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In this work semiconductor sample of GaAs and InP doped and non-doped with a fast-mapping equipment by photoluminescence at room temperature. The samples were gown by the LEC technique, with the photo luminescent technique the images were obtained and line spectrum to analyze characterization parameters such as: wavelength and intensity of the maximum, wide spectral in the middle of the maximum height (FWHM) and the integrated signal for all the samples. The spectrum of the not dope GaAs showed 2 peaks around 1,426 eV and another in 1,36 eV, which corresponds to superficial defect originated by the oxidation process of itself. The spectrum of the GaAs:Cr showed us a peak around 1,437, it did not present any defect zone when treated chemically due to the presence of the Cr en el GaAs that originates an acceptor deep level located in 0,63 eV and under the conduction band. The spectrum of the InP:S showed a peak around the 1,375 eV and when it was treated chemically showed 2 peaks: 1,380eV with acetone and 1,392 eV with sulfuric acid. These peaks show us the crystalline quality that these semiconductor samples present, allowing the manufacture of optoelectronic devices such as: lasers, microchips and detectors. [ABSTRACT FROM AUTHOR]

The sustainability and efficiency of ecotourism regarding biodiversity conservation are under constant scrutiny and often dismissed based on negative effects arising from other types of nature-based tourism. Our study assess the impacts of infrastructure, human activity, and environmental factors on medium-large ground terrestrial species within the Lapa Rios Ecolodge Nature Reserve; results indicate that restoration, preservation, and conservation efforts are responsible for the wide range of species found within their reserve, including increased abundance of highly threatened rodents and ground birds. There is no indication that visitation or tour activities have negative impacts on wildlife; instead, the Ecolodge effectively created a 'human shield' that weakens threats to wildlife arising from hunting, logging, and gold mining. This shield effect ripples across the Osa Peninsula through the socio-economic benefits provided by ecotourism. Our results support a conservation model incorporating private reserves and parks to sustain biodiversity. [ABSTRACT FROM AUTHOR]

The article offers information about Non-meningothelial meningeal tumors with meningioangiomatosis. Topics discussed include perivascular spread of meningothelial and fibroblastic cells results Meningioangiomatosis; talks about biopsy of parieto-occipital mass reveals cellular neoplasm involving the leptomeninges; and mentions morphological and immunohistochemical sarcoma, shows features of rhabdomyosarcoma.

Copyright of Revista Técnica Energía is the property of Centro Nacional de Control de Energia CENACE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Técnica Energía is the property of Centro Nacional de Control de Energia CENACE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On the north coast of present-day Peru, between the Andes and the Pacific Ocean, approximately between 100 and 600 ad, the Moche civilization prospered. The Moche were very sophisticated artisans and metal smiths, so that they are considered the finest producers of jewels and artifacts of the region. Their metalworking ability was impressively demonstrated by the excavations of the tomb of the 'Lady of Cao' (dated around third-fourth century ad) discovered by Regulo Franco in 2005. Impressive is the beauty of the artifacts, and also the variety of metallurgical solutions, demonstrated by not only the presence of objects composed of gold and silver alloys but also of gilded copper, gilded silver, and tumbaga, a poor gold Cu-Au alloy subject to depletion gilding. About 100 metal artifacts from the tomb of the Lady of Cao, never before analyzed, were studied by using various portable equipments based on following non-destructive and non-invasive methods: energy-dispersive X-ray fluorescence with completely portable equipments;, transmission of monenergetic X-rays;, radiographic techniques; and, optical microscopy., Gold objects and gold areas of nose decorations are characterized by approximately the same composition, that is, Au = (79.5 ± 2.5) %, Ag = (16 ± 3) %, and Cu = (4.5 ± 1.5) %, while silver objects and silver areas of the same nose decorations show completely erratic results, and a systematic high gold concentration. Many gilded copper and tumbaga artifacts were identified and analyzed. Further, soldering gold-silver was specifically studied by radiographs. Additional measurements are needed, particularly because of the suspect that depletion gilding was systematically employed also in the case of some nose decorations. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Revista Técnica Energía is the property of Centro Nacional de Control de Energia CENACE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Superficies y Vacío is the property of Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Detecting determinism in univariate and multivariate time series is difficult if the underlying process is nonlinear, and the noise level is high. In a previous paper, the authors proposed a method based on observable ordinal patterns. This method exploits the robustness of admissible ordinal patterns against observational noise, and the super-exponential growth of forbidden ordinal patterns with the length of the patterns. The new method compared favorably to the Brock-Dechert-Scheinkman independence test when applied to time series projected from the Hénon attractor and contaminated with Gaussian noise of different variances. In this paper, we extend this comparison to higher fractal dimensions by using noisy orbits on the attractors of the Lorenz map, and the time-delayed Hénon map. Finally, we make an analysis that enlightens the robustness of admissible ordinal patterns in the presence of observational noise. [ABSTRACT FROM AUTHOR]

