Identification of red supergiants in nearby galaxies with mid-IR photometry

The role of episodic mass loss in massive star evolution is one of the most important open questions of current stellar evolution theory. Episodic mass loss produces dust and therefore causes evolved massive stars to be very luminous in the mid-infrared and dim at optical wavelengths. We aim to increase the number of investigated luminous mid-IR sources to shed light on the late stages of these objects. To achieve this we employed mid-IR selection criteria to identity dusty evolved massive stars in two nearby galaxies. The method is based on mid-IR colors, using 3.6 {\mu}m and 4.5 {\mu}m photometry from archival Spitzer Space Telescope images of nearby galaxies and J-band photometry from 2MASS. We applied our criteria to two nearby star-forming dwarf irregular galaxies, Sextans A and IC 1613, selecting eight targets, which we followed up with spectroscopy. Our spectral classification and analysis yielded the discovery of two M-type supergiants in IC 1613, three K-type supergiants and one candidate F-type giant in Sextans A, and two foreground M giants. We show that the proposed criteria provide an independent way for identifying dusty evolved massive stars, that can be extended to all nearby galaxies with available Spitzer/IRAC images at 3.6 {\mu}m and 4.5 {\mu}m.Comment: 8 pages, 4 figures, A&A in pres

Secure Geographic Routing in Ad Hoc and Wireless Sensor Networks

Security in sensor networks is one of the most relevant research topics in resource constrained wireless devices and networks. Several attacks can be suffered in ad hoc and wireless sensor networks (WSN), which are highly susceptible to attacks, due to the limited resources of the nodes. In this paper, we propose innovative and lightweight localization techniques that allow for intrusion identification and isolation schemes and provide accurate location information. This information is used by our routing protocol which additionally incorporates a distributed trust model to prevent several routing attacks to the network. We finally evaluate our algorithms for accurate localization and for secure routing which have been implemented and tested in real ad hoc and wireless sensor networks

Architectures for Future Media Internet

Among the major reasons for the success of the Internet have been the simple networking architecture and the IP interoperation layer. However, the traffic model has recently changed. More and more applications (e.g. peerto-peer, content delivery networks) target on the content that they deliver rather than on the addresses of the servers who (originally) published/hosted that content. This trend has motivated a number of content-oriented networking studies. In this paper we summarize some the most important approache

Cirrus high-definition optical coherence tomography compared with Stratus optical coherence tomography in glaucoma diagnosis

To compare the retinal nerve fiber layer (RNFL) evaluation using Cirrus optical coherence tomography (OCT) and Stratus OCT in glaucoma diagnosis. METHODS: One hundred thirty normal and 86 patients with glaucoma were included in this prospective study. The signal strengths of the OCTs were evaluated. The sensitivities and specificities of global RNFL average thickness were compared in the four quadrants and in each clock hour sector. Receiver operating characteristic (ROC) curves, areas under the ROC (AUC), and the likelihood ratio (LR) were plotted for RNFL thickness. Agreement between the OCTs was calculated by using the Bland-Altman method and kappa (kappa) coefficient. RESULTS: Twenty-three percent of all cases examined with Stratus OCT and 1.9% examined with Cirrus OCT had a signal strength below 6 (P = 0.01). In cases with signal strengths > or =6, the mean signal strength was higher with Cirrus OCT than with Stratus OCT (P = 0.01). The RNFL measurements by Cirrus were thicker than those of Stratus OCT (P < 0.05). The AUCs were 0.829 for Stratus and 0.837 for Cirrus OCT (P = 0.706) for global RNFL average. LRs were similar in both OCTs in global RNFL classification but varied in quadrants. The widths of the limits of agreement varied between 42.16 and 97.79 microm. There was almost perfect agreement (kappa = 0.82) in the average RNFL classification. CONCLUSIONS: Cirrus OCT has better scan quality than Stratus OCT, especially in glaucomatous eyes. In cases with good-quality scans, the sensitivity and specificity, and AUCs were similar. The best agreement was in the global average RNFL classification. The widths of limits of agreements exceed the limits of resolution of the OCTs

