As well, we present 7
new transiting planet candidates that do not appear among the recently released
list of 706 candidates by the Kepler team, nor in the Kepler False Positive
Catalog, along with several other new and interesting systems. We also present
novel techniques for the identification, period analysis, and modeling of
eclipsing binaries.Comment: 22 pages in emulateapj format. 9 figures, 4 tables, 2 appendices.
Accepted to AJ. Includes a significant addition of new material since last
arXiv submission and an updated method for estimating masses and radi
The influence of sludge retention time on mixed culture microbial fuel cell start-ups
In this work, the start-ups of air-cathode microbial fuel cells (MFCs) seeds with conventional activated
sludge cultivated at different solid retention times (SRTs) are compared. A clear influence of the SRT of the
inoculum was observed, corresponding to an SRT of 10 days to the higher current density exerted, about
0.2 A m 122. This observation points out that, in this type of electrochemical device, it is recommended to
use high SRT seeds. The work also points out that in order to promote an efficient start-up, it is not only
necessary to use high SRT seeds, but also to feed a high COD concentration. When feeding 10,000 ppm
COD and keeping SRT of 10 d differences of current densities up to 0.1 A m 122 were observed within a
cycle. Additionally it was observed that SRT influences direct and indirect electron transfer mechanisms,
being the direct mechanisms the most relevant ones, accounting for more than 95% of the total electricity
production
Virtual reality simulation of a quadrotor to monitor dependent people at home
Unmanned aerial vehicles (UAVs) represent an assistance solution for home care of dependent persons. These aircraft can cover the home, accompany the person, and position themselves to take photographs that can be analyzed to determine the person's mood and the assistance needed. In this context, this work principally aims to design a tool to aid in the development and validation of the navigation algorithms of an autonomous vision-based UAV for monitoring dependent people. For that, a distributed architecture has been proposed based on the real-time communication of two modules, one of them in charge of the dynamics of the UAV, the trajectory planning and the control algorithms, and the other devoted to visualizing the simulation in an immersive virtual environment. Thus, a system has been developed that allows the evaluation of the behavior of the assistant UAV from a technological point of view, as well as to carry out studies from the assisted person's viewpoint. An initial validation of a quadrotor model monitoring a virtual character demonstrates the advantages of the proposed system, which is an effective, safe and adaptable tool for the development of vision-based UAVs to help dependents at home.This work was partially supported by Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación/European Regional Development Fund under PID2019106084RB-I00 and DPI2016-80894-R grants, and by CIBERSAM of the Instituto de Salud Carlos III
Cervical cancer, human papillomavirus (HPV), and HPV vaccination: Exploring gendered perspectives, knowledge, attitudes, and cultural taboos among Mexican American adults
Background: Gendered perspectives may be particularly important in shaping norms and values around HPV and HPV vaccination, as previous research suggests that sexuality taboos (e.g. promiscuity) may contribute to low perceived risk among adolescent and young adult Hispanic females. However, research to date focuses primarily on Hispanic mothers, adolescent females, and women of HPV vaccine-eligible age. Hispanic father\u27s perspectives are relatively unknown despite father\u27s important role in shaping norms for their female children.
Objective: To close this gap, this study examines gendered perspectives in knowledge, beliefs, and attitudes about HPV and HPV vaccination from Hispanic parents (mothers and fathers), women of vaccine-eligible age (18-26 years old), and women eligible for Pap Test screening (\u3e26 years old) living in two counties along the Texas-Mexico border.
Design: We conducted eight focus groups. Research staff transcribed audio recordings verbatim and uploaded them into Atlas(ti) 5.0 for analysis. The research team analyzed the data for content, meaning, patterns and themes using the constant comparison approach.
Results: Perspectives were highly gendered. Women\u27s (all groups combined) beliefs focused on misconceptions around how the HPV virus is contracted (e.g. toilet surfaces). Women also linked HPV-related sexual risk to adultery and indiscretion of male partners. Fathers (men) were more likely to link risk to female promiscuity. Fathers also worried that HPV vaccination might increase promiscuity. All groups believe that HPV vaccination is a way to protect Hispanic females in the face of beliefs around sexual behavior and risk of contracting HPV.
Conclusion: Results suggest gendered differences in risk beliefs concerning HPV among Hispanics living along the Texas-Mexico border. Researchers can use these findings to address barriers to HPV vaccination, as well as to create culturally appropriate prevention messages that may help reduce disparities in HPV among Hispanic women
Qualitative and quantitative analyses of the bifidobacterial microbiota in the colonic mucosa of patients with colorectal cancer, diverticulitis and infl ammatory bowel disease
AIM: To characterize the bifidobacterial microbiota of the colonic mucosa in patients with colon cancer, inflammatory bowel disease or diverticulitis.
