Management of Multipurpose Heterogeneous Fishing Fleets Under Uncertainty

This paper describes an approach to modeling fisheries that can be useful in policy analysis when the population dynamics are not well known and the fleet is composed of a variety of multipurpose vessels. An empirical application of the methodology to the northern California Dungeness crab fishery is discussed. A multivariate time-series model provides the intertemporal (year-to-year) relationships for a simulation model describing both within season and year-to-year fleet behavior. Appropriate modifications of the simulation model parameters reflect alternative policy scenarios. The analysis of the simulation outcomes provide insight into fleet response to several management alternatives that have been considered for the crab fishery.Environmental Economics and Policy, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy, Risk and Uncertainty,

Trade Restrictions and Trade Reversal: Lessons from the U.S.-Canada Herring Dispute

This paper analyzes international trade in value added products when free trade and perfect competition in the market for an intermediate product, such as raw fish, are the exception rather than the rule. Current evidence from the General Agreement on Tariffs and Trade (GATT) regarding disputes between countries, such as the V.S.-Canada dispute over trade in raw herring, suggests that bilateral trade in raw fish among major exporters of seafood products may not be completely free of structural and political barriers. The study presents models showing that restrictions on the exportation of raw fish from an exporting country can make possible monopsony behavior by fish processors in a rival exporting country and they outline the market behavior of the players under such circumstances. The analysis illustrates how, under such conditions, economic forces contribute to the creation of trade disputes. It further demonstrates how expansion of the demand for final product may, through trade reversal pressures, dilute the market power of the processor monopsony and make trade restriction policies irrelevant.roe herring, trade reversal, trade restrictions, monopsony, trade dispute, GATT, market imperfection, free trade, fishery management, comparative advantage reversal, Environmental Economics and Policy, International Relations/Trade,

Mustard catch crop enhances denitrification in shallow groundwater beneath a spring barley field

The study was funded by Department of Agriculture and Food through the Research Stimulus Fund Programme (Grant RSF 06383) in collaboration with the Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland.peer-reviewedOver-winter green cover crops have been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N + N2-N) mole fractions were measured in situ with a push–pull method in shallow groundwater under a spring barley system in experimental plots with and without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate NO3--N via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 μg kg−1 d−1, respectively. Estimated N2O-N/(N2O-N + N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L−1) than no cover crop (0.90 mg L−1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land and thus helps minimise the uncertainty in agricultural N and N2O-N balances

Fruit Processing, Seed Viability And Dormancy Mechanisms Of Persoonia Sericea A. Cunn. ex R. Br. and P. Virgata R.Br. (Proteaceae)

The morphology of the fruit and difficulties with fruit processing impose major limitations to germination of Persoonia sericea and P. virgata. The mesocarp must be removed without harming the embryo. Fermentation of fruit or manual removal of the mesocarp was effective but digestion in 32% hydrochloric acid (HCl) completely inhibited germination. The endocarp is extremely hard and therefore very difficult and time consuming to remove without damaging the seeds. The most efficient method was cracking the endocarp with pliers, followed by manual removal of seeds. Germination was completely inhibited unless at least half of the endocarp was removed. Microbial contamination of the fruit and seeds was controlled by disinfestation and germination of the seed under aseptic conditions. The results suggest that dormancy in these species is primarily due to physical restriction of the embryo by the hard endocarp

Environmental Contaminant Concentrations in Canada Goose (\u3ci\u3eBranta canadensis\u3c/i\u3e) Muscle: Probabilistic Risk Assessment for Human Consumers

The issue of food insecurity affects millions of people in the United States every year. Often these people rely on soup kitchens, food banks, and shelters for proper meals, and these organizations often depend on donations to meet needs. One of the most limited food resources is meat. To help alleviate this problem, the U.S. Department of Agriculture Wildlife Services donates more than 60 tons of wild game (deer, moose, feral hogs, goats, geese, and ducks) to a variety of charitable organizations each year. Although commercially produced meat routinely undergoes screening for contaminants, potential exposure to environmental contaminants from eating wild game is not well characterized. In this study, the concentration of 17 contaminants of concern in the breast meat of wild geese was examined. These concentrations were then used in a probabilistic model to estimate potential risk associated with consumption of this meat. Based on model predictions, more than 99% of all adults were below exposure limits for all of the compounds tested. For all consumer age classes modeled, consumption of wild goose meat may expose a small fraction of these populations to levels of lead higher than the recommended exposure limits. Similarly, mercury exposure was predicted to be higher than the recommended limits when the meat was served as steaks. This information about concentrations of contaminants of concern in goose meat and potential exposures associated with meat consumption based on probabilistic models will enable others to make informed decisions about the risks associated with the consumption of wild meat

Environmental Contaminant Concentrations in Canada Goose (\u3ci\u3eBranta canadensis\u3c/i\u3e) Muscle: Probabilistic Risk Assessment for Human Consumers

The issue of food insecurity affects millions of people in the United States every year. Often these people rely on soup kitchens, food banks, and shelters for proper meals, and these organizations often depend on donations to meet needs. One of the most limited food resources is meat. To help alleviate this problem, the U.S. Department of Agriculture Wildlife Services donates more than 60 tons of wild game (deer, moose, feral hogs, goats, geese, and ducks) to a variety of charitable organizations each year. Although commercially produced meat routinely undergoes screening for contaminants, potential exposure to environmental contaminants from eating wild game is not well characterized. In this study, the concentration of 17 contaminants of concern in the breast meat of wild geese was examined. These concentrations were then used in a probabilistic model to estimate potential risk associated with consumption of this meat. Based on model predictions, more than 99% of all adults were below exposure limits for all of the compounds tested. For all consumer age classes modeled, consumption of wild goose meat may expose a small fraction of these populations to levels of lead higher than the recommended exposure limits. Similarly, mercury exposure was predicted to be higher than the recommended limits when the meat was served as steaks. This information about concentrations of contaminants of concern in goose meat and potential exposures associated with meat consumption based on probabilistic models will enable others to make informed decisions about the risks associated with the consumption of wild meat

