ArcAngelC: a Refinement Tactic Language for Circus

AbstractCircus is a refinement language, in which specifications define both data and behavioural aspects of concurrent systems using a combination of Z and CSP. Its refinement theory and calculus are distinctive, but refinements may be long and repetitive, and using this technique can be hard. Some useful strategies have already been identified, described, and used. By documenting and using them as tactics, a lot can be gained since they can be repeatedly used as single transformation rules. Here, we present ArcAngelC, a language for defining such refinement tactics; we present the language and its application in the formalisation of an existing informal strategy for verification of Ada implementations of control systems

Are ecosystem services provided by insects “bugged” by micro (nano)plastics?

Although the study of the effects of microplastics increased in the last years, terrestrial ecosystems remain less studied. In fact, the effects of microplastics in insects, the most abundant group of animals and major providers of key Ecosystem Services, are not well known despite the potential cascading negative effects on the ecosystems functioning in the habitats where they occur. In this paper, a revision on available studies on microplastics contamination is provided and potential consequences to major Ecosystem Services provided by insects are discussed, using the Common International Classification of Ecosystem Services (CICES) methodology. The revision underpinned probable and potential impacts for all tree CICES divisions, i.e.: Provision, Regulation and Maintenance and Cultural Services. The available studies seem to show that different groups react differently to microplastics contamination, which clearly indicates that the effects in Ecosystem Services provided by insects need a more empirical and targeted approach.publishe

Relationship between polymorphism of growth hormone and precocity traits in Nellore heifers

Avaliaram-se as relações entre o polimorfismo do gene do hormônio do crescimento (GH) e as características de precocidade, em novilhas da raça Nelore. Amostras de sangue periférico foram obtidas de 181 animais de três rebanhos distintos do estado da Bahia, nas quais foi realizada a extração de DNA e a amplificação por PCR, seguidas por digestão com enzima de restrição AluI. Os fragmentos resultantes da digestão enzimática foram analisados em gel de agarose 2% para determinação dos respectivos genótipos. A frequência do alelo Leu nas amostras analisadas foi estimada em 100%. Em decorrência da alta incidência de homozigose para o alelo Leu, sugere-se que o restriction fragment lenght polymorphism AluI do gene GH não possa ser considerado como marcador molecular para precocidade sexual em novilhas Nelore nesses rebanhos.The relationships between polymorphism of growth hormone gene (GH) and precocity traits in Nellore heifers were evaluated. A total of 181 animals from three different farms of Bahia state, Brazil, were blood sampled. The DNA of each animal was extracted, amplified by PCR, and digested by "AluI" restriction enzyme, and the resultant fragments were analyzed in 2% agarose gel for genotype identification. The frequency of Leu allele in the analyzed samples was estimated in 100%. Due to the high incidence of homozygose for the Leu allele, it is suggested that the restriction fragment lenght polymorphism AluI of GH gene can not be considered as a molecular marker for sexual precocity in Nellore heifers of those herds.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Environmental Fate of Zinc Oxide Nanoparticles: Risks and Benefits

Zinc oxide nanoparticles (ZnO-NPs) are among nanoscale materials displaying exponentially growing production due to their applications in the field of cosmetology, medicine, as antibacterial agent and catalyst. The ZnO nanomaterials release into the aquatic ecosystems through domestic and industrial wastewaters has the potential to induce pernicious effects on fish and other organisms. Increasing concerns on the environmental hazard to aquatic biota have been highlighted by the toxic potential of some metal-based nanomaterials. Several characteristics of ZnO-NPs (e.g. size, shape, surface charge and agglomeration state) play a central role in biological effects such as genotoxic, mutagenic or cytotoxic effects. Overall, Zn bioaccumulation, histopathological, and hematological changes with oxidative and cellular stress have been reported in ZnO-NPs exposed animals

Bacterially assembled biopolyester nanobeads for removing cadmium from water

Cadmium (Cd)-contaminated waterbodies are a worldwide concern for the environment, impacting human health. To address the need for efficient, sustainable and cost-effective remediation measures, we developed innovative Cd bioremediation agents by engineering Escherichia coli to assemble poly(3-hydroxybutyric acid) (PHB) beads densely coated with Cd-binding peptides. This was accomplished by translational fusion of Cd-binding peptides to the N- or C-terminus of a PHB synthase that catalyzes PHB synthesis and mediates assembly of Cd2 or Cd1 coated PHB beads, respectively. Cd1 beads showed greater Cd adsorption with 441 nmol Cd mg-1 bead mass when compared to Cd2 beads (334 nmol Cd mg-1 bead-mass) and plain beads (238 nmol Cd mg-1 bead-mass). The Cd beads were not ecotoxic and did attenuate Cd-spiked solutions toxicity. Overall, the bioengineered beads provide a means to remediate Cd-contaminated sites, can be cost-effectively produced at large scale, and offer a biodegradable and safe alternative to synthetic ecotoxic treatments.publishe