A evolução urbana durante a Alta Idade Média

(Primeiro Parágrafo do Artigo)Que entendemos por problema urbano da Alta Idade Média?É tradicional focalizá-lo quase únicamente no Nordeste da Europa, na França, nos Países-Baixos, na Inglaterra; e assim focalizado, ele se inscreve entre dois irrefutáveis que tem um ponto de partida e um ponto de chegada muito nítidos

O ouro muçulmano do VII ao XI século. As bases monetárias de uma supremacia econômica

(Primeiro Parágrafo do Artigo)As conquistas muçulmanas do VII e VIII séculos não sómente criaram um vasto império, que se estendia do Oceano ìndico ao Oceano Atlântico; de todas as regiões conquistadas que, até então, pertenciam a áreas economicas diferentes, Oriente sassânida, Império Bizantino ou Ocidente bárbaro - fizeram um novo domínio econômico, o munod muçulmano, que sobreviverá o desmembramento do Califado do mesmo modo que o mundo helenístico sobreviveu ao Império de Alexandre

Early evolution of the biotin-dependent carboxylase family

<p>Abstract</p> <p>Background</p> <p>Biotin-dependent carboxylases are a diverse family of carboxylating enzymes widespread in the three domains of life, and thus thought to be very ancient. This family includes enzymes that carboxylate acetyl-CoA, propionyl-CoA, methylcrotonyl-CoA, geranyl-CoA, acyl-CoA, pyruvate and urea. They share a common catalytic mechanism involving a biotin carboxylase domain, which fixes a CO₂molecule on a biotin carboxyl carrier peptide, and a carboxyl transferase domain, which transfers the CO₂moiety to the specific substrate of each enzyme. Despite this overall similarity, biotin-dependent carboxylases from the three domains of life carrying their reaction on different substrates adopt very diverse protein domain arrangements. This has made difficult the resolution of their evolutionary history up to now.</p> <p>Results</p> <p>Taking advantage of the availability of a large amount of genomic data, we have carried out phylogenomic analyses to get new insights on the ancient evolution of the biotin-dependent carboxylases. This allowed us to infer the set of enzymes present in the last common ancestor of each domain of life and in the last common ancestor of all living organisms (the cenancestor). Our results suggest that the last common archaeal ancestor had two biotin-dependent carboxylases, whereas the last common bacterial ancestor had three. One of these biotin-dependent carboxylases ancestral to Bacteria most likely belonged to a large family, the CoA-bearing-substrate carboxylases, that we define here according to protein domain composition and phylogenetic analysis. Eukaryotes most likely acquired their biotin-dependent carboxylases through the mitochondrial and plastid endosymbioses as well as from other unknown bacterial donors. Finally, phylogenetic analyses support previous suggestions about the existence of an ancient bifunctional biotin-protein ligase bound to a regulatory transcription factor.</p> <p>Conclusions</p> <p>The most parsimonious scenario for the early evolution of the biotin-dependent carboxylases, supported by the study of protein domain composition and phylogenomic analyses, entails that the cenancestor possessed two different carboxylases able to carry out the specific carboxylation of pyruvate and the non-specific carboxylation of several CoA-bearing substrates, respectively. These enzymes may have been able to participate in very diverse metabolic pathways in the cenancestor, such as in ancestral versions of fatty acid biosynthesis, anaplerosis, gluconeogenesis and the autotrophic fixation of CO₂.</p

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p&lt;0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (&lt;1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (&lt;1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

R. S. Lopez, Speculum, Silk industry in the Byzantine Empire

Lombard Maurice. R. S. Lopez, Speculum, Silk industry in the Byzantine Empire. In: Annales. Économies, Sociétés, Civilisations. 3ᵉ année, N. 3, 1948. pp. 380-382

R. S. Lopez, Journal of economic History, European merchants in the medieval Indies: the evidence of a commercial document

Lombard Maurice. R. S. Lopez, Journal of economic History, European merchants in the medieval Indies: the evidence of a commercial document. In: Annales. Économies, Sociétés, Civilisations. 3ᵉ année, N. 3, 1948. pp. 382-383

La synthèse musulmane : une étape dans la « conquête minérale »

Sans vouloir réduire l’histoire des civilisations au seul dénominateur commun de l’histoire des métaux, il paraît utile de marquer le rôle essentiel joué par l’approvisionnement en métaux utiles, comme le fer, ou précieux, comme l’or et l’argent, dans l’histoire des empires et des unités économiques qui se sont constituées au cours des temps. Pour la grande masse de l’humanité les métaux sont demeurés des produits rares jusqu’à la fin du Moyen Age et même jusqu’au xviiie siècle. Cela est vrai..

Paul Rousset, Les origines et les caractères des premières croisades

Lombard Maurice. Paul Rousset, Les origines et les caractères des premières croisades. In: Annales. Économies, Sociétés, Civilisations. 4ᵉ année, N. 3, 1949. p. 350

Carl Stephenson, In praise of medieval thinkers (article)

Lombard Maurice. Carl Stephenson, In praise of medieval thinkers (article). In: Annales. Économies, Sociétés, Civilisations. 4ᵉ année, N. 4, 1949. p. 499