Geodia barretti is a massive nearly spherical sponge that forms dense assemblages on the continental shelf of the North Atlantic and the Norwegian Sea. We studied the metabolism of individual sponges collected using a remotely operated vehicle and maintained in large tanks with high volumes of unfiltered water brought from 160 m depth. We used direct methods (In‐Ex) to measure excurrent flow rates, oxygen removed, and carbon and nutrient flux through the sponges. G. barretti had very low specific filtration (0.26 mL min−1 mL−1 sponge tissue) and low respiration (5.34 ± 0.98 nmol O2 min−1 mL−1 sponge tissue; 8.44 ± 1.51 μmol O2 h−1 g C−1) rates in comparison to other sponges. A net release of nitrogen was detected as NO3−. Bacteria were removed from the water filtered with up to 99% efficiency, yet comprised only 5% of the sponges′ total carbon budget; the remainder consisted of dissolved organic carbon and detritus. High bacterial removal was aided by the presence of a tight gasket of cells that surrounds the collar of each choanocyte filter. A test for potential bypass canals showed removal of fluorescent microspheres until they were excreted 5–12 h after feeding. Electron micrographs showed active uptake of Escherichia coli “fed” to the sponge as well as phagocytosis of symbiont microbes by sponge cells in the mesohyl. These data provide the first comprehensive study of metabolism in a deep‐water high microbial abundance sponge.

Glass sponges are conspicuous members of the deep-sea fauna, but in the northeastern Pacific they form unusual reefs covering kilometers of seafloor. Individual sponges in fjords can process up to 10 m 3 water d 21 osculum 21 ; sponge reefs must therefore process considerable volumes and could significantly affect local water properties. We measured, in situ, the flux of carbon and nitrogen through Aphrocallistes vastus, the dominant reef-building species on Fraser Ridge reef, and calculated the energetics of feeding for all reefs in the Strait of Georgia, British Columbia. Sponges removed up to 90% of bacteria from the water and released ammonium. Because of the high density of sponges, high volumetric flow rates (up to 210 6 35 m 3 m 22 d 21 , mean 6 standard error, 95% confidence interval (CI) 132-288 m 3 m 22 d 21 ), and the efficient extraction of bacteria, we calculate a grazing rate of 165 6 29 m 3 m 22 d 21 (95% CI 102-228 m 3 m 22 d 21 ) for sponge reefs, the highest benthic grazing rate of any suspension-feeding community measured to date. Reefs of A. vastus extract seven times more carbon (3.4 6 1.4 g C m 22 d 21 ) than can be supported by vertical flux of total carbon alone and therefore require productive waters and steady currents to sustain their strong grazing. We calculate that modern sponge reefs in the northeastern Pacific remove 2.27 3 10 5 6 0.91 3 10 5 kg of bacterial carbon daily, nearly an order of magnitude less than the 1.38 3 10 6 6 0.55 3 10 6 kg removed by past sponge reefs estimated to have covered the continental shelf.

ObjectiveTo detect rare coding variants underlying loci detected by genome‐wide association studies (GWAS) of late onset Alzheimer disease (LOAD).MethodsWe conducted targeted sequencing of ABCA7, BIN1, CD2AP, CLU, CR1, EPHA1, MS4A4A/MS4A6A, and PICALM in 3 independent LOAD cohorts: 176 patients from 124 Caribbean Hispanics families, 120 patients and 33 unaffected individuals from the 129 National Institute on Aging LOAD Family Study; and 263 unrelated Canadian individuals of European ancestry (210 sporadic patients and 53 controls). Rare coding variants found in at least 2 data sets were genotyped in independent groups of ancestry‐matched controls. Additionally, the Exome Aggregation Consortium was used as a reference data set for population‐based allele frequencies.ResultsOverall we detected a statistically significant 3.1‐fold enrichment of the nonsynonymous mutations in the Caucasian LOAD cases compared with controls (p = 0.002) and no difference in synonymous variants. A stop‐gain mutation in ABCA7 (E1679X) and missense mutation in CD2AP (K633R) were highly significant in Caucasian LOAD cases, and mutations in EPHA1 (P460L) and BIN1 (K358R) were significant in Caribbean Hispanic families with LOAD. The EPHA1 variant segregated completely in an extended Caribbean Hispanic family and was also nominally significant in the Caucasians. Additionally, BIN1 (K358R) segregated in 2 of the 6 Caribbean Hispanic families where the mutations were discovered.InterpretationTargeted sequencing of confirmed GWAS loci revealed an excess burden of deleterious coding mutations in LOAD, with the greatest burden observed in ABCA7 and BIN1. Identifying coding variants in LOAD will facilitate the creation of tractable models for investigation of disease‐related mechanisms and potential therapies. Ann Neurol 2015;78:487–498

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San Francisco Bay has been contaminated historically by mercury from mine tailings as well as contemporary industrial sources. Native Spartina foliosa and non-native S. alterniflora-hybrid cordgrasses are dominant florae within the SF Bay estuary environment. Understanding mercury uptake and transformations in these plants will help to characterize the significance of their roles in mercury biogeochemical cycling in the estuarine environment. Methylated mercury can be biomagnified up the food web, resulting in levels in sport fish up to one million times greater than in surrounding waters and resulting in advisories to limit fish intake. Understanding the uptake and methylation of mercury in the plant rhizosphere can yield insight into ways to manage mercury contamination. The transmission x-ray microscope on beamline 6-2 at the Stanford Synchrotron Radiation Lightsource (SSRL) was used to obtain absorption contrast images and 3D tomography of Spartina foliosa roots that were exposed to 1 ppm Hg (as HgCl2) hydroponically for one week. Absorption contrast images of micron-sized roots from S. foliosa revealed dark particles, and dark channels within the root, due to Hg absorption. 3D tomography showed that the particles are on the root surface, and slices from the tomographic reconstruction revealed that the particles are hollow, consistent with microorganisms with a thin layer of Hg on the surface. Hg L3 XANES of ground-up plant roots and Hg L3 micro-XANES from microprobe analysis of micron-sized roots (60–120 microns in size) revealed three main types of speciation in both Spartina species: Hg-S ligation in a form similar to Hg(II) cysteine, Hg-S bonding as in cinnabar and metacinnabar, and methylmercury-carboxyl bonding in a form similar to methylmercury acetate. These results are interpreted within the context of obtaining a “snapshot” of mercury methylation in progress.