In this work we present the study of the dispersive processes in InGaAs/InAlAs quantum wells using the photoreflectance (PR) and photoluminescence (PL) techniques. The samples of InGaAs/InAlAs were grown by the Metal Organic Chemical Vapor Deposition (MOCVD) with wells widths ranging from 6,5 nm to 10,5 nm. PR spectra were measured in the temperature range from 220 K to 300 K and the PL spectra in the temperature range from 11K to 300K. There was a comparative analysis of the line shapes of the PR and PL spectras. We found inhomogeneus broadening in these spectras, which were atributed to the local stresses in the well barrier interface. From the analysis, we identified that the main dispersive process present in the studied optical transitions, is due to the exciton-phonon interaction [ABSTRACT FROM AUTHOR]

• Soft tissue sarcoma (STS) and gastrointestinal tumors (GIST) encompass > 80 different histologic subtypes. • Clinical practice guidelines for STS and GIST still lack in Latin-American countries. • Tailored clinical guidelines are instrumental to improve outcome in sarcoma patients in LatinAmerican countries. • This is the first review establishing STS and GIST guidelines for the purpose of LatinAmerican clinical practices to our knowledge. [ABSTRACT FROM AUTHOR]

Tropical dry forests may be among the world's most threatened ecosystems, but few studies have objectively quantified their status and threats. This study analysed Venezuelan dry forests at multiple scales, assessing status, present threats and the policy context shaping their future. Historical and current dry forest cover at both national and local scales were contrasted, and a set of quantitative risk assessment criteria applied. While dry forests were vulnerable nationally, in northern-central locations they were endangered. Clearing for cattle ranching and for intensive and subsistence agriculture were the principal factors driving dry forest loss at the national scale, while at a local level, urbanization and fire seemed to be the primary threats. The analysis emphasized the separation of risk assessment from the very different task of establishing conservation priorities; high risk areas may not necessarily be the highest priority for investment, and policy makers may become explicitly aware of the spatial scale at which their policies are implemented, as well as how these policies may affect or be affected by the status of ecosystems beyond their area of influence. The main challenge to future dry forest conservation is a paucity of explicit policies for management and use. However, scientifically-based management can support positive dry forest policies in many ways, including identifying locations and protocols for ecological restoration, maintaining seed banks, quantifying baseline conditions, and monitoring genetic diversity and other indicators. [ABSTRACT FROM PUBLISHER]

Copyright of Cirugía Plástica Ibero-Latinoamericana is the property of Cirugia Plastica Ibero-Latinoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Palliative sedation (PS) is the subject of ethical and legal debates worldwide. Statistics of its utilization are available in developed countries; however, in Latin America, these data are scarcely known. The purpose of this research was to determine the practices and attitudes of palliativists in Latin America towards PS.Materials and Methods: Data was collected during the Latin American Congress on Palliative Care in Isla Margarita, Venezuela. A total of 89 professionals participated in this survey.Results: It was found that the use of PS was positively associated with being a physician and being members of a palliative care (PC) group. On the other hand, it was found that being a psychologist and identifying barriers toward PS limited its utilization.Discussion: The findings of this study support the need to establish clinical guidelines for its utilization and to educate other specialists on end-of-life care approaches, and the need to develop PC programs in acute care hospitals in Latin America. [ABSTRACT FROM AUTHOR]

