THE CALIFORNIA ROCKFISH CONSERVATION AREA AND GROUNDFISH TRAWLERS AT MOSS LANDING HARBOR

This article uses a bioeconomic model and data for groundfish trawlers at Moss Landing Harbor in Central California to analyze effects of spatial closures that were implemented recently by West Coast fishery managers to reduce bycatch of overfished groundfish stocks. The model has a dynamic linear rational expectations structure, and estimates of its parameters exhibit spatial variation in microeconomic and ecological factors that affect decisions about where and when to fish. Test results show that variation in marginal costs of crowding externalities and biological rates of stock productivity are the most significant factors to consider in the spatial management of roundfish trawlers at Moss Landing.Resource /Energy Economics and Policy,

Interactions of age-dependent mortality and selectivity functions in age-based stock assessment models

The natural mortality rate (M) of fish varies with size and age, although it is often assumed to be constant in stock assessments. Misspecification of M may bias important assessment quantities. We simulated fishery data, using an age-based population model, and then conducted stock assessments on the simulated data. Results were compared to known values. Misspecification of M had a negligible effect on the estimation of relative stock depletion; however, misspecification of M had a large effect on the estimation of parameters describing the stock recruitment relationship, age-specific selectivity, and catchability. If high M occurs in juvenile and old fish, but is misspecified in the assessment model, virgin biomass and catchability are often poorly estimated. In addition, stock recruitment relationships are often very difficult to estimate, and steepness values are commonly estimated at the upper bound (1.0) and overfishing limits tend to be biased low. Natural mortality can be estimated in assessment models if M is constant across ages or if selectivity is asymptotic. However if M is higher in old fish and selectivity is dome-shaped, M and the selectivity cannot both be adequately estimated because of strong interactions between M and selectivity

The Pathogenesis and Management of Malignancy-Associated Hypercalcaemia

Traditionally, accelerated bone resorption has been considered to play the principal pathogenic role in malignancy-associated hypercalcaemia (MH), by one of two basic mechanisms. Hypercalcaemia in patients with metastatic bone disease, is thought to be due to the local release of skeletal calcium at a rate in excess of that which can be excreted by the kidney. In patients without bone metastases, hypercalcaemia is also thought to arise as the result of bone resorption, in this case stimulated by humoral mediators, which are released by the primary tumour. Although both humoral and metastatic mechanisms of hypercalcaemia could in theory coexist, the demonstration of bone metastases has conventionally been considered to provide reason enough for the occurrence of hypercalcaemia without invoking an additional humoral component. The humoral mediators responsible for MH are at present poorly defined, but have been generally been considered to differ from parathyroid hormone (PTH) both structurally and functionally. Previous investigators have failed to find evidence of increased renal tubular calcium reabsorption or stimulation of 1,25 dihydroxyvitamin (1,25(OH)2D3) synthesis in MH. The skeletal effects of these humoral mediators have also been considered to be distinct from PTH, in causing "uncoupling" of bone cell activity, with greatly increased osteoclastic bone resorption and depressed bone formation. While metastatic bone disease has traditionally been considered to be the commonest cause of MH, a retrospective study of 195 cancer patients undergoing bone scan examinations showed no correlation between the extent of skeletal involvement and serum calcium values. These observations, indicated that, in most cases, the development of hypercalcaemia could not simply have been explained on the basis of local bone destruction, but rather may have been due to humoral mechanisms (chapter 3.1). A further prospective study of bone scan appearances in 87 consecutive cancer patients confirmed these results but in addition, showed that other biochemical indices of bone resorption were significantly higher in hypercalcaemic when compared with normocalcaemic patients, and were disproportionately raised with respect to the extent of metastatic disease seen on the bone scan. These observations indicated that in MH, bone resorption was largely occurring on a systemic, humorally mediated basis, rather than on a local "metastatic" basis (chapter 3.2). Further studies compared renal tubular reabsorption of calcium in MH, primary hyperparathyroidism (HPT) and normal subjects undergoing acute calcium infusions. While immunoreactive PTH levels were invariably low or undetectable in the cancer patients, renal tubular reabsorption of calcium was raised to a level comparable with that in HPT. These observations raised the possibility that there frequently may be released a humoral mediator in MH which, although immunologically distinct from PTH, did possess a "PTH-like" effect on renal tubular reabsorption of calcium (chapter 4.1). Studies of renal tubular calcium reabsorption in patients with benign, non-parathyroid hypercalcaemia revealed generally normal results, excluding the possibility that the raised levels of renal tubular calcium reabsorption in malignancy may simply have been the result of chronic hypercalcaemia per se (chapter 4.2). Further studies also excluded the possibility that the raised levels of renal tubular reabsorption of calcium in malignancy may have been due to sodium depletion, since the renal handling of sodium in relation to renal tubular calcium reabsorption was similar in MH and HPT (chapter 4.3). Studies performed during the surgical exploration of tumours associated with humoral hypercalcaemia (HHM) demonstrated that a fall in renal tubular calcium reabsorption was the major factor responsible for the normalisation of serum calcium values after surgical resection (chapter 6.1). A comparison of the mechanisms of hypercalcaemia in patients with early and advanced HHM showed that in the early stages, increased renal tubular reabsorption of calcium was the most important pathogenic mechanism, often occurring in the absence of increased bone resorption. With progression of the tumour and increasing immobilisation however, accelerated osteoclastic bone resorption with depressed bone formation became more apparent. This indicated that, the HHM-associated humoral factor, like PTH itself, had more potent effects on the kidney than on osteoclastic bone resorption. A possible explanation for the increased bone resorption and depressed bone formation associated with advanced tumours may however have been due to the synergistic effects of immobilisation and HHM-associated humoral factors on bone cells (chapter 6.2)

