277 research outputs found
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Mapping surficial geologic habitats of the Oregon continental margin using integrated interpretive GIS techniques
We map the regional physiography and surficial lithology (Surficial Geologic Habitat or
SGH) over the continental margin of Oregon. This thesis develops, describes, and
implements an iterative interpretive method to map seafloor habitat types from disparate
geological and geophysical datasets including: bathymetric images, sidescan sonar
images, seismic reflection profiles, sediment samples, geologic maps of structure, and
observations from submersibles. An indirect technique for the assessment of map
accuracy or habitat type misidentification error is also explored and used to derive
supplemental maps of varying interpretative confidence, or "quality".
The geological and geophysical datasets used to produce the SGH maps of the Oregon
margin are by their nature patchy, and form an irregular mosaic of variable data density
and quality. Uniform sampling of continental margins does not yet exist, thus these
maps are an attempt to glean as much information as possible from the framework of
existing data. In any given area the quantity and quality of data available varied
considerably, and required a flexible method of interpretation based on this availability.
The integrated interpretative GIS techniques are developed to facilitate mapping
geologic habitat types over this region of discontinuous and patchy seafloor data.
The SGH map and thematic map accuracy assessment support improved habitat-based
inventory and assessment methods. They also serve as habitat reference materials for
marine resources management and planning activities at local to national scales. SGH
and data quality maps are incorporated as thematic layers within a broader habitat
geodatabase for west coast groundfish and are directly applied for modeling Essential
Fish Habitat (EFH) for these species
Leptin constrains acetylcholine-induced insulin secretion from pancreatic islets of ob/ob mice
Abstract Hypersecretion of insulin from the pancreas is among the earliest detectable metabolic alterations in some genetically obese animals including the ob/ob mouse and in some obesity-prone humans. Since the primary cause of obesity in the ob/ob mouse is a lack of leptin due to a mutation in the ob gene, we tested the hypothesis that leptin targets a regulatory pathway in pancreatic islets to prevent hypersecretion of insulin. Insulin secretion is regulated by changes in blood glucose, as well as by peptides from the gastrointestinal tract and neurotransmitters that activate the pancreatic islet adenylyl cyclase (e.g., glucagon-like peptide-1) and phospholipase C (PLC) (e.g., acetylcholine) signaling pathways to further potentiate glucose-induced insulin secretion. Effects of leptin on each of these regulatory pathways were thus examined. Leptin did not influence glucose or glucagon-like peptide-1-induced insulin secretion from islets of either ob/ob or lean mice, consistent with earlier findings that these regulatory pathways do not contribute to the early-onset hypersecretion of insulin from islets of ob/ob mice. However, leptin did constrain the enhanced PLCmediated insulin secretion characteristic of islets from ob/ob mice, without influencing release from islets of lean mice. A specific enhancement in PLC-mediated insulin secretion is the earliest reported developmental alteration in insulin secretion from islets of ob/ob mice, and thus a logical target for leptin action. This action of leptin on PLC-mediated insulin secretion was dose-dependent, rapid-onset (i.e., within 3 min), and reversible. Leptin was equally effective in constraining the enhanced insulin release from islets of ob/ob mice caused by protein kinase C (PKC) activation, a downstream mediator of the PLC signal pathway. One function of leptin in control of body composition is thus to target a PKC-regulated component of the PLC-PKC signaling system within islets to prevent hypersecretion of insulin. ( J
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Comparative Characterization of Two Nearshore Rocky Reef Areas: A high-use recreational fishing reef vs. an unfished reef
This project has provided the ODFW Marine Habitat Project with a unique
opportunity to make a comparative examination of the habitats and fish communities of a
heavily fished reef off of Siletz Bay, and a nearly unfished reef off Cape Perpetua. There
are over 17,000 angler trips for groundfish out of Depoe Bay annually, many choosing to
fish Siletz Reef. In addition, numerous whale watching and sightseeing charter vessels
operate in the vicinity of the reef. Cape Perpetua Reef consists of isolated patches of
rock, and is too far from Newport (the nearest port) to receive much fishing effort.
