Right-heart infective endocarditis: apropos of 10 cases

The prevalence and characteristics of right heart endocarditis in Africa are not well known. The aim of this study was to describe the epidemiological, clinical and laboratory profiles of patients with right-heart infective endocarditis. This was a 10-year retrospective study conducted in 2 cardiology departments in Dakar, Senegal. All patients who met the diagnosis of right heart infective endocarditis according to the Duke's criteria were included. We studied the epidemiological, clinical as well as their laboratory profiles. There were 10 cases of right-heart infective endocarditis representing 3.04% of cases of infective endocarditis. There was a valvulopathy in 3 patients, an atrial septal defect in 1 patient, parturiency in 2 patients and the presence of a pacemaker in one patient. Anaemia was present in 9 patients whilst leukocytosis in 6 patients. The port of entry was found to be oral in three cases, ENT in one case and urogenital in two cases. Apart from one patient with vegetations in the tricuspid and pulmonary valves, the rest had localized vegetation only at the tricuspid valve. However, blood culture was positive in only three patients. There was a favorable outcome after antibiotic treatment in 4 patients with others having complications; three cases of renal impairment, two cases of heart failure and one case of pulmonary embolism. There was one mortality. Right heart infective endocarditis is rare but associated with potentially fatal complications.Pan African Medical Journal 2015; 2

Évaluation de vingt méthodes d'estimation de l'évapotranspiration journalière de référence au Burkina Faso

Knowledge of evapotranspiration (ET) is very important for water resources planning and management. Several methods have been developed to estimate ET. Among them the PENMAN-MONTEITH method is recommended by the Food and Agriculture Organization as a reference method. However, its use is difficult in some areas particularly in developing countries where climate data are not always available. One of the alternatives is then to use methods integrating fewer climatic variables. This study aims to evaluate alternative evapotranspiration methods and to calibrate and validate the two best ones. Daily climate data (Tmax, Tmin, Sr, RHmax, RHmin and u2) of eight stations from 1998 to 2012 were used. Each of the twenty models was compared to evaluate ET0 estimated by the PENMAN-MONTEITH by determining different statistical indices. The results show that the methods of H.L. PENMAN (1963), W. ABTEW (1996), J.D. VALIANTZAS 1 and 3 (2012-a, 2012-b) and G.H. HARGREAVES (1975) have given the best estimations of the evapotranspiration. Among these five methods, the two best are retained for calibration and validation. After calibration, the PENMAN method logically provides the best estimation of reference evapotranspiration, in front of that of ABTEW

Paradoxe d'évaporation dans la vallée du fleuve Sénégal

The increase in temperatures in a context of climate change should be accompanied by an increase in evaporation or evapotranspiration (ET0). However, studies have shown a decrease in evaporation (or evapotranspiration) in certain regions of the world. This contrast between the decrease in evaporation and the increase in temperature, which varies according to the climatic zones, is known as the "evaporation paradox". The objective of this work is to examine the causes in the climatic context of the Senegal River Valley. The climatic data (evaporation, rain, temperature, relative humidity, insolation) observed at the stations of Bakel, Podor, Matam and Saint-Louis were used over the period 1981-2015. The methodology includes: 1/ the detection of ruptures by the PETTITT test, 2/ the analysis of the relationship between evaporation / evapotranspiration and climatic variables by the PEARSON correlation test, 3/ the detection of trends in Evaporation / ET0 and climate variables by the MANN-KENDALL test and SEN’s slope. The breaks in evaporation and evapotranspiration are respectively identified in the 1990s and 2000s. The PEARSON correlation shows that evaporation and ET0 have their strongest relationship with the relative humidity. MANN-KENDALL's test reveals a significant decrease (p-value ˂ 0.001) in evaporation and a mixed trend (decrease and increase) in reference evapotranspiration. This decrease in evaporation, combined with a significant increase in temperature, highlights the existence of an evaporation paradox in the Senegal river valley. This evaporation paradox is explained here by the significant increase in relative humidity and rainfall, but also by the significant decrease in sunshine hours

