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Grass-legume mixtures characterized by high productivity, efficient nitrogen (N) use and strong weed suppression were proposed to increase sustainability of grassland production. Adding competitive forbs to grassclover mixtures can be expected to further enhance the high productivity of grass-clover mixtures. This study investigates whether and to what extent adding forbs to a grass-clover mixture results in yield gains, and estimates the contributions of forb species (identity effect) and interactions with the grass-clover mixture (diversity effect) to these gains. It further examines the effectiveness of weed suppression in forb-containing grass-clover mixtures. Fifteen pure and mixed stands, all comprising the grass Lolium perenne L. and the legume Trifolium pratense L., and one or three competitive forb species (Cichorium intybus L., Carum carvi L., Plantago lanceolata L.) were established in a two-year field experiment and fertilised at two levels of N application. The diversity effect between P. lanceolata and the L. perenne-T. pratense mixture and a strong identity effect of P. lanceolata jointly contributed to yield gains of 10–21% over the binary L. perenne-T. pratense reference mixture for a wide range of P. lanceolata proportions across years and N fertilisation levels. In contrast, comparably smaller diversity and/or identity effects of C. intybus and C. carvi resulted in maximal yield gains of 5% and 7%, respectively, occurring at a narrower proportional range, but also in yield losses at high forb proportion. Including up to 80% forb in the L. perenne-T. pratense mixture effectively maintained weed suppression, but the degree of weed suppression decreased with increasing forb proportion in the following year. Including selected forbs, especially P. lanceolata, in productive grass-clover mixtures is promising for further enhancing productivity, meanwhile effectively suppressing short-term weed growth in intensively managed grasslands.

1.Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from three years of a 31-site continental-scale field experiment.2.At each site, fifteen grassland communities comprising four monocultures and 11 4-species mixtures based on a wide range of species’ proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, ‘method-of-nitrogen-acquisition’ and ‘pattern-of-temporal- development’.3.Across sites, years, and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t DM ha−1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and, in two thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.4.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval 30% to 75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.5.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77).6.Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertilizer nitrogen. In this study, effects of diversity on weed suppression

Background: Vertical banded gastroplasty (VBG) has long been the main restrictive procedure for morbid obesity but has many long-term complications for which conversion to Roux-en-Y gastric bypass (RYGBP) is often considered the best option. Methods: This series regroups patients operated on by three different surgeons in four different centers. All data were collected prospectively, then pooled and analyzed retrospectively. Results: Out of 2,522 RYGBP performed between 1998 and 2010, 538 were reoperations, including 203 laparoscopic RYGBP after VBG. There were 175 women and 28 men. The mean BMI before VBG was 43.2 ± 6.3, and the mean BMI before reoperation was 37.4 ± 8.3. Most patients had more than one indication for reoperation and/or had regained significant weight. There was no conversion to open surgery. A total of 24 patients (11.8%) developed complications, including nine (4.5%) who required reoperation and one death. With a follow-up of 88.9% after 8years, the mean BMI after 1, 3, 5, 7, and 9years was 29.1, 28.8, 28.7, 29.9, and 28.8, respectively. Conclusions: On the basis of this experience, the largest with laparoscopic reoperative RYGBP after failed VBG, we conclude that this procedure can safely be performed in experienced hands, with weight loss results similar to those observed after primary RYGBP. In patients with too difficult an anatomy below the cardia, dividing the esophagus just above the esophago-gastric junction and performing an esophagojejunostomy may be a safe alternative to converting to a Scopinaro-type BPD, obviating the additional long-term risks associated with malabsorption

