Supporting the automated generation of modular product line safety cases

Abstract The effective reuse of design assets in safety-critical Software Product Lines (SPL) would require the reuse of safety analyses of those assets in the variant contexts of certification of products derived from the SPL. This in turn requires the traceability of SPL variation across design, including variation in safety analysis and safety cases. In this paper, we propose a method and tool to support the automatic generation of modular SPL safety case architectures from the information provided by SPL feature modeling and model-based safety analysis. The Goal Structuring Notation (GSN) safety case modeling notation and its modular extensions supported by the D-Case Editor were used to implement the method in an automated tool support. The tool was used to generate a modular safety case for an automotive Hybrid Braking System SPL

Automatic allocation of safety requirements to components of a software product line

Safety critical systems developed as part of a product line must still comply with safety standards. Standards use the concept of Safety Integrity Levels (SILs) to drive the assignment of system safety requirements to components of a system under design. However, for a Software Product Line (SPL), the safety requirements that need to be allocated to a component may vary in different products. Variation in design can indeed change the possible hazards incurred in each product, their causes, and can alter the safety requirements placed on individual components in different SPL products. Establishing common SILs for components of a large scale SPL by considering all possible usage scenarios, is desirable for economies of scale, but it also poses challenges to the safety engineering process. In this paper, we propose a method for automatic allocation of SILs to components of a product line. The approach is applied to a Hybrid Braking System SPL design

Characteristics of carcass and non-carcass components of lambs fed diets containing silages of forages adapted to the semi-arid environment

The aim of this study was to evaluate the effects of diets containing silages of forages that are adapted to the semi-arid environment on the characteristics of the carcass and of non-carcass components of 32 mixed-breed lambs at approximately six months old, with an average live weight of 17.61 ± 2.63 kg. Lambs were assigned to four treatments (diets containing silages of Atriplex nummularia Lind, Cenchrus ciliaris, Gliricidia sepium and Manihot sp.) in a completely randomized design with eight replicates. Animals fed the diet containing old man saltbush showed higher values for the intakes of dry matter (1.080 g/day), crude protein (190 g/day) and total digestible nutrients (740 g/day), body condition score (2.81 points), fatness (2.87 points), carcass conformation (3.19 points), live weight (29.1 kg), empty bodyweight (23.41 kg), weights of the commercial cuts neck, shoulder and ribs (0.46, 0.82 and 1.12 kg, respectively), and skin weight (1.972 kg). No differences were found between the diets for carcass dressing percentage, external and internal carcass lengths, leg length and circumference, rump circumference and width, chest width and depth, full bodyweight, empty bodyweight, cooling losses, pH before and after cooling, loin, and leg. Silages of old man saltbush, buffelgrass, gliricidia and pornunça are recommended for inclusion in lamb diets. Diets with old man saltbush silage provide the best results for characteristics of the carcass and of non-carcass components besides weight gain, which can reach up to 200 g/day depending on the formulation.Keywords: Carcass composition, feedlot, saltbush, shee

Regulação fenólica da resistência à infecção por Microcyclus ulei Henn v. Arx em progênie de Hevea.

Three progenies of Hevea, with different levels of resistance to isolation of M. ulei (UNA) were studied. The progenies were: Fx 25 (moderately susceptible), Fx 2804 (highly susceptible) and P10 (resistant). The inoculation was made at the fourth flushing, with six to eight day-old leaflets. The progenies were maintained in a growth chamber. After 24, 72 and 144 hours, inoculated and noninoculated leaflets were collected to determine phenol, anthocyanin and chlorophyll contents. Progenies Fx 25 and Fx 2804 showed low phenol levels, decreasing levels of chlorophyll and a great number of injuries and sporulation. Progenie P10 showed high levels of phenol and chlorophyll, compared to the control. It did not show any injury. The anthocyanin levels decreased in all progenies. Consequently, Hevea resistance to M. ulei infection seems to be related to variations of leaf phenol levels.Foram estudadas três progênies de seringueira, com diferentes níveis de resistência ao isolamento de M. ulei, denominado UNA: Fx 25 (moderadamente suscetível), Fx 2804 (altamente suscetível) e P10 (resistente). A inoculação foi realizada no quarto lançamento, com folfolos de seis a oito dias de idade. As progênies foram mantidas em câmara de crescimento. Após 24, 72 e 144 horas foram feitas coletas dos folíolos inoculados e não inoculados e realizou-se a quantificação do teor de fenóis, antocianina e clorofila. Observou-se que as progênies Fx 25 e Fx 2804 apresentaram baixos níveis de fenóis e decréscimo no nível de clorofila, grande número de lesões e esporulação. A progênie P10 apresentou alto teor de fenóis com relação à testemunha, bem como de clorofila, não apresentando lesões. O nível de antocianina decresceu em todas as progênies. Assim, a resistência da seringueira à infecção por M. ulei parece estar associada à variação do teor de fenóis em suas folhas

Incidence of healthcare-associated Clostridioides difficile infection in a quaternary referral university hospital in Brazil

Clostridioides difficile infection (CDI) is an important cause of diarrhea in hospitals worldwide. The incidence of CDI in Latin America has not yet been standardized. To fill this gap, the present study performed a daily active surveillance, for three months, between April to July of 2021, at a quaternary referral university hospital in Brazil. The incidence density was 9.2 cases per 10,000 patient-days. Cases were associated mostly with ribotypes 014 and 106 (44% and 22%, respectively). Ribotype 027 was not identified. The findings strongly reinforce the need for broad epidemiological studies on the incidence of CDI in Brazilian hospitals to increase the understanding, prevention, and treatment of this infection.(c) 2022 Elsevier Ltd. All rights reserved.Medical Microbiolog

Non-vacuum Solutions of Bianchi Type VI_0 Universe in f(R) Gravity

In this paper, we solve the field equations in metric f(R) gravity for Bianchi type VI_0 spacetime and discuss evolution of the expanding universe. We find two types of non-vacuum solutions by taking isotropic and anisotropic fluids as the source of matter and dark energy. The physical behavior of these solutions is analyzed and compared in the future evolution with the help of some physical and geometrical parameters. It is concluded that in the presence of isotropic fluid, the model has singularity at $\tilde{t}=0$ and represents continuously expanding shearing universe currently entering into phantom phase. In anisotropic fluid, the model has no initial singularity and exhibits the uniform accelerating expansion. However, the spacetime does not achieve isotropy as $t\rightarrow\infty$ in both of these solutions.Comment: 20 pages, 5 figures, accepted for publication in Astrophys. Space Sc