173 research outputs found
A long survival of a patient with brain metastasis of unknown site of the primary tumor
Eighty percent of brain metastases (BM) are diagnosed in patients with known primary site of cancer. BM of unknown primary represents a difficult diagnosis. In up to 15% of patients with BM, the site of the primary tumor will not be detected despite investigations. The prognosis of this entity is very poor. We report here a case of a long survival of a patient with brain metastasis of unknown primary. The conclusion that can be drawn is that within BM of unknown primary exist patients with a very good prognosis that must be collected and published in order to base recommendations
Comparative Analysis of CBRM Cases in Kenya, Ethiopia and Tunisia
In various countries, development and conservation organizations and national policymakers have been experimenting with ways of applying the community-based natural resource management approach to the unique social and biophysical characteristics of pastoralist rangeland settings, with mixed results. We carried out comparative case study research on community-based rangeland management (CBRM) in a variety of settings in Ethiopia, Kenya and Tunisia with the objective of identifying what kinds of strategies and methods work in which social and ecological contexts. We used an “options by context” approach guided by a research protocol that includes key variables and descriptors for characterizing the implementing organization’s approach to CBRM and important contextual factors that may vary from place to place and affect the implementation and success of the approach. The commonalities among our cases include: i) community governance and management structures for rangeland management; ii) the geographic rangeland unit which those structures are managing, and iii) a development agent that is supporting the community. We found that differences among the cases in the challenges faced and their degree of success depended at least as much on certain aspects of social and biophysical context as it did on the exact nature of the approach being implemented by the development agent. For example, the extent to which there are effective natural or social borders that provide the rangeland community with some degree of separation from neighbours is crucial; without such landscape features, the design principle of clearly defined rights to a clearly defined piece of land belonging to a clearly defined community is difficult to implement in any straightforward way. In some pastoral rangeland contexts, conventional community-based approaches need substantial modification to be effective in contexts with the highest levels of spatio-temporal variability, mobility and openness of the landscape
Analysis of Simulated Output Characteristics of Gas Sensor Based on Graphene Nanoribbon
This work presents simulated output characteristics of gas sensor transistors based on graphene nanoribbon (GNRFET). The device studied in this work is a new generation of gas sensing devices, which are easy to use, ultracompact, ultrasensitive, and highly selective. We will explain how the exposure to the gas changes the conductivity of graphene nanoribbon. The equations of the GNRFET gas sensor model include the Poisson equation in the weak nonlocality approximation with proposed sensing parameters. As we have developed this model as a platform for a gas detection sensor, we will analyze the current-voltage characteristics after exposure of the GNRFET nanosensor device to NH3 gas. A sensitivity of nearly 2.7% was indicated in our sensor device after exposure of 1 ppm of NH3. The given results make GNRFET the right candidate for use in gas sensing/measuring appliances. Thus, we will investigate the effect of the channel length on the ON- and OFF-current
D14.9: A cross-country comparative report integrating the results from impact assessment in WP7-WP13
Community-based rangeland management in Tataouine, south-east Tunisia: Institutional settings to revive traditional land restoration “Gdel”
Kinetics of Graphene Growth on Liquid Copper by Chemical Vapor Deposition
We report a combined experimental and computational study of the kinetics of
graphene growth during chemical vapor deposition on a liquid copper catalyst.
The use of liquid metal catalysts offers bright perspectives for controllable
large-scale, high-quality synthesis technologies of two-dimensional materials.
We carried out a series of growth experiments varying CH4-to-H2 pressure ratios
and deposition temperature. By monitoring the graphene flake morphology in real
time during growth using in situ optical microscopy in radiation mode, we
explored the morphology and kinetics of the growth within a wide range of
experimental conditions. Following an analysis of the flakes' growth rates, we
conclude that the growth mode was attachment-limited. The attachment and
detachment activation energies of carbon species are derived as 1.9 +- 0.3 eV
and 2.0 +- 0.1 eV, respectively. We also conducted free-energy calculations by
a moment tensor potential trained to density functional theory data. Our
simulations propose that carbon dimers are most likely the active carbon
species during growth, with attachment and detachment barriers of 1.71 +- 0.15
eV and 2.09 +- 0.02 eV, respectively, being in good agreement with the
experimental results
Barium effect on germination, plant growth, and antioxidant enzymes in Cucumis sativus L. plants
Barium (Ba) is a nonessential element that can cause several deleterious effects in
most organisms. Elevated Ba concentrations can be toxic for plants and may affect
growth and disturbances in homeostasis. This study aimed to evaluate the Ba stress,
the plant-tolerance limits, and the detoxification strategy adopted by Cucumis sativus
L. The effect of Ba on seed's germination and vegetative development of this species
was evaluated. For germination test, different Ba concentrations were used (0, 200,
500, 1,000, and 2,000 μM). Results showed that germination was stimulated with
500 and 2,000 µM of Ba. The toxicity effect on plant development was studied by
treating the plants with increasing doses of Ba (100, 200, 300, and 500 μM) during
45 days. Shoot and root dry biomass production decreased significantly with elevated
Ba concentrations, although water content enhanced in the roots. The concentration
of Ba, 500 µM, induced high Ba accumulation in shoots and roots (9 times higher
than in the control plants). Moreover, results showed that catalase, guaiacol peroxidase, and ascorbate peroxidase activities were stimulated in the different tissues of
cucumber plants which highlight the occurring of an oxidative damage through Ba
treatments and the involvement of the plant enzymatic antioxidant defense system
A multipurpose experimental facility for advanced X-ray Spectrometry applications
Ponencia presentada en la European Conference on X-Ray Spectrometry (EXRS). 2014Motivation, Ultra High Vacuum Chamber (UHVC) project: To support/enhance the training of scientists/engineers from developing countries in the operation of synchrotron radiation instrumentation; To provide beam time access for R&D projects and hands-on training in SR-XRS based techniques; To promote networking and knowledge sharing; To increase the quality and the competitiveness of the developing countries to apply beam time proposals at SR facilities; To contribute in the further development of XRS techniques in applications with socioeconomicalrelevance (characterization of energy storage/conversion materials, environmental, biological and biomedical applications)Fil: Leani, Juan José. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Leani, Juan José. Nuclear Science and Instrumentation Laboratory, IAEA Laboratories; Austria.Física Atómica, Molecular y Química (física de átomos y moléculas incluyendo colisión, interacción con radiación, resonancia magnética, Moessbauer Efecto.
Status and Trends of Land Degradation and Restoration and Associated Changes in Biodiversity and Ecosystem Functions
Unique features of a global human ectoparasite identified through sequencing of the bed bug genome
The bed bug, Cimex lectularius, has re-established itself as a ubiquitous
human ectoparasite throughout much of the world during the past two decades.
This global resurgence is likely linked to increased international travel and
commerce in addition to widespread insecticide resistance. Analyses of the C.
lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding
genes provide a comprehensive representation of genes that are linked to
traumatic insemination, a reduced chemosensory repertoire of genes related to
obligate hematophagy, host–symbiont interactions, and several mechanisms of
insecticide resistance. In addition, we document the presence of multiple
putative lateral gene transfer events. Genome sequencing and annotation
establish a solid foundation for future research on mechanisms of insecticide
resistance, human–bed bug and symbiont–bed bug associations, and unique
features of bed bug biology that contribute to the unprecedented success of C.
lectularius as a human ectoparasite
- …