Dietary variations in three co-occurring rockfish species off the Pacific Northwest during anomalous oceanographic events in 1998 and 1999

Stomach samples from three rockfish species, yellowtail (Sebastes f lavidus), widow (S. entomelas), and canary (S. pinniger) rockfish, seasonally collected off the Pacific Northwest in 1998 and 1999, provided quantitative information on the food habits of these species during and after the 1997–98 El Niño event. Although euphausiids were the most common major prey of all three predators, gelatinous zooplankton and fishes were the most commonly consumed prey items during some seasonal quarters. The influence of the El Niño event was evident in the diets. Anomalous prey items, including the southern euphausiid species Nyctiphanes simplex and juveniles of Pacific whiting (Merluccius productus) frequently appeared in the diets in the spring and summer of 1998. The results of stomach contents analyses, based on 905 stomach samples from 49 trawl hauls during seven commercial fishing trips and from 56 stations during research surveys, were consistent with the timing of occurrence and the magnitude of change in biomass of some zooplankton species reported from zooplankton studies in the northern California Current during the 1997–98 El Niño. Our findings indicate that the observed variations of prey groups in some rockfish diets may be a function of prey variability related to climate and environment changes

Bias and Precision of Estimates from an Age-Structured Stock Assessment Program in Relation to Stock and Data Characteristics

Assessments for many U.S. Pacific coast groundfish stocks have been developed using the statistical catch-at-age method known as Stock Synthesis. This study used Monte Carlo simulation and a fractional factorial experiment to evaluate the effects of input data errors and stock characteristics on bias and precision in estimates of ending exploitable biomass, rate of fishing mortality, depletion, and other output variables. Nine factors were examined: length of the data series, rate of natural mortality, shape of the fishery selectivity curve, trend in fishing mortality, recruitment pattern, and level of sampling error in the data for catch, fishing effort, a survey biomass index, and sample size for fishery and survey age compositions. Length of the data series, age composition sample size, survey biomass variability, and fishing effort variability were the most influential factors for most of the output variables. The estimates of depletion had the least bias and the estimates of starting biomass the smallest variability; the estimates of ending recruitment had the greatest bias and largest variability. For all the output variables examined the estimates appeared to be median- unbiased. For the conditions considered in the experiment, it appears that the accuracy of assessment estimates for ending exploitable biomass and projected catch would be more readily improved by increased age composition sampling than by comparable (but much more expensive) improvements in survey estimates of stock biomass.Keywords: biomass, bias, stock assessment, age composition, error

The relationships between predatory fish, forage fishes, and juvenile salmonid marine survival off the Columbia River: a simple trophic model analysis

A trophic model that simulates interactions between a predatory fish (Pacific hake, Merluccius productus), forage fish, and juvenile salmon off the Columbia River was constructed to identify if trophic interactions could account for marine mortality of Columbia River juvenile salmon. The model estimates the number of juvenile salmon that are eaten annually by Pacific hake off the Columbia River for a given hake and forage fish population. Model results indicate that the presence of high numbers of Pacific hake could account for high mortality of some juvenile salmonid species/stocks leaving the Columbia River, and that this mortality would be much reduced when forage fish are abundant. Estimates of hake and forage fish abundance, based on field data collected from 1998–2005, were used in the model to derive annual estimates of the number of salmon possibly eaten by hake. A multiple regression analysis using the output from the trophic model and average May/June Columbia River flows accounted for much of the annual variation in Columbia River fall Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon marine survival (p 60%), but not spring or summer Chinook salmon. For these two stocks, average May/June sea-surface temperature was the best predictor of marine survival. Results support the hypothesis that for some Columbia River salmon species/stocks, marine survival is predation-driven and affected by the interaction between the abundance of Pacific hake, forage fish, Columbia River flows, and possibly ocean turbidity. Future modeling work should include predation estimates of other large fishes, marine mammals, and sea birds.Previously published in California Cooperative Oceanic Fisheries Investigations, Progress Report v. 48 (2007); access courtesy of publisher and authors.Keywords: Juvenile salmonid, Predatory fish, Forage fishKeywords: Juvenile salmonid, Predatory fish, Forage fis

The Co-Production of Sustainable Future Scenarios

Scenarios are a tool to develop plausible, coherent visions about the future and to foster anticipatory knowledge. We present the Sustainable Future Scenarios (SFS) framework and demonstrate its application through the Central Arizona-Phoenix Long-term Ecological Research (CAP LTER) urban site. The SFS approach emphasizes the co-development of positive and long-term alternative future visions. Through a collaboration of practitioner and academic stakeholders, this research integrates participatory scenario development, modeling, and qualitative scenario assessments. The SFS engagement process creates space to question the limits of what is normally considered possible, desirable, or inevitable in the face of future challenges. Comparative analyses among the future scenarios demonstrate trade-offs among regional and microscale temperature, water use, land-use change, and co-developed resilience and sustainability indices. SFS incorporate diverse perspectives in co-producing positive future visions, thereby expanding traditional future projections. The iterative, interactive process also creates opportunities to bridge science and policy by building anticipatory and systems-based decision-making and research capacity for long-term sustainability planning

The Center for Independent Experts: The National External Peer Review Program of NOAA's National Marine Fisheries Service

