Global potential for the growth of fresh groundwater resources with large beach nourishments.

Whether a coastal area is suitable for beach nourishments and can induce a growth in fresh groundwater resources depends on the appropriateness of the intended site for beach nourishments, and the attainable growth in fresh groundwater resources. In this study we presume that all eroding sandy beaches are suitable for large beach nourishments, and focus on the impact of these nourishments on fresh groundwater in various coastal settings. The growth in fresh groundwater resources - as a consequence of the construction of a beach nourishment - was quantified with 2-D variable-density groundwater models, for a global range in geological parameters and hydrological processes. Our simulation results suggest that large beach nourishments will likely lead to a (temporary) increase of fresh groundwater resources in most settings. However, for a substantial growth in fresh groundwater, the coastal site should receive sufficient groundwater recharge, consist of sediment with a low to medium hydraulic conductivity, and be subject to a limited number of land-surface inundations. Our global analysis shows that 17% of shorelines may consist of erosive sandy beaches, and of these sites 50% have a high potential suitability. This shows a considerable potential worldwide to combine coastal protection with an increase in fresh groundwater resources.

Low-Resolution Modeling of Dense Drainage Networks in Confining Layers.

Groundwater-surface water (GW-SW) interaction in numerical groundwater flow models is generally simulated using a Cauchy boundary condition, which relates the flow between the surface water and the groundwater to the product of the head difference between the node and the surface water level, and a coefficient, often referred to as the "conductance." Previous studies have shown that in models with a low grid resolution, the resistance to GW-SW interaction below the surface water bed should often be accounted for in the parameterization of the conductance, in addition to the resistance across the surface water bed. Three conductance expressions that take this resistance into account were investigated: two that were presented by Mehl and Hill (2010) and the one that was presented by De Lange (1999). Their accuracy in low-resolution models regarding salt and water fluxes to a dense drainage network in a confined aquifer system was determined. For a wide range of hydrogeological conditions, the influence of (1) variable groundwater density; (2) vertical grid discretization; and (3) simulation of both ditches and tile drains in a single model cell was investigated. The results indicate that the conductance expression of De Lange (1999) should be used in similar hydrogeological conditions as considered in this paper, as it is better taking into account the resistance to flow below the surface water bed. For the cases that were considered, the influence of variable groundwater density and vertical grid discretization on the accuracy of the conductance expression of De Lange (1999) is small.

Oral bioavailability of phenobarbital: a comparison of a solution in Myvacet 9-08, a suspension, and a tablet.

PURPOSE: A three-way crossover study with seven healthy male volunteers was conducted to determine the relative bioavailability of phenobarbital after single dose administration of 100 mg of phenobarbital as oral solution in Myvacet 9-08, and as a suspension, compared with a 100 mg phenobarbital tablet. MATERIALS AND METHODS: At 4-week intervals each subject received the solution in Myvacet 9-08, the suspension and the tablet in randomized order. Blood samples were collected for 48 h after each dose for analysis of phenobarbital. From the individual serum concentration-versus-time curves Cmax and Tmax were determined and AUC0-48 was calculated. RESULTS: All three oral dosage forms of phenobarbital are bioequivalent. No significant differences in Tmax were observed. CONCLUSION: The oral solution in Myvacet 9-08, and the suspension of phenobarbital proved to be bioequivalent to a tablet.

Depression in rural family practice. Easy to recognize, difficult to diagnose.

OBJECTIVE: To explore rural family physicians' decision-making processes when they encounter depression. DESIGN: Exploratory qualitative "field study" using individual in-depth interviews and participant observation. Interviews were audiotaped, transcribed, and analyzed by an editing approach. SETTING: Rural Nebraska family physicians' offices. PARTICIPANTS: A purposeful sample of six rural Nebraska family physicians, including five men and one woman, aged 35 to 65 years; two in solo practice, three in two-person practices, and one in a group practice; in communities with populations ranging from 600 to 6500. MAIN OUTCOME MEASURES: Themes common to all interviews. RESULTS: Themes included the following: depression is easy to recognize but difficult to diagnose; depression is readily treatable but requires negotiation to manage; and depression is important but time and resources are limited. The inadequate diagnosis and treatment of depression appeared to be partly artifactual and must be understood against a background of perceived stigma, high prevalence of depressive symptoms, structural barriers to care, and context of rural practice. CONCLUSIONS: Rural family physicians may have a more deliberate, organized, and rational approach to depressive disorders than previously reported. Depression is commonly recognized by rural family physicians; however, they hesitate to diagnose this condition because of diagnostic uncertainty, perceived stigma, the desire to preserve the physician-patient relationship, time and financial pressures, and a lack of supporting resources.