Seasonal changes in growth of coho salmon (Oncorhynchus kisutch) off Oregon and Washington and concurrent changes in the spacing of scale circuli

In this study we present new information on seasonal variation in absolute growth rate in length of coho salmon (Oncorhynchus kisutch) in the ocean off Oregon and Washington, and relate these changes in growth rate to concurrent changes in the spacing of scale circuli. Average spacing of scale circuli and average rate of circulus formation were significantly and positively correlated with average growth rate among groups of juvenile and maturing coho salmon and thus could provide estimates of growth between age groups and seasons. Regression analyses indicated that the spacing of circuli was proportional to the scale growth rate raised to the 0.4−0.6 power. Seasonal changes in the spacing of scale circuli reflected seasonal changes in apparent growth rates of fish. Spacing of circuli at the scale margin was greatest during the spring and early summer, decreased during the summer, and was lowest in winter or early spring. Changes over time in length of fish caught during research cruises indicated that the average growth rate of juvenile coho salmon between June and September was about 1.3 mm/d and then decreased during the fall and winter to about 0.6 mm/d. Average growth rate of maturing fish was about 2 mm/d between May and June, then decreased to about 1 mm/d between June and September. Average apparent growth rates of groups of maturing coded-wire−tagged coho salmon caught in the ocean hook-and-line fisheries also decreased between June and September. Our results indicate that seasonal change in the spacing of scale circuli is a useful indicator of seasonal change in growth rate of coho salmon in the ocean

Distribution and Abundance of Juvenile Salmonids off Oregon and Washington, 1981-1985

This report is a summary of the results of 883 purse seine sets made for juvenile salmonids during 15 cruises off the coasts of Oregon and Washington during the springs and summers of 1981-1985. Juvenile coho salmon (Oncorhynchus kisutch) occurred most frequently, followed by chinook salmon (0. tshawytscha). The juveniles of these two species co-occurred more frequently than expected. Juvenile chum, pink and sockeye salmon (0. keta, O. gorbuscha, and O. nerka), steelhead (0. mykiss) and cutthroat trout (0. clarki clarki) were caught much less frequently and in lower numbers than coho or chinook salmon. We found no evidence of large schools ofjuvenile salmonids. A northerly movement of juvenile coho salmon wa~ suggested by decreased catches off Oregon and increased catches off Washington between early and late summer. Highest catch per set of juvenile coho salmon was usually found inshore of 37.2 km. Juvenile chinook salmon were usually found within 27.9 km of the coast. Juvenile salmonids were found over a broad range of surface salinities and temperatures. High catches of juvenile coho salmon occurred in both the low salinity waters of the Columbia River plume and in adjacent higher salinity waters. Preferences for specific salinities or temperatures were not obvious for any species, although catch rates of juvenile coho salmon were highest in years when chlorophyll content was also high. Based on expansions of fish with coded wire tags, we estimated that hatchery coho salmon smolts comprised 74%, on average, of the juvenile coho salmon catches. The remaining 26% were presumably wild fish or hatchery fish released as fingerlings. Hatchery coho salmon were caught roughly in proportion to the numbers released. However, hatchery fish from the Columbia River and private coastal facilities were caught at slightly higher rates while those from coastal Washington and public coastal Oregon hatcheries were caught at slightly lower rates than expected from the numbers released. No juvenile coho salmon with coded wire tags were caught that had originated from either California or Puget Sound hatcheries. (PDF file contains 88 pages.

Ocean distribution of the American shad (Alosa sapidissima) along the Pacific coast of North America

We examined the incidental catches of American shad (Alosa sapidissima) taken during research cruises and in commercial and recreational landings along the Pacific coast of North America during over 30 years of sampling. Shad, an introduced species, was mainly found over the shallow continental shelf, and largest catches and highest frequency of occurrences were found north of central Oregon, along the coasts of Washington and Vancouver Island, and in California around San Francisco Bay. Migrations to the north off Washington and Vancouver were seen during spring to fall, but we found no evidence for large-scale seasonal migrations to the south during the fall or winter. The average weight of shad increased in deeper water. Sizes were also larger in early years of the study. Most were caught over a wide range of sea surface temperatures (11–17°C) and bottom temperatures (6.4–8.0°C). Abundance of shad on the continental shelf north of 44°N was highly correlated with counts of shad at Bonneville Dam on the Columbia River in the same year. Counts were negatively related to average weights and also negatively correlated with the survival of hatchery coho salmon (Oncorhynchus kisutch), indicating that survival of shad is favored by warm ocean conditions. Examining the catch during research cruises and commercial and recreational landings, we concluded that American shad along the Pacific coast have adapted to the prevailing environmental conditions and undertake only moderate seasonal migrations compared with the long seasonal migrations of shad along the Atlantic coast of North America. We suggest that the large spawning populations in the Columbia River and San Francisco Bay areas explain most of the distributional features along the Pacific coast