Distribution and co-occurrence of rockfishes (family: Sebastidae) over trawlable shelf and slope habitats of California and southern Oregon

The rockfishes of the sebastid genus Sebastes are a very important fishery resource off the coasts of California and southern Oregon. How-ever, many of the 54 managed stocks of west coast rockfish have recently reached historically low population levels, leading fishery managers to re-examine current management practices. Management of rockfish stocks as multispecies aggregates, as opposed to independent stocks within the ground-fish fishery, can be more desirable when nontargeted bycatch, discard, and management complexity are considered. Rockfish assemblage structure and species co-occurrences were determined by using data from the Alaska Fisheries Science Center triennial continental shelf bottom trawl survey. The weight of rockfish species in trawl catches was expressed as a catch-per-unit-of-effort (CPUE) statistic, from which species spatial distributions, overlaps, diversity, and richness were analyzed. Multidimensional scaling of transformed CPUE data was employed in indirect gradient and multivariate partitioning analyses to quantify assemblage relationships. Results indicated that rockfish distributions closely match the bathymetry of coastal waters. Indirect gradient analysis suggested that depth and latitude are the principal factors in structuring the spatial distributions of rockfish on trawlable habitat. In addition, four assemblages were identified through the joint evaluation of species’ distributions and multivariate partitioning analyses: 1) deep-water slope; 2) northern shelf; 3) southern shelf; and 4) nearshore. The slope, shelf, and near-shore groups are found in depth ranges of 200–500 m, 100–250 m, and 50–150 m, respectively. The division of northern and southern shelf assemblages occurs over a broad area between Cape Mendocino and Monterey Canyon. The results of this analysis are likely to have direct application in the management of rockfish stocks off the coasts of southern Oregon and California

The STRS (shortness of breath, tremulousness, racing heart, and sweating): A brief checklist for acute distress with panic-like autonomic indicators; development and factor structure