Requirements are growing for peer review of the science used for governmental management decisions. This is particularly true for fisheries science, where management decisions are often controversial. The National Oceanic and Atmospheric Administration's National Marine Fisheries Service instituted the Center for Independent Experts (CIE) in 1998 as a national peer-review program. Operations of the CIE, run under a contract with the University of Miami, maintain the independence of reviewers from the agency, and follow strict conflict of interest guidelines. Reviews by the CIE fulfill the requirements of the Information Quality Act and the Office of Management and Budget's Peer Review Bulletin. The CIE completed 101 reviews between 1999 and September 2006. Ninety-eight reviewers have participated in CIE reviews, with 72% of them coming from overseas. Case studies involving groundfish data and stock assessments, and marine-mammal abundance, are described, including the scientific issues, CIE operations, requirements for the reviews, conclusions of the reviewers, and the agency's responses. Impacts of the CIE on the agency's science include improvements to regional stock assessment processes and to stock-assessment and field-survey methods, and reductions in contentious challenges to the agency's science.Keywords: Experts, Peer Review, Fishery Managemen

Subthreshold PTSD and PTSD in a prospective‐longitudinal cohort of military personnel: Potential targets for preventive interventions

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146501/1/da22819_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146501/2/da22819.pd

Ultrahigh-resolution optical coherence elastography through a micro-endoscope: towards in vivo imaging of cellular-scale mechanics

In this paper, we describe a technique capable of visualizing mechanical properties at the cellular scale deep in living tissue, by incorporating a gradient-index (GRIN)-lens micro-endoscope into an ultrahigh-resolution optical coherence elastography system. The optical system, after the endoscope, has a lateral resolution of 1.6 µm and an axial resolution of 2.2 µm. Bessel beam illumination and Gaussian mode detection are used to provide an extended depth-of-field of 80 µm, which is a 4-fold improvement over a fully Gaussian beam case with the same lateral resolution. Using this system, we demonstrate quantitative elasticity imaging of a soft silicone phantom containing a stiff inclusion and a freshly excised malignant murine pancreatic tumor. We also demonstrate qualitative strain imaging below the tissue surface on in situ murine muscle. The approach we introduce here can provide high-quality extended-focus images through a micro-endoscope with potential to measure cellular-scale mechanics deep in tissue. We believe this tool is promising for studying biological processes and disease progression in vivo.This research was supported by grants and fellowships from the Australian Research Council, the National Health and Medical Research Council (Australia), the National Breast Cancer Foundation (Australia), the Department of Health, Western Australia, and the Cancer Council, Western Australia

The Variation of Mechanical Properties of M300 Maraging Steel Manufactured with Varying Process Parameters in Laser Powder Bed Fusion

Laser power bed fusion (L-PBF) is a type of additive manufacturing (AM) that uses layers of powdered metal and a laser to manufacture a part in a layer-by-layer fashion. L-PBF uses a variety of process parameters that ultimately determine the overall quality and mechanical properties of a print. The ability to alter parameters allows for the utilization of various metals in this form of AM. Maraging 300 steel (M300) is a material of particular interest due to its combined tensile strength and high strength-to-weight ratio. By using an assortment of parameters and comparing the resulting mechanical properties it can be determined which process parameters result in a more favorable part to be used in a variety of applications. A favorable process parameter set was selected for future use. This study aims to determine which process parameters result in the best overall mechanical properties of M300 manufactured using L-PBF.Mechanical Engineerin

Application of Dyes in Nonlinear Optical Materials

An outline of some azobenzene derivatives which are being used in ICI as the basis for new nonlinear optical materials is presented

Optical coherence tomography-based contact indentation for diaphragm mechanics in a mouse model of transforming growth factor alpha induced lung disease

Funding provided by the National Health and Medical Research Council (NHMRC) of Australia (1027218). P.N. and K.W. are supported by NHMRC Fellowships (1045824, 1090888). P.W. was supported by the William and Marlene Schrader Postgraduate Scholarship, The University of Western Australia, and C.A. by an NHMRC Preterm Infants CRE top-up scholarship.This study tested the utility of optical coherence tomography (OCT)-based indentation to assess mechanical properties of respiratory tissues in disease. Using OCT-based indentation, the elastic modulus of mouse diaphragm was measured from changes in diaphragm thickness in response to an applied force provided by an indenter. We used a transgenic mouse model of chronic lung disease induced by the overexpression of transforming growth factor-alpha (TGF-α), established by the presence of pleural and peribronchial fibrosis and impaired lung mechanics determined by the forced oscillation technique and plethysmography. Diaphragm elastic modulus assessed by OCT-based indentation was reduced by TGF-α at both left and right lateral locations (p < 0.05). Diaphragm elastic modulus at left and right lateral locations were correlated within mice (r = 0.67, p < 0.01) suggesting that measurements were representative of tissue beyond the indenter field. Co-localised images of diaphragm after TGF-α overexpression revealed a layered fibrotic appearance. Maximum diaphragm force in conventional organ bath studies was also reduced by TGF-α overexpression (p < 0.01). Results show that OCT-based indentation provided clear delineation of diseased diaphragm, and together with organ bath assessment, provides new evidence suggesting that TGF-α overexpression produces impairment in diaphragm function and, therefore, an increase in the work of breathing in chronic lung disease.Publisher PDFPeer reviewe