A new approach to non-invasive oxygenated mixed venous PCO(sub)2

A clinically practical technique was developed to calculate mixed venous CO2 partial pressure for the calculation of cardiac output by the Fick technique. The Fick principle states that the cardiac output is equal to the CO2 production divided by the arterio-venous CO2 content difference of the pulmonary vessels. A review of the principles involved in the various techniques used to estimate venous CO2 partial pressure is presented

What's Cooking in Your Food System? A Guide to Community Food Assessment

Learn about Community Food Assessments, a creative way to highlight food-related resources and needs, promote collaboration and community participation, and create lasting change. This Guide includes case studies of nine Community Food Assessments; tips for planning and organizing an assessment; guidance on research methods and strategies for promoting community participation; and ideas for translating an assessment into action for change

Development and applications of neural networks for economic forecasting

Neural networks are one of a variety of machine learning models which are beginning to be widely used in economic forecasting applications. Despite this, there is relatively little understanding of the conditions in which neural networks provide accurate forecasts, the uncertainty bounds which can be put on such forecasts, and the most suitable network types and parameters for forecasting in the relatively small-sample settings encountered within economics. This thesis fits into a growing body of literature which aims to answer some of these questions. In Chapter 1, we present a detailed study of the accuracy of neural networks for forecasting financial volatility, and present a novel adaptation of networks for time series data. In Chapter 2, we present an adaptation to the output layer of neural networks which allows the generation of prediction intervals for forecasts, and present variants to the architecture which improve the accuracy of these prediction intervals. In Chapter 3, we focus on confidence intervals, and present the first simulation study of the suitability of bootstrapping for neural networks for generating confidence intervals with correct coverage. Finally, in Chapter 4, we focus on an alternate application of neural networks in forecasting; that of converting free-form text data into indices, and present a novel neural network architecture for improving the recognition of named entities (companies, people etc.) in text, a necessary first step in such forecasting

When is diabetes distress clinically meaningful?: establishing cut points for the Diabetes Distress Scale.

ObjectiveTo identify the pattern of relationships between the 17-item Diabetes Distress Scale (DDS17) and diabetes variables to establish scale cut points for high distress among patients with type 2 diabetes.Research design and methodsRecruited were 506 study 1 and 392 study 2 adults with type 2 diabetes from community medical groups. Multiple regression equations associated the DDS17, a 17-item scale that yields a mean-item score, with HbA(1c), diabetes self-efficacy, diet, and physical activity. Associations also were undertaken for the two-item DDS (DDS2) screener. Analyses included control variables, linear, and quadratic (curvilinear) DDS terms.ResultsSignificant quadratic effects occurred between the DDS17 and each diabetes variable, with increases in distress associated with poorer outcomes: study 1 HbA(1c) (P < 0.02), self-efficacy (P < 0.001), diet (P < 0.001), physical activity (P < 0.04); study 2 HbA(1c) (P < 0.03), self-efficacy (P < 0.004), diet (P < 0.04), physical activity (P = NS). Substantive curvilinear associations with all four variables in both studies began at unexpectedly low levels of DDS17: the slope increased linearly between scores 1 and 2, was more muted between 2 and 3, and reached a maximum between 3 and 4. This suggested three patient subgroups: little or no distress, <2.0; moderate distress, 2.0-2.9; high distress, ≥3.0. Parallel findings occurred for the DDS2.ConclusionsIn two samples of type 2 diabetic patients we found a consistent pattern of curvilinear relationships between the DDS and HbA(1c), diabetes self-efficacy, diet, and physical activity. The shape of these relationships suggests cut points for three patient groups: little or no, moderate, and high distress

Motivating Teachers to Lead in Low-performing Schools: A Qualitative Study of School Leaders in Three Arkansas High Schools

This qualitative research study addressed the problem of motivating teachers to take on leadership roles in “low-performing” schools. Coupled with the high demands of the Every Student Succeeds Act (ESSA) being placed on public school principals to ensure that all students achieve and successfully graduate high school, better ways to distribute leadership and share responsibilities among teachers were identified. The research question and purpose of this phenomenological study was to identify the perceived leadership behaviors of high school principals in once labeled “low-performing” schools that support the motivation of teachers to take on leadership roles. Nine identified teacher leaders and three experienced high school principals with at least three years of administrative experience in once identified “low performing” high schools participated in individual in-depth interviews conducted by the researcher using semi-structured questioning techniques. Interviews were transcribed and coded and triangulated with observations and document reviews to identify emergent themes. Data analysis determined what behaviors teachers perceived as motivating them to take on leadership roles within their schools. By incorporating the findings of this study into educational leadership programs at colleges and universities, masters-level students will benefit by participating in improved practical experiences needed to better prepare them for all types of high school settings. Moreover, veteran principals at the high school level will be able to incorporate the identified leadership behaviors, leadership strategies, and lived experiences into their current context to build more sustainable leadership practices within their schools