Estimating daily evaporation from poorly-monitored lakes using limited meteorological data: A case study within Qaraoun dam - Lebanon.

Open water evaporation is influenced by several meteorological parameters such as: irradiance, soil temperature, relative humidity, atmospheric pressure and wind speed. However, dealing with that matter, in a case of measurements scarcity, is a challenging task. To overcome this problem, the authors sought a less-dimensional method to estimate lake evaporation. This technique takes into account only three weather variables: temperature, relative Humidity and dew point. In fact, the approach is summarized as follows: 1- using Levenberg-Marquardt algorithm, a Nonlinear Regression model based on Magnus formula is trained and tested to estimate the dew point. 2- a simplified Penman formula provides an estimate for the lake evaporation rate. To test the approach effectiveness, the suggested method was applied on Qaraoun Lake - Lebanon. Upon testing, the regression model exhibited high accuracy with a goodness of fit value equal to 0.99. Afterwards, the evaporation rates were estimated using Penman formula. Unfortunately, evaporation measurements are not available on site to carry the testing procedures. Instead, outcomes were investigated and compared with the monthly evaporation average retrieved from the nearest region to the lake. Estimated rates were reasonably good with a correlation coefficient equal to 0.89 and mean absolute percentage error around 9.8%. At the final stage of this study, sensitivity analysis is performed to quantify the impact of temperature and relative humidity change on evaporation. Overall, the achieved results were reliable enough to carry out a further assessment of the economic impact of evaporation losses from Qaraoun reservoir on the hydropower generation and on the irrigation sector.

Colonic response to food in constipation.

OBJECTIVES: Colonic response to food is possibly abnormal in constipation. METHODS: The colonic response to food was evaluated in 323 patients and 60 healthy subjects by following the movements of radiopaque markers after ingestion of a standard 1,000-cal test meal. Constipated patients were divided into four groups: one with a normal, and three with a delayed colorectal transit time. When the delay was found mainly in the ascending colon, the group was labeled as suffering from "colonic inertia". In "hindgut dysfunction", the delay was predominantly found in the descending colon, whereas the term "outlet obstruction" was reserved for constipated patients whose major site of delay was the rectosigmoid area. Colonic response to food was quantified by evaluating the variation of markers in a given abdominal region and the evolution of the geometric center on the entire plain film of the abdomen. RESULTS: Emptying of the caecum-ascending colon and filling of the rectosigmoid area characterize the colonic response to food in healthy subjects. Constipated patients also filled the rectosigmoid, but different patterns were found in the colon. In constipated patients with transit in the normal range, there was a frequent (41%) absence of colonic response to food as compared to controls (13%) and constipated patients with delayed transit (p<0.0001). The response to food of patients with colonic inertia was similar to that of healthy subjects in terms of distal progression, but less marked. The hindgut dysfunction group emptied the entire left colon but failed to empty the caecum and ascending colon. In the outlet obstruction group, there was no distal progress of the geometric center after meal. CONCLUSIONS: Abnormal colonic response to food is frequently found in constipated patients, with different patterns according to the type of constipation.

Effect of an oral bulking agent and a rectal laxative administered alone or in combination for the treatment of constipation.

OBJECTIVES: The aim of the present study was to search for a synergetic action between psyllium and a defecation-inducing drug, Eductyl, for symptom relief in patients suffering from chronic constipation. METHODS: Twenty healthy volunteers and 20 patients complaining of chronic constipation were included in a randomized crossover study. The study was divided into four 2-weeks periods: pre-inclusion and three periods of treatment with psyllium, Eductyl, and Eductyl + psyllium respectively. Colonic transit time was determined at the end of each period of treatment. During each of the four periods, a self-administered questionnaire was used to assess symptoms of constipation. RESULTS: For constipated patients, treatment with Eductyl and Eductyl-psyllium improved clinical symptoms of constipation: increased stool frequency, resulted in fewer hard stools and less sensation of incomplete evacuation and less straining to defecate. The improvement was associated with a decrease in total and segmental colonic transit time. The Eductyl-psyllium combination did not exhibit any synergetic effect. CONCLUSION: Treatment with Eductyl alone is more efficient than with psyllium alone in providing symptom relief. Combination with psyllium is not synergetic.

Trauma care systems in France.

The French Republic includes approximatively 60 millions inhabitants for almost 550,000 km(2). Prehospital management is organised at department level (96). This management involves a regulatory system initiated from a unique phone number (15 national). The medical regulator sends either first-aid providers or a medical team. On-site care is highly developed and prehospital medically assisted care is really the first phase of the treatment of the injured. The team ensures that the victim is in the best condition for transport and participates in monitoring. Intra-hospital care begins either in an emergency room, with a physician qualified in Emergency Medicine, or in a recovery room, with a surgical intensive-care team. There is no specialisation in trauma in France. All specialist surgeons treat those aspects of trauma pathology that concern them. All surgeons operate on trauma patients and with regard to the organ concerned: digestive, orthopaedic, em leader. The challenge nevertheless remains that of maintaining facilities at a sufficient level to deal with everyday pathology, known for the seriousness of its consequences in both human and financial terms, within an increasingly sparse hospital infrastructure. Suggestions are emerging in response to these preoccupations. Organisation at the European level of hand emergency units (FESUM) is a targeted example.

Importance of colonic transit evaluation in the management of fecal incontinence.

BACKGROUND AND AIMS: Fecal incontinence is common. The potential contribution of colon function to continence has not been studied. Treatment is poorly codified. To evaluate colonic transit time (CTT) and its importance in the management of fecal incontinence we analyzed in a retrospective study the CTT in patients with fecal incontinence, and on this basis in a prospective study used a treatment algorithm taking colonic transit into account. PATIENTS AND METHODS: We studied 30 healthy subjects and 171 patients (110 in the retrospective and 61 in the prospective study). Anorectal manometry and CTT measurement using radio-opaque markers were performed. Patients were divided into three groups according to their CTT: rapid (<24 h), normal, and delayed (>65 h). In patients with abnormal CTT modifiers of transit time were used as first line of treatment. Biofeedback therapy was used alone in patients with normal transit and used in the other patients after 6 weeks of medication when there was no or only partial improvement. RESULTS: Incontinent patients had less upper and lower anal pressure and maximal squeeze pressure and longer CTT than controls. Rapid and delayed transit times were found, respectively, in 17% and 32% of patients. After 6 weeks of treatment 77% of patients had recovered from fecal incontinence. Biofeedback therapy increased total improvement to 95%. CONCLUSION: We conclude that evaluation of CTT is useful in the management of fecal incontinence, and that medical therapy is sufficient to treat most incontinent patients. This implies the use of a careful selection algorithm prior to surgery for fecal incontinence.