Preferential flow modelling of chlorpyrifos leaching in two arid soils of irrigated agricultural production areas in Argentine Patagonia.

An analysis was made of the transport and fate of the organophosphate pesticide chlorpyrifos in productive soils from the Alto Valle of the Río Negro in Argentine Patagonia. The climate of the region is arid, so traditional fruit production is under flood irrigation. The soils in the floodplain are predominantly Aridisols with textures ranging from sandy loam to clay loam. The calibration was performed with water table data and chlorpyrifos concentration in the soil horizons. Field experiments made with Brilliant Blue FCF at the profile scale enabled the parametrisation of the dual-permeability model MACRO. The model calibration was evaluated by a comparison of observed and simulated data and statistics. The simulation of the groundwater table depth was satisfactory and the chlorpyrifos leaching revealed a different pattern in the two soil types studied. The sandy loam texture soil produced more percolation of irrigation water, but the clay loam soil produced greater leaching of chlorpyrifos under similar application conditions, presumably due to preferential flow under non-equilibrium conditions. Productive management alternatives to reduce leaching into the underlying unconfined aquifer were simulated. Among these, the incorporation of organic matter was the best alternative.

A multicentric comparison of transabdominal versus totally extraperitoneal laparoscopic hernia repair using PARIETEX meshes.

The authors report a series of 1972 inguinal hernias treated between 1993 and 1997 by the insertion of a PARIETEX mesh via either a transabdominal-preperitoneal (TAPP) (1,290 procedures) or a totally extraperitoneal TEP approach (682 procedures). Pain scores were equivalent in both groups, while the hospital stay and time to return to normal activity was lower in the TEP group than in the TAPP group (p<0.001). In both groups, the average incidence of the total reported events (complications) was around 10% with no statistical difference. This ratio seemed to compare favorably to previously published reports. Chronic pain was extremely rare (0.6% and 0.7% in the TAPP and TEP groups, respectively). Whatever the approach was, sepsis was also very rare (1/1,526 laparoscopic procedures). These findings illustrate the local tolerance of the mesh. Recurrence rates were below 1% with no statistical difference between groups. This retrospective study demonstrates the clinically apparent local tolerance of this type of mesh. Prospective and long-term clinical results will be necessary to demonstrate that the optimized short-term tolerance of PARIETEX mesh will influence the long term functional results.

Ulnar artery aneurysm of the hand.

A case of traumatic ulnar artery aneurysm is presented in this study, and the relationship between the various forms of ulnar artery aneurysm and the different methods of treatment, as well as the arterial implications are discussed. The individual palmar arch anatomy may indicate and influence the choice of management technique, in each case.