METHODS: A sample of the distal colonic mucosa was taken during surgery from a total of 34 patients, twenty-one with diagnosed colorectal cancer, nine with diverticulitis and four with inflammatory bowel disease, requiring surgery for their condition. Bacterial DNA was extracted from the resected mucosal samples and bifidobacterial mucosa-associated microbiota was qualitatively and quantitatively determined by means of qualitative and quantitative PCR.
RESULTS: Bifidobacteria were found in 100% of the samples from patients with diverticulitis or IBD and a 76% of those suffering colon cancer. The species B. longum and B. bifidum were the most widely found, followed by B. animalis, B. catenulatum and B. adolescentis. B. breve, B. dentium and B. angulatum were not detected in any sample. A significantly higher occurrence of B. longum was observed in patients with diverticulitis than in those with colon cancer or IBD (100%, 62% and 75%, respectively, P < 0.05). Similar results were obtained for B. animalis (56%, 0% and 25%, P < 0.05), while B. adolescentis was only found in the mucosa from patients with colon cancer (5 out of 21, 24%). At the quantitative level, patients with colon cancer or IBD showed lower counts of total Bifidobacterium (4.94 and 5.91 vs 6.96 log Cells/sample, respectively, P < 0.05) and of the species B. longum (4.05 and 4.79 vs 6.76, P < 0.05) than those with diverticulitis.
CONCLUSION: Aberrancies in mucosa associated microbiota are present in different intestinal diseases. This may indicate a role of the microbiota in the pathogenesis of these diseasesPeer reviewe
Magnetic Nanoparticles for Power Absorption: optimizing size, shape and magnetic properties
We present a study on the magnetic properties of naked and silica-coated
Fe3O4 nanoparticles with sizes between 5 and 110 nm. Their efficiency as
heating agents was assessed through specific power absorption (SPA)
measurements as a function of particle size and shape. The results show a
strong dependence of the SPA with the particle size, with a maximum around 30
nm, as expected for a Neel relaxation mechanism in single-domain particles. The
SiO2 shell thickness was found to play an important role in the SPA mechanism
by hindering the heat outflow, thus decreasing the heating efficiency. It is
concluded that a compromise between good heating efficiency and surface
functionality for biomedical purposes can be attained by making the SiO2
functional coating as thin as possible.Comment: 15 pages, 7 figures, 2 table
Enhancing structure relaxations for first-principles codes: an approximate Hessian approach
We present a method for improving the speed of geometry relaxation by using a
harmonic approximation for the interaction potential between nearest neighbor
atoms to construct an initial Hessian estimate. The model is quite robust, and
yields approximately a 30% or better reduction in the number of calculations
compared to an optimized diagonal initialization. Convergence with this
initializer approaches the speed of a converged BFGS Hessian, therefore it is
close to the best that can be achieved. Hessian preconditioning is discussed,
and it is found that a compromise between an average condition number and a
narrow distribution in eigenvalues produces the best optimization.Comment: 9 pages, 3 figures, added references, expanded optimization sectio
Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments
Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped-and luminescent Terbium3+ (Tb3+)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 °C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loadednanoparticles were monitored in an in vitro osteoblast’s cytokine–induced inflammation model by evaluating COX-2 mRNA expression and production of PGE2. Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 °C were higher than at 25 °C, and particularly when using the Tb3+-doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb3+-doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb3+-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 expression and decreased PGE2 production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence
Red de alta precisión, láser escáner y fotogrametría, combinados para generar el modelado 3D de alta resolución e información derivada, aplicados a la Sagrada Familia de Barcelona
For maintenance needs, conservation and restoration, it has been requested by the Board of the SagradaFamilia, the study of the methodology and development to carry out the full three-dimensional model of the original part of the temple (the façade of the Birth, and the adjacent towers and chapels) and metric documents, including those who have to emphasize the architectonics planes, the digital orthomosaic of the different planes, and a full high-resolution surface model. The uniqueness of this façade is that it is an about 12 meters thick irregular element with spaces inside, which can be walked across most its outside spaces and inside the towers at different levels.
High accuracy surveying methods are used for this project, which must be used as a basis to generate the necessary support network, considering that the topographic bases must be placed throughout all the façade, inside the temple, at different levels and in positions with good visibility.In the methodology they are considered combined methods of laser scanning and high resolution photogrammetry, which can generate equivalent and complementary point clouds.The areas that the laser scanner can’t reach, photogrammetry is used, and vice versa.Job success is due to a good coordination and planning of the various phases to execute (photographic shots, Terrestrial Laser Scanning, topographic bases distribution and support points, etc).
This project is currently being carried out and the first results have been obtainedwholly satisfactory and above the highest expectations. The results have been point clouds of 2mm resolution for the sculptures and 5mm resolution for the architectural set made with the Terrestrial Laser Scanning technology, 5mm orthophotos with fotogrametry and a 3D mesh.Postprint (published version
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