Historia de los medios de comunicación de Misiones: LT 85 TV Canal 12, el canal de TV de los Misioneros. 16H295

Actividades desarrolladas durante el período: avance en la búsqueda de información respecto de documentación y de fuentes orales de información sobre la historia del Canal 12; rescate testimonios fotográficos y de cintas fílmicas de los primeros años del Canal 12 que están en poder de particulares; rescate de material fílmico existente en el Canal; desgravaciones de las entrevistas realizadas para la entrega posterior a los informantes. Sistematización de la organización de las fotografías que han sido facilitadas para la construcción de la investigación

Aging-associated symptoms in the physician-patient dialogue in a group of long-term diagnosed HIV-infected individuals

Background: The significant decrease in mortality has resulted in a large number of individuals aged over 50 living with HIV infection. Additionally, the coexistence of certain pathologies suggests premature aging. In this scenario, the presence of aging-associated symptoms in the physician-patient dialogue is yet to be explored. Methods: Cross-sectional observational study to evaluate the presence of aging-associated symptoms in the physician-patient dialogue and to explore the possible differences between genders in a sample of 100 HIV-1 infected subjects diagnosed at least 15 years ago. The survey assessed questions/comments made by the patient, questions/comments made by the physician and patients&#x2019; interest in obtaining more information than was provided. Number of patients and percentages were given and compared using the w2 or Fisher exact test (as appropriate). Results: Participants were 60 men and 40 women, diagnosed with HIV infection a median (IQ) of 18 (15.7&#x2013;21) years ago, who had a nadir CD4 and CD4 cell count at the study entry of 172 (95&#x2013;272) and 543 (403&#x2013;677), respectively. Eighty percent of the subjects had VL &#x3C;25 copies and 42% were HCV/HIV co-infected (31 subjects with low fibrosis stage). The infection route had been mainly intravenous drug use (37%) and MSM (32%). Men and women had similar demographic and clinical characteristics. Sixty-two percent of the participants acknowledged asking their physicians about aging-associated symptoms (58% men vs 66% women; p=0.50), 48% reported that their physicians had provided information without having been asked (48% men vs 55% women; p=0.51) and 75% confirmed that they would like to have more information about aging-associated symptoms (22% men vs 80% women; p&#x3C;0.001). Conclusions: Around half of the men and women interviewed had discussed aging-associated symptoms with their physician. However, this seemed insufficient for four-fifths of the women, who would have liked to have obtained more information about aging

Detailed diagnostics of an X-ray flare in the single giant HR 9024

We analyze a 96 ks Chandra/HETGS observation of the single G-type giant HR 9024. The high flux allows us to examine spectral line and continuum diagnostics at high temporal resolution, to derive plasma parameters. A time-dependent 1D hydrodynamic model of a loop with half-length $L = 5 \times 10^{11}$ cm ($\sim R_{\star}/2$), cross-section radius $r = 4.3 \times 10^{10}$ cm, with a heat pulse of 15 ks and $2 \times 10^{11}$~erg cm$^{-2}$ s$^{-1}$ deposited at the loop footpoints, satisfactorily reproduces the observed evolution of temperature and emission measure, derived from the analysis of the strong continuum emission. For the first time we can compare predictions from the hydrodynamic model with single spectral features, other than with global spectral properties. We find that the model closely matches the observed line emission, especially for the hot ($\sim 10^8$ K) plasma emission of the FeXXV complex at $\sim 1.85$\AA. The model loop has $L/R_{\star} \sim 1/2$ and aspect ratio $r/L \sim 0.1$ as typically derived for flares observed in active stellar coronae, suggesting that the underlying physics is the same for these very dynamic and extreme phenomena in stellar coronae independently on stellar parameters and evolutionary stage.Comment: 26 pages. Accepted for publication on the Astrophysical Journa