This examination of the influences of fishing pressure in nearshore rocky habitat
complements, and is embedded in, a broader effort to understand the distribution and
character of Oregonâs nearshore rocky reefs, and the species that are dependent upon
them for habitat. The ODFW Marine Habitat Project has spent the last eight years
working in cooperation with scientists and other resource agencies to develop methods
for classifying and mapping nearshore rocky reefs habitats off Oregon. Because
nearshore reefs are in state waters, Oregon is responsible for managing these living
resources and habitats to sustain their long-term use and productivity. To date, eight reefs
have been surveyed and mapped with sidescan and/or multibeam bathymetry at a
resolution indicative of fish habitat. ODFW has also been developing non-extractive fish
survey techniques to describe fish-habitat associations and estimate fish abundance at the
habitat and reef scale. The importance of habitat to reef species cannot be over-stated and
is now widely accepted in the scientific community and is the focus of major research
efforts in other Pacific coastal states. Better understanding of the degree to which harvest
influences relative and absolute abundance, combined with species-habitat relationships,
is essential for resource managers to exercise their stewardship responsibilities to protect
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essential habitat, develop population indices for species at risk, and maintain healthy and
productive ecological systems
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Seismoturbidite record as preserved at core sites at the Cascadia and SumatraâAndaman subduction zones
Turbidite deposition along slope and trench settings is evaluated for the Cascadia and Sumatra-Andaman subduction zones. Source proximity, basin effects, turbidity current flow path, temporal and spatial earthquake rupture, hydrodynamics, and topography all likely play roles in the deposition of the turbidites as evidenced by the vertical structure of the final deposits. Channel systems tend to promote low-frequency components of the content of the current over longer distances, while more proximal slope basins and base-of-slope apron fan settings result in a turbidite structure that is likely influenced by local physiography and other factors. Cascadia's margin is dominated by glacial cycle constructed pathways which promote turbidity current flows for large distances. Sumatra margin pathways do not inherit these antecedent sedimentary systems, so turbidity currents are more localized.Keywords: Fore arc,
Submarine landslides,
Deep sea sedimentation,
Radiocarbon age calibration,
Holocene earthquakes,
San Andreas Fault,
Magnetic susceptibility,
Megathrust earthquakes,
Active deformation,
Late pleistocen
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Effects of season on occupancy and implications for habitat modeling: the Pacific marten Martes caurina
Season affects many characteristics of populations and, as a result, the interpretations of surveys conducted at different seasons. We explored seasonal variation in occupancy using data from four studies on the Pacific marten Martes caurina. Detection surveys were conducted during winter and summer using either cameras or track stations. We conducted a âmultiple location, paired seasonâ analysis using data from all four study areas and a âmultiple seasonâ analysis using seasonally replicated occupancy data collected at one of the areas. In the former analysis, summer occupancy estimates were significantly lower than winter and per visit probabilities of detection were indistinguishable between seasons. The probabilities of detection for the complete survey protocol were high (0.83 summer, 0.95 winter). Where summer and winter surveys were replicated, probability of occupancy was > 5 times higher in winter (0.52) than summer (0.09). We considered the effect of seasonal variation in occupancy on the habitat models developed using summer and winter survey data. Using the same habitat suitability threshold (0.5), the weighted average of winter models predicted significantly more suitable habitat than summer models. The habitat predicted by the summer model was at higher elevation, and was distributed among more, and smaller, patches of habitat than the model developed using winter data. We expect a similar magnitude of differences if summer or winter data were used to monitor occupancy. The higher occupancy in winter is probably due to the abundance of young animals detected during dispersal. Summer survey results reflect the distribution of territory-holding adults, thus these surveys may reliably detect breeding individuals and represent reproductive habitat. The implications of season on the interpretation of survey results, and corresponding habitat models and monitoring programs, provide a challenge to managers that make decisions about habitat management for martens, and other species with disparate occupancy among seasons
The Digital MIQE Guidelines Update: Minimum Information for Publication of Quantitative Digital PCR Experiments for 2020
Digital PCR (dPCR) has developed considerably since the publication of the Minimum Information for Publication of Digital PCR Experiments (dMIQE) guidelines in 2013, with advances in instrumentation, software, applications, and our understanding of its technological potential. Yet these developments also have associated challenges; data analysis steps, including threshold setting, can be difficult and preanalytical steps required to purify, concentrate, and modify nucleic acids can lead to measurement error. To assist independent corroboration of conclusions, comprehensive disclosure of all relevant experimental details is required. To support the community and reflect the growing use of dPCR, we present an update to dMIQE, dMIQE2020, including a simplified dMIQE table format to assist researchers in providing key experimental information and understanding of the associated experimental process. Adoption of dMIQE2020 by the scientific community will assist in standardizing experimental protocols, maximize efficient utilization of resources, and further enhance the impact of this powerful technology
EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre
This Opinion of the EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA) deals with the establishment of Dietary Reference Values for carbohydrates and dietary fibre. Nutritionally, two broad categories of carbohydrates can be differentiated: \u201cglycaemic carbohydrates\u201d, i.e. carbohydrates digested and absorbed in the human small intestine, and \u201edietary fibre\u201f, non-digestible carbohydrates passing to the large intestine. In this Opinion, dietary fibre is defined as non-digestible carbohydrates plus lignin. The absolute dietary requirement for glycaemic carbohydrates is not precisely known but will depend on the amount of fat and protein ingested. The Panel proposes 45 to 60 E% as the reference Intake range for carbohydrates applicable to both adults and children older than one year of age. Although high frequency of intake of sugar-containing foods can increase the risk of dental caries, there are insufficient data to set an upper limit for (added) sugar intake. Based on the available evidence on bowel function, the Panel considers dietary fibre intakes of 25 g/day to be adequate for normal laxation in adults. A fibre intake of 2 g/MJ is considered adequate for normal laxation in children from the age of one year. Although there is some experimental evidence that a reduction of the dietary glycaemic index and glycaemic load may have favourable effects on some metabolic risk factors such as serum lipids, the evidence for a role in weight maintenance and prevention of diet-related diseases is inconclusiv
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