Linearizability with Ownership Transfer

Linearizability is a commonly accepted notion of correctness for libraries of concurrent algorithms. Unfortunately, it assumes a complete isolation between a library and its client, with interactions limited to passing values of a given data type. This is inappropriate for common programming languages, where libraries and their clients can communicate via the heap, transferring the ownership of data structures, and can even run in a shared address space without any memory protection. In this paper, we present the first definition of linearizability that lifts this limitation and establish an Abstraction Theorem: while proving a property of a client of a concurrent library, we can soundly replace the library by its abstract implementation related to the original one by our generalisation of linearizability. This allows abstracting from the details of the library implementation while reasoning about the client. We also prove that linearizability with ownership transfer can be derived from the classical one if the library does not access some of data structures transferred to it by the client

Fractures After Denosumab Discontinuation: A Retrospective Study of 797 Cases.

A rebound of osteoclast activity during the 2 years after a treatment or prevention of osteoporosis with denosumab (Dmab) leads to an increased risk of vertebral fractures (VFs). We attempted to identify the risk factors for these VF and to examine the protective role of bisphosphonates. For that, 22 specialists in Switzerland provided data of unselected patients, treated with denosumab for osteoporosis or breast cancer without metastases under aromatase inhibitors, who have received at least two injections of Dmab, with at least 1 year of follow-up after discontinuation. The questionnaire covered separately the periods before, during, and after Dmab treatment, and registered clinical, radiological, and lab data. For the analysis of the risk factors, the main outcomes were the time to the first VF after the treatment, the presence of multiple VFs (MVFs), and the number of VFs. The incidence of VF was 16.4% before, 2.2% during, and 10.3% after the treatment with Dmab. The risk of VF after Dmab discontinuation was associated with an increased risk of non-vertebral fractures. The pretreatment predictors of the post-treatment fracture risk were a parental hip fracture and previous VFs. Further risk factors appeared later, such as low total hip bone mineral density (BMD) during and after denosumab, increased bone resorption markers, and the loss of total hip BMD after the denosumab. Treatment with bisphosphonates, especially after Dmab, had a protective effect. Bisphosphonates given before Dmab did not further decrease the risk of VF in cases who got bisphosphonates after Dmab. This study shows that the risk of VF is poorly predictable before the prescription of denosumab. But during and after the treatment, bone resorption markers and BMD have a significant predictive value. Bisphosphonates after the treatment with denosumab are protective against VFs. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)

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

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

Resumo

Ocorrência de Isogonoceraia divergipennis White & Hodkinson (1980) associado a Caesalpinia pluviosa (Fabaceae) em Mato Grosso, Brasil.

Resumo

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

Two introduced psyllid species (Hemiptera, Psylloidea) in Brazilian eucalypt plantations.

1 CD-ROM. Autoria bilíngue: CONGRESSO E EXPOSICAO INTERNACIONAL SOBRE FLORESTAS, 5., 1999, Curitiba

Checking bounded reachability in asynchronous systems by symbolic event tracing

This report presents a new symbolic technique for checking reachability properties of asynchronous systems by reducing the problem to satisfiability in restrained difference logic. The analysis is bounded by fixing a finite set of potential events, each of which may occur at most once in any order. The events are specified using high-level Petri nets. The logic encoding describes the space of possible causal links between events rather than possible sequences of states as in Bounded Model Checking. Independence between events is exploited intrinsically without partial order reductions, and the handling of data is symbolic. On a family of benchmarks, the proposed approach is consistently faster than Bounded Model Checking. In addition, this report presents a compact encoding of the restrained subset of difference logic in propositional logic