Background: Peritraumatic response, as currently assessed by Posttraumatic Stress Disorder (PTSD) diagnostic criterion A2, has weak positive predictive value (PPV) with respect to PTSD diagnosis. Research suggests that indicators of peritraumatic autonomic activation may supplement the PPV of PTSD criterion A2. We describe the development and factor structure of the STRS (Shortness of Breath, Tremulousness, Racing Heart, and Sweating), a one page, two-minute checklist with a five-point Likert-type response format based on a previously unpublished scale. It is the first validated self-report measure of peritraumatic activation of the autonomic nervous system.\ud \ud Methods: We selected items from the Potential Stressful Events Interview (PSEI) to represent two latent variables: 1) PTSD diagnostic criterion A, and 2) acute autonomic activation. Participants (a convenience sample of 162 non-treatment seeking young adults) rated the most distressing incident of their lives on these items. We examined the factor structure of the STRS in this sample using factor and cluster analysis.\ud \ud Results: Results confirmed a two-factor model. The factors together accounted for 68% of the variance. The variance in each item accounted for by the two factors together ranged from 41% to 74%. The item loadings on the two factors mapped precisely onto the two proposed latent variables.\ud \ud Conclusion: The factor structure of the STRS is robust and interpretable. Autonomic activation signs tapped by the STRS constitute a dimension of the acute autonomic activation in response to stress that is distinct from the current PTSD criterion A2. Since the PTSD diagnostic criteria are likely to change in the DSM-V, further research is warranted to determine whether signs of peritraumatic autonomic activation such as those measured by this two-minute scale add to the positive predictive power of the current PTSD criterion A2. Additionally, future research is warranted to explore whether the four automatic activation items of the STRS can be useful as the basis for a possible PTSD criterion A3 in the DSM-V

Your community gets a B-: analysis of the specific and curious realm of airport bond rating

Commercial airports are publicly-owned transportation infrastructure, usually funded with bonds. The bond rating decision for these entities thus has important ramifications for bond investors, issuers, airport managers, and even the communities the airports serve, but the rating decision process is not well understood. This paper discusses a simulation of the rating process in two decision environments, including a downgrade. The effect of information framing in an environment of incomplete data is examined using amateur evaluators. Amateur evaluators were utilized to understand how people with limited financial analysis skills would respond when presented with incomplete information and a primed scenario. The results indicate that amateur evaluators were more likely to downgrade a bond grade than a ratings agency, but this effect was moderated for amateur evaluators with more work experience. Implications for airport and supply chain infrastructure are discussed

An approach to estimating rockfish biomass based on larval production, with application to Sebastes jordani

An assessment of the total biomass of shortbelly rockfish (Sebastes jordani) off the central California coast is presented that is based on a spatially extensive but temporally restricted ichthyoplankton survey conducted during the 1991 spawning season. Contemporaneous samples of adults were obtained by trawl sampling in the study region. Daily larval production (7.56 × 1010 larvae/d) and the larval mortality rate (Z=0.11/d) during the cruise were estimated from a larval “catch curve,” wherein the logarithm of total age-specific larval abundance was regressed against larval age. For this analysis, larval age compositions at each of the 150 sample sites were determined by examination of otolith microstructure from subsampled larvae (n=2203), which were weighted by the polygonal Sette-Ahlstrom area surrounding each station. Female population weight-specific fecundity was estimated through a life table analysis that incorporated sex-specific differences in adult growth rate, female maturity, fecundity, and natural mortality (M). The resulting statistic (102.17 larvae/g) was insensitive to errors in estimating M and to the pattern of recruitment. Together, the two analyses indicated that a total biomass equal to 1366 metric tons (t)/d of age-1+ shortbelly rockfish (sexes combined) was needed to account for the observed level of spawning output during the cruise. Given the long-term seasonal distribution of spawning activity in the study area, as elucidated from a retrospective examination of California Cooperative Oceanic Fisheries Investigation (CalCOFI) ichthyoplankton samples from 1952 to 1984, the “daily” total biomass was expanded to an annual total of 67,392 t. An attempt to account for all sources of error in the derivation of this estimate was made by application of the delta-method, which yielded a coefficient of variation of 19%. The relatively high precision of this larval production method, and the rapidity with which an absolute biomass estimate can be obtained, establishes that, for some species of rockfish (Sebastes spp.), it is an attractive alternative to traditional age-structured stock assessments

Predicting market squid (Doryteuthis opalescens) landings from pre-recruit abundance

