Proving sequential consistency by model checking

Sequential consistency is a multiprocessor memory model of both practical and theoretical importance. Unfortunately, the general problem of verifying that a finitestate protocol implements sequential consistency is undecidable, and in practice, validating that a real-world, finitestate protocol implements sequential consistency is very time-consuming and costly. In this work, we show that for memory protocols that occur in practice, a small amount of manual effort can reduce the problem of verifying sequential consistency into a verification task that can be discharged automatically via model checking. Furthermore, we present experimental results on a substantial, directorybased cache coherence protocol, which demonstrate the practicality of our approach.

Habitat corridor utilization by the gray mouse lemur, Microcebus murinus, in the littoral forest fragments of southeastern Madagascar

Habitat fragmentation has reached a dramatic level in Madagascar. As the size of many remaining forest fragments is unlikely to maintain viable animal populations in the long-term, connecting isolated subpopulations by creating corridors is important to support gene flow and the persistence of the endemic fauna, including lemurs. Since restoration with endemic trees is slow, exotic trees may represent a faster alternative to initiate habitats that can be used by animals. Here, we studied whether or not grey mouse lemurs, Microcebus murinus, use corridors composed of exotic and native trees of different age and composition to move between littoral forest fragments. For this, we trapped M. murinus in four forest fragments and mixed tree plantations between the fragments. One of the corridors was composed of a mixture of endemic and mature exotic Eucalyptus robusta trees. The second corridor consisted mainly of an old stand of exotic Melaleuca quinquenervia. The third corridor was composed of exotic Acacia mangium trees planted in 2009. During four years of study, only one male M.murinus used the Melaleuca corridor, while several M. murinus were caught in the Eucalyptus and the Acacia corridor in 2013. The density of the corridor under-story appeared to influence the number of individuals captured; the corridor with highest understory density was used most. The captures within the corridors illustrate that exotic trees allow movements of mouse lemurs within less than 5 years after plantation

Rice yields decline with higher night temperature from global warming

The impact of projected global warming on crop yields has been evaluated by indirect methods using simulation models. Direct studies on the effects of observed climate change on crop growth and yield could provide more accurate information for assessing the impact of climate change on crop production. We analyzed weather data at the International Rice Research Institute Farm from 1979 to 2003 to examine temperature trends and the relationship between rice yield and temperature by using data from irrigated field experiments conducted at the International Rice Research Institute Farm from 1992 to 2003. Here we report that annual mean maximum and minimum temperatures have increased by 0.35°C and 1.13°C, respectively, for the period 1979–2003 and a close linkage between rice grain yield and mean minimum temperature during the dry cropping season (January to April). Grain yield declined by 10% for each 1°C increase in growing-season minimum temperature in the dry season, whereas the effect of maximum temperature on crop yield was insignificant. This report provides a direct evidence of decreased rice yields from increased nighttime temperature associated with global warming

Poly(styrene-co-vinylbenzylchloride-co-divinylbenzene) coated iron oxide: Synthesis and effects on size and morphology

Iron oxide nanoparticles were coated with a polymer synthesized from the monomers of styrene, divinylbenzene, and vinylbenzylchloride. The resultant polymer microspheres from synthesis without nanoparticle loading are primarily monodispersed with a diameter of 3.45 μm as measured by scanning electron microscopy. The addition of 1% nanoparticles by mass appears to decrease the size of the microspheres down to 2.04 μm as well as increase the polydispersity. This trend is also seen to continue as you add more nanoparticles to the system going from 3.45 μm with 0% nanoparticles down to below 1 μm for 5% nanoparticles. This indicates that the particles are not just incorporated into the polymer matrix but act as nucleation sites to begin the polymerization process. The polymerization process was found to have no effect on the nanoparticles themselves as the magnetic characterization showed only a mass dilution in saturation when corrected by thermal gravimetric analysis

ASPECTS ON MECHANICAL FILTERING IN AQUACULTURE SYSTEMS

Filtering plays an essential part in the process of intensive fish farming, because faeces and unconsumed food remain in the water inside the basins where the fish are raised and in time generate bacteria and infections that lead to the death of fish. Therefore, the water in these basins is permanently recycled in order to be filtered and refreshed, this paper presenting the actuated filtering systems used in the country and worldwide in recirculating aquaculture systems (RAS) for intensive fish farming

Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio

A model of COVID-19 pandemic evolution in African countries

We studied the COVID-19 pandemic evolution in selected African countries. For each country considered, we modeled simultaneously the data of the active, recovered and death cases. In this study, we used a year of data since the first cases were reported. We estimated the time-dependent basic reproduction numbers, $R_0$, and the fractions of infected but unaffected populations, to offer insights into containment and vaccine strategies in African countries. We found that $R_0\leq 4$ at the start of the pandemic but has since fallen to $R_0 \sim 1$. The unaffected fractions of the populations studied vary between $1-10$\% of the recovered cases.Comment: 27 pages, 9 figures and 1 tabl

The Role of IL-15 Deficiency in the Pathogenesis of Virus-Induced Asthma Exacerbations

Rhinovirus infections are the major cause of asthma exacerbations. We hypothesised that IL-15, a cytokine implicated in innate and acquired antiviral immunity, may be deficient in asthma and important in the pathogenesis of asthma exacerbations. We investigated regulation of IL-15 induction by rhinovirus in human macrophages in vitro, IL-15 levels in bronchoalveolar lavage (BAL) fluid and IL-15 induction by rhinovirus in BAL macrophages from asthmatic and control subjects, and related these to outcomes of infection in vivo. Rhinovirus induced IL-15 in macrophages was replication-, NF-κB- and α/β interferon-dependent. BAL macrophage IL-15 induction by rhinovirus was impaired in asthmatics and inversely related to lower respiratory symptom severity during experimental rhinovirus infection. IL-15 levels in BAL fluid were also decreased in asthmatics and inversely related with airway hyperresponsiveness and with virus load during in vivo rhinovirus infection. Deficient IL-15 production in asthma may be important in the pathogenesis of asthma exacerbations