On the Behaviour of General-Purpose Applications on Cloud Storages

Managing data over cloud infrastructures raises novel challenges with respect to existing and well studied approaches such as ACID and long running transactions. One of the main requirements is to provide availability and partition tolerance in a scenario with replicas and distributed control. This comes at the price of a weaker consistency, usually called eventual consistency. These weak memory models have proved to be suitable in a number of scenarios, such as the analysis of large data with Map-Reduce. However, due to the widespread availability of cloud infrastructures, weak storages are used not only by specialised applications but also by general purpose applications. We provide a formal approach, based on process calculi, to reason about the behaviour of programs that rely on cloud stores. For instance, one can check that the composition of a process with a cloud store ensures `strong' properties through a wise usage of asynchronous message-passing

Diversity and distribution of jumping plant-lice (Hemiptera: Psylloidea) along edges of Amazon - Cerrado transitional forests in Sorriso, Mato Grosso, Brazil.

Little is known about the jumping plant-lice of Brazil from where seven families, 45 genera and 76 species have been previously reported, but estimates suggest that there may be as many as 1,000 species. This study reports 34 species of Psylloidea which were collected along the edges of Amazon?Cerrado natural transitional forests in the municipality of Sorriso, state of Mato Grosso, from August 2013 to July 2014. Of the species reported in this study only nine represent described taxa, two of which are reported for the first time from Mato Grosso.hardt et al. 2013; Mazzardo 2014; Mazzardo et al. 2016): the two introduced eucalypt pests Blastopsylla occidentalis and Glycaspis brimblecombei, the three Fabaceae feeders Euphalerus clitoriae, Isogonoceraia divergipennis and Macrocorsa beeryi, the Toona pest Mastigimas anjosi, and the Nectandra psylloid Limataphalara lautereri. To improve the apparent lack of knowledge, a survey of the psylloid fauna of the edges of Amazon?Cerrado native transitional forests was conducted in Sorriso, Mato Grosso, Brazil. Here we present a commented inventory of the species encountered during the dry and rainy seasons

Locality and Singularity for Store-Atomic Memory Models

Robustness is a correctness notion for concurrent programs running under relaxed consistency models. The task is to check that the relaxed behavior coincides (up to traces) with sequential consistency (SC). Although computationally simple on paper (robustness has been shown to be PSPACE-complete for TSO, PGAS, and Power), building a practical robustness checker remains a challenge. The problem is that the various relaxations lead to a dramatic number of computations, only few of which violate robustness. In the present paper, we set out to reduce the search space for robustness checkers. We focus on store-atomic consistency models and establish two completeness results. The first result, called locality, states that a non-robust program always contains a violating computation where only one thread delays commands. The second result, called singularity, is even stronger but restricted to programs without lightweight fences. It states that there is a violating computation where a single store is delayed. As an application of the results, we derive a linear-size source-to-source translation of robustness to SC-reachability. It applies to general programs, regardless of the data domain and potentially with an unbounded number of threads and with unbounded buffers. We have implemented the translation and verified, for the first time, PGAS algorithms in a fully automated fashion. For TSO, our analysis outperforms existing tools

New country, Brazilian states and host records of the eucalypt shoot psyllid Blastopsylla occidentalis.

O psilídeo das ponteiras do eucalipto, Blastopsylla occidentalis Taylor, 1985 (Hemiptera: Psylloidea) é relatado aqui pela primeira vez para o Burundi, Indonésia (Sumatra), Nicarágua, Filipinas e Iêmen. O registro desta para o Paraguai mostrou ser um erro. Novos registros são dados para os estados brasileiros Bahia, Ceará, Piauí e Rio Grande do Sul. Eucalyptus viminalis é listado pela primeira vez como hospedeiro de B. occidentalis.Nota científica

Faster linearizability checking via PP-compositionality

Linearizability is a well-established consistency and correctness criterion for concurrent data types. An important feature of linearizability is Herlihy and Wing's locality principle, which says that a concurrent system is linearizable if and only if all of its constituent parts (so-called objects) are linearizable. This paper presents $P$-compositionality, which generalizes the idea behind the locality principle to operations on the same concurrent data type. We implement $P$-compositionality in a novel linearizability checker. Our experiments with over nine implementations of concurrent sets, including Intel's TBB library, show that our linearizability checker is one order of magnitude faster and/or more space efficient than the state-of-the-art algorithm.Comment: 15 pages, 2 figure

Redescription of the little-known psyllid Cacopsylla dissimilis (Baeva, 1963) comb. nov. (Hemiptera: Psyllidae) from Iran

During a faunistic survey of the jumping plant-lice (Hemiptera: Psylloidea) in the Iranian province of Kerman in spring 2015, Cacopsylla dissimilis (Baeva) comb. nov. was collected on Salix pycnostachya. This species was previously known only from Tajikistan. It is reported here for the first time from Iran. The host species, Salix pycnostachya, is also newly recorded. We provide detailed morphological descriptions of adults and fifth instar immatures, and discuss differences to closely related species, in particular Cacopsylla nigrita (Zetterstedt)

Diversidade de psilídeos (Hemiptera: Psylloidea) em Sorriso, MT.

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