The fishery for market squid (Doryteuthis opalescens) in California is typical of many of the world’s cephalopod fisheries, in that a very short life span and the effect of environmental forcing on recruitment result in enormous interannual variability in catches and population size. We evaluate the utility of a pre-recruit index of squid abundance that is based on midwater trawl sampling in the 3–5 months preceding the onset of the fishery as a basis for predicting landings. Catches in the survey largely represent squid in the 30–50 mm dorsal mantle length size range, representing individuals 30–90 day old. Catch-per-unit-effort statistics are derived from simple twofactor Δ-Generalized Linear Models, with year and station as main effects and numbers per tow as the dependent variable. Regional models for northern and southern squid populations are developed. Pre-recruit indices, as well as indices of squid prey (krill) abundance are compared with landings data, as well as estimates of squid spawning stock biomass derived from an egg escapement model. Our results show that the abundance of prerecruit market squid and krill sampled in the survey tracks both catches and overall population size, providing the potential to forecast landings. Our findings are consistent with a sparse but growing literature showing the potential utility of pre-recruit surveys to inform fisheries participants and managers

Local Food Systems: Concepts, Impacts, and Issues

This comprehensive overview of local food systems explores alternative definitions of local food, estimates market size and reach, describes the characteristics of local consumers and producers, and examines early indications of the economic and health impacts of local food systems. There is no consensus on a definition of “local” or “local food systems” in terms of the geographic distance between production and consumption. But defining “local” based on marketing arrangements, such as farmers selling directly to consumers at regional farmers’ markets or to schools, is well recognized. Statistics suggest that local food markets account for a small, but growing, share of U.S. agricultural production. For smaller farms, direct marketing to consumers accounts for a higher percentage of their sales than for larger farms. Findings are mixed on the impact of local food systems on local economic development and better nutrition levels among consumers, and sparse literature is so far inconclusive about whether localization reduces energy use or greenhouse gas emissions.local food systems, farmers’ markets, direct-to-consumer marketing, direct-to-retail/ foodservice marketing, community supported agriculture, farm to school programs, Farmers’ Market Promotion Program, food miles, Community/Rural/Urban Development,

