SMAC multi-hop mesh routing protocol using IEEE 802.15.4

This paper discusses some aspects related to Wireless Sensor Networks over the IEEE 802.15.4 standard, and proposes, for the very first time, a mesh network topology with geographic routing integrated to the open Freescale protocol (SMAC - Simple Medium Access Control). For this is proposed the SMAC routing protocol. Before this work the SMAC protocol was suitable to perform one hop communications only. However, with the developed mechanisms, it is possible to use multi-hop communication. Performance results from the implemented protocol are presented and analyzed in order to define important requirements for wireless sensor networks, such as robustness, self-healing property and low latency. (c) 2011 Elsevier Ltd. All rights reserved.

The skull of the Upper Cretaceous snake Dinilysia patagonica Smith-Woodward, 1901, and its phylogenetic position revisited

The cranial anatomy of Dinilysia patagonica, a terrestrial snake from the Upper Cretaceous of Argentina, is redescribed and illustrated, based on high-resolution X-ray computed tomography and better preparations made on previously known specimens, including the holotype. Previously unreported characters reinforce the intriguing mosaic nature of the skull of Dinilysia, with a suite of plesiomorphic and apomorphic characters with respect to extant snakes. Newly recognized plesiomorphies are the absence of the medial vertical flange of the nasal, lateral position of the prefrontal, lizard-like contact between vomer and palatine, floor of the recessus scalae tympani formed by the basioccipital, posterolateral corners of the basisphenoid strongly ventrolaterally projected, and absence of a medial parietal pillar separating the telencephalon and mesencephalon, amongst others. We also reinterpreted the structures forming the otic region of Dinilysia, confirming the presence of a crista circumfenestralis, which represents an important derived ophidian synapomorphy. Both plesiomorphic and apomorphic traits of Dinilysia are treated in detail and illustrated accordingly. Results of a phylogenetic analysis support a basal position of Dinilysia, as the sister-taxon to all extant snakes. The fossil taxa Yurlunggur, Haasiophis, Eupodophis, Pachyrhachis, and Wonambi appear as derived snakes nested within the extant clade Alethinophidia, as stem-taxa to the crown-clade Macrostomata. The hypothesis of a sister-group relationship between Dinilysia and Najash rionegrina, as suggested by some authors, is rejected by the results of our analysis.

Efeito da azadiractina sobre Chaetosiphon fragaefolli (Cockerell, 1901) (Hemiptera: Aphididae) na cultura do morangueiro

O pulgão-verde Chaetosiphon fragaefolli é o principal inseto-praga da cultura do morangueiro. Neste trabalho, foi avaliado o efeito da azadiractina para o controle do inseto em laboratório e casa de vegetação. Os tratamentos avaliados foram a azadiractina (Azamax®, 100; 200 e 300 ml.100L-1) comparado com o tiametoxam (Actara 250 WG®, 10 g.100L-1), lambda-cialotrina (Karate Zeon 50 CS®, 80 ml.100L-1) e uma testemunha (água). Os produtos foram pulverizados sobre plantas de morangueiro da cultivar Aromas infestadas artificialmente em casa de vegetação. A azadiractina foi equivalente a lambda-cialotrina e ao tiametoxam no controle de C. fragaefolii desde que realizada uma segunda pulverização sete dias após a primeira. A persistência biológica dos inseticidas lambda-cialotrina e tiametoxam foi superior a 28 dias, com um controle de 75% da população de pulgões, enquanto azadiractina apresentou menor persistência biológica, controlando 70% da população por sete dias.