Site U1310 Anon
01/2006, Letnik:
304 & 305
Book Chapter
Odprti dostop
Site U1310 is located similar to 10 km west of the center of the rift valley. Towed ocean-bottom instrument and DSL120 side-scan sonar data and bathymetry indicate that the site is on a small ...fault-bound horst, similar to 600 m east of the break in slope inferred to mark the termination of the detachment fault exposed on the central dome. The site coincides with the eastern end of Alvin dive 3643, cruise AT3-60, in an area with numerous small northeast-striking scarps (both southeast and northwest facing). Based on nearby Alvin observations and sampling, these scarps expose pillow basalts.
Site U1309 Anon
01/2006, Letnik:
304 & 305
Book Chapter
Odprti dostop
Integrated Ocean Drilling Program (IODP) Site U1309 is located on the central dome of Atlantis Massif, 14-15 km west of the median valley axis of the Mid-Atlantic Ridge (MAR), where the seafloor ...coincides with what is interpreted to be a gently sloping, corrugated detachment fault surface. Two drill holes at this site (Holes U1309B and U1309D) penetrate a multiply intruded and faulted crustal section, providing core that documents the interplay between magmatism, deformation, and. hydrothermal alteration prior to, during, and subsequent to a period of footwall displacement and denudation associated with detachment faulting. Five shallow-penetration holes (Holes U1309A and U1309E-U1309H) were designed to sample the sedimentary carapace and upper few meters of basement, to test the hypothesis that the upper surface coincides with a detachment fault, and to help constrain the temporal history of denudation. Collected sedimentary deposits may provide constraints on the timing of exposure across the dome based on the age and isotopic character of preserved microfossils. Basement rock sampled in these short holes provides initial information on deformation and alteration within the exposed fault and, perhaps, rock adjacent to the fault zone.
Expedition 304/305 summary Blackman, D K; Ildefonse, B; John, B E ...
01/2006, Letnik:
304 & 305
Book Chapter
Odprti dostop
Integrated Ocean Drilling Program Expeditions 304 and 305 composed a two-expedition program at Atlantis Massif, Mid-Atlantic Ridge 30 degree N, designed to investigate the processes that control ...oceanic core complex formation and the exposure of ultramafic rocks in young oceanic lithosphere. Geophysical interpretations of unaltered mantle rock occurring <1 km below the seafloor suggested we could drill through an alteration front in ultramafic rocks and obtain fresh mantle peridotite. In order to accomplish these objectives, we drilled at two sites: one in the footwall through an exposed detachment fault and one in the hanging wall. Drilling the fractured basalt in the hanging wall was thwarted by difficulties, whereas drilling in the footwall was very successful. The main hole at Site U1309 penetrated 1415.5 meters below seafloor, and recovery averaged 75%. Igneous rocks recovered from the hole are the most primitive ever cored in slow-spreading ocean lithosphere and provide an exceptional record of magmatic and tectonic accommodation to extension in this environment. The core recovered was dominantly crustal rock types; basalt ( similar to 3%) and gabbroic ( similar to 91%). A series of olivine-rich rocks ( similar to 5%; dunites, wehrlites, troctolites), grouped as olivine-rich troctolites, part of which likely represent primitive cumulates, are interlayered with gabbroic rocks. A few thin mantle peridotite intervals are recognized in the upper 180 m of the section. Overall, the section is moderately altered at conditions ranging from granulite to zeolite facies. The rocks record initial alteration at low strains under granulite- and amphibolite-facies conditions and subsequent, more fully developed, lower temperature alteration (greenschist facies). Fault zone(s) comprising the detachment system must be highly localized to within tens of meters of the present-day seafloor. The existence of a fault at the top of the domal surface is supported by fragments of brecciated talc-tremolite fault schist and fractured metadiabase recovered in Hole U1309B and during the series of shallow cores drilled. Extensive amphibolite facies deformation is lacking, and high-strain ductile shear zones are rare. The absence of a thick, high-temperature ductile deformation zone in the footwall, and the apparent tectonic history (less rotation in the upper 180 m and variable rotations between several distinct, few-hundred meter sections downhole) suggested by paleomagnetic inclination measurements indicate complexity in structural evolution that differs from the simplest models of deep-rooted detachment faults, predicted to be associated with high-temperature deformation, and with constant or monotonically varying footwall rotation with depth. Another challenge is that the central dome is clearly not an uplifted dominantly upper mantle section, as had been inferred prior to drilling. The exposures of peridotite along the southern wall of Atlantis Massif, the geophysical results suggesting at least portions of the dome contain fresh olivine-rich rock, and the downhole variability at Site U1309 all likely indicate significant lateral heterogeneity over short distances across the footwall.
Site U1311 Anon
01/2006, Letnik:
304 & 305
Book Chapter
Odprti dostop
Site U1311 is located on a small knoll near the break in slope where the corrugated dome meets the adjacent volcanic hanging wall block (see Fig. F2 in the "Site U1309" chapter and Fig. F2 in the ..."Expedition 304/305 summary" chapter). The hole was cited based on the possibility that the knoll represents a thin klippe of basalt above the detachment surface. Recovery of fresh glassy vesicular basalt in Hole U1311A does not provide a definitive test of this hypothesis. The eruptive basalt could have come from the inferred hanging wall, as hypothesized, or it could have been erupted onto or against the slope of the easternmost surface of the dome at any time after exposure at the seafloor.
