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Atlantic sturgeon Acipenser oxyrinchus oxyrinchus were listed as 5 distinct population segments under the US Endangered Species Act in 2012. At that time, only 2 abundance estimates of the Atlantic sturgeon population were available: one from commercial fisheries landings in the Hudson River ending in 1995 and one from mark-recapture research in the Altamaha River, Georgia, in 2004 and 2005. In 2013, we verified spawning in the York River, Virginia, system and initiated a multiple-year mark-recapture study focusing on spawning-run abundance. We used a Schumacher-Eschmeyer model and Program CAPTURE to produce estimates of annual spawning abundances from 2013 to 2018. The Schumacher-Eschmeyer estimates of spawning-run abundance with 95% confidence intervals from 2013 to 2018 were 75 (31-190), 157 (115-244), 184 (150-238), 222 (137-576), 212 (157-328), and 145 (89-381), respectively. Because Atlantic sturgeon do not spawn every year, the trends in estimates do not suggest a recovering or declining population, but rather variability in proportions of the adult population that return to spawn each year. The estimates produced in Program CAPTURE using M0 (null), Mt (Chao Mt and Darroch), Mh (Chao Mh and Jackknife), and Mth (Chao Mth) models all produced similarly reliable estimates. The models that consider a behavioral response to initial capture (Mb, Mbh, and Mtb) failed to produce reliable estimates for this data, likely because as an endangered species, the dataset for Atlantic sturgeon was sparse. The Jackknife equation (model Mh) was the most precise every year with reliable accuracy and therefore is recommended.

The purpose of this study is to use the mechanisms of deformation band formation to help with interpreting the timing of phases of deformation in an area with a complex geological history. Deformation bands and zones of deformation bands are described from the quartzites of the Lower Devonian Muth Formation in the Pin Valley, NW Himalayas. Thin-section analyses show that the deformation bands in the Muth Formation formed early in the diagenetic history before porosity was lost. Deformation mechanisms involved cataclasis, translation, rotation of quartz grains and effective porosity reduction. The orientations of the deformation bands cannot be reasonably grouped with the orientations of faults related to Himalayan deformation in the Pin Valley. Additionally, the deformation bands are deformed by Eo-Himalayan (Eocene) folds, which in turn are cnt by later faults. The later faults that cross-cut the Eo-Himalayan folds developed in the already-cemented Muth Formation at much higher temperature and pressure conditions by crystal plastic deformation mechanisms, indicated by quartz crystals with undulatory extinction, abundant kink bands, dislocation glide, elongated subgrains, slightly curved deformation lamellae and pronounced shape-preferred orientation. These two completely contrasting deformation mechanisms on the microstructural scale characterize two distinct fault sets that formed at different depths in the crust. Based on these differences, a pre-Himalayan origin of the deformation bands is concluded, thus representing a set of rare pre-Himalayan deformation structures. After unfolding to remove Eo-Himalayan crustal shortening, the orientation of the deformation bands and restored relative offsets of sedimentary bedding are most compatible with E-W-oriented shortening associated with N-S extension. The age of the deformation bands in the Muth Formation is bracketed by an early Devonian sedimentation age of the Muth Formation and a middle Cretaceous age of considerable cementation as deduced from compiled burial histories. Accepting a pre-middle Cretaceous age of the deformation bands, maximum conditions of about 80 [degrees]C and 60 MPa lithostatic pressure during their formation are estimated from the amount of overburden during the middle Cretaceous. We suggest the deformation bands are a result of either the Neo-Tethys rifting event beginning in the early Carboniferous or the extension related to late Carnian/early Norian rapid subsidence, although a hitherto unknown deformation event cannot be excluded. Keywords: deformation bands, pre-Himalayan deformation, India, quartz arenite, Muth Formation.

A dual annealing cap composed of a thin, low temperature metal-organic chemical vapor deposition (MOCVD) deposited AlN adhesion layer and a thicker, sputtered AlN film for added mechanical strength enabled us to anneal Si-implanted layers for 30 min at temperatures up to 1250 °C. At higher temperatures the cap was destroyed by the large partial pressure of the N2 from the GaN, which exceeds the yield strength of AlN. Electrical activations as high as 70% and electron mobilities comparable to those of in situ doped films were achieved. Compared to other methods, the surfaces are better protected using this cap because it adheres better than sputtered AlN, SiO2, or Si3N4; does not crack like MOCVD grown AlN films deposited at normal temperatures (∼1100 °C); and is stronger than thin MOCVD grown AlN films deposited at low temperatures (∼600 °C). Even though N does not escape, and in so doing, forms thermal etch pits, the surface of the annealed GaN is roughened by solid state diffusion with the surface roughness increasing with the annealing temperature. [ABSTRACT FROM AUTHOR]