Long-Term Trend Analysis in Annual and Seasonal Precipitation, Maximum and Minimum Temperatures in the Southwest United States

The objective of this study is to perform trend analysis in the historic data sets of annual and crop season [May–September] precipitation and daily maximum and minimum temperatures across the southwest United States. Eighteen ground-based weather stations were considered across the southwest United States for a total period from 1902 to 2017. The non-parametric Mann–Kendall test method was used for the significance of the trend analysis and the Sen’s slope estimator was used to derive the long-term average rates of change in the parameters. The results showed a decreasing trend in annual precipitation at 44.4% of the stations with the Sen’s slopes varying from −1.35 to −0.02 mm/year while the other stations showed an increasing trend. Crop season total precipitation showed non-significant variation at most of the stations except two stations in Arizona. Seventy-five percent of the stations showed increasing trend in annual maximum temperature at the rates that varied from 0.6 to 3.1 °C per century. Air cooling varied from 0.2 to 1.0 °C per century with dominant warming phenomenon at the regional scale of the southwest United States. Average annual minimum temperature had increased at 69% of the stations at the rates that varied from 0.1 to 8 °C over the last century, while the annual temperature amplitude showed a decreasing trend at 63% of stations. Crop season maximum temperature had significant increasing trend at 68.8% of the stations at the rates varying from 0.7 to 3.5 °C per century, while the season minimum temperature had increased at 75% of the stations

Future trend and sensitivity analysis of evapotranspiration in the Senegal River Basin

International audienceThis work aimed to assess reference evapotranspiration (ET0) trends and its sensitivity to climate variables on the period 2036–2065 in the Senegal River basin. Seven General Circulation Models (GCMs) and seven Regional Climate Models (RCMs) of the CMIP5 project were used under the scenarios RCP4.5 and RCP8.5. The performance of GCMs and RCMs was first evaluated by comparing their outputs with the reanalyses data. The change of ET0 is determined between the periods 1971–2000 and 2036–2065. A sensitivity coefficient was calculated to analyze the influence of climatic variables on ET0. Finally, the Mann Kendall test and Sen slope were used to detect future trends in ET0 and climate variables.New hydrological insights for the regionIt was found that RCMs were here more robust than GCMs in estimating reference evapotranspiration over the period 1984–2000. Compared to the period 1971–2000, the RCMs show that ET0 will increase by 14–293 mm under RCP4.5 and by 55–387 mm under RCP8.5 according to the climatic zones. The maximum values are observed in Sahelian zone and the minimum one in Guinean area. The sensitivity analysis shows that ET0 is more sensitive to relative humidity, maximum temperature and solar radiation. The trend analysis reveals, generally, a significant increase in ET0 and in maximum and minimum temperatures in the period 2036–2065 under the RCP4.5 and RCP8.5 scenarios. This means that ET0 will not be stationary and may continue to increase after 2065 because of the increase of temperature

Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins

International audienceAnalysis of reference evapotranspiration (ET0) trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotranspiration is noted in some parts of the world. This contrast is called the "evaporation paradox" and is thought to be related to the variation in wind speed, relative humidity and solar radiation. The objective of this work is to analyze, based on the Reanalysis weather data from the NASA Langley Research Center (LaRC) POWER project, the annual and seasonal trends of ET0 and climate variables at the scale of the Senegal, Gambia and Casamance rivers basins over the period 1984-2019. Mann Kendall's test and Sen slope were used to analyze trends in ET0 and climate variables. Results show that on annual scale, ET0 increases significantly in 32% of the Senegal basin and decreases in less than 1% of it. In contrast, in the Casamance and Gambia basins, the annual ET0 drops by 65% and 18%, respectively. On an annual scale, temperature and relative humidity show an increasing trend over all basins while wind speed and radiation decrease significantly. This confirms the existence of the "evaporation paradox" in the three basins. This phenomenon is explained by the increase in relative humidity and the decrease in wind speed