Extended antigen (C, E, K) matching decreased the incidence of alloantibody (alloAB) and autoantibody (autoAB) formation, in addition to eliminating transfusion reactions in the multiply transfused sickle cell disease patients. AlloAB formation possibly transforms the immune system into a hyperactive state leading to further and earlier alloAB and autoAB formation. However, additional CEK matching results in marked overuse of Rh-negative packed red blood cell (pRBC) units, 30 minutes' extra time of a skilled technologist, and 153 dollars extra CEK reagent cost per unit to find CEK-matched pRBCs for every transfusion for these multiply transfused patients.

Abstract. Large-scale volcanism, in the form of areally extensive flow fields, is a previously unrecognized important aspect of the evolution of at least 41% of all coronae on Venus.The timing and scale of many coronae flow fields is consistent with an origin due to the arrival and pressure-release melting of material in the head of a mantle plume or diapir. The production of voluminous amounts of volcanism at some coronae is proposed to be the result of larger plume size and/or the intersection of mantle upwellings with regions of lithospheric extension and rifting.

Mylitta Fluctus is a volcanic flow field that covers approximately 300,000 km2 in southern Lavinia Planitia. The flows are typically radar‐bright with uniform surface textures. Central channels are common. Maximum flow lengths range from 400 to 1000 km; flow widths range 30–100 km in the medial and distal portions of the flow field. The total volume of the flow field, based on estimates of flow thickness, is of the order of 2 × 104 km3. The flow field is composed of six smaller flow fields that are interpreted to represent major eruption events in the evolution of Mylitta. An asymmetric shield volcano 200 km in radius with a central caldera has been identified as the single major source. It is located along a possible rift zone at the northern edge of Lada Terra. No evidence for fissure‐fed eruptions is observed, although eruptions may have occurred along fissures within the rift before the main vent centralized. Mylitta is similar in scale to many terrestrial flood basalt provinces, although it is lower in total estimated volume and is distinguished by the presence of a central source edifice. The origin of Mylitta is proposed to be linked to regional extension and possible hotspot activity in a manner similar to that suggested for the origin of terrestrial flood basalts. The lower apparent volume of Mylitta relative to terrestrial flood basalts suggests that the amount of material upwelling from the mantle may have been lower in this case or that the formation of the flow field has not yet finished. Detailed studies of the morphology and distribution of flow fields similar to Mylitta should yield insight into the variation and evolution of hotspot‐related volcanism and the formation of possible flood basalts on Venus.

Lakshmi Planum is distinctive and unique on the surface of Venus as an expansive (-2 x lo6 km2), relatively smooth, flat plateau containing two large shield volcanoes and abundant volcanic plains in the midst of a region of extreme relief. It rises 3-5 km above the datum and is surrounded on all sides by bands of mountains interpreted to be of compressional tectonic origin. The major units mapped on Lakshmi are volcanic edifices, smooth, ridged and grooved plains units, and structural units referred to as ridged terrain. Three styles of volcanism are observed to dominate the surface of Lakshmi. Distributed effusive volcanism is associated with extensive plains deposits and many of the small shields, domes and cones mapped within the plateau. Centralized effusive volcanism is primarily associated with the paterae, Colette and Sacajawea, and their circumferential low-shieldforming deposits. The precise origin and evolution of these unusually large and complex structures is not understood, although a catastrophic, explosive origin is unlikely. Pyroclastic volcanism may be represented by a unit referred to as the "diffuse halo". The origin and evolution of Lakshmi Planum is closely related to its compressional tectonic environment; volcanism on Lakshmi has occurred synchronously with tectonism in the surrounding erogenic belts. A model for the origin and evolution of Lakshmi Planum consisting of a continuous sequence of convergence and horizontal shortening of crustal segments against a preexisting block of tessera seems best able to account for the elevation, plateau shape and irregular polygonal outline of Lakshmi, as well as the presence of ridged terrain and its resemblance to tessera. Volcanism on Lakshmi is proposed to be the result of basal melting of a thickened crustal root. According to this model, the origin and evolution of Lakshmi Planum has consisted of the following sequence of events: (1) formation of a large, elevated block of tessera surrounded by low-lying plains; (2) convergence and underthrusting of crustal segments to produce peripheral mountain ranges, thickening, and uplift of the plateau; and (3) basal melting of the thickened crust and underthrust material and surface volcanism that occurred synchronously with continued edge deformation.