Prophylactic TAE in patients with duodenal ulcers at high risk for rebleeding was feasible, effective at preventing the need for surgery, and had low major complication rates. Given these promising outcomes, prophylactic TAE should be further evaluated as a preventative therapy in high-risk patients.

The architecture of the critical zone includes the distribution, thickness, and contacts of various types of slope deposits and weathering products such as saprolite and weathered bedrock resting on solid bedrock. A quantitative analysis of architecture is necessary for many model-driven approaches used by pedologic, geomorphic, hydrologic or biologic studies. We have used electrical resistivity tomography, a well-established geophysical technique causing minimum surficial disturbance, to portray the subsurface electrical resistivity differences at three study sites (Green Lakes Valley; Gordon Gulch; Betasso) at the Boulder Creek Critical Zone Observatory (BcCZO). Possible limitations of the technique are discussed. Interpretation of the specific resistivity values using natural outcrops, pits, roadcuts and drilling data as ground truth information allows us to image the critical zone architecture of each site. Green Lakes Valley (3700 MASL), a glacially eroded alpine basin, shows a rather simple, split configuration with coarse blockfields and sediments, partly containing permafrost above bedrock. The critical zone in Gordon Gulch (2650 MASL), a montane basin with rolling hills, and Betasso (1925 MASL), a lower montane basin with v-shaped valleys, is more variable due to a complex Quaternary geomorphic history. Boundaries between overlying stratified slope deposits and saprolite were identified at mean depths of 3.0 AE 2.2 m and 4.1 AE 3.6 m in the respective sites. The boundary between saprolite and weathered bedrock is deeper in Betasso at 5.8 AE 3.7 m, compared with 4.3 AE 3.0 m in Gordon Gulch. In general, the data are consistent with results from seismic studies, but electrical resistivity tomography documents a 0.5-1.5 m shallower critical zone above the weathered bedrock on average. Additionally, we document high lateral variability, which results from the weathering and sedimentation history and seems to be a consistent aspect of critical zone architecture within the BcCZO.

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Wadis emerging from the southwestern Sinai Mountains (Egypt) westwards to the Guif of Suez are fiiied by >40 m thici< iate Pielstocene sediments, which have been subsequently incised to bedrock after the Last Giaciai Maximum (LGM). Sedimentation and erosion resuited from changes in the basin's hydroiogical conditions caused by climate variations. Sediment characteristics indicate distinct processes ranging from high to low energy flow regimes. Airborne material is important as a sediment source. The fills are associated with alluvial fans at wadi mouths at the mountain fronts. Each alluvial fan is associated and physically correlated with the respective sediment fill in its contributing wadi. The alluvial fans have steep gradients and are only a few kilometers long or wide. The alluvial fans converge as they emerge from the adjacent vaiieys. According to optically stimuiated iuminescence dating, the initial sediment has an age of ~45 ka and the sedimentation ends ~19 ka, i.e., happened mainly during marine isotope stage (MIS) 3 and early MIS 2 formation and initial incision sometime during LGM.As the delivery of sediments in such a hyper-arid environment is by extreme floods, this study indicates an interval of intense fluvial activity, probably related to increased frequency of extreme floods in Southern Sinai. This potentially indicates a paleoclimatic change in this hyper-arid environment.