Local food systems: concepts, impacts, and issues

Consumer demand for food that is locally produced,marketed, and consumed is generating increased interest in local food throughout the United States. As interest grows, so do questions about what constitutes local food and what characterizes local food systems. What Is the Issue? This study provides a comprehensive literature-review-based overview of the current understanding of local food systems, including: alternative defi nitions; estimates of market size and reach; descriptions of the characteristics of local food consumers and producers; and an examination of early evidence on the economic and health impacts of such systems. What Did the Study Find? There is no generally accepted definition of “local” food. Though “local” has a geographic connotation, there is no consensus on a definition in terms of the distance between production and consumption. Definitions related to geographic distance between production and sales vary by regions, companies, consumers, and local food markets. According to the definition adopted by the U.S. Congress in the 2008 Food, Conservation, and Energy Act,the total distance that a product can be transported and still be considered a “locally or regionally produced agricultural food product” is less than 400 miles from its origin, or within the State in which it is produced. Definitions based on market arrangements, including direct-to-consumer arrangements such as regional farmers’ markets, or direct-to-retail/foodservice arrangements such as farm sales to schools, are well-recognized categories and are used in this report to provide statistics on the market development of local foods. Local food markets account for a small but growing share of total U.S. agricultural sales. • Direct-to-consumer marketing amounted to $1.2 billion in current dollar sales in 2007, according to the 2007 Census of Agriculture, compared with$551 million in 1997. • Direct-to-consumer sales accounted for 0.4 percent of total agricultural sales in 2007, up from 0.3 percent in 1997. If nonedible products are excluded from total agricultural sales, direct-to consumer sales accounted for 0.8 percent of agricultural sales in 2007. • The number of farmers’ markets rose to 5,274 in 2009, up from 2,756 in 1998 and 1,755 in 1994, according to USDA’s Agricultural Marketing Service. • In 2005, there were 1,144 community-supported agriculture organizations, up from 400 in 2001 and 2 in 1986, according to a study by the National Center for Appropriate Technology. In early 2010, estimates exceeded 1,400, but the number could be much larger. • The number of farm to school programs, which use local farms as food suppliers for school meals programs and promote relationships between schools and farms, increased to 2,095 in 2009, up from 400 in 2004 and 2 in the 1996-97 school year, according to the National Farm to School Network. Data from the 2005 School Nutrition and Dietary Assessment Survey, sponsored by USDA’s Food and Nutrition Service, showed that 14 percent of school districts participated in Farm to School programs, and 16 percent reported having guidelines for purchasing locally grown produce. Production of locally marketed food is more likely to occur on small farms located in or near metropolitan counties. Local food markets typically involve small farmers, heterogeneous products, and short supply chains in which farmers also perform marketing functions, including storage, packaging, transportation, distribution, and advertising. According to the 2007 U.S. Census of Agriculture, most farms that sell directly to consumers are small farms with less than $50,000 in total farm sales, located in urban corridors of the Northeast and the West Coast. In 2007, direct-to-consumer sales accounted for a larger share of sales for small farms, as defi ned above, than for medium-sized farms (total farm sales of$50,000 to $499,999) and large farms (total farm sales of$500,000 or more). Produce farms engaged in local marketing made 56 percent of total agricultural direct sales to consumers, while accounting for 26 percent of all farms engaged in direct-to-consumer marketing. Direct-to-consumer sales are higher for the farms engaged in other entrepreneurial activities, such as organic production, tourism, and customwork (planting, plowing, harvesting, etc. for others), than for other farms. In 2007, direct sales by all U.S. farms surpassed customwork to become the leading on-farm entrepreneurial activity in terms of farm household participation. Barriers to local food-market entry and expansion include: capacity constraints for small farms and lack of distribution systems for moving local food into mainstream markets; limited research, education, and training for marketing local food; and uncertainties related to regulations that may affect local food production, such as food safety requirements. Consumers who value high-quality foods produced with low environmental impact are willing to pay more for locally produced food. Several studies have explored consumer preferences for locally produced food. Motives for “buying local” include perceived quality and freshness of local food and support for the local economy. Consumers who are willing to pay higher prices for locally produced foods place importance on product quality, nutritional value, methods of raising a product and those methods’ effects on the environment, and support for local farmers. Federal, State, and local government programs increasingly support local food systems. Many existing government programs and policies support local food initiatives, and the number of such programs is growing. Federal policies have grown over time to include the Community Food Project Grants Program, the WIC Farmers’ Market Nutrition Program, Senior Farmers’ Market Nutrition Program, Federal State Marketing Improvement Program, National Farmers’ Market Promotion Program, Specialty Crop Block Grant Program, and the Community Facilities Program. State and local policies include those related to farm-to-institution procurement, promotion of local food markets, incentives for low-income consumers to shop at farmers’ markets, and creation of State Food Policy Councils to discuss opportunities and potential impact of government intervention. (WIC is the acronym for the Special Supplemental Nutrition Program for Women, Infants, and Children). As of early 2010, there were few studies on the impact of local food markets on economic development, health, or environmental quality. • Empirical research has found that expanding local food systems in a community can increase employment and income in that community. • Empirical evidence is insuffi cient to determine whether local food availability improves diet quality or food security. • Life-cycle assessments—analyses of energy use at all stages of the food system including consumption and disposal—suggest that localization can but does not necessarily reduce energy use or greenhouse gas emissions. How Was the Study Conducted? Existing analyses of local food markets by universities, government agencies, national nonprofit organizations, and others of local food markets were synthesized to evaluate the definition of local foods and the effects of local food systems on economic development, health and nutrition, food security, and energy use and greenhouse gas emissions. The report’s content relies on data collected through the 2007 Census of Agriculture, as well as other surveys by USDA’s Agricultural Marketing Service, the National Farm to School Network, university extension departments, and others, to provide a comprehensive picture of types of local food markets, their characteristics, and their importance over time.Local food systems; farmers’ markets; direct-to-consumer marketing; direct-to-retail/foodservice marketing; community supported agriculture; farm to school programs; Farmers’ Market Promotion Program; food miles; ERS; USDA