The impact of climate change on the agriculture and the economy of Southern Gaul: New perspectives of agent-based modelling.

What impact did the Roman Climate Optimum (RCO) and the Late Antique Little Ice Age (LALIA) have on the rise and fall of the Roman Empire? Our article presents an agent-based modelling (ABM) approach developed to evaluate the impact of climate change on the profitability of vineyards, olive groves, and grain farms in Southern Gaul, which were the main source of wealth in the roman period. This ABM simulates an agroecosystem model which processes potential agricultural yield values from paleoclimatic data. The model calculates the revenues made by agricultural exploitations from the sale of crops whose annual volumes vary according to climate and market prices. The potential profits made by the different agricultural exploitations are calculated by deducting from the income the operating and transportation costs. We conclude that the warm and wet climate of the Roman period may have had an extremely beneficial effect on the profitability of wine and olive farms between the 2nd century BCE and the 3rd century CE, but a more modest effect on grain production. Subsequently, there is a significant decrease in the potential profitability of farms during the Late Antique Little Ice Age (4th-7th century CE). Comparing the results of our model with archaeological data enables us to discuss the impact of these climatic fluctuations on the agricultural and economic growth, and then their subsequent recession in Southern Gaul from the beginning to the end of antiquity.

Reconstructing the hydraulics of the world's first industrial complex, the second century CE Barbegal watermills, France.

The Barbegal watermill complex, a unique cluster of 16 waterwheels in southern France, was the first known attempt in Europe to set up an industrial-scale complex of machines during the culmination of Roman Civilization in the second century CE. Little is known about the state of technological advance in this period, especially in hydraulics and the contemporary diffusion of knowledge. Since the upper part of the Barbegal mill complex has been destroyed and no traces of the wooden machinery survived, the mode of operation of these mills has long remained elusive. Carbonate incrustations that formed on the woodwork of the mills were used to reconstruct its structure and function, revealing a sophisticated hydraulic setup unique in the history of water mills. The lower mills used an elbow shaped flume to bring water onto overshot millwheels. This flume was specially adapted to the small water basins and serial arrangement of the mills on the slope. Carbonate deposits from ancient water systems are therefore a powerful tool in archaeological reconstructions and provide tantalizing insights into the skills of Roman engineers during a period of history that is the direct predecessor of our modern civilization.

The second century CE Roman watermills of Barbegal: Unraveling the enigma of one of the oldest industrial complexes.

The second century CE Roman watermill complex of Barbegal, France, is regarded as one of the first industrial complexes in human history. The 16 water wheels are no longer extant as all woodwork has decayed. However, carbonate deposits precipitated from water during operation of the mills forming casts on the woodwork. These casts are preserved in fragments and provide unique insights into the frequency of use and maintenance of the mills, and even into the structure of the water wheel chambers. Stable isotope time series of carbonate deposits reveal that the mill activity was regularly interrupted for several months. This strongly suggests that the mill complex was not used for a steady supply of flour to a major population center, as previously thought, but likely served to produce nonperishable hardtack for the nearby harbors.

Appropriateness of diagnostic management and outcomes of suspected pulmonary embolism.

BACKGROUND: International guidelines include several strategies for diagnosing pulmonary embolism with confidence, but little is known about how these guidelines are implemented in routine practice. OBJECTIVE: To evaluate the appropriateness of diagnostic management of suspected pulmonary embolism and the relationship between diagnostic criteria and outcome. DESIGN: Prospective cohort study with a 3-month follow-up. SETTING: 116 emergency departments in France and 1 in Belgium. PATIENTS: 1529 consecutive outpatients with suspected pulmonary embolism. MEASUREMENTS: Appropriateness of diagnostic criteria according to international guidelines; incidence of thromboembolic events during follow-up. RESULTS: Diagnostic management was inappropriate in 662 (43%) patients: 36 of 429 (8%) patients with confirmed pulmonary embolism and 626 of 1100 (57%) patients in whom pulmonary embolism was ruled out. Independent risk factors for inappropriate management were age older than 75 years (adjusted odds ratio, 2.27 [95% CI, 1.48 to 3.47]), known heart failure (odds ratio, 1.53 [CI, 1.11 to 2.12]), chronic lung disease (odds ratio, 1.39 [CI, 1.00 to 1.94]), current or recent pregnancy (odds ratio, 5.92 [CI, 1.81 to 19.30]), currently receiving anticoagulant treatment (odds ratio, 4.57 [CI, 2.51 to 8.31]), and the lack of a written diagnostic algorithm and clinical probability scoring in the emergency department (odds ratio, 2.54 [CI, 1.51 to 4.28]). Among patients who did not receive anticoagulant treatment, 44 had a thromboembolic event during follow-up: 5 of 418 (1.2%) patients who received appropriate management and 39 of 506 (7.7%) patients who received inappropriate management (absolute risk difference, 6.5 percentage points [CI, 4.0 to 9.1 percentage points]; P < 0.001). Inappropriateness was independently associated with thromboembolism occurrence (adjusted odds ratio, 4.29 [CI, 1.45 to 12.70]). LIMITATIONS: This was an observational study without evaluation of the risk for overdiagnosis. CONCLUSIONS: Diagnostic management that does not adhere to guidelines is frequent and harmful in patients with suspected pulmonary embolism. Several risk factors for inappropriateness constitute useful findings for subsequent interventions.

[Diagnostic strategy in pulmonary embolism. National French survey]. / Démarche diagnostique de l'embolie pulmonaire. Enquête nationale française.

OBJECTIVE: Since the clinical expression of pulmonary edema (PE) is neither sensitive nor specific, its diagnosis relies on several complementary examinations that are interpreted according to the clinical probability of the disease. Various non-invasive examinations now complete the standard policy. Our aim was to study their use in practice. METHOD: We sent a postal survey to 199 french metropolitan hospital departments of cardiology or pneumology and sent a reminder two months later. RESULTS: We obtained replies from 94 departments, divided among 22 university hospitals, 52 departments of cardiology and 27 departments of pneumology. Among these departments, 87% had a PE diagnosis strategy depending on clinical suspicion. However, only 34% used different examination sequences depending on whether suspicion was strong or weak. The complementary examinations were helical computed thoracic tomography in 64% of cases, pulmonary angiography in 42% and ventilation-perfusion scintigraphy in 23%. DISCUSSION: The response rates were the same, whatever the department surveyed. Other than the more frequent use of cardiac sonography by cardiologists, there was no significant qualitative difference between the diagnosis strategies of the departments of cardiology and pneumology. The examination most frequently used at the end of the diagnostic proceeding was thoracic angiographic scan, although its diagnostic efficacy remains insufficient. With regard to international recommendations, pulmonary angiography is underused.