1,268 research outputs found
First Record of leucism in Tropidurus hispidus (Spix, 1825) (Squamata: Tropiduridae) in north Brazil, Eastern Amazon
In vertebrates leucism does not occur frequently in nature but has been recorded in amphibians and reptiles. Herein we report the first record of leucism in Tropidurus hispidus from north Brazil, Eastern Amazon. During fieldwork in an amphibian and reptile assessment, we photographed on a rocky surface and leaf litter an individual T. hispidus with leucism.En los vertebrados el leucismo no ocurre con frecuencia en la naturaleza, pero se ha registrado en anfibios y reptiles. Aquí informamos el primer registro de leucismo en Tropidurus hispidus del norte de Brasil, Amazonas Oriental. Durante el trabajo de campo en una evaluación de anfibios y reptiles, fotografiamos sobre una superficie rocosa y hojarasca un individuo de T. hispidus con leucismo
An SFC-enabled approach for processing SSL/TLS encrypted traffic in future enterprise networks
In this paper, we propose an architecture based on NFV and SDN which allows to balance traffic analysis techniques using a Classifier. It steers flows to the appropriate Service Function Chaining (to open traffic or not) according to network requirements (such as, effectiveness, flexibility, scalability, performance, and privacy). The SSL/TLS traffic processing is carried-out by the centerpiece of this work, the SFC-enabled MITM. A Proof-of-Concept was conducted (focusing on our SFC-enabled MITM) which showed that functionalities lost due to encryption (Content Optimization, Caching, Network Anti-virus, and Content Filter) were recovered when processing opened traffic within its Service Function Chains. We also evaluated its impact on performance. The results show that cipher suite overhead plays a role but can be mitigated, the Classifier can alleviate the performance overhead of different traffic analysis techniques, network functions have lower impact to performance, and Service Function Chaining length influences page load time.publishe
Rainfall Prediction in the State of Paraíba, Northeastern Brazil Using Generalized Additive Models
The state of Paraíba is part of the semi-arid region of Brazil, where severe droughts have occurred in recent years, resulting in significant socio-economic losses associated with climate variability. Thus, understanding to what extent precipitation can be influenced by sea surface temperature (SST) patterns in the tropical region can help, along with a monitoring system, to set up an early warning system, the first pillar in drought management. In this study, Generalized Additive Models for Location, Scale and Shape (GAMLSS) were used to filter climatic indices with higher predictive efficiency and, as a result, to perform rainfall predictions. The results show the persistent influence of tropical SST patterns in Paraíba rainfall, the tropical Atlantic Ocean impacting the rainfall distribution more effectively than the tropical Pacific Ocean. The GAMLSS model showed predictive capability during summer and southern autumn in Paraíba, highlighting the JFM (January, February and March), FMA (February, March and April), MAM (March, April and May), and AMJ (April, May and June) trimesters as those with the highest predictive potential. The methodology demonstrates the ability to be integrated with regional forecasting models (ensemble). Such information has the potential to inform decisions in multiple sectors, such as agriculture and water resources, aiming at the sustainable management of water resources and resilience to climate risk
Orchestrating an SFC-enabled SSL/TLS traffic processing architecture using MANO
The heterogeneity of 5G requirements commands
more complex network architectures, imposing the need for
network orchestration. ETSI NFV MANO is the standard which
defines a common framework for vendors and operators to
integrate their orchestration efforts. In this paper, we evaluated
how an ETSI NFV MANO compliant orchestrator (OSM) fares
while orchestrating an SFC-enabled SSL/TLS encrypted traffic
processing architecture, which supports both edge and cloud
deployments. A quantitative evaluation was carried-out, which
assessed the responsiveness and overheads of OSM, as well as the
actual functionality of our SSL/TLS processing architecture (with
edge computing components). A qualitative evaluation was also
carried-out, providing insight into the maturity of the current
OSM release, what works well, what requires workarounds,
and the actual limitations. A demonstration of the architecture
evaluated in this work was accepted as a contribution to the
ETSI OSM PoC Framework.publishe
Limiting Carleman weights and anisotropic inverse problems
In this article we consider the anisotropic Calderon problem and related
inverse problems. The approach is based on limiting Carleman weights,
introduced in Kenig-Sjoestrand-Uhlmann (Ann. of Math. 2007) in the Euclidean
case. We characterize those Riemannian manifolds which admit limiting Carleman
weights, and give a complex geometrical optics construction for a class of such
manifolds. This is used to prove uniqueness results for anisotropic inverse
problems, via the attenuated geodesic X-ray transform. Earlier results in
dimension were restricted to real-analytic metrics.Comment: 58 page
Disruption of the inositol phosphorylceramide synthase gene affects Trypanosoma cruzi differentiation and infection capacity
Sphingolipids (SLs) are essential components of all eukaryotic cellular membranes. In fungi, plants and many protozoa, the primary SL is inositol-phosphorylceramide (IPC). Trypanosoma cruzi is a protozoan parasite that causes Chagas disease (CD), a chronic illness for which no vaccines or effective treatments are available. IPC synthase (IPCS) has been considered an ideal target enzyme for drug development because phosphoinositol-containing SL is absent in mammalian cells and the enzyme activity has been described in all parasite forms of T. cruzi. Furthermore, IPCS is an integral membrane protein conserved amongst other kinetoplastids, including Leishmania major, for which specific inhibitors have been identified. Using a CRISPR-Cas9 protocol, we generated T. cruzi knockout (KO) mutants in which both alleles of the IPCS gene were disrupted. We demonstrated that the lack of IPCS activity does not affect epimastigote proliferation or its susceptibility to compounds that have been identified as inhibitors of the L. major IPCS. However, disruption of the T. cruzi IPCS gene negatively affected epimastigote differentiation into metacyclic trypomastigotes as well as proliferation of intracellular amastigotes and differentiation of amastigotes into tissue culture-derived trypomastigotes. In accordance with previous studies suggesting that IPC is a membrane component essential for parasite survival in the mammalian host, we showed that T. cruzi IPCS null mutants are unable to establish an infection in vivo, even in immune deficient mice
- …