We have proposed an adaptive procedure in order to estimate unknown parameters of a numerical model of a chaotic CO2 laser, which is observed through a time series that represents the output intensity of the laser. To do that, we consider a coupled system with the same functional form and adjustable parameters. The salient feature of the proposed technique is that accurate parameter estimation and identical synchronization can be jointly achieved by adaptively adjusting the desired parameters of the coupled system. [ABSTRACT FROM AUTHOR]

The InGaAs/InA1As quantum wells have an enormous potential as semiconductors lasers, but factors like the interfaces roughness, internal defects, located pressures or local electric fields, they alter the width of the laser light beam with the rising loss of the intensity and coherence. Therefore in this work we realized the photoreflectance analysis in two In- GaAs/InA1As quantum wells semiconductors heterostructures sample with thicknesses from 5 nm to 13 nm. The photoreflectance spectra were carried out in the rank of temperatures from 220K to 300K. For the analysis of these spectra we used the two dimensional critical point of third derived from asymmetric Lorentzian lineshape. Of the respectives fittings we obtained that the experimental transition energy values agree with the calculated theoretically values. It was also found that the broadening parameters are proportionals to the temperature as expected and that the factors of asymmetry are direct proportionals to the temperature, that which can be attributed to the local tensions in the interfaces. [ABSTRACT FROM AUTHOR]

Phase control of chaos is a powerful technique but little is known about its physical constraints, relevant for real systems. As a fact, it has not been explored whether this technique can also be applied when the controlling perturbation is not harmonic. Here we apply phase control on a driven double well Duffing oscillator using periodic rectangular pulsed perturbations instead of the classical sinusoidal perturbations. Experimental measurements and numerical simulations show that this kind of perturbation is also able to stabilize the chaotic orbits for an adequate selection of the phase. Furthermore, as the duty cycle of the perturbation (that is, the fraction of the time that the periodically pulsed control is active) is increased, two separate regimes occur. In the first one, the perturbations leading to stabilization of periodic solutions are of constant energy (taken as the product of the duty cycle and the amplitude) and in the second one, a saturation phenomenon occurs, implying that increasing energy values of the perturbations are wasted. Our results unveil the versatility of the pulsed phase control scheme and the importance of energy constraints. [ABSTRACT FROM AUTHOR]

The InGaAs/InAlAs quantum wells offer a huge potential as lasers of semiconductors, but factors as interface roughness, internal defects, localized pressures or local electrical fields, generate a broadening spectral that in the practice is manifested through an alteration the laser light beam width and consequently the loss of intensity and coherence. The spectral asymmetry was studied here in two samples of heteroestructures semiconductors of quantum wells of InGaAs/InAlAs with vary thickness from 4 to 13 nm. The photoluminescence spectra were analyzed with symmetrical and asymmetric Lorentzians to different temperatures. It was found that the adjustments with asymmetric Lorentzians produced the best reproductions of the experimental data, it was also found that the spectral widths are proportional to the widths of each well with presence of a process that is activated to intermediate temperatures and that the factor of asymmetry is inverse to the width of the wells. [ABSTRACT FROM AUTHOR]

The InGaAs/InAlAs quantum wells offer a huge potential as semiconductor lasers, but factors as interface roughness, internal defects, localized pressures or local electrical fields alter the laser light beam width and consequently the loss of intensity and coherence. The inhomogeneous broadening was studied in the photoluminescence spectra in the InGaAs/InAlAs. It was found that the presence of volumetric and not superficial defects is those responsible for the formation of the inhomogeneous broadening [ABSTRACT FROM AUTHOR]

Phase-control techniques of chaos aim to extract periodic behaviors from chaotic systems by applying weak harmonic perturbations with a suitably chosen phase. However, little is known about the best strategy for selecting adequate perturbations to reach desired states. Here we use experimental measures and numerical simulations to assess the benefits of controlling individually the three terms of a Duffing oscillator. Using a real-time analog indicator able to discriminate on-the-fly periodic behaviors from chaos, we reconstruct experimentally the phase versus perturbation strength stability areas when periodic perturbations are applied to different terms governing the oscillator. We verify the system to be more sensitive to perturbations applied to the quadratic term of the double-well Duffing oscillator and to the quartic term of the single-well Duffing oscillator. [ABSTRACT FROM AUTHOR]