Transformation of B Specifications into UML Class Diagrams and State Machines

We propose a rule-based approach for transforming B abstract machines into UML diagrams. We believe that important insight into the structure underlying a B model can be gained by representing it in UML, for example in order to explain the model to stakeholders that are not experts in the B formalism. We focus on the generation of class diagram and state machines. Our approach does not prescribe a mechanic algorithm for translation, giving the modeler choices to adapt the resulting UML models as appropriate

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Lymphoid tyrosine phosphatase R620W variant and inflammatory bowel disease in Tunisia

AIM: To assess the possible association between PTPN22 (R620W) gene polymorphism and inflammatory bowel disease (IBD)

Complement receptor 1 gene polymorphisms in Tunisian

patients with systemic lupus erythematosu

Association of Fas/Apo1 gene promoter (-670 A/G) polymorphism in Tunisian patients with IBD

AIM: To detect a possible association between the polymorphism of the (-670 A/G) Fas/Apo1 gene promoter and susceptibility to Crohn’s disease (CD) and ulcerative colitis (UC) in the Tunisian population. METHODS: The (-670 A/G) Fas polymorphism was analyzed in 105 patients with CD, 59 patients with UC, and 100 controls using the polymerase chain reaction restriction fragment length polymorphism method. RESULTS: Significantly lower frequencies of the Fas -670 A allele and A/A homozygous individuals were observed in CD and UC patients when compared with controls. Analysis of (-670 A/G) Fas polymorphism with respect to sex in CD and UC showed a significant difference in A/A genotypes between female patients and controls (P corrected = 0.004 in CD patients and P corrected = 0.02 in UC patients, respectively). Analysis also showed a statistically significant association between genotype AA of the (-670 A/G) polymorphism and the ileum localization of the lesions (P corrected = 0.048) and between genotype GG and the colon localization (P corrected = 0.009). The analysis of inflammatory bowel disease patients according to clinical behavior revealed no difference. CONCLUSION: Fas-670 polymorphism was associated with the development of CD and UC in the Tunisian population

Association between CTLA-4 Gene Promoter (49 A/G) in Exon 1 Polymorphisms and Inflammatory Bowel Disease in the Tunisian Population

<b>Background/Aim:</b> To investigate the possible association between the polymorphism of the <i> CTLA-4 </i> exon 1 &#x002B;49 A/G and susceptibility to Crohn&#x2032;s disease (CD) and ulcerative colitis (UC) in the Tunisian population. <b> Methods:</b> The &#x002B;49 A/G dimorphism was analyzed in 119 patients with CD, 65 patients with UC, and 100 controls by the polymerase chain reaction-restriction fragment length polymorphism method. <b> Results:</b> Significantly higher frequencies of the <i> CTLA-4 </i> &#x002B;49A allele and A/A homozygous individuals were observed in patients with CD when compared with controls (pc = 0.0023 and pc = 0.0003, respectively). Analysis of <i> CTLA-4</i> A/G polymorphism with respect to sex in CD showed a significant difference in A/A genotypes between female patients and controls (pc = 0.0001 and pc = 0.038, respectively). There were no differences in the subgroups of patients with CD. <b> Conclusions:</b> Forty-nine A alleles and AA genotype are associated with CD susceptibility in Tunisians. Other genes involved in the T-cell regulation remain strong candidates for IBD susceptibility and require further investigation

© 2010 Academic Journals Full Length Research Paper

polymorphisms and susceptibility to systemic lupus and rheumatoid arthritis in Tunisian populatio