The Complex Wind Torus and Jets of PSR B1706-44

We report on Chandra ACIS imaging of the pulsar wind nebula (PWN) of the young Vela-like PSR B1706-44, which shows the now common pattern of an equatorial wind and polar jets. The structure is particularly rich, showing a relativistically boosted termination shock, jets with strong confinement, a surrounding radio/X-ray PWN and evidence for a quasi-static `bubble nebula'. The structures trace the pulsar spin geometry and illuminate its possible relation to SNR G343.1-2.3. We also obtain improved estimates of the pulsar flux and nebular spectrum, constraining the system age and energetics.Comment: To appear in the Astrophysical Journal. 15pp, 4 figures in 7 file

A History of Pediatric Immunology

Immunology has played a prominent role in the history of medicine. Pediatric immunologists have focused on immune aberrations in pediatric disorders, particularly those involving host defense mechanisms. These efforts have paid rich dividends in terms of fundamental knowledge of the immune system and major therapeutic advances, including 1) i.v. immunoglobulin therapy, 2) hematopoietic stem cell transplantation, and 3) gene therapy. Pediatric immunology as an organized discipline emerged in the early 1950s, when pediatricians and their basic scientist colleagues began to focus on clinical and basic research related to immunodeficiency. Since then, key organizations and infrastructure have been developed to support this research and the clinical care of immunodeficient patients. We review here the evolution of contemporary pediatric immunology, particularly in North America, from its roots in 19th-century Europe to its current expression as one of the fundamental scientific and clinical disciplines of pediatrics. Immunology touches every pediatric subspecialty. Most closely aligned to allergy and rheumatology, immunology also has close ties to infectious diseases, hematology, and nephrology. Furthermore, each other specialty has its autoimmune diseases, relies on immunologic tests for diagnosis, and uses immunosuppressive drugs or i.v. immunoglobulin (IVIG) treatment; yet there are only a handful of patients, those with a primary immunodeficiency, to whom no other specialist lays claim. Because these patients are fairly rare, a practicing pediatrician who devoted his practice to primary immunodeficiency would probably starve. Furthermore, no separate board for pediatric immunology exists, although the American Board of Allergy and Immunology, while emphasizing allergy, now has considerable emphasis on clinical immunology and immunodeficiency. This article details the scientific advances as well as the individuals and the organizations involved in the development of the specialty of pediatric immunology. FOUNDATIONS OF PEDIATRIC IMMUNOLOGY Variolation and vaccination. Conventional wisdom traces the birth of immunology to 1798, when Edward Jenner (1749 -1823) of Gloucestershire, UK, inoculated (vaccinated) material from the cowpox sores of milkmaid Sarah Nelmes into the arms of several teenage boys. One boy, James Phipps, was subsequently exposed to smallpox and found to be fully protected (1). A less well-known event, termed the "Royal Experiment," preceded Jenner's work by several decades. During the smallpox epidemic of 1721, Caroline, Princess of Wales (daughter of King George I), was understandably concerned that her 3-y-old daughter Mary would become infected. She had heard the rumors from China and Turkey and reports by Cotton Mather of Boston and Lady Mary Worthley Montagu, wife of the British Ambassador to Constantinople, that suggested that cutaneous inoculation of a small amount of material from a smallpox lesion (i.e., variolation) would protect against smallpox. Princess Caroline ordered safety and efficacy tests on six prisoners and five orphan children (including smallpox challenge of the inoculated prisoners). Only then did she allow Dr. Charles Mailtand to inoculate Mary (2). 19th-century immunology. A detailed history of immunology has been published (3), and only a summary is provided here. Rudolf Virchow's 1859 treatise on cellular pathology provided the first formal theory for the cellular basis for disease as opposed to disturbances of the humors (blood, phlegm, black bile, and yellow bile) that had reigned for 2000 y. In th

Physical characterization and origin of binary near-Earth asteroid (175706) 1996 FG3

The near-Earth asteroid (NEA) (175706) 1996 FG3 is a particularly interesting spacecraft target: a binary asteroid with a low-DeltaV heliocentric orbit. The orbit of its satellite has provided valuable information about its mass density while its albedo and colors suggest it is primitive or part of the C-complex taxonomic grouping. We extend the physical characterization of this object with new observations of its emission at mid-Infrared (IR) wavelengths and with near-IR reflection spectroscopy. We derive an area-equivalent system diameter of 1.90 \pm 0.28 km (corresponding to approximate component diameters of 1.83 km and 0.51 km, respectively) and a geometric albedo of 0.039 \pm 0.012. 1996 FG3 was previously classified as a C-type asteroid, though the combined 0.4--2.5 micron spectrum with thermal correction indicates classification as B-type; both are consistent with the low measured albedo. Dynamical studies show that 1996 FG3 has most probably originated in the inner main asteroid belt. Recent work has suggested the inner Main Belt (142) Polana family as the possible origin of another low-DeltaV B-type NEA, (101955) 1999 RQ36. A similar origin for 1996 FG3 would require delivery by the overlapping Jupiter 7:2 and Mars 5:9 mean motion resonances rather than the nu-6 resonance, and we find this to be a low probability, but possible, origin.Comment: Published in Ap