Combined analysis of high-resolution seismic images of the Alaska and Cascadia subduction zones reveals where metamorphic fl uids are released. Both images show the subducted oceanic crust as a dipping low-velocity layer with a clear termination depth. However, in Alaska the crust is thicker (15–20 km compared to 8 km) and terminates at greater depth (120 km compared to 40 km) than in Cascadia....

This Letter describes a scalar curvature invariant for general relativity with a certain, distinctive feature. While many such invariants exist, this one vanishes in regions of space-time which can be said unambiguously to contain no gravitational radiation. In more general regions which incontrovertibly support nontrivial radiation fields, it can be used to extract local, coordinate-independen...

In the past few years our national consciousness has been altered by haunting images of mass slaughters in American high schools, carried out by troubled young boys with guns. It's now clear that no matter where we live or how hard we try as parents, our children are likely to be going to school with boys who are capable of getting guns and pulling triggers. What has caused teen violence to spr...

Germinal centers (GC) are an essential part of the humoral immune response. They develop a clear structure during maturation: Centroblasts and centrocytes are separated into two zones, the dark and the light zone. The mechanisms leading to this specific morphology as well as the reason for zone-depletion during a later phase of the GC reaction have not clearly been revealed in experiment. We di...

Forest management practices such as clearcutting, site preparation, ditching, and ditch network maintenance increase nitrogen (N) load to streams. In environmentally sustainable forestry, water protection actions are required to decrease the nutrient loading. These include e.g. use of uncut buffer zones between a clear-cut area and a waterbody, sedimentation ponds in the ditch network and overl...

the shah-kuh granitoid has intruded in the triassic–jurassic, pelitic and psammitic low-grade metamorphic rocks of the ne lutblock, in central iran. cordierite porphyroblasts are common in the southern pelitic sediments, but are rare in the northern psammiticrocks, in the contact aureole. deformation fabrics in the contact aureole are well-preserved within the cordierite porphyroblasts. therela...