Introduction: Laparoscopic gastric banding (LGB) is currently the most popular purely restrictive bariatric operation in Europe and many other countries. It has a low operative morbidity, but is associated with a substantial late complication rate. Many late complications have been attributed to technical errors or to the learning curve. The aim of this paper is to present our results with gastric banding after the learning curve in order to disclose the true incidence of long-term complications. Methods: LGB was introduced in our department in December 1995. Thirty patients were operated on until June 1997 using the early banding technique (band within the lesser sac), at which time the surgical technique was slightly modified in order to place the band above the lesser sac. Then another 300 patients underwent LGB using either the Lapband or the SAGB system. This report focuses on the latter patients. All the data were collected prospectively. Results: The series includes 300 patients (257 women and 43 men) with a mean age of 38.3 years (19-64). The mean initial weight was 119.2 kg (57-179), initial body mass index (BMI) was 43.3 kg/m2 (21-64), and initial excess weight was 96.5% (0-191). The mean duration of surgery was 90 min, decreasing over time to a mean of 75 min for the last 50 cases. Early overall morbidity was 6.6%. Major complications occurred in 7 patients (2.3%). Excess weight loss (EWL) was at least 50% in 66% of the patients after 2 years, averaging 60%, with no substantial change until 4 years, and the BMI stabilized between 30 and 31 kg/m2. Forty-nine patients developed a total of 52 long-term complications, of which 23 (7.6%) were related only to the port or catheter. Band erosion occurred in 17 (5.6%), pouch dilatation with slippage in 8 (2.6%), and infection in 4 (1.3%) patients. Fifty-five reoperations were necessary. Twenty-five of these were related only to the port. The band was removed from 26 (9%) patients, of whom 17 were converted to Roux

Background: Morbidly obese patients are at high risk to develop gallstones, and rapid weight loss after bariatric surgery further enhances this risk. The concept of prophylactic cholecystectomy during gastric bypass has been challenged recently because the risk may be lower than reported earlier and because cholecystectomy during laparoscopic gastric bypass may be more difficult and risky. Methods: A review of prospectively collected data on 772 patients who underwent laparoscopic primary gastric bypass between January 2000 and August 2007 was performed. The charts of patients operated before 2004 were retrospectively reviewed regarding preoperative echography and histopathological findings. Results: Fifty-eight (7.5%) patients had had previous cholecystectomy. In the remaining patients, echography showed gallstones or sludge in 81 (11.3%). Cholecystectomy was performed at the time of gastric bypass in 665 patients (91.7%). Gallstones were found intraoperatively in 25 patients (3.9%), for a total prevalence of gallstones of 21.2%. The age of patients with gallstones was higher than that of gallstone-free patients (43.5 vs 38.7years, p < 0.0001). Of the removed specimens, 81.8% showed abnormal histologic findings, mainly chronic cholecystitis and cholesterolosis. Cholecystectomy was associated with no procedure-related complication, prolonged duration of surgery by a mean of 19min (4-45), and had no effect on the duration of hospital stay. Cholecystectomy was deemed too risky in 59 patients (8.3%) who were prescribed a 6-month course of ursodeoxycolic acid. Conclusion: Concomitant cholecystectomy can be performed safely in most patients during laparoscopic gastric bypass and does not prolong hospital stay. As such, it is an acceptable form of prophylaxis against stones forming during rapid weight loss. Whether it is superior to chemical prophylaxis remains to be demonstrated in a large prospective randomized study

Roux-en-Y gastric bypass (RYGBP) is currently the most common bariatric procedure. One of its late complications is the development of internal hernia, which can lead to acute intestinal obstruction or recurrent colicky abdominal pain. The aim of this paper is to present a new, unusual, and so far not reported type of internal hernia. A common computerized database is maintained for all patients undergoing bariatric surgery in our departments. The charts of patients with the diagnosis of internal hernia were reviewed. Three patients were identified who developed acute intestinal obstruction due to an internal hernia located between the jejunojejunostomy and the end of the biliopancreatic limb, directly between two jejunal limbs with no mesentery involved. Another seven patients with intermittent colicky abdominal pain, re-explored for the suspicion of internal hernia, were found to also have an open window of the same location apart from a hernia at one of the typical hernia sites. Since this gap is systematically closed during RYGBP, no other patient has been observed with this problem. Even very small defects can lead to the development of internal hernias after RYGBP. Patients with suggestive symptoms must be explored. Closure of the jejunojejunal defect with nonabsorbable sutures prevents the development of an internal hernia between the jejunal loops at the jejunojejunostomy