Significance Colorectal cancer is a leading cause of cancer-related deaths world-wide. African Americans exhibit the highest colon cancer incidence and mortality among all ethnic groups in the United ...States. Despite this finding, there is a dearth of knowledge on the genetic mechanisms underlying colon carcinogenesis in African Americans. We thus initiated this study to characterize the mutational landscapes of African American colon cancers. We identified new genes that are significantly mutated in colon cancer and that are highly preferentially targeted for mutations in colon cancers arising in African Americans as compared with Caucasians. These findings suggest differences in routes of colon carcinogenesis between the different ethnic groups and also may have implications for the ethnicity associated differences in tumor incidence and outcome.
We used whole-exome and targeted sequencing to characterize somatic mutations in 103 colorectal cancers (CRC) from African Americans, identifying 20 new genes as significantly mutated in CRC. Resequencing 129 Caucasian derived CRCs confirmed a 15-gene set as a preferential target for mutations in African American CRCs. Two predominant genes, ephrin type A receptor 6 ( EPHA6 ) and folliculin ( FLCN ), with mutations exclusive to African American CRCs, are by genetic and biological criteria highly likely African American CRC driver genes. These previously unsuspected differences in the mutational landscapes of CRCs arising among individuals of different ethnicities have potential to impact on broader disparities in cancer behaviors.
In addition to mutations in genes, aberrant enhancer element activity at non-coding regions of the genome is a key driver of tumorigenesis. Here, we perform epigenomic enhancer profiling of a cohort ...of more than forty genetically diverse human colorectal cancer (CRC) specimens. Using normal colonic crypt epithelium as a comparator, we identify enhancers with recurrently gained or lost activity across CRC specimens. Of the enhancers highly recurrently activated in CRC, most are constituents of super enhancers, are occupied by AP-1 and cohesin complex members, and originate from primed chromatin. Many activate known oncogenes, and CRC growth can be mitigated through pharmacologic inhibition or genome editing of these loci. Nearly half of all GWAS CRC risk loci co-localize to recurrently activated enhancers. These findings indicate that the CRC epigenome is defined by highly recurrent epigenetic alterations at enhancers which activate a common, aberrant transcriptional programme critical for CRC growth and survival.
Costas arrays are permutation matrices that meet the additional Costas condition. The Costas condition requires that when a Costas array defines the frequencies in a frequency jump burst and a signal ...is processed with a matched filter, then for any time or Doppler offset other than both zero, only one pulse will be at peak response at a time. Specific formulations of the Costas conditions provide a vector-matrix arithmetic representation where the matrix has eigenvalues that are square roots of integers and eigenvectors that can be scaled to have elements that are all integers. Polynomials are given for squared eigenvalues and for elements of scaled right eigenvector elements. A database of these singular value decompositions is provided on IEEE DataPort for orders from 3 to 1030, with left eigenvectors to order 100. We include proofs of validity and configuration. The right eigenvectors and the eigenvalues map a Costas array vector into its eigenspace. Functions of these vectors can be associated with system performance metrics so that these mapped vectors may be used to select and rank Costas arrays and is suitable for real-time system implementation.
Prior studies suggest brick workers in Nepal may be chronically exposed to hazardous levels of fine particulate matter (PM2.5) from ambient, occupational, and household sources. However, findings ...from these studies were based on stationary monitoring data, and thus may not reflect a worker’s individual exposures. In this study, we used RTI International’s MicroPEMs to collect 24 h PM2.5 personal breathing zone (PBZ) samples among brick workers (n = 48) to estimate daily exposures from ambient, occupational, and household air pollution sources. Participants were sampled from five job categories at one kiln. The geometric mean (GM) PM2.5 exposure across all participants was 116 µg/m3 (95% confidence interval CI: 94.03, 143.42). Job category was significantly (p < 0.001) associated with PBZ PM2.5 concentrations. There were significant pairwise differences in geometric mean (GM) PBZ PM2.5 concentrations among workers in administration (GM: 47.92, 95% CI: 29.81, 77.03 µg/m3) vs. firemen (GM: 163.46, 95 CI: 108.36, 246.58 µg/m3, p = 0.003), administration vs. green brick hand molder (GM: 163.35, 95% CI: 122.15, 218.46 µg/m3, p < 0.001), administration vs. top loader (GM: 158.94, 95% CI: 102.42, 246.66 µg/m3, p = 0.005), firemen vs. green brick machine molder (GM: 73.18, 95% CI: 51.54, 103.90 µg/m3, p = 0.03), and green brick hand molder vs. green brick machine molder (p = 0.008). Temporal exposure trends suggested workers had chronic exposure to hazardous levels of PM2.5 with little to no recovery period during non-working hours. Multi-faceted interventions should focus on the control of ambient and household air pollution and tailored job-specific exposure controls